Search

Soybean nutritional quality traits are generally quantitative traits and are regulated by multiple genes. At present, a large number of molecular markers related to quality traits have been located, but there were few available markers verified in soybean breeding populations. In this study, we selected 288 soybean varieties from Huang-Huai-Hai region and 19 wild/semi-wild soybean accessions as a natural population. We analyzed their protein, oil, fatty acid, and isoflavone contents by NIR, GC, and HPLC methods. We selected 18 SSR markers closely linked to quality traits to identify their genotypes by capillary electrophoresis method, and verify the molecular markers associated with nutritional quality traits using association analysis based on the Tassel 2.1 software. The results showed that there were three markers associated with oil content, three markers associated with the content of protein plus oil, one marker associated with palmitic acid, one marker associated with stearic acid, two markers associated with oleic acid, and two markers associated with linolenic acid, and the elite alleles of these loci were also investigated. Our study provided reliable molecular markers for soybean quality molecular breeding. [ABSTRACT FROM AUTHOR]

This long-term fertilization experiment was conducted since 1981, included non-fertilization (NF), chemical fertilizer (CF), double chemical fertilizer (DCF) and chemicals with organic fertilizer (COF). In 2017, soil samples were collected at the tillering, heading and maturity stages of early-season rice (Oryza sativa L.). The activities of urease (UR), α-glucosidase (AG), glucosaminidase (NAG), β-1,4 glucosidase (BG), β-cellobiosidase (CBH), β-xylosidase (BXYL), acid phosphatase (ACP), phenoloxidase (POX) and peroxidase (PER) were measured. The activities of AG, NAG, BG, CBH, BXYL, ACP and POX in the maturity stage were significantly higher than in the tillering stage by 343.0%, 153.4%, 55.0%, 8.5%, 1791.5%, 1237.7% and 1179.4%, respectively. Compared with the CF treatment, the activities of UR, AG, BG, and POX in the COF treatment increased by 33.5%, 23.3%, 19.5% and 40.1%, respectively. Meanwhile, both CBH and ACP in the COF treatment were higher than in the DCF treatment by 33.4% and 66.7%, respectively. A significant relationship was identified between UR/PER activities and soil available nitrogen, phosphorus, potassium/rice biomass using the redundancy analysis method. Therefore, the application of organic and chemical fertilizers could increase most enzymatic activities and soil productivity. UR and PER were key factors indicating soil nutrient turnover and rice growth. [ABSTRACT FROM AUTHOR]

We aimed to explore changes in basic soil productivity ( BSP) under different fertilization regimes in the Poyang Lake region, Jiangxi Province, China. Soil samples were collected from a long-term fertilization experiment (since 98) that included treatments of no fertilization (CK), chemical fertilization ( NPK), and combined chemical and organic fertilization ( NPKM) . Then, a three-year pot experiment (from 0 to 0) with double rice cropping was conducted with two different fertilization regimes (no fertilization, F0; fertilization, F1) using CK, NPK and NPKM soils. Grain yield and BSP were analyzed among soils with different fertilization regimes to identify the key factors driving changes in BSP. Results showed that grain yields in NPKM soil were higher than in NPK and CK soils regardless of fertilization in the pot experiment. Under the F0 condition, annual grain yields of NPKM soil were 7.7%-.9% and 0.8%-66.7% higher than CK and NPK soils, respectively. The BSP values of CK, NPK and NPKM soils in three years were .8%-5.%, 5.%-6.6% and 59.%-88.%, respectively. NPKM soil had significantly higher BSP than NPK and CK soils. Furthermore, there were significant positive correlations between soil organic matter and BSP as well as between organic carbon balance and BSP. These results suggested that long-term application of chemical and organic fertilizers could improve BSP in the double rice cropping system of the Poyang Lake region. In addition, soil organic matter and organic carbon balance are important factors for improving BSP in this region. [ABSTRACT FROM AUTHOR]

GmFT2a is a key gene in photoperiodic pathway of soybean. However, the underlying molecular mechanism of GmFT2a expression is not clear. In this study, a photoperiod-sensitive soybean cultivar Zigongdongdou and insensitive cultivar Heihe 27 were used as materials to compare the GmFT2a promoter sequences. It revealed that there were 2 insertion/deletion (InDel) fragments, T1 and T2, which contained light reaction elements in the GmFT2a promoter of Zigongdongdou. However, the same fragments were not in that of Heihe 27. The bait constructs were prepared according to the sequences of light reaction elements of I-box and SP1 to screen cDNA library of Heihe 27 leaves, and a MYB transcription factor bound with T1 was isolated with the yeast one-hybrid system. The obtaining of the MYB transcription factor provided a favorable clue for further study of the molecular mechanism GmFT2a expression regulation. [ABSTRACT FROM AUTHOR]

WUS plays an essential role in plant regeneration. To preliminarily understand the function of Gm- WUS, the related bioinformatics analysis was conducted based on the soybean database. GmWUS and AtWUS proteins were different in the acidic region, while other domains were conservative. Meanwhile, GmWUSa full - length sequence had been cloned. The protein mainly localized in the nucleus, showing that it might be a homeodomain transcription factor. The expression of GmWUS in cotyledons had been detected by qPCR during seeds germination. The results showed that both GmWUSa and GmWUSb expression levels kept rising, but GmWUSa expression decreased in the late stage. GmWUS expression in cotyledon node during cluster buds induction shown an approximate periodic pattern, indicating that GmWUS involved cluster buds diferentiation and regeneration. Comparing the expression of GmWUSa with GmWUSb, they might play a temporal complementary in their functions. The results in this study will help to investigate roles of GmWUS in soybean regeneration, to explain the mechanism of cluster buds formation, and to promote soybean regenerative capacity so as to improve the genetic transformation efficiency by overexpressing this gene. [ABSTRACT FROM AUTHOR]

Molecular breeding is the main force driving the global soybean production development, and has become the core technology in competition of the international soybean seed industry. This review summarized the progress in molecular breeding of soybean made in 2012 and 2013. In these two years, there was rapid development in research of functional genomics due to the application of high-throughput technologies. New genes involved in flowering, yield, nodulation, resistance and tolerances had been isolated from soybean. In the field of molecular mapping, some new markers or QTLs had been identified, and the integration between conventional markers and novel technologies have been enhanced. Soybean genetic transformation system had been further optimized and some genes have been transformed into soybean to identify their functions. New individual or stacked transgenic events conferring insect resistance and herbicide resistance had been approved for import as food, feed or commercial planting in many countries. The paper also prospected the development of soybean molecular breeding in the near future in this article. [ABSTRACT FROM AUTHOR]

In this study, the grafting method was used to create composite plants material with the same scion but different cotyledons and the parts below cotyledons. The cut - in grafting method was used to study the changes of cotyledon area from cotyledon stage ( Vc ) to second - node ( V2 ) stage. The widely - planting soybean varieties over the years in Huanghuaihai Plains of China were used as stock genotypes, and Zhonghuang 39 was as scion. 3 soybean varieties with diiferent 100 - seed weight were selected as test materials, and the post - emergence changes of cotyledons area and physiological indices and their effects on seedling growth and development in soybean by setting the shading and normal sunshine treatments were studied. The results showed that cotyledon area increased during the seedling period from VC to V2 among all the tested varieties, with the increment range from 65.61% to 209.29%. The increment of cotyledon area from V2 to VC was negatively correlated with the cotyledon area at VC stage. The cotyledon area increment from VC to V2 decreased with the releasing years of the varieties. Beginning from Day 9 after emergence, the cotyledon area constantly declined in all varieties, and the contents of chlorophyll a, total chlorophylls and the dry weight of cotyledons decreased along with the seedling growth, the chlorophyll b content increased first and then decreased. Cotyledon soluble sugar content decreased for some days and then increased gradually, and finally decreased with aging cotyledons. After the shading, the changes of cotyledon area, dry weight, chlorophyll a, b and soluble sugar contents became more prominent than those in normal sunshine treatment, indicating that limiting the cotyledon "source" functions could affect the synthesis, degradation and transport of chlorophylls and soluble sugars in cotyledons, and the changes of cotyledon area and their dry weight. Removing cotyledons had impacts on seedling growth and development, with shorter seedling height, slower development process, and lower seedling dry weight. It was concluded that cotyledon is one of the important vegetative organs of soybean at seedling stage. Cotyledons should be protected and effectively utilized in soybean management. [ABSTRACT FROM AUTHOR]

Effects of different cut - in grafting methods on the survival rate and recover day of grafted soybean plants in soybean young seedlings ( Vc - V1 ) stage were studied to develop a grafting technique for shoot - root relationship research of soybean. Three cultivars were used, Zhonghuang 30(ZH30), Zhonghuang 39(ZH39) and Jidou 12(JD12),for cut - in grafting method, and two treatments were designed as follows : scion with and without cotyledons were grafted on the stock with cotyledons ; scion with cotyledons were grafted on the stock with and without cotyledons, respectively. The results showed that the mean survival rate of cut - in grafting method was above 90% . The recover days of stock with cotyledons and scion without cotyledons treatments were 3 -4d. The treatment remained scion cotyledons and stock cotyledons showed a significant impact on the survival rates of the grafted plants. Scion treatments did not show significant impact on the survival rates of stock with cotyledons treatment. The diference of grafting site did not affect the survival rate of grafted plants. But the combination of stock with cotyledons and scion without cotyledons was superior to others. [ABSTRACT FROM AUTHOR]

We aimed to explore changes in basic soil productivity (BSP) under different fertilization regimes in the Poyang Lake region, Jiangxi Province, China. Soil samples were collected from a long-term fertilization experiment (since 1981) that included treatments of no fertilization (CK), chemical fertilization (NPK), and combined chemical and organic fertilization (NPKM). Then, a three-year pot experiment (from 2012 to 2014) with double rice cropping was conducted with two different fertilization regimes (no fertilization, F 0 ; fertilization, F 1 ) using CK, NPK and NPKM soils. Grain yield and BSP were analyzed among soils with different fertilization regimes to identify the key factors driving changes in BSP. Results showed that grain yields in NPKM soil were higher than in NPK and CK soils regardless of fertilization in the pot experiment. Under the F 0 condition, annual grain yields of NPKM soil were 37.7%-143.9% and 20.8%-66.7% higher than CK and NPK soils, respectively. The BSP values of CK, NPK and NPKM soils in three years were 41.8%-53.1%, 45.2%-62.6% and 59.1%-88.1%, respectively. NPKM soil had significantly higher BSP than NPK and CK soils. Furthermore, there were significant positive correlations between soil organic matter and BSP as well as between organic carbon balance and BSP. These results suggested that long-term application of chemical and organic fertilizers could improve BSP in the double rice cropping system of the Poyang Lake region. In addition, soil organic matter and organic carbon balance are important factors for improving BSP in this region.