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[Objective] The present paper aimed to study the physiological changes and gene dynamic changes of rice under low temperature stress, which was helpful to analyze the physiological basis and molecular mechanism of rice response to low temperature stress, and laid a theoretical foundation for screening suitable rice variety with cold tolerance and studying how to improve the cold-tolerance inheritance of rice. [Method] Taking three rice varieties with different cold-tolerance levels, P427 ( strong cold-tolerance), Nipponbare (cold-tolerance), 9311 (cold-sensitivity) as testing materials, and using method of phenotype combined with physiochemical index, the paper studied the effect of 3 -4 °C low temperature stress on phenotype, chlorophyll content and electric conductivity, and used RNA-Seq to analyze enrichment pathways and the dynamic change of gene response to low temperature stress. [Result] The rice variety with strong cold-tolerance P427 showed strong adaptability to low temperature. It maintained higher chlorophyll content under low-temperature stress, and its chlorophyll content before low temperature treatment, on the third day of low temperature treatment, on the third day of recovery growth was 29. 64, 29. 30 and 27. 96 µgig, respectively. Its electric conductivity on the first day, third day, fifth day of low-temperature was 10. 39%, 13. 08% and 17. 04%, and its membrane system had the lightest damage. A large number of genes were differentially expressed in both cold tolerant and cold sensitive varieties under low temperature induction, and the number of differentially expressed genes ( DEGs) continued to increase with the extension of low temperature treatment time,but the number of specific DEGs in P427 decreased from 2408 to 1717. In addition, only 576 specific genes of P427 were differentially expressed from 1 days to 3 days under low temperature treatment. GO and KEGG enrichment analysis showed that the specific DEGs of P427 after low temperature treatment were mainly enriched in metabolic pathways such as biosynthesis of secondary metabolites, plant hormone signal transduction and phenylpropane biosynthesis. [ Conclusion] There may be differences in cold-tolerance response genes and regulatory mechanisms among cultivars with different cold tolerance. There was a set of cold-tolerance response genes in P427 cultivar with strong cold tolerance, which was different from that in Nipponbare and 9311. Plant hormone signal transduction and phenylalanine metabolism were significantly affected by low temperature stress in seedling rice. P427 may respond to cold tolerance of seedling rice through metabolic pathways such as biosynthesis of secondary metabolites, plant hormone signal transduction and phenylpropane biosynthesis pathway. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the pathogenicity and dominant physiological groups and physiological races of Magnaporthe oryzae in Guangxi, analyze avirulence genes, find out the composition and distribution of physiological races and avirulence genes, providing reference for resistance breeding and variety promotion. [Method] Pathogenicity of 128 M. oryzae single spore isolates from 4 rice growing regions of southern Guangxi (Guinan), central Guangxi (Guizhong), northern Guangxi (Guibei) and alpine region were deter- mined by artificial spraying inoculation on the 7 unified identification of varieties in China and 26 near-isogenic lines (NILs) that contained only one resistance gene. (Result) Among the 128 rice blast strains, the proportion of strong pathogenic strains was 60.16%. The 128 M. oryzae strains could be divided into 7 groups and 26 physiological races, and the dominant group was ZB with a frequency of 69.53%. Dominant physiological races were ZB13 and ZB,, whose frequencies were 25.00% and 14.84%. Virulence frequency of the tested isolates ranged from 28.12% to 100.00%. Among them, the virulence frequency of the isolates group to resistance genes Pik, Pikm, Pil and Pi9 was lower, with frequencies of 28. 12%, 28.91%, 35.94% and 37.50%, respectively. Avirulence genes corresponding to the tested resistance genes were detected in the collected rice blast fungi, and 15 avirulence genes were detected in the four regions. Avirulence genes Aur-Pia (1), Aur-Pia(2), Aur-Pii, Aur-Pik, Aur-Pib, Aur-Pit, Aur-Pish (2), Aur-Pi3(1), Aur-Pi5 (1), Aur-Pil2(t) and Avr-Pi19(t) occurred at a frequency less than 20.00%. Most of isolates contained 5, 6, 7, 8, 10 avirulence genes with combination frequency of 19.53%, 11.72%, 11.72%, 15.63% and 10. 16% in the tested strains. [Conclusion] Rice blast fungi in Guangxi from 2021 have strong pathogenicity. The dominant physiological group is ZB and dominant physiological races are ZB13 and ZB9. Avirulence genes Aur-Pia (1), Avr-Pia (2), Aur-Pii, Aur-Pik, Aur-Pib, Aur-Pit, Avr-Pish (2), Aur-Pi3 (1), Aur-Pi5(1), Aur-Pil2(t) and Aur-Pil9(t) occurr at low frequency, which suggests that resistance genes corresponding to the avirulence genes should not be suitable for applying rice breeding and variety distribution in Guangxi. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to investigate the effects of different mineral conditioners on the soil properties of cadmium (Cd)-contaminated paddy fields and the Cd content of rice in Guangxi, so as to provide a reference basis for the utilization of paddy fields to produce safe rice. (Method) Calcium-magnesium-silicon conditioners A and B, calcium-silicon conditioner C and calcium-magnesium conditioner D(set up as treatments A, B, C and D, respectively) were selected to carry out Cd-contaminated field remediation and treatment experiments in a Cd-contaminated paddy field in Guangxi, and no n-conditioner was applied as control (CK). The pH, cation exchange capacity (CEC), total Cd and soil available Cd content, Cd content of rice roots, stems, leaves and seeds were determined at the rice maturity stage after the treatment to analyze the remediation and treatment effects of different mineral conditioners on Cd-contaminated paddy soils and the residual status of Cd in various parts of rice, and to analyze the correlation between soil total Cd content, CEC and pH and available Cd content. [Result] The application of mineral conditioner could significantly increase soil pH and CEC of Cd-contaminated paddy fields (P<0.05, the same as below), both of which were increased by 15.0% 16.6% and 20.4% -23.8% respectively compared with those of CK; And it could significantly reduce the Cd content in the available state of soil in Cd-contaminated paddy fields, which was decreased by 14.0%-19. 3% compared with that of CK. The soil available state Cd content of the paddy field after the application of mineral conditioners showed a significantly negative correlation with pH, and the correlation coefficient between the log In(pH) value of pH and the soil available state Cd content was 0. 4053; It showed a highly significantly negative correlation with CEC(P<0.01), and the correlation coefficient was 0.6326; With the increase in soil pH and CEC, the soil available state Cd content continuously decreased. The applications of mineral conditioners were all available in reducing the Cd content of rice roots, stems, leaves and seeds as well as the enrichment factor of Cd in the aboveground part of rice, in which the total Cd content of rice seeds was decreased by 35.9% 50.2%, and the enrichment factor of Cd in the aboveground part of rice (stems, leaves and seeds) was decreased by 19.5% -33.5%,32.1%-44.9% and 38.6%-52.6%, respectively. [Conclusion] The application of different mineral conditioners can significantly increase the pH and CEC of paddy soils, thereby reducing the Cd content in the active state of the soil, inhibiting the migration of Cd from the soil to the roots, stems, leaves, and seeds of rice, decreasing the Cd content in rice, and reducing the enrichment of Cd in the aboveground parts of rice (stems, leaves and seeds). [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to overexpress and purify rice cold stress response protein OsCML16 in Escherichia coli, and prepare OsCML16 protein antibody to provide antigen, and provide reference for further study of biological function of rice OsCML16 protein by using the antibody. 【Method】 At first, the transmembrane region of the target protein OsCML16 was analyzed online using TMHMM 2.0 software, and then the fragment of target gene was amplified by high fidelity PCR, the prokaryotic expression vector pET30a-OsCML16 was constructed by gene recombination method, and the recombinant plasmid was transformed into expression E.coli line BL21 (DE3). OsCML16 protein expression was induced by IPTG, and purified by affinity chromatography, then the authenticity of the protein sequence was verified by mass spectrometry. 【Result】 By analyzing the transmembrane region of OsCML16 protein, it was found that the protein did not contain transmembrane region, and it was suitable for heterologous expression of the full-length protein. The prokaryotic expression vector PET30A-OSCML16 was successfully constructed by linking OsCML16 gene to pET30a vector. The result showed that the target gene had no mutation site and could be used for expression of the target protein. Exogenous expression OsCML16 protein was analyzed by SDS-PAGE electrophoresis, and results showed that OsCML16 protein could be induced expression at 28 ℃.The fusion protein His6-OsCML16-His6 could be purified by affinity chromatography, and the 30 kD fusion protein was obtained successfully. The purified protein was validated by mass spectrometry, and a total of three peptides were identified as OsCML16 protein, indicating that the exogenously expressed protein was the OsCML16 protein. 【Conclusion】 The rice cold stress response gene OsCML16 was expressed in E.coli by prokaryotic expression method. The fusion expression protein His6-OsCML16-His6 was purified by affinity chromatography according to the histide-carrying label of the fusion protein, and the sequence of the protein was verified by protein spectroscopy. Rice OsCML16 protein can be used for antibody preparation and protein function study in the future. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to illustrate the potential utilization of the gene of resistance to bacterial blight and bacterial leaf streak, so as to provide reference for enriching genetic base of rice breeding.【Method】A total of 102 rice cultivars were used to screen by molecular marker for the gene xa5, which mediated the resistance for both for resistance to bacterial blight and bacterial leaf streak. The parents carrying xa5 gene and having good resistance to bacterial blight and bacterial leaf streak were used as resistant sources to cross with susceptible cultivated rice. Through pedigree method and molecular marker-assisted selection（MAS）, elite hybrid rice restorer lines were cultivated. The excellent restorer lines and sterile lines were combined with strong heterosis combinations to analyze the resistance and comprehensive agronomic traits of strong heterosis combinations.【Result】A total of 17 cultivars were screened, which carried xa5 gene from 102 rice germplasm resources（materials）. Among these cultivars, DP3, IRBB5, N36, N776, N777, N779 and P89 were well resistant to both bacterial blight and bacterial leaf streak. An elite line Y240-1 was selected from the cross between DP3 and 9311. Moreover, 998 R was crossed with elite individual Y240-1. With molecular MAS, an elite restorer line Yexiangzhan with xa5 was developed from the cross of 998 R and Y240-1, after multiple generations of selfing. Yexiangzhan was combined with sterile line Pingfeng A to produce an elite hybrid cultivar Pingfengyouxiangzhan, which showed higher resistance to bacterial blight and bacterial leaf streak in comparison with Pingfeng A. Pingfengyouxiangzhan was resistant to rice blast at moderate level and meet the 2nd class standard of fine quality issued by Ministry of Agriculture of China.【Conclusion】xa5 gene with resistance to bacterial blight and bacterial leaf streak of rice has partial dominant effect, which can be used for breeding improvement of hybrid rice; It is helpful to enrich and broaden the genetic basis of rice breeding by cultivating the superior hybrid combinations of rice with moderate resistance to bacterial blight and stripe disease with wild rice blood. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to analyze the blocking effect of different blocking inhibitors on cadmium（Cd） and arsenic（As） in heavy metal contaminated rice fields and their effect on the yield of different varieties of rice, in order to provide a reference basis for the screening of rice varieties with low accumulation of heavy metals and the production of safe rice.【Method】Using the field test method, 16 Guangxi main planted late rice varieties were planted in the soil with high risk of heavy metal pollution, and two kinds of inhibitors, selenium-inhibitor and silicon-inhibitor, were tested for heavy metal control. The Cd and As contents in the rice samples of each variety were measured, and the blocking effects of different blocking agents on Cd and As and the yields of different varieties of rice were compared and analyzed.【Result】The Cd and As contents of the 16 rice varieties differed significantly, among which five varieties, namely, Shenliangyou 8386,Guang 8 you jinzhan, Fengtianyou 553,Guixiang 12 and Guang 8 you 169,had lower Cd enrichment ability, and four varieties, namely, Yexiangyou 703,Hengfengyou 666,Guang 8 you jinzhan and Yexiangyou lisi, had lower As enrichment ability. The yield of each rice variety sprayed with selenium-inhibitor and silicon-inhibitor was significantly improved, with an average yield increase of 6.5% and 5.4%,respectively, compared with the control（CK）. After spraying selenium-inhibitor and silica-inhibitor, the Cd content of rice of 16 rice varieties was lower than 0.200 mg/kg, and the average content was 0.119 and 0.125 mg/kg, respectively, which were significantly lower than that of CK（0.189 mg/kg）. The average contents were 0.119 and 0.125 mg/kg, which were 37.03% and 33.33% lower than those of CK（P<0.05）. The mean As contents of rice were 0.197 and 0.185 mg/kg, respectively, which were not significantly different（P>0.05） compared to CK（0.186 mg/kg）.【Conclusion】The test results show that there are significant differences in the adsorption capacity of different late rice varieties of rice for heavy metals Cd and As.Foliar spraying of selenium and silicon inhibitors in Cd-contaminated rice fields can significantly improve rice yield and also significantly reduce the Cd content of rice, but has no significant effect on reducing the As content of rice. The five low Cd accumulation rice varieties, namely Shenliangyou 8386,Guang 8 you jinzhan, Fengtianyou 553,Guixiang 12 and Guang 8 you 169,can be promoted and planted in local Cd contaminated rice fields, and the four low As accumulation rice varieties, namely Yexiangyou 703,Hengfengyou 666,Guang 8 you jinzhan and Yexiangyou lisi, can be promoted and planted in local As contaminated rice fields. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to clarify the relationship between rice flavor quality and nitrogen nutrient absorption and utilization, the genotypes of high nitrogen efficient and good taste value rice were selected.【Method】The excellent japonica rice varieties（strains） cultivated along the yellow area were used as the test materials, and the influence of nitrogen on different rice genotype rice quality and nitrogen absorption and utilization was studied by setting different nitrogen fertilizer levels. 【Result】The taste value of different genotypes rice showed high difference, which decreased with nitrogen application increasing. The taste value of no nitrogen fertilizer was the highest and up to 83.9. Protein and straight starches increased with nitrogen application increasing. The linear analysis showed a significant open downward parabolic relationship and was performed with the nitrogen application quantity and the taste value(r=0.998**). The milled rice rate and the whole head rice rate increased with the nitrogen amount increasing, and the chalky grain rate and the chalkiness decreased with the nitrogen amount increasing. The nitrogen use efficiency, nitrogen grain production efficiency and nitrogen harvest index differed greatly between genotypes. The excellent and high-efficient nitrogen rice genotypes represented by by xindao 89 and xinkedao 31 were generally manifested with good appearance quality and relative high nitrogen grain production efficiency, up to 56.44 kg/kg. The related analysis showed that the nitrogen grain production efficiency was significantly positively with the rice taste value and significantly negatively with the protein content. The nitrogen use efficiency was significantly negatively with the taste value, negatively with the chalky grain rice rate and chalkiness, and positively with the milled rice rate and the whole head rice rate. It showed that the taste quality of rice improved and the appearance quality decreased under the level of no or less nitrogen fertilizer.【Conclusion】The nitrogen grain production efficiency can be used as an important evaluation index of excellent quality and high nitrogen efficient rice breeding. Improving the nitrogen use efficiency may be more conducive to improving rice processing, appearance quality and rice yield level. Good quality with high nitrogen efficiency（high nitrogen grain production efficiency） and high yield with high nitrogen efficiency（high nitrogen use efficiency） can be used as important evaluation standards for excellent food taste rice breeding and high yield rice breeding, respectively. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to clarify the distribution of rice blast resistance genes Pib, Pi9, Pi2, Pi54 and Pish in Japonica rice varieties (lines) and the resistance levels of different genotype to rice blast. [Method] A total of 93 rice materials were assessed by artificial inoculation and screening of molecular markers tightly linked to 5 major resistance genes. [Result] Three, two and one resistance genes were found in 19 (20. 4%), 25 (26. 9%) and 28 (30. 1%) materials, respectively, and five resistance genes corresponding to markers were found in all varieties (lines). There were 49 (52. 7%), 16 (17. 2%), 8 (8. 6%), 31 (33. 3%) and 31 varieties (lines) (33. 3%) containing rice blast resistance gene Pib, Pi9, Pi2, Pi54 and Pish in 93 varieties (lines), and the genetic frequency of Pib was the highest within this collection. A total of six genotypes and gene combinations (Pi9, Pi54, Pib + Pi9, Pib + Pi2, Pib + Pish and Pi9 + Pi54) are applicable in the rice-breeding, due to the resistance to rice blast but with low distribution in the tested varieties (lines). [Conclution] The study provided a scientific basis for breeding rice cultivars with rice blast-resistance. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the effects of microbial agents combined with leaf barrier on the translocation and accumulation of Cd in rice, and provided important reference for the safe production of moderate and mild Cd contaminated farmland. [Method] The field experiment was adopted, organosilicon and chelated iron were selected as foliar control agents, combined with microbial agents, and a total of 6 treatments were set up in the field: conventional planting pattern ( CK), spraying on the leaf with organosilicone and EDD HA-Fe ( Y), microbial agents derived from Bacillus amyloliquefaciens and Enterobacter ludwigii as base fertilizer applied separately to soil ( Dl and D2), microbial agents derived from B. amyloliquefaciens and E. ludwigii applied separately to soil, meanwhile spraying on the leaf with organosilicone and EDDHA-Fe ( D1 + Y and D2 + Y) . [Result] ( i) Leaf spraying with organosilicone and EDDHA-Fe significantly reduced the content of Cd in leaves, decreased TF roct-maw , and increased the proportion of Cd in roots by 38. 3%, compared with the control. Foliar fertilizer could effectively prevent the translocation and accumulation of Cd to the shoot of rice. (ii) The two formulations of basal application of microbial agents had different effects on Cd accumulation in rice. Compared with the control, the content of Cd in different parts of rice was decreased by basal application of B. amyloliquefaciens, and t he variation of Cd proportion was small. Applying with E. ludu!igii, Cd content in leaves of rice decreased, and Cd content in stems and grains increased significantly, which were 2. 06 and 1. 17 times higher than those in control, respectively. Meanwhile, the accumulation of Cd in whole plant was increased by 9 . 8 % . ( iii) The accumulation of Cd in rice plants decreased and the distribution of Cd in different parts of rice was significantly changed by basal application of microbial agents combined with foliar fertilizer. When treated with Dl + Y, the proportion of Cd in grains was 1. 68 times higher than that in the control, and the proportion of Cd in roots was 63. 5 % equivalent to the control. The combination of microbial agent in B. amyloliquefaciens and foliar fertilizer could accelerate the translocation of Cd to the shoot and grains of rice. Wben treated with D2 + Y, the TF,root-straw of Cd decreased by 64. 5 % compared with CK, the root Cd content was 1. 57 times higher than that of the control, and the proportion of Cd in the root increased by 57 . 7 % . Cd was restricted to the root by the combination of the basal application of E. ludwigii and foliar fertilizer, so that limited Cd was transferred to the shoot of rice. [Conclusion] The application of B. amyloliquefaciens agents, combined with leaf spraying of organosilicone and EDD HA-Fe can reduce the accumulation of Cd in the root and increase the transfer of Cd to the shoot of rice. Combined application of E. ludwigii and foliar fertilizer can effectively reduce the accumulation of Cd in the straw and grain of rice, which is one of the important measures for the safety production of medium and mild Cd contaminated farmland. [ABSTRACT FROM AUTHOR]

[ Objective] In this paper, the endophyte and rice blast infected rice ( Oryza sativa L ) Liaoxing 1 seedlings were used as tested materials to explore whether Suaeda salsa endophyte ( EF0801) could improve rice seedlings tolerance to rice blast. [ Methods] Morphological indicators, photosynthetic pigment content, defensive enzyme activity, MDA content and chlorophyll fluorescence parameters of rice seedlings with endophyte( EF0801) and/ or rice blast were determined. [Results] Rice-blast infection significantly decreased Chlb content, inhibited the photosystem ll ( PSll) oxygen-evolving complex, altered the electron transfer, decreased the photosynthetic efficiency and the photosynthetic perlormance index; After infection with rice-blast, the morphological indicators of seedlings with endophytic infection were better than those with endophytic uninfection, moreover endophytic infection increased the defensive enzyme activity, decreased MDA content, increased Cars content, as well as maintained PS II oxygen-evolving complex stability and normal electron transfer proceeds, meanwhile improved photosynthetic perlormance index and photosynthetic efficiency. [ Conclusion] Infection by endophytes ( EF0801) increased the activity of defensive enzymes in rice seedlings, reduced the content of MDA, alleviated the damage of rice-blast to PS II and improved the resistance of rice to riceblast. [ABSTRACT FROM AUTHOR]

[ Objective] This paper aimed to overcome the easy breakdown of conventional disease resistant plants. [ Method] A new kind of transgenic rice plant5 was generated based on Host Induced Gene Silencing ( HIGS) technology. [Results] SEC11, a key subunit of signal peptide complex in Magnaporthe oryzae, was selected for generating the HIGS expression vector by gateway technology. HIGS vector was transferred into the Japonica rice cultivar Nipponbare by agrobacterium mediated transformation to obtain transgenic rice plants. The spray assay with conidia of rice blast indicated that the HIGS transgenic rice plants were improved in rice blast resistance. [Conclusion] This study lays the foundation for molecular breading of rice blast resistant varieties with HIGS technology. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the effects of Cd stress on the absorption and transport of mineral elements in rice.[Method] 29 rice varieties were selected and treated with two groups (0,0.5 mg/kg). The contents of eight mineral elements (Ca, Fe, Zn, Mg, Cu, Mn, K,Na) in the upper and lower parts of rice were measured by atomic absorption flame spectrophotometer.[Result] In the underground part, compared with control group, the effect of Cd on Fe was shown to inhibit absorption; Zn, Mg, K and Na were resistant to Cd, and Zn was more resistant than Cu, and Cd was more competitive than Mn and Mg.Its Cd resistance and competitiveness were greater than that of Ca. Zhuzhen B and Japonica 7623 showed Cd tolerance among the eight mineral elements. [Conclusion] Zhuzhen B was the only rice variety that promoted the absorption of eight mineral elements after Cd stress; Liusha 1 was the least Cd-tolerant rice variety. [ABSTRACT FROM AUTHOR]

[Objective] The purpose of this paper was to clarify the effect of diversity mixed interplanting mode on rice photosynthesis, and provide a favorable basis for the further application of diversity mixed interplanting in the field. [Method] The rice varieties Gangyou 157 (main planted variety) and Huangkenuo (interplanted variety) were selected, and their relative chlorophyll content SPAD values and photosynthesis were measured under the mixed interplanting and mono-planting modes, and the occurrence and damage of rice blast and the agronomic characteristics of rice were investigated. [Result] When Gangyou 157 in the interplanting mode, the SPAD value of the inner row was significantly higher than that of the outer row and mono-planting treatments.There was no significant difference in the SPAD value of Huangkenuo under the two planting modes.The net photosynthetic rate of Gangyou 157 in the interplanting mode was significantly lower than that of the mono-planting treatment (decrease by 14.36%), and there was no significant difference when compared with the outer row. The transpiration rate, stomatal conductance and intercellular CO2 concentration were significant differences in all treatments. The net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration of Huangkenuo were not significantly different under the interplanting and mono-planting modes.Gangyou 157 and Huangkenuo had no significant difference in water use efficiency under interplanting and mono-planting modes. The rice blast disease index of Huangkenuo under the interplanting mode（2.79 ± 0.86） was significantly lower than that of the mono-planting（43.65 ± 6.11）,and its plant height under the interplanting mode（138.93±2.91）cm was significantly lower than that of the mono-planting（152.07 ± 2.27）cm, and the number of tillers of Huangkenuo under the mono-planting mode（9.75 ± 0.59） was significantly higher than that of the interplanting（7.04 ± 0.73）.There was no significant difference in disease index, plant height and tiller number of Gangyou 157 under the two planting modes. The yield per hectare of Huangkenuo under the diversity mixed-interplanting mode(6.23 t/hm² ) was significantly higher than that of the mono-planting model（4.50 t/hm²; the yield per hectare of Gangyou 157 under two planting modes was no significant difference. [Conclusion] Under the diversity mixed interplanting mode, the chlorophyll content of the main cultivars increased significantly, the photosynthetic rate decreased significantly, and other photosynthetic characteristics were no significant changes; the performance of the interplanted cultivars was not significantly different from that in the mono-planting mode. At the same time, the incidence of diseases of interplanted varieties was significantly reduced, without affecting the main varieties. [ABSTRACT FROM AUTHOR]

[ Objective] The present paper aimed to determine the effects of matriceson rice seedling quality, root morphology and nutrient ab sorption in the western of Liaoning. [Method] Taken rice variety Daohuaxiang as tested materials, and the differences of rice seedling mor phology, root morphology and nutrient absorption among five matrix treatments, such as the Shenyang Jinqiao matrix ( Ml), Fakuqifeng ma trix ( M2), Xinzhufeng biochar matrix ( M3), Liaoning Rice Research lnstirute matrix ( M4) and nutritional soil matrix ( M5) were com pared. [ Result] At weaning stage, the plants in M4 grew vigorously, accumulated a large amount of dry matter and had the best root morphol ogy and strongest uptake of nitrogen, while the M3 had the strongest uptake capacity of phosphorus and potassium. During the transplanting period, when the growth rate of seedlings by matrix was significantly accelerated, the plants in M4 had the highest root length, adventitious roots, root consolidation force, the accumulation of dry matter and nutrient absorption, especially for nitrogen. [Conclusion] The results sug gested that the matrix produced by Liaoning Rice Research Institute had the advantages of better seedling quality, greater root morphology and reasonable nutrient ratio. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to study the effects of three rice genes(OsGS3,OsGW2 and OsGN1 a) knockout on the field agronomic characters and quality of Jijing 809. 【Method】A randomized block test was used to compare the agronomic traits, quality and yield of the three gene knockout mutants with the wild type. 【Result】Compared with wild type, the tiller number and seed setting rate of mutants were significantly decreased, but the plant height, grain length, grain width and 1000 grain weight were significantly increased, and the yield was increased by more than 12 %. In addition, the change of brown rice rate was not significant, milled rice rate and head milled rice rate were significantly reduced, chalky grain rate and chalkiness degree were significantly increased, which affected the appearance and quality of milled rice. But amylose content, protein content and taste value did not change significantly. 【Conclusion】 The results suggested that three rice genes(OsGS3,OsGW2 and OsGN1 a) knockout could improve some characters and yield of rice, which provided practical evidence for the application of genome directed editing in breeding. [ABSTRACT FROM AUTHOR]

[Objective] In order to provide scientific basis for controlling diseases and pests of high-efficiency nitrogen utilization rice variety and reducing nitrogen fertilizer in high-efficiency nitrogen utilization rice production, the effect of high-efficiency nitrogen utilization rice cultivar Guiyu No. 11 on rice pests and diseases was analyzed in this study. [Method] The occurrence and damage of rice planthopper, rice leaf folder and rice sheath blight disease on Guiyu No. 11, Liushayouzhan 202 and Baixiangyou 9978 and the yield of those rice varieties in highnitrogen (pure N 225 kg/hm2), medium-nitrogen (pure N 150 kg/hm2) and low-nitrogen (pure N 75 kg/hm2) conditions were researched, and the effect of Guiyu No. 11 on rice planthopper, rice leaf folder and rice sheath blight disease was compared and analyzed in this paper. [Result ] The occurrence of rice planthopper, rice leaf folder and rice sheath blight disease on Guiyu No. 11, Liushayouzhan 202 and Baixiangyou 9978 were affected by nitrogen application rate, and the influence levels varied with variety. Guiyu No. 11 showed significantly inhibitory effect on planthopper population (P < 0. 05, the same as below), the inhibitory effect of Guiyu No. 11 to rice leaf folder was not significantly different with Liushayouzhan 202 in the late growth period (after the booting stage) of rice with low nitrogen level (P > 0. 05, the same as below), but significantly higher than Liushayouzhan 202 and Baixiangyou 9978 at medium and high nitrogen level. In addition, the resistance of Guiyu No. 11 to rice sheath blight was similar to that of Baixiangyou 9978, both of which were more susceptible to rice sheath blight than Liushayouzhan 202 in paddy. The yield of Guiyu No. 11 in high, medium and low nitrogen application rate was not obviously different with Baixiangyou 9978, but significantly higher than Llushayouzhan 202, and it was higher in medium and low nitrogen application rate than in high nitrogen application rate. [Conclusion] Guiyu No. 11 showed a significant control effect on the population of rice planthopper, a certain inhibition effect on rice leaf roller, and susceptible to rice sheath blight, similar to hybrid rice Baixiangyou 9978 in this study. Therefore, high-efficiency nitrogen utilization rice cultivar Guiyu No. 11 can be promoted to plant to reduce the damage of rice planthoppers and rice leaf rollers in field. However, pay more attention to the prevention and control of rice sheath blight in the process of Guiyu No. 11 planting. And on the premise of considering the occurrence of diseases and pests and the yield, the recommended nitrogen application on Guiyu No. 11 is 75 - 150 kg per hectare. [ABSTRACT FROM AUTHOR]

[Objective] This paper studies the optimal rice nitrogen fertilizer management measures under the condition of returning the whole wheat straw to the field, in order to provide a theoretical basis for the utilization of straw returning to the field and the reduction of high-efficiency nitrogen application. [Method] The soil culture experiment was adopted, and the nitrogen application rate was set as constant nitrogen application (A1, 270 kg/hm²) and reduced nitrogen application (A2, 240 kg/hm²). Nitrogen management was used to set a high-ratio basal nitrogen fertilizer (B1, basal fertilizer: tiller Fertilizer: ear fertilizer = 5: 2: 3) and high-ratio tiller nitrogen fertilizer (B2, base fertilizer: tiller fertilizer: ear fertilizer = 2: 5: 3), with no nitrogen (CK, 0 kg/hm²) as the control, The characteristics of plant height, dry matter accumulation and distribution of different nitrogen levels and nitrogen management in key growth stages of rice were systematically compared. [Result] Under the condition of returning all wheat straw to the field, the plant height of rice in the late stage of the reduced nitrogen application was significantly lower than that of the constant nitrogen application, and the plant height increased under the two nitrogen application rates to increase the ratio of tiller nitrogen fertilizer (2∶5∶3). high. From booting stage to maturity stage, the dry matter quality of the aboveground rice in the treatment of reduced nitrogen application was lower than that of the treatment of constant nitrogen application. From the heading stage to the maturity stage, the rice leaf biomass and its proportion to the total biomass of the reduced nitrogen application were lower than that of the constant nitrogen application, and the proportion of the leaves under the high-ratio tiller nitrogen fertilizer treatment under the two nitrogen application rates was higher; The stalk biomass of the reduced nitrogen fertilization treatment was lower than that of the constant nitrogen fertilization, and the ratio of the tiller nitrogen fertilizer ratio was increased under the two nitrogen fertilization rates. The stalk biomass proportion of the stalk biomass was reduced; the reduced nitrogen fertilization treatment had a constant leaf sheath biomass and distribution Nitrogen application decreased, and the difference in leaf sheath biomass at heading stage reached a significant level; ear biomass and its proportion were higher than that of constant nitrogen application under reduced nitrogen application, and the ratio of tiller nitrogen fertilizer increased under reduced nitrogen application. The amount is reduced. [Conclusion] It can be seen from the above that under the condition of fully returning wheat straw to the field, high plant height and above-ground dry matter quality can be obtained in the middle and late stages of rice under constant nitrogen application, and the biomass and distribution ratio of leaves, stems and leaf sheaths are generally increased. Under constant nitrogen application, increasing the ratio of tiller nitrogen fertilizer is beneficial to the material production and accumulation of rice vegetative organs, while reduced nitrogen application is beneficial to the material accumulation and distribution of rice panicles. [ABSTRACT FROM AUTHOR]

[ Objective] The present paper aimed to understand the dynamics of physiological races and the composition of a virulence genes of Pyricularia oryzae in Liaoning province, which would provide a theoretical basis for rational distribution of rice varieties and breeding of blast resistant cultivars. [ Method] identified rice varieties were used to identify the Physiological races of 151 isolates of P. oryzae collected &om 2017 to 2018 in Liaoning province, and the primers were designed to amplify the target sequences based on the sequences of 10 Avr-genes which had been cloned. [Result] The tested isolates were divided into 6 groups of 41 physiological races, ZA and ZB were the predominant groups, accounting for42.36 % and 31. 76 %, respectively, ZC, ZD, ZE and ZF were 5.96 %, 3.97 %, 3. 31 % and 12.58 %, and ZG was not detected. All the test isolates carried the a virulence genes Aw-Pi9. Most carried the a virulence genes Avr-Pita, Avr-Piz-t, Avr-Pik, PWL2 and ACEI, carrying frequencies of 90. 07 %, 94. 04 %, 93. 38 %, 92. 72 % and 98. 68 % . Avr-pib a virulence gene carries low frequency, only 27. 81 % . The a virulence genes Avr-Piz, Avr-C039 and AIIT-Pia were not detected. [ Conclusion] In summary, the comp06ition and structure of the physiological races and a virulence genes of P. oryzae are complex in Liaoning province. In the rice variety layout, the rice cultivars carrying resistant genes Pita, Pi9, Pizt and Pik should be generalized in Liaoning province. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to evaluate the potential of white clover (Trifolium repens L.) as forage grass and ecological engineering plant on paddy field ridges in southern China. [Method] The clover was planted on the ridge of paddy fields in Ilengnan, Ilunan province and Jiangyou, Sichuan province in the spring of 2015. Cabover-ground parts, mainly leaves and petioles, were harvested monthly from July of 2016 to June of 2017. Dry matter was weighted after desiccation in a stove at 105 °C for 15 minutes and 70 °C for 24 hours. Dry samples harvested in the same season were mixed after storing at -20 °C . The contents of crude protein, nitrogen, phosphorus and potassium of such mixed samples were then determined by the standard procedures. The antagonism experiment with Alternant her a philoxeroides was conducted by face-to-face cultivation in concreted circles located in a plastic greenhouse from July of 2017 to March of 2018. [Result] At the experiment site in Sichuan, the highest dry matter weight of the white clove was obtained at the first harvest and the dropped until January of 2017 and increase gradually till the end of the experiment. It dropped also in Ilunan after the first harvest but started to increase since August and reached the highest point in April of 2017. The contents of crude protein, nitrogen and phosphorus were the highest in the first quarter at both sites. The content of potassium was the highest in the third quarter at Jiangvou but in the second quarter at Ilengnan. In the antagonism experiment, the growth of A. philoxeroides under each treatment was obviously better than that of clover in the summer, but white clover grew significantly better than A. philoxeroides under each irrigation regime and dominated the community in terms of occupying area, fresh weight and dry weight. [Conclusion] White clover on paddy didges has shown strong regeneration ability both in Sichuan and Hunan and could be used as high-quality forage and green manure crop. It could strongly inhibit the growth of A. philoxeroides at low temperature and soil humidity. [ABSTRACT FROM AUTHOR]

[Objective] The purpose of the paper is to further understand the effects of different growth environments on the growth and yield characteristics of rice. [Method] Two varieties, indica and japonica rice, were selected and pot cultured to test at four different altitudes in Dongehuan District of Kunming City. [ Result] With the increase of planting altitude, the effective accumulated temperature of rice decreased and the heat intensity decreased, resulting in the decline of maximum net photosynthetic rate and apparent quantum efficiency and the increase of light saturation point and CO2 saturation point during the booting stage of rice, which meant the weakening of photosynthetic intensity in vigorous grow stage. Meanwhile, the photosynthetic efficiency and photosynthetic accumulation of rice decreased during the later period of rice reproductive stage because of the decrease of photosaturation point, dark respiration rate, photorespiration rate and photosynthetic compensation point. Then the dry matter of leaf and stem sheath ,leaf area, the number of effective panicles and effective grains per spike were significantly reduced. [Conclusion] The upper limit of suitable altitudes for indica rice and japonica rice in Dongehuan District of Kunming City were lower than 1500 meters and 2000 meters respectively. Cold injury had significant effects on the effective-panicles number of indica rice, the effective-grains number and effective-panicles number of japonica rice. The differences of rice growth characteristics and yield traits among different planting altitudes were mainly ascribed to tiny photosynthetic physiological effects of rice, the growth and development change of rice resulting from the disparity of air temperature and the adverse effect of low temperature. [ABSTRACT FROM AUTHOR]

【Objective】This paper aimed to study the drought resistance mechanism of plants and the effect of drought on plant antioxidant systems for the important role in agricultural production.【Method】Taken rice as the experimental material,the effects of PEG-pretreated rice leaves on drought-resistance-related antioxidant enzyme activities and antioxidants content after re-water were studied.【Result】The activities of SOD and POD in untreated groups increased,while the activity of SOD in the pretreatment group and the pretreatment-rehydration group did not change significantly,and the activity of POD increased but the extent was smaller than that in the untreated group.The activity of CAT in the pretreatment-rehydration group continued to increase,while the activity of CAT in untreated group increased first and then decreased.The activities of APX and GR in the leaves of the four groups increased first and then decreased.The contents of AsA and GsH in the pretreatment group under stress 0 hour was higher than that in the control group and the untreated group,and the AsA content of the four groups of rice leaves decreased.The GsH content of the pretreatment-rehydration group decreased slightly,and the GsH content of the rice leaves of other three groups decreased,which were also slowly falling.【Conclusion】The early PEG pretreatment can increase the resistance of the rice leaf antioxidant system to generate resistance and eliminate ROS,and the rice leaves can produce resistance to memory,so that they can better respond to subsequent drought stress. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to explore the effect of light on CO2 exchange at the root and leaf interfaces of rice with different growth stages, 【Method】A self-designed gaseous compound volatilization test device was used in the experiment to determine the CO2 exchange rate at the leaf and rhizosphere interfaces of rice under the conditions of close separation and simultaneous measurement in the inner and outer chambers. 【Result】（i）Under natural sunlight, the rice phyllosphere CO2 exchange rate in the daytime at tillering stage, flowering and seed setting stage and mature aging rice plants was-13.58,-10.84 and 27.36 μg/pot·h, respectively. It showed that rice phyllosphere was an important CO2 sink at early-middle rice growth stage, and as well an important source of CO2 emission at mature aging stage. In early-middle period, CO2 emissions of the rice plants were mainly from rice phyllosphere at night time.（ii）Under weak illumination, there were a large number of CO2 emissions from rice phyllosphere and rhizosphere at different rice growth stages, but the main CO2 emissions mainly came from rice phyllosphere. Compared with LED green and yellow light, CO2 emissions of rice phyllosphere was inhibited markedly by red and blue light. 【Conclusion】In summary, increasing the ratio of red and blue light and light intensity in different growth periods, the effect of reducing CO2 emissions from rice ecosystems should be reduced. [ABSTRACT FROM AUTHOR]

[Objective] This paper aimed to explore the correlation between methane emission difference and root characteristics among different rice varieties. [Method] The six rice varieties from early to late rice were used for water culture experiment to observe the methane emission rate and root characteristics at different stages, and the correlation analysis was also made. [Result]There was significant difrence in methane emission rate among different early and late rice varieties. The highest methane emission rate was in Luliangyou 996, and the lowest was mid-early 39 in the whole growing stage, with a difference of 0.186 mmol·m-2s-1;The highest methane emission rate of late rice variety was Yuzhenxiang, and the lowest was Y Liangyou 1, with a difference of 0.282 mmol·m-2 s-1. There was a significant positive correlation between root oxidation capacity, root porosity and methane emission in early and late rice（P <0.05）, and a very significant negative correlation between methane emission rate and active absorption area and total root absorption area in early rice（P <0.01）. There was a very significant positive correlation between methane emission rate and active root absorption area and total root absorption area in late rice（P<0.01）. [Conclusion] The results showed that the root activity and root porosity were the key factors affecting the methane emission of rice. Among them, conventional early rice varieties and hybrid late rice varieties showed low emission characteristics, which provided a choice for planting rice varieties with low methane emission. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to analyze the effect of water regulation on the growth and development of rice and irrigation water use efficiency. 【Method】Three water gradients were set at tillering stage to control water content. At the end of each growth period, the indexes were sampled and measured. 【Result】Water regulation at tillering stage had significant effect on rice growth and irrigation water use efficiency under two cultivation methods. W1 and W2 treatments had little effect on rice plant height, and W3 treatment reduced plant height seriously under water stress. Water regulation at tillering stage has obvious influence on the final tiller number, which shows that the average number of tillers under mulching cultivation is 17.44 per hole, and the average number of tillers under bare land cultivation is 17.60 per hole. W2 treatment can maintain a higher leaf area at the later growth stage, which is more conducive to the accumulation of photosynthetic products and the formation of final yield of rice. Under the condition of film mulching and bare land cultivation, the utilization rate of irrigation water of W2 treatment was the highest, which was 0.64 and 0.46 kg/m~3 respectively. 【Conclusion】Appropriate water stress at tillering stage of drip irrigation rice is beneficial to rice growth and development and then to increase yield. From the perspective of drip irrigation rice to improve irrigation water use efficiency and yield, W2 water treatment of drip irrigation rice film mulching cultivation mode can be used as a more appropriate control measure based on the experimental conditions. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimedto analyze the change of resistance of different resistance genes and gene combinations to panicle neck pest. 【Method】The genotype of 80 resource materials screened for annual resistance were detected with the functional or closely linked markers of rice blast resistance genes Pi-ta, Pi-b, Pigm and Pi54 in rice, combined with the identification of rice panicle blast resistance for two consecutive years. 【Result】The results showed that among 80 experimental materials, 4 cultivars only carried Pi-b, 5 cultivars only carried Pi54, 8 cultivars carried Pi-b+Pi54, and 10 cultivars carried Pi-b+Pi54+Pigm. Rice cultivars carrying Pi-b+Pi54+Pigm gene combination did not show high susceptibility in two continuous years’ artificial identification. Two years’ correlation analysis between resistant genes and neck blast resistance showed that the disease resistance of single gene was gradually weakened and even lost. 【Conclusion】It was an effective way to enhance the disease resistance of rice to polymerized genes with broad antimicrobial spectrum and strong resistance in rice breeding. [ABSTRACT FROM AUTHOR]

[Objective] The aim of this paper was to provide a theoretical relerence for the application of loss-control urea in rice production in yellow soil. [Method] Based on the same application rates of phosphorus and potassium fertilizer, the rice cultivar Leyou 58 was employed to explore the ellects of loss-control urea, with various adding amount of loss-control agent (1 %,2%,3%,4%,5%,6%), on rice yield, nutrients uptake and utilization. Meanwhile, no nitrogen and common urea fertilizer were taken as the controls. [Result] No regular changes of rice yield observed with increasing the dosage of loss-control agent, while the accumulation of nitrogen in rice grain, nitrogen, phosphorus and potassium in rice straw, and potassium in aboveground parts showed regular variation. At the same time, regular changes were also observed on rice nitrogen, phosphorus, potassium harvest index and potassium absorption efficiency. Compared with common urea treatment, six kinds of loss-control urea with the loss-control agent of 1 % -6 % could increase the rice yield in some degree, among which 1 % adding amount performed the best. The yield increasing rate was up to 12.22 %. The adding amounts of 1 % , 2 % and 6 % enables absorption of nitrogen, phosphorus, potassium by rice and accumulation in the rice seeds sufficiently to promote the yield and quality of rice. The adding amount of 3 % enhanced the accumulation of nitrogen, phosphorus and potassium in rice straw, increased the resistance and promoted the growth. [Conclusion] To sum up, the effect of urea with 1 % loss-control agent performed the best in rice production. [ABSTRACT FROM AUTHOR]

[Objective]The purpose of this paper is to study the effect of grain size and weight on the total anthocyanin content(TAC) of ‘ Yungu No. 1 ’ . [ Method] Anthocyanins from black rice were extracted by extraction method, and the absorbance value of solution was determined by pH differential method. Date analysis was carried out by statistical method. [ Result] There were significantly positive correlations between TAC of black rice and grain size and weight (P<0.001). Grain thickness had the highest correlations with TAC, followed by grain weight, width and finally the length. The difference of TAC was not obvious when grain thickness exceeded 1.80 mm, and there was an intermediate transition state which the thickness between 1.70 to 1.80 mm. A new comprehensive variable was extracted by the Partial Least Squares (PLS) analysis, which explained 96.3 % of the x-variability and 78.8 % of the y-variance, respectively, and the prediction rate for TAC was 77. 1 %. [ Conclusion] Grain size and weight not only affect the appearance quality and physical properties of rice, but are also closely related to some nutrient contents. [ABSTRACT FROM AUTHOR]

[Objective] Eating and cooking qualities in the low amylose content rice with different ecotypes were studied in this paper. [Method]The cooking physico-chemical factors and the RVA profile characteristics of 21 low AC rice varieties grown at different altitudes were determined, and the cooking and eating quality characteristics ol indica and japonica were analyzed, and the correlation among the eating quality indexes was also analyzed. The differences of cooking and eating quality characteristics of different ecological low AC indica rice were compared, and the correlation among different eating quality indexes under different altitudes was analyzed. [ Result]The PAT and ASV was significant and extremely significant between low AC indica and japonica rice. The correlation among the cooking physico-chemical factors was not significant, but the correlation between RVA profile characteristic values was large, and was significant with some cooking physico-chemical factors. There were significant differences in AC, FC and SRV among different ecotypes of low AC indica rice, which were greatly affected by the environment. With the decrease ol planting altitude, the increase ol temperature, the decrease ol AC and SRV , rice became soft and sticky. The correlation ol the PKV , BDV and CSV of indica rice with different ecotypes was the same, but there was a significant correlation between AC and some RVA profile characteristics in Zhefang. [Conclusion]The GT of low AC indica rice was significantly higher than that of Japonica rice, and its taste quality was slightly better than that of Japonica rice. The cooking and eating quality characteristics of low AC rice were mainly caused by the difference ol amylopectin. The key index determining the food quality ol die RVA profile characteristics was the PKV , that is, the higher the PKV , the softer and stickier the rice, and the lower GT, the less time to reach the PKV. For rice varieties of low AC with different ecotypes, the lower the planting altitude, the lower AC, the closer the relationship between the cooking physico-chemical factor of and the RVA profile characteristics. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to clarify the genetic diversity and composition of non-toxic genes of Magnaporthe oryzae in Taojiang. [Method] Genetic diversity of 29 M. oryzae isolated and purified from several late rice varieties in Taojiang disease nursery was analyzed by 8 pairs of SSR primers. And nontoxic gene of 19 isolates were identified through 18 near-isogeniclines(NILs) whose resistance gene to blast were known. [Result]The results indicated that under the 0. 70 similarity coefficient and 0. 30 difference coefficient level, the total isolates of twenty-nine could be divided into seven genealogies. The dominant genealogy 1 contained 12 isolates, accounting for 41.3 % of the total isolates. The V genealogy contained 7 isolates, accounting for 24. 1 % of the total isolates. The other 5 genealogies contain 1 -3 isolates, accounting for 34.6 % of the total number of isolates. The pathogenic frequency (pathogenic frequency = the number of susceptible rice varieties / the number of total tested rice varieties x 100 %) ranged from 35 % to 75 % , and there were 3 strong pathogenic iso-lates (pathogenic frequency > 70 %) which accounted for 15. 7 % of the total isolates ;7 isolates were highly pathogenic (70 % > pathogenic frequency ^50 %) , accounting for 36. 8 % of the total isolates. Nine medium pathogenic isolates (50 % > pathogenic frequency ^20 %) , accounted for 47. 5 % of the total isolates, and the average pathogenic frequency of the tested isolates was 49.86 % . The virulence frequencies of 19 isolates to NILs (virulence frequencies = the number of isolatesto be tested the virulence with NILs / the number of all isolates x 100 %) were identified by avirulence gene, it was shown that more than 70 % of the virulent genes what with highly virulent were Pi-ks, Pi-ztand Pi-ta. The resistance gene whose virulence frequency was between 50 % and 70 % with medium virulence were pi-kp , pi-z5 , pi-t, pi-sh and Pi-5. The virulence frequency of the other resistance genes was less than 50 %. [Conclusion] The population of Pyricularia oryzae in Taojiang, Hunan province has abundant genetic diversity and complicated pathogenicity differentiation. The resistance genes Pi-3, Pi-i, Pi-11, Pi-19 and Pi-12 have excellent resistance to M. oryzae in Taojiang area and can be used in disease resistance breeding. [ABSTRACT FROM AUTHOR]

Objective] This paper aimed to investigate the effects of different nitrogen levels on the expression of 0sAAP6 gene in rice and further explore the effects of OsAAP6 gene on the contents of protein (including glutenin, prolamin, globulin and albumin) and amino acids in rice grains under different nitrogen fertilizer conditions so as to utilize OsAAP6 gene for improving the nutritional quality of rice in the future. [Method] Five nitrogen concentration gradients were set up to detect the expression level of OsAAP6 gene from the genetic materials in rice, and the protein contents and amino acid contents in the mature seeds by near infrared grain analyzer and Coomassie Brilliant Blue G-250 method were analyzed. [Result]With the increase of nitrogen fertilizer concentration in the field, the expression level of OsAAP6 gene increased significantly, which could promote the accumulation of glutenin in rice grain and then increased the total content of grain protein in rice. Simultaneously, with the increase of nitrogenous fertilizer application, OsAAP6 gene could significantly increase the total content of amino acids in rice grain. [Conclusion] OsAAP6 gene expression level increased with the increase of nitrogen fertilizer concentration in the field, and could promote the nutritional quality in rice, such as the protein content and amino acids content in the grain, which provided an important reference for the future utilize of OsAAP6 gene to improve the nutritional quality of rice grain. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to the effects of different nitrogen treatments on milling quality, appearance quality, nutritional quality and eating quality of rice under soda-saline-alkali soil.【Method】 Taking Kenjing7 and Kenjing8 as tested materials, the nitrogen fertilizers were set as base fertilizer:tiller fertilizer:adjusting fertilizer:panicle fertilizer, and their percentage was 0(N0), 6:4:0:0(N1), 5:3:0:2(N2), 4:3:1:2(N3), 4:3:1:2(0.9 N3, the total amount of nitrogen reduced by 10 %) under the condition of the field. 【Result】When the amount of nitrogen fertilizer applied in the whole growth period was 150 kg/hm~2, the rate of fine rice and whole concentrate rice decreased, the chalkiness and chalkiness rate of rice decreased significantly, the content of amylose decreased, and the protein and taste quality of rice increased in the two varieties. Under the same nitrogen distribution ratio(4:3:1:2), the nutrient quality of Kenjing7 was improved when the total amount of nitrogen fertilizer was reduced by 10 %, and the milling, appearance, nutrition and taste quality of Kenjing8 were improved. Considering the comprehensive quality of rice, the total nitrogen application amount during the growth period was 150 kg/hm~2, and basal fertilizer:tiller fertilizer:adjusting fertilizer:panicle fertilizer was 4:3:1:2 condition, which was conducive to improving the quality of Kenjing 7. During the growth period, the total nitrogen application rate was 135 kg/hm~2, base fertilizer:tiller fertilizer:adjusting fertilizer:the spike fertilizer was 4:3:1:2, and the quality of rice variety Kenjing8 was at the best level. The nutrition and appearance quality of Kenjing 7 was better than that of Kenjing 8, but Kenjing 8 had better eating quality and milling quality. 【Conclusion】In summary, the appropriate nitrogen reduction according to the variety characteristics and the ratio of regulating fertilizer and panicle fertilizer to total nitrogen amount was beneficial to the improvement of rice quality. The results can provide a theoretical reference for rational management of nitrogen fertilizer in rice in soda-saline-alkali soil. [ABSTRACT FROM AUTHOR]

[Objective] The Vacuum infiltration transformation method is simple, fast and effective because of non-tissue culture. This paper first worldwide reported a new transformation method in rice-vacuum infiltration transformation method. [Method] Using a set of special e-quipment designed by ourselves, the most robust plants in vivo before flowering were vacuum infiltrated insuspension, Sophora Flavevescens Lectin (SFL) was successfully introduced into rice. [Result] A large number of T0 transgenic seeds were harvested. A number of transgenic plants were gained by Basta resistance selection, ehlomphenol-red (CPR) and PCR determination suggested that the SFL gene had been integrated into the rice genome. The transgenic plants showed high blast resistance by means of the seedling spray inoculation in the field compared to non-transgenic rice. This implied that SFL gene was expressed in transgenic rice plants. [Conclusion] Vacuum infiltration transformation method provided a rapid and effective new approach for genetic transformation in rice and other cereal crops. At the same time, it also laid the foundation for research on the SFL gene function and breeding of high blast resistant rice varieties in the future. [ABSTRACT FROM AUTHOR]

【Objective】In this paper, the rice varieties resistance to southern rice black-streaked dwarf disease(SRBSDV) were evaluated. 【Method】Taking the way of induced in field, the resistance of 343 main rice cultivars were evaluated to southern rice black-streaked dwarf disease in Xing’an Guangxi Province. 【Result】First, rice varieties were evaluated by one-row plot experiment and the resulted showed that the infected plant rate by SRBSDV was low 5.00 %, the number of rice varieties was 291, 84.84 % of the total rice varieties; including conventional indica rice varieties and indica hybrid rice varieties were 259, Japonica conventional rice varieties were 32; early rice varieties were 100, and the rest for middle-later rice varieties. Chosen rice varieties with the different resistance to SRBSDV, evaluated the resistance by the plot experiment for two years. The results indicated that 7 cultivars were resistant, including Cliangyou4418, Yexiangyou688, Yexiangyou3 hao, Qianliangyou58, Zhongzheyou8 hao, Zhongzheyou1 hao and Zhongzheyou10 hao. 【Conclusion】The SRBSDV resistance resources identified in this study not only will guide the development of resistant varieties and help the prediction of damage caused by SRBSDV, but also will provide the useful tools and materials for the identification of SRBSDV resistance gene(s) and development of SRBSDV resistance varieties. [ABSTRACT FROM AUTHOR]

【Objective】The aim of this paper is to clarify the distribution status of resistant genes to rice blast in Guizhou HE. 【Method】The field rice blast resistance and four molecular markers linked with rice blast resistant genes Pik-h, Pi2, Pi9 and Pi5 of 82 local varieties of Guizhou HE came from 5 counties of Guizhou province were identified in this study. 【Result】The results of field test showed that 46 varieties, accounted for 56.1 % of all, were high resistance to leaf blast. The genetic frequencies of Pi5, Pikh, Pi9 and Pi2 were 32.35 %, 30.86 %, 2.56 % and 2.47 % in all varieties. The resistant genes combined 7 genotypes, including 0(with no one of 4 genes), Pikh, Pi5, Pi9, Pi5 + Pikh, Pi2 + Pi5, Pi9 + Pi5, and their frequencies were 50 %, 21.95 %, 14.63 %, 1.22 %, 8.54 %, 2.44 %, 1.22 %, respectively. Two to six genotypes of 7 genotypes were found in a county. The dominant genotype in Congjiang county was‘0’genotype, accounted for 61.54 %, and in Liping county were‘0’and‘Pikh’genotypes, accounted for 46.43 % and 42.86 % respectively. Six genotypes were detected in Libo county, but there was no obvious dominant type among them. The variety types were more abundant in Libo county than in Congjiang county or Liping county. The average blast resistance level of 4 genotype, ‘0’, ‘Pikh’, ‘Pi5 + Pikh’and‘Pi5’, were 2.39, 1.28, 1.57 and 1.17, which indicated that the blast resistance could be associated with genes of Pi5 and Pikh. Some varieties with‘0’genotype showed resistance to leaf blast, which indicated these varieties carried other resistance genes. 【Conclusion】The results provide a reference for the exploitation and utilization of the genetic resources of rice blast resistance in Guizhou HE. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to understand the expression patterns of Chl content related genes at different stages. 【Method】using a recombinant inbred(RI) population consisting of 173 lines(F10) derived from a cross between two indica rice varieties, Gang46 B and A232, with corresponding genetic map comprising 130 SSR markers. The quantitative trait loci(QTLs) for Chl content of the top three leaves at two developmental stages(tillering stage and heading stage) in 2016 and 2017 was detected by Inclusive Composite Interval Mapping. 【Result】A total of 30 QTLs in 16 intervals on chromosome 1, 2, 3, 4, 5 and 7 were identified and explained 5.91 %-38.69 %phenotypic variations by a single QTL. The marker interval RM231-RM3392 on chromosome 3 were detected eights times, suggesting that these QTLs in the interval were less affected by the environment and stably expressed at two developmental stages, which might be beneficial for improving the leaf chlorophyll content, promoting the rice photosynthesis. Comparison with other studies revealed that major QTLs were easily re-detected in different populations and environments. These QTLs located in RM5626-RM1350 and RM231-RM3392 of chromosome 3, RM280-RM1113 and RM5473-RM303 of chromosome 4, and RM21253-RM248 of chromosome 7. 【Conclusion】These QTLs information would help us to understand the genetic basis of chlorophyll content in detail and could be used in marker-assistant-selected method for rice breeding. [ABSTRACT FROM AUTHOR]

【Objective】The present paper was conducted to study the accuracy of using Landsat8 OLI remote sensing image to monitor the rice planting area in hilly areas of Sichuan province.【Method】Four kinds of rice cultivars from shallow hill and deep hill rice were selected respectively according to the valley height. And the area of rice planting was obtained by ground sampling survey and Google Earth image interpretation in the same growing season as validation data. This result was used to evaluate the monitoring accuracy of rice planting area in the hilly region of Sichuan Province based on OLI fusion images. After orthophoto correction of OLI image,15 m panchromatic band image and30 m multispectral images were used to fusion to get 15 m resolution fusion image. And supervised the classification with maximum likelihood method to get the monitoring result.【Result】Compared with the quadrat verification data,the results of rice planting area monitoring based on OLI images with the same sample area showed that the average accuracy of the shallow hill area was 93. 7 %,the error range was 1 % to 8. 7 %. And the depth area was 92. 5 %,the error range was 1. 5 % to 15. 8 %.【Conclusion】According to the error range of the monitoring results in the shallow hilly area and the deep hilly area,with the increase of the valley height,the terrain tended to be complicated,the plot tended to be narrow and broken,and the uncertainty of the OLI image monitoring result increases. And in the same time,the accuracy of OLI image monitoring has a downward trend. This study provides a reference for improving the accuracy of OLI image monitoring of rice planting area in hilly areas of Sichuan province. [ABSTRACT FROM AUTHOR]

[Objective] In this paper, the integrated technology to control southern rice black-streaked dwarf disease (SRBSDV) on hybrid rice was stuthed. [Method] Three varieties including ‘ Zhongzheyou 8’, ‘ Hliangyou 991 ’and ‘Taichung Nalive(TNl)’ were sown in the disease nursery located in Xing’ an county of Guangxi Zhuang region and applied with fly net and insecticides. The effects of the treatments including seed-coating with 25 % imidacloprid sowing, mulching of fly net immediately alter sowing, spraying ol 25 % buproluzin on uncovered seedlings 15 days after the emergence of the seedlings, spraying 25 % pymelrozin 2 days before transplantation and the different combinations of treatments on the ratios of shortened plants and plants with high position tillers of each variety were investigated at the end of milk stage. [Result]The obtained data indicated the resistance of ‘zhongzheyou 8’ to SBRSDV. The rales of the diseased plants of ‘Zhongzheyou 8’ averaged at 6.97 % and were significantly lower than that of susceptible ‘Hliangyou 991’ and ‘TNI'. The lowest rate of diseased plants of ‘Zhongzheyou 8’ was obtained from the plots of fly net mulching combined with pymelrozin spraying. All of the physical and chemical treatments or their combination significantly reduced the rate of diseased plants in ‘ Hliangyou 991 ’ and there was no significant difference in the rale of diseased plants between such treatments. The rate of diseased plants in TNI with or without physical and chemical treatments was all 100.0 %. [Conclusion] It was concluded that seed-coating, fly net mulching as well as spraying before transplantation could protect resistant and susceptible varieties from the infection of SBRSDV while variety resistance plus whole stage protection of the seedlings controlled the disease more efficiently. [ABSTRACT FROM AUTHOR]

[Objective] In this paper, the genetic diversity and similarity of rice germplasm introduced from elsewhere in recent years and sell-bred in Ningxia were studied to provide some references for the abundant genetic diversity of rice and expand its genetic basis. [Method ] A total of 24 SSR markers distributed in 12 chromosomes were used to analyze the genetic diversity and their genetic relationship of rice germ-plasm which were introduced from elsewhere and self-bred rice varieties of Ningxia. [Result] Of the 170 materials involved in trials, 1 12 alleles were revealed, the mean number of alleles per locus was 4. 67, and total genetic diversity index of Nei varied greatly among loci from 0. 2271 to 0. 7986, with an average of 0. 6079. To investigate the genetic relationship of different geographical rice germplasm, the similarity coefficient of different varieties of geographical source was between 0.4053 and 0. 8620, with the average coefficient of 0.7109. The maximum similarity coefficient between The northeast China and Japan varieties was 0. 8620, and the minimum between the Jiangsu and the south (mainly in Yunnan) varieties was 0. 4053. There was a high genetic similarity among the rice germplasm of introduction and self-bred, especially in the three provinces of northeast's largest, reaching at 0. 8344. [Conclusion] Most of the introduced rice variety resources and Ningxia were close relatives, indicating that the genetic diversity of germplasm resources in Ningxia although had a tendency to increase but the narrow genetic basis. In rice creating and utilizing in the future, we should make full use of the introduction of the genetic differences of resources, increase the genetic distance of the parents and enrich the genetic basis of bred varieties. [ABSTRACT FROM AUTHOR]

[Objective]The stigma exsertion of rice(Oryza saliva L.) was an important trait determining the outcrossing rates, which was also a key factor influencing the hybrid seed production and sterile line breeding, so the research of tissue-specific expression of stigma exsertion of rice would laid the foundation of the molecular mechanism in heterosis of rice. [Method] In this paper, a specific expression promoter p51408 related with stigma exsertion of wild rice (Oryza rujipogon Griff.) from Yuanjiang City was cloned, the structural character of its sequence and expression feature of os51408 was analyzed. [Result ] With the construction of GUS expression vector and histochemical staining, the results showed that it was specific expression in stigma and style, no or low expression in root, stem, leaf and spikelet. [Conclusion]So it could be a tissue-stigma specific expression promoter, and might play a very important role in rice stigma exsertion research. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aims to figure out physiological races variation and genetic structure of Magnaporthe oryzae in Guangxi and providea basis for breeding and distribution of rice resistant varieties in the future. 【Method】 Physiological races identification with seven differential varieties and genetic diversity analysis with SSR of M. oryzae from 2012 to 2014 in Guangxi were conducted in the present work. 【Result】24 physiological races belonging to 7 groups which included ZA, ZB, ZC , ZD , ZE , ZF and ZG were identified from 142 isolates collected from 2012 to 2014. Among them, the predominant group was ZB with an occurrence frequency of 67. 61 % , and the predominant races were ZB9and ZB13with an occurrence frequency of 19. 01 % , respectively. The UPGMA method was used to analyze the genetic diversity of 107 isolates and 14 lineages at similarity coefficient of 0. 88 were obtained. Among them, lineage L01 was the dominant lineage accounting for 44. 86 % of the isolates, lineage L03 , L06 and L11 were subordinate lineages accounting for 19. 63 % , 13. 08 % and 10. 28 % of the isolates, respectively. In addition, the number of isolates and their corresponding physiological race of every lineage was counted and the result showed that there was no correlation between genetic lineages and races. ' Conclusion】 Between the year of 2012 and 2014 in Guangxi, the predominant group of M. oryzae was ZB while the predominant races were ZB9 and ZB13, and there was no correlation between genetic lineages and races. [ABSTRACT FROM AUTHOR]

Cadmium(Cd) in grains came from the soil. The form of cadmium in soil was closely related to the amount absorption of crops. The purpose of this paper was to find out the correlationship between the form of cadmium in soil and cadmium in grains, aimed to explore the source of cadmium in wheat/ rice grain, which provided theoretical basis for blocking-up cadmium absorption. Through investigating and sampling method, Cd content in paddy soil of tillage layer on Chengdu plain cadmium polluted area and the corresponding crop straw and grain were analyzed, which used to research the distribution characteristics and biological effects of different forms cadmium in these paddy soils. The results showed that the order of average content of different Cd forms in paddy soil was; O-FeMn > RE > EX > OM > CAB. The content distribution of different forms of Cd were extremely uneven, and the proportion of bio-available form was larger. There was a significant positive correlation between O-FeMn and pH, (r = 0. 712, P <0. 01) . The Cd content in wheat and rice were significantly positive correlated with wheat straw(r= 0.854* *, P< 0.01) and rice straw(r= 0.872* ", P<0.01) respectively. The EX-Cd in soil correlated with wheat straw and seed, respectively (r = 0.677 * and 0. 867 *, P < 0.01), but not other forms of Cd in soil. The EX-Cd content in soil was only correlated with Cd in rice grain (r = 0. 573 *, P <0. 05). The risk of Cd-exceed the standard in the grain of the crops which was grown on the polluted soil was high. [ABSTRACT FROM AUTHOR]

Pita is a broad-spectrum resistance gene for rice blast and has been applied in different rice resistance breeding programs. In order to improve the efficiency for Pita selection based on molecular marker-assistant selection (MAS)，a gene-specific dCAPs marker，Pita918, targeted on single nucleotide polymorphism that result in single amino acid changed between resistant and susceptible allele of Pita on 918th aa has been developed in this paper. The result showed that Pita specific DNA marker Pita918 can distinguish Pita from other R genes and susceptible allele gene clearly，providing breeders an efficient and accurate marker for Pita selection. Additionally，Pita918 has been used for genotype characterization among 13 resistant rice landraces collected from south and southwest of China，the result showed that those landraces do not harboring Pita for their rice blast resistance，suggesting that Pita918 is a valuable DNA marker for genotype identification in rice germplasm，which will give breeders abundant genetic information in new resistance genes discovery [ABSTRACT FROM AUTHOR]

Through the stability and relevance analysis,by using DUS-test data of 22 rice varieties,this paper discussed the test performance of 11 quantitative traits for DUS. The result showed that various characters variation coefficient were 4. 87 %- 20. 69 %. The variation coefficients of flag leaf width( C5),panicle length( C6),grain length( C8),grain width( C9),unpolished rice length( C10) and unpolished rice width( C11) all had less than 10 %,which meant they were high stability; The remaining 5 characters exceeded 10 %,which showed they were low stability. The Correlation was more different among characters,and the correlation coefficient was- 0. 56 %- 0. 978 %.The correlation coefficient between unpolished rice length( C10) and unpolished rice width( C11) was highest,which was 0. 978; The followed were grain length( C8) and unpolished rice length( C10),grain length( C8) and unpolished rice width( C11),the correlation coefficient were 0. 955 and 0. 938,respectively; And there were higher relevance between grain width( C9) and unpolished rice length( C10),grain width( C9) and unpolished rice width( C11),grain length( C8) and grain width( C9),the correlation coefficient were0. 87,0. 876 and 0. 853,which all were significantly correlated at the level when a = 0. 01. But the correlation coefficient between Length of the reciprocal second leaf blade( C1) and grain width( C9),length of the reciprocal second leaf blade( C1) and unpolished rice width( C11) were lowest,which was- 0. 56. And the average correlation coefficient between each test character and the other 10 test traits was form 0. 1259 to 0. 1345. Relevance and stability of Characters were consistent. If a character had higher relevance with other test-character,it would had higher stability. Five characters,as grain length( C8),unpolished rice width( C11),unpolished rice length( C10),grain width( C9) and flag leaf width( C5),could be used as necessary characters in DUS testing. Because the variation coefficient of them less than 10 %,between 4. 87 %- 7. 81 %; And the correlation coefficient with other traits of them between 0. 1345- 0. 0876. The result showed that a character with high stability and relevance must be with strong test performance; To a character,of which the stability should be stress considered,when stability and relevance were not consistent. Any character with high stability would be with high test performance. It was reasonable that flag leaf width( C5) be used as necessary characters for DUS testing in‘guide’of rice. On the existing basis,in order to enhance scientific nature of ‘guide’,four characters named grain length( C8),unpolished rice width( C11),unpolished rice length( C10) and grain width( C9) should have been used as additionally necessary traits for DUS testing. In view of the high stability,it was rationality that panicle length( C6) had been listed as the traits which must be measured for DUS-testing. Although it had higher correlation with other traits,it was more appropriate that flag leaf length( C4)should have been used as complementary traits,because the stability of which was not good enough. [ABSTRACT FROM AUTHOR]

In this paper, taken weedy rice ‘JS-Y1' and rice cultivar ‘Nanjing 44' as tested materials, the field experiments were conducted to study the effects of fulvic acid (FA) soaking rice seeds with different concentrations (FA concentrations 0, 4, 6, 8 g/L) on the photosynthetic performance, root activity and yield components of cultivated rice under the stress of weedy rice with different densities ( 0, 4, 8 plants/m2). The results showed that the weed suppressed the physiological stress indicators of cultivated rice in varying degrees at different growth stages comparing with the control, and weedy rice affected the normal physiological functions of cultivated rice at the different developmental stages. The inhibition rates of SPAD, dry weight, net photosynthetic rate, root system oxidizing power and root sap bleeding reached to 5. 61 %， 24. 91 %， 18. 00 %， 25. 23 %， 20. 52 %， respectively, which resulted in the decrease of cultivated rice yields by 10. 02 % - 23. 06 %. The treatment of FA soaking significantly improved the photosynthetic performance and root activity of cultivated rice, enhanced the cultivated rice physiological functions under weedy rice stress and alleviated the adverse effect of weedy rice on cultivated rice. It was concluded that the adverse effects of weedy rice on cultivated rice were decreased by increasing the competitiveness of cultivated rice treated with fulvic acid soaking. [ABSTRACT FROM AUTHOR]

In this paper, the genetic diversity analyses of 23 varieties were conducted by 35 SSR primers. The result showed that 342 DNA fingerprints were obtained from 23 varieties by 35 SSR primers, of which 288 polymorphic DNA fingerprints occupied 84. 21 % of all. There were significantly resistant differences among 23 varieties with 8. 20 % - 75. 93 % for the DPR and 2. 19 - 52. 67 for the DI. Genetic similarity analysis based on SSR molecular marker showed that the genetic similarity of paired varieties ranged from 0. 614 to 0. 954, and mean was 0. 740, while that of single varieties was from 0. 686 to 0. 778. The means of genetic similarity of 11 varieties were lower than that of the total (0. 740 ), while the means of 12 varieties were higher than 0. 740. The 23 rice varieties were clustered into 5 genetic groups at 0. 75 similar coefficient. The varieties with different growth periods (the most differences reaching 11 days) were clustered into the same group, while the varieties with the same growth period were existed in different groups. [ABSTRACT FROM AUTHOR]