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Barley is one of the major cereal crops, which can provide a significant source of genes for stress tolerance due to its high diversity and adaptability. Metabolite traits are considered to be significant for adaptation of barley to heat stress. In the present study, genetic relationships between 120 barley genotypes were determined with 50 simple sequence repeat (SSR) and 26 inter simple sequence repeat (ISSR) markers under heat stress and non-stress conditions. Moreover, genetic diversity of barley accessions was investigated using the studied markers covering 7 chromosomes of barley. In general, 153 and 85 polymorphic alleles were detected for SSR and ISSR and number of the observed polymorphic allele varied between 2–9 and 2–6, with an average of 3.26 and 3.26 alleles per locus, respectively. Markers of Bmag0223, GBMS180/180, HVM7, ISSR22, ISSR25, and ISSR48 were the most informative due to their high polymorphism information content value demonstrating that putative techniques utilized in this research can be powerful and valuable tools in breeding program of barley. Association analysis was performed between 9 important traits and SSR and ISSR markers using four statistical models. The results revealed that the model containing both population structure (Q) and general similarity in genetic background arising from shared kinship (K) factors reduced false positive associations between markers and phenotypes. According to the results, some of markers related to more than one trait under normal conditions (ISSR31-2, HVM62, and GBMS180/180) and heat stress conditions (ISSR20-5, EBmac635, HVM14, and ISSR37-3) were determined, which can be considered to be the most interesting candidates for further studies and simultaneously will provide a useful target for the future breeding programs, such as marker-assisted selection (MAS).

Aegilops is known as the ancestor species of wheat and has a major role in the evolution of wheat. Considering the importance of this species and the fact that Iran is the center of the distribution, fifteen IRAP and REMAP markers were used to evaluate the genetic diversity of Ae. tauschii accessions from different regions of Iran and its relationship with Triticum durum and Triticum aestivum. A high level of polymorphism (99%) was observed for both retrotransposon markers. Polymorphism information content, the effective number of alleles (Ne), Nei’s genetic diversity (H), and Shannon’s information index (I) for IRAP markers were more than REMAP markers. The most genetic diversity was detected in Ae. tauschii accessions. The cluster analysis separated the accessions into three distinct groups. Ae. tauschii accessions from Golestan province grouped in the same cluster with T. aestivum genotypes, indicating that these accessions are probably more like to the progenitor of the bread wheat D genome. Our results revealed that retrotransposon-based molecular markers could be used as the appropriate and reliable marker system to evaluate genetic diversity and relationship in Triticum and Aegilops accessions.

Yarrowia lipolytica, as a good cell factory to speed up the production of plant pharmaceutical components, has been considered to be one of the most important and attractive micro-organisms in recent years, due to its high secretion capacity, limited glycosylation, large range of genetic markers and molecular tools. Naringenin, as a central core of flavonoids production, plays important roles both in plants and in the treatment of different types of human diseases. For this purpose, specific naringenin biosynthesis genes from different origins were selected and introduced after comparative expression profiling in Y. lipolytica. This research indicated that chs plays the main role in the production of naringenin, so the increase copy number of this gene in each construct was investigated. The HPLC results confirmed that the construct with 5 copy numbers of chs resulted in 7.14 fold increase of naringenin extracellular titer to 90.16 mg/L in shake flask cultures. The results reported in this study demonstrated that sufficient knowledge of genes involved in the specific biosynthesis pathway, synthetic gene pathway and using Y. lipolytica as a capable and cheap host could help bioengineers to produce significant amounts of pharmaceutical components.

Melon (Cucumis melo L.) is an important popular high-consumption product in the world. Melon Fusarium wilt (Fusarium oxysporum f.sp. melonis: FOM) is a global destructive disease. In this research, 88 melon landraces from different geographical regions of Iran together with reference genotypes as control genotypes were screened for resistance to 0 and 1 races of Fusarium wilt disease agent using artificial inoculation and two functional markers for the presence or absence of Fom-2 gene. The landraces in multiple replicates were examined in a greenhouse experiment. Thirty-five out of the 88 landraces were selected to determine the disease incidence percentage (DIP), disease severity percentage (DSP) and area under disease progress curve (AUDPC). Based on the results of marker-assisted selection, 83 genotypes had at least one susceptible allele, while 43 heterozygote genotypes had at least one resistance allele. Among genotypes evaluated in artificial inoculation test, three landraces including Shahd-e-Shiraz Gosht Narenji, Korki and Alam Gorgor indicated the highest level of resistance. It seems that these landraces can be considered as the most useful sources of resistance in breeding programs for introducing Fusarium resistant melons. In contrast, Jalali, Petra falat and Habib-Abad landraces were the most sensitive genotypes, which can be used to produce sensitive standard check lines.

The present research was conducted to validate and verify the association of SSR markers with traits related to leaf blast disease in 121 rice cultivars. Number of spots, number of spore-producing spots, spot size, infection type, infection percentage, and the area under the disease progress curve (AUDPC) were the blast-related traits measured in the rice blast nursery. Evaluation of genetic diversity of markers indicated that RM166 had the highest level of diversity indices including observed number of alleles, effective number of alleles, polymorphism information content (PIC) value, gene diversity, and Shannon’s index. Thus, RM166 is the more valuable marker which can be used in association mapping because of the high opportunity of linkage to valuable disease resistance traits. Association mapping was performed using population structure matrix through the general linear model (GLM) and the mixed linear model (MLM). Based on a structure analysis, three subpopulations were observed in the rice population of this study. Among the set of selected markers, 30 and 29 markers exhibited a significant linkage with traits related to blast disease in GLM and MLM, respectively. RM224 had the most significant relationship with evaluated traits in both GLM and MLM, suggesting that this marker can be used in breeding programs.

The presence of dormant embryos in seeds and nonuniformity in seedling growth are the main limiting factors for kiwifruit propagation. Studies on the germination of hybrid genotypes are limited, especially at different ploidy levels. Low germination percentages and nonuniformity in seedling growth are two of the limiting factors of kiwifruit breeding, especially new and imported germplasm. The effect of cold moist stratification and growing substances on seed germination and seedling growth, respectively, on different kiwifruit seed populations were evaluated in this study. The effect of cold moist stratification (3, 4 and 5 weeks at 4 °C) and growing substrate composition (peat, perlite and coco peat) on seed germination and seedling growth of different Actinidia genotypes were assessed. In general, increasing stratification period duration often increased germination speed and uniformity. It was also found that increasing the ratio of peat moss improved the vegetative growth parameters of all kiwifruit seedlings. Stratification treatment, light and temperature fluctuation and consequently suitable substrate can accelerate and increase the production of seedlings and reduce seedling losses. It was also found that peat–perlite (1:1) medium was the best medium for kiwifruit seedling growth.

Fruit shape index (round shape) and seed size have important effects on pumpkin yield. To investigate these traits and create the most desirable state, a cross was made between two pumpkin cultivars. The objective of this study was to estimate the main gene effects (additive, dominant and di-genic epistasis) and to determine the mode of inheritance for fruit shape and seed size by generation mean analysis. Six generations, namely P1, P2, F1, F2, BC1, and BC2 from a cross between Zucchini and hull-less seed Pumpkin, S10×P25, were constructed and evaluated for fruit length, fruit width, fruit shape index, and some seed-related traits (seed length, seed width, seed thickness). The experiment was conducted in the research field of the Faculty of Agricultural Science, University of Guilan, Rasht, Iran in 2019. Results showed a significant difference between generations in terms of fruit and seed traits. Scale and joint scale tests showed the presence of epistasis for some traits. According to the results of the average traits of different generations, standard heterosis and hetrobeltiosis were observed. Concerning the fruit shape index and seed width, there was an over-dominance effect. The broad-sense heritability of the traits was relatively high for all traits and between 52 and 92%. Narrow sense heritability was between 26 and 86% and relatively low for the fruit shape index and seed width. Therefore, selection of elite lines and production of their hybrids are recommended as two methods suitable for breeding to achieve the round shape index and larger seed size.

Triterpenic acids (TAs), a large group of natural compounds with diverse biological activity, are produced by several plant taxa. Betulinic, oleanolic, and ursolic acids are the most medicinally important TAs and are mainly found in plants of the mint family. Metabolic engineering is strongly dependent on identifying the key genes in biosynthetic pathways toward the products of interest. In this study, gene expression tracking was performed by transcriptome mining, co-expression network analysis, and tissue-specific metabolite-expression analysis in order to identify possible key genes involved in TAs biosynthetic pathways. To this end, taxa-specific degenerate primers of six important genes were designed using an effective method based on the MEME algorithm in a phylogenetically related group of sequences and successfully applied in three members of the Lamiaceae (Rosmarinus officinalis, Salvia officinalis, and Thymus persicus). Based on the results of in-depth data analysis, genes encoding squalene epoxidase and oxido squalene cyclases are proposed as targets for boosting triterpene production. The results emphasize the importance of identifying key genes in triterpene biosynthesis, which may facilitate genetic manipulation or overexpression of target genes.

In this study, the genetic diversity of Thymus collected from Gilan province in Northern Iran was evaluated using AFLP markers and chemical compositions of the essential oil derived from GC/MS. Polymorphic information content varied from 0.26 to 0.37 with an average of 0.31. Estimating Nei’s gene diversity (H) and Shannon’s information index (I) showed that the highest and lowest genetic variation was related to markers E32-M93 (H = 0.32 and I = 0.47) and E33-M39 (H = 0.19 and I = 0.32), respectively. Cluster analysis classified the studied populations in four major groups. Furthermore, essential oil of the studied populations was extracted by hydro-distillation and the chemical compositions of essential oil were identified by capillary GC and GC/MS. In total, 37 compounds were identified in the essential oil of all populations which ranged from 42.786 to 93.337%. Also, the populations of each species had similar chemical compositions. Results of cluster analysis of the chemical compositions grouped the studied populations into four groups. Generally, the observed variation in AFLP markers was associated with the geographical variation.

Investigating the traits of rice in conditions of blast disease and its relationship with grain yield can help to identify suitable strategies for selecting high-yielding cultivars, especially in areas prevalent with the disease. One hundred and twenty-one rice cultivars and lines (genotypes) selected from the collection of the Rice Research Institute of Iran were evaluated for the traits related to neck blast disease, including number of filled and unfilled grains per panicle, neck blast infection type, 1000-grain weight, number of productive panicles per plant, and grain yield. Mean square of genotypes was highly significant (P

In Iran, approximately 70 % of goats are bred for meat and wool. Markhoz goat is one of the most important goat breeds reared in Kurdistan and Kermanshah regions for Angora - mohair production. Previous research has introduced several QTLs affecting mohair traits in Angora goats; this study aimed to confirm QTLs controlling mohair traits on chromosomes 1, 2, 5, 13, 19, and 24. For this purpose, eight bucks with an average of 32 offspring were taken into consideration. The studied traits included fleece weight, average fiber diameter, staple length, and fine, medullated, kemp fiber percentage. Thirty microsatellite markers on chromosomes 1, 2, 5, 13, 19, and 24 were used for genotyping. Microsatellite markers were selected according to previous studies and goat genetic map, based on their distance on the chromosome. The least-squares regression method was used to locate QTLs. Five QTLs significant affecting mohair traits: two of them related to mohair weight traits; one QTL was significant for fiber features and quality, in particular for fiber diameter, staple length and kemp fiber. Two of them are reported for the first time in chromosomes 1 and 2 for kemp fiber and fleece weight traits respectively.

Tomato is an attractive fruiting vegetable crop that can be used as an ornamental plant. Agronomical traits have been subjected to extensive genetic dissection to enhance vegetable breeding programs. By contrast, there are few genetic studies of ornamental traits for the development of ornamental tomato varieties. To investigate genetic loci linked to desired ornamental traits, we performed genetic analyses using an intraspecific mapping population that segregated for fruit color (yellow or red), fruit shape (round or pear), and plant height (high or compact). A genetic map was constructed with 965 single nucleotide polymorphisms (SNPs) and 33 simple sequence repeat markers. Subsequent linkage analysis using quantitative locus analysis and genome‐wide association study detected four genetic loci for the three selected traits, all of which were located near the reported genes. We performed KASP—kompetitive allele‐specific PCR—to develop SNP markers that were tightly linked to the four loci. Highly accurate genotyping data were obtained from the four SNPs across 187 F2 plants, which enabled us to select two lines with homozygous alleles for compact plant size and yellow pear‐shaped fruits. These newly developed SNP markers and genetic strategies could be used to accelerate breeding programs for ornamental tomato plants.

Soils pollution with heavy metals is due to the presence of various metals such as copper, nickel, cadmium, zinc, chromium and lead. Heavy metals have a negative effect on the biological parameters of soil, including size, activity and diversity of soil microbial population, as well as the enzymes involved in the deformation of such elements as P, N, C, and S. Thus, the activity of soil enzymes as a bioavailable agent is reflected as a cheap and fast method for the natural and anthropogenic distribution of heavy metals contamination. The purpose of this study was to investigate the effect of lead, humidity and their interaction on urease and phosphatase enzyme activity during a 10 week incubation period. Different levels of acetate lead (50,100, 150 and 200 mg/kg soil) were added to the plots containing two different moisture regimes (field capacity and flooding). The activity of urease and phosphatase (alkaline and acidity) was measured after 2,4,6,8 and 10 weeks of incubation. The results indicated different levels of lead had no significant effect on the activity of urease and acidity phosphatase. In contrast, high levels of lead significantly reduced the activity of alkaline phosphatase. Moreover, moisture served a different role in the activity of these enzymes, and it was related to the lead concentration and incubation time. Additionally, the function and interaction of lead, moisture and time were very influential on urease and phosphatase activity. Therefore, the above three characteristics are very important to study soil contamination for the polluted soils.

Thymus vulgaris L. (Lamiaceae), a well-known aromatic medicinal herb, has many important essential constituents in its oil, including γ-terpinene, carvacrol, thymol, and p-cymene. Gibberellins comprise hundreds of components, which regulate several various growths and underlying developmental processes, such as cell division and elongation, shoot elongation, seed germination, and gene expression. In this study, we investigated the influence of sprayed gibberellic acid (GA3) treatments on the internode length, leaf morphology, length of new shoot, expression of monoterpene synthase genes and monoterpenes content during two plant growth stages. Our results showed that increasing of internode length was a clear effect of GA3 that was varied with internode position. The results also showed that all internodes displayed a dramatic increase in the highest concentration of GA3. Also, the foliar application of GA3 resulted in not only an increased expression level of monoterpene synthase genes, but also the improved production of a monoterpene, especially in the moderate concentration of GA3 that they were up-regulated. In the lowest GA3 concentrations, relative expression levels were similar or lower than the control plants and a notable downregulation in those genes was observed in the application of the highest concentration of GA3 rather than the moderate concentrations. Overall, the expression of two out of five monoterpene synthase genes, TPS and CYP71D181, showed a correlation with the level of γ-terpinene and carvacrol, respectively, indicating that they are regulated at the transcriptional levels.

Drought stress is one of the major abiotic stresses that limits rice productivity in the world. In this study 83 diverse rice genotypes were evaluated under reproductive-stage drought stress and non-stress conditions in a completely randomized design with three replications. Eleven well known stress tolerance and susceptibility indices were calculated based on the grain yield under stress and non-stress conditions. Also rank mean (RM) indices were calculated based on the ranks of genotypes for the former calculated indices. The highest seed yield under non-stress condition belonged to the genotypes Sangjo, Zenith, IR70445-146-3-3, Norin 22 and Ghasroldashti. Under stress condition, however, IR83750-131-1, IR74718-24-2-3, Sepidrood, TETEP and IR71739-24-3-5 genotypes showed the highest seed yield. STI, GMP, MRP and REI indices with positive and significant correlations with grain yield in stress and non-stress conditions were found to be the most suitable indices for selection of drought tolerant rice genotypes. According to these indices, IR83750-131-1, Sangjo, Sepidrood, Zenith and IR58 genotypes showed the highest ranks and had a higher tolerance to drought stress. Based on RM index, IR83750-131-1, IR74718-24-2-3, Sepidrod, TETEP and IR74720-13-1-2 obtained the highest ranks. Cluster analysis grouped the most drought tolerant genotypes in the second cluster.

Gerbera is one of the cut flowers with short vase life. In this research, silver nanoparticles (SNP) (0, 5, 15, and 25 mg L−1) and 8-hydroxyquinoline citrate (8-HQC) (0, 100, 200, and 300 mg L−1) as pulse treatment for 24 h in combination with 6% sucrose were used in order to increase the quality and vase life of cut Gerbera 'Sunway’ flowers. The results indicated that the vase life of cut flowers treated with 15 mg L−1 SNP plus 200 mg L−1 of 8-HQC and 6% sucrose was higher than the other treatments (20.68 days). Fresh weight and water uptake of Gerberas were relatively higher than other treatments, and also, this treatment resulted in less protein degradation and lower malondialdehyde, higher carotenoid pigmentation. Treatment with 200 mg L−1 of 8-HQC and 6% sucrose and 15 mg L−1 SNP with 6% sucrose separately showed higher SOD activity than other treatments. The use of nanoparticles and 8- HQC in combination with sucrose in the preservative solution showed the best treatment in delaying senescence and increased the life of cut Gerbera flowers compared to other treatments (Distilled water and sucrose solution).

To assess the effects of IAA and Kinetin plant growth regulators in order to improve the drought tolerance in rice seedlings (Oryza sativa L.), a factorial experiment was carried out based on complete randomized design with three replications. The experimental factors included different rice genotypes [‘Gharib’, ‘Khazar’, ‘Sepidrood’ and ‘IR83750 -131-1’ (‘IR83750’ )], drought stress from 1 to 4 code of the Vergara coding system and control (normal irrigation) and growth regulators in three levels (IAA and Kinetin through foliar spraying and non-application as control). The results indicated, under normal irrigation condition together with IAA application, ‘IR83750’ rice had the highest number of tillers and leaf greenness, with mean of 18.27 and 49.46, respectively. The highest amount of leaf relative water content) 95.11 percent) was related to ‘Sepidrood’. Under drought stress condition, the highest electrolyte leakage (36.59 percent) was observed in ‘Gharib’. In drought condition, the highest leaf drying score was related to ‘Gharib’ in both years, but the highest score of leaf rolling index (9) was observed in ‘Gharib’ and ‘Khazar’. The present findings showed that drought stress had harmful effects in all examined genotypes and the impact in susceptible genotypes (‘Gharib’ and ‘Khazar’) was more than ‘IR83750’ and ‘Sepidrood’. Application of growth regulators (IAA and Kin) improved conditions for the growth of all genotypes. Therefore, using the tolerant genotypes along with growth regulators can improve the rice growth traits.

Drought is the most serious abiotic stress that limits crop production in rain-fed environments. In this study genetic diversity of SNAC1 gene investigated in a collection of 83 diverse rice accessions from different geographical origins. Amplification of SNAC1 gene exons was performed by combined hot start-touchdown PCR protocol. The average number of alleles was 9.5 alleles. A total of 6 rare alleles were identified from exons of SNAC1. The average gene diversity index, PIC (Polymorphism information content) and Shannon value were 0.8518, 0.8343 and 2.0469, respectively. Evolutionary study based on Ewens-Watterson test showed that exon 1 of SNAC1 gene was probability under genetic drift. To identify potential SSR markers in SNAC1 gene sequence, SSR distributions within rice SNAC1 gene sequence were mined. Totally 15 microsatellite loci were detected which tri-nucleotide motifs (8) was being most abundant, followed by di- (6) and tetra-nucleotide (1) motifs. Maximum loci were found in 3′ UTR (5) (Untranslated regions), followed by in 5′ UTR (4) and coding sequences (3 for each exon). The present study revealed genetic divergence of SNAC1 gene coding regions and also mined SSR distributions within SNAC1 gene sequence and introduced an optimized PCR method. This information can be used for the development of drought tolerant rice varieties.

Salinity stress is the most important and common environmental stresses throughout the world, including Iran. The aim of this study was to investigate the expression of several important genes involved in the salinity tolerance of the rice cultivars differing in salt sensitivity. In this research, the expression of four mitochondrial genes, H2O2, malondialdehyde (MDA), proline, sodium, potassium and superoxide dismutase (SOD), was measured in Iranian rice cultivars and two well-known international varieties as checks in response to 100 mM salt stress. The results show that the activity of SOD in the tolerant cultivars is much higher than in the susceptible ones under saline conditions (100 mM NaCl). The study of the gene expression in the tolerant and sensitive cultivars also showed that the expression of the genes increased in the early hours of the stress, with the exception of the OsGR1. Moreover, the amount of the expression in the tolerant cultivars was far more than the susceptible ones. The result of this study showed that the function of a set of antioxidant enzymes can lead to detoxification of the reactive oxygen species, so in order to better understand ROS scavengers, a comprehensive study on the antioxidant system should be conducted.

Soil salinity is a major abiotic stress affecting the performance of crop plants around the world adversely. Salinity can create a mix of complex interactions that affect plant nutrient uptake, metabolism, and susceptibility to biotic stresses. This negative interaction may reduce nutrient use efficiency and thus reduces the growth parameters. In addition to various management operations, such as crop management, to reduce the negative effects of salinity on plant growth, application of salinity-tolerant varieties or genotypes is a very interesting strategy to reduce the cost of salinity and environmental contamination. Salinity tolerance in plants not only varies widely among different species but is also strongly influenced by the environmental conditions. The salinity tolerance mechanisms of the plant are investigated at three levels of whole plant- cellular, and molecular levels. Particularly, the response at the whole plant is vital for some plants but is generally not used for all plants. It seems that cellular responses are conserved among many plants. Considering the advances made in recent decades, breeding for increased tolerance through gene transfer and the production of transgenic plants is considered as excellent and low-cost method. Perhaps the most valuable outcome of the biotechnology program is to use molecular tools for the breeding programs. Identifying tightly linked molecular markers with the target gene and mapping it on the chromosome is an important goal for cloning the genes and marker-assisted selection (MAS).

Knowledge of genetic diversity could aid in providing useful information in the selection of material for breeding such as hybridization programs and quantitative trait loci mapping. The present study was conducted to evaluate salinity tolerance of Iranian rice varieties. This research was carried out in three separate experiments (control, 6 and 12 dS m−1 NaCl) each based on completely randomized design with 44 rice varieties and three replications. Fourteen days after salt treatments, root and shoot fresh and dry weight, Na+ and K+ concentration, Na+/K+ ratio, root and shoot length, biomass gain, total fresh weight, root/shoot length ratio and shoot/root weight ratio were measured. The varieties were also genotyped for 12 closely linked microsatellite markers to SalTol. Haplotype and association analysis was conducted using these SSR markers for identification of loci related to salt tolerance. The tolerance scores under salinity stress showed that the varieties FL478, Hassani, Gharib, Shahpasand, Nemat, Domzard, Ghasroddashti, Ahlamitarom, Hassansaraee and Binam with more biomass, root and shoot lengths, and low Na+/K+ ratio were tolerant to salinity stress. Association analysis was indicated that there are some informative markers on chromosome 1 in the local and improved Iranian rice varieties genetic background including RM8094, RM1287, AP3206 and RM3412 explaining considerable percentage of the salt tolerance-related traits. These informative markers can be used in future breeding programs such as marker-assisted selection.

Flavonoids represent a diversified family of phenylpropanoid-derived plant secondary metabolites. They are widely found in fruits, vegetables, and medicinal herbs. There has been increasing interest on flavonoids because of their proven bioactivity associated with anti-obesity and anti-cancer, anti-inflammatory and anti-diabetic activity. Low bioavailability of flavonoids is a major challenge restricting their applications. Due to safety and economic issues, plant extraction or chemical synthesis could not provide a scalable route for large-scale production. Alternatively, reconstruction of biosynthetic gene clusters in plants and industrially relevant microbes offer significant promise for discovery and scalable synthesis of flavonoids. This review provides an update on biotechnological production of flavonoids. The recent advances on plant metabolic engineering, microbial host, and genetically encoded biosensors are summarized. Plant metabolic engineering holds the promise to improve the yield of specific flavonoids and expand the chemical space of novel flavonoids. The choice of microbial host provides the cellular chassis that could be tailored for various stereo- or regio-selective chemistries that are crucial for their bioactivities. When coupled with transcriptional biosensing, genetically encoded biosensors could be welded into cellular metabolism to achieve high throughput screening or dynamic carbon flux re-allocation to deliver efficient microbial workhorse. The convergence of these technologies will translate the vast majority of plant genetic resources into valuable flavonoids with pharmaceutical/nutraceutical values in the foreseeable future.

This study was conducted to determine the combining ability and heritability of rice grain yield, its components and some grain quality traits such as amylose content (AC), gelatinization temperature (GT), gel consistency (GC) and head rice recovery (HRR). The study was commenced by crossing the selected rice varieties based on a full diallel mating design. The F1 was harvested at the end of the season. In the following season, the crossed, reciprocal and parental lines were planted in randomly complete block design with three replications. Analysis of variance indicated that genotypes were significantly different for all traits. The diallel analysis by Griffing`s method showed highly significant differences for GCA for number of panicles per plant (PN), amylose content, gelatinization temperature and head rice recovery. Highly significant differences were also observed for both SCA and REC for all evaluated characters. The results showed that the grain yield (GY), number of filled grains (FGN), 100-grain weight (HGW) and GC were controlled by non-additive gene action, while the inheritance of PN, AC, GT and HRR were largely controlled by additive gene effects, although non- additive genetic components and reciprocal effect were also involved, which suggest that a selection process could be done in the early generations. The two improved lines (RI18442-1 and RI18430-46) were found to be good general combiners for GY and FGN, while the best combiners for PN was Tarom Mohali and IR50 and for HGW was RI18430-46. The best combinations for GY were RI18430-46 × IR50, Tarom Mohali × RI18447-2 and Daylamani × RI18430-46. The good hybrids were Tarom Mohali × IR50, Line23 × RI18447-2 and Line23 × Backcross line for AC. Narrow sense heritability showed that the GY and GC had the lowest values while the other traits had either moderate or high heritability, which indicates selection in the early generations could be done to fix the favorable genes. In present study, narrow sense heritability was high for AC and moderate for GT, PN and HRR.

Drought is one of the major abiotic stresses, which hampers the production of rice worldwide. Informative molecular markers are valuable tools for improving the drought tolerance in various varieties of rice. The present study was conducted to evaluate the informative simple sequence repeat (SSR) markers in a diverse set of rice genotypes. The genetic diversity analyses of the 83 studied rice genotypes were performed using 34 SSR markers closely linked to the major quantitative trait loci (QTLs) of grain yield under drought stress (qDTYs). In general, our results indicated high levels of polymorphism. In addition, we screened these rice genotypes at the reproductive stage under both drought stress and nonstressful conditions. The results of the regression analysis demonstrated a significant relationship between 11 SSR marker alleles and the plant paddy weight under stressful conditions. Under the nonstressful conditions, 16 SSR marker alleles showed a significant correlation with the plant paddy weight. Finally, four markers (RM279, RM231, RM166, and RM231) demonstrated a significant association with the plant paddy weight under both stressful and nonstressful conditions. These informative-associated alleles may be useful for improving the crop yield under both drought stress and nonstressful conditions in breeding programs.

This study investigated the relationship of morphological and molecular genetic distance with hybrid performance and heterosis in cucumber in an attempt to make use of genetic distance in predicting hybrid performance. The results of this study showed that GD, in general, correlated poorly with heterosis and SCA. Results showed that the mean values of the hybrids were significantly larger or smaller for many traits when compared with the mean of parental lines, indicating that heterosis was present for these traits. In next step we compare inter group hybrids versus intra group hybrids. This test showed that intra group hybridization although increased the yield and yield component but decrease some fruit quality such as fruit color and shape.

An F2 : 4 population derived from the cross between salt-tolerant variety ‘Gharib’ (indica) and salt-sensitive variety Sepidroud (indica) was used to determine the germination traits. The seeds were treated with 80 mm NaCl (salt stress), and 11 traits were determined as indicators for salt-tolerant including germination rate, germination percentage, radicle length, plumule length, coleoptile length, plumule fresh and dry weight, radicle fresh and dry weight and coleoptile fresh and dry weight. A linkage map of 2475.7 cM with an average interval of 10.48 cM was constructed using 105 amplified fragment length polymorphism (AFLP) markers and 131 SSR markers. As many as that 17 quantitative trait loci (QTLs) were detected related to germination traits under salt stress condition; some of them are being reported for first time. Also, overlapping of QTLs related to salt tolerance was observed in this study. The identification of genomic regions associated with salt-tolerant and its components under salt stress will be useful for marker-based approaches to improve salt-tolerant for farmers in salt-prone rice environments.

A total of 52 rice SSR markers well distributed on 12 chromosomes were used to characterize and assess the genetic diversity among ninety four rice genotypes. The total number of polymorphic alleles was 361 alleles with the average of 5.86 alleles per SSR locus. The study revealed that some markers such as RM276 and RM5642 on chromosome 6 and RM14 and RM1 on chromosome 1 have more than 9 observed alleles compared to other primers like RM16, RM207, RM208 and RM317 with 3-4 alleles. The highest and lowest PIC values were observed for primers RM276 (0.892 and RM208 (0.423) respectively. Using Shannon´s diversity index, a mean genetic diversity of 1.641 was obtained from the analysis, indicating a high level of genetic variation among these cultivars. Cluster analysis using the complete linkage method based on jaccard similarity coefficient revealed that all genotypes were classified to nine clusters at genetic similarity level of 0.010.75, which contained 12, 16, 2, 18, 3, 6, 16, 10 and 11 varieties, respectively. Results of discriminant analysis showed that the nine cluster groups were confirmed at high levels of correct percent (96.8) and revealed true differences among these clusters. As a final result from this study, we selected eight cultivars from different cluster including Daylamani, Tarom mohali (landrace rice cultivars), RI1843046, Back cross line, RI184472, RI184421 (promising cultivars), Line 23 and IR50 (IRRI lines) as parents. All of the selected cultivars will be arranged in complete diallel design to obtain combining abilities, gene effects and heterosis for each important morphology and physico-chemical characters.

The data normalization is a major subject in studies on the gene expression by quantitative polymerase chain reaction (qPCR) to ensure the reliability of obtained results. The normalization aims to remove variation sources with non-biological origins at the highest possible level. The accurate expression analysis greatly relies on the utilization of stable reference gene as an internal control for data normalization because expression patterns of these genes considerably alter across various kinds of tissue or within individual experimental conditions. However, little information is available on the stable reference genes in Rosmarinus officinalis L. The present study selected seven genes from the frequently-used housekeeping genes as candidate reference genes including Elongation factor1-alpha ( EF1-α ), 18S ribosomal RNA ( 18S rRNA ), Actin ( ACT ), alpha-Tubulin ( α-TUB ), Glyceraldehyde-3-phosphate dehydrogenase ( GAPDH ), Cyclophilin ( CYP ), and beta-Tubulin ( β-TUB ). Four widely-used statistical algorithms, called NormFinder, geNorm, RefFinder, and BestKeeper, were utilized to evaluate the stability of expressing candidate reference genes in different types of tissue (callus, leaf, flower, stem, and root) and under the elicitor treatment (salicylic acid and methyl jasmonate). According to comprehensive results, GAPDH and 18S rRNA were suitable and unsuitable candidate genes, respectively. The obtained findings are helpful for future studies on the gene expression in R. officinalis so as to attain improved and reliable results.

Identification of genetic factors controlling traits associated with seed germination under drought stress conditions, leads to identification and development of drought tolerant varieties. Present study by using a population of F2:4 derived from a cross between a drought tolerant variety, Gharib (indica) and a drought sensitive variety, Sepidroud (indica), is to identify and compare QTLs associated with germination traits under drought stress and non-stress conditions. Through QTL analysis, using composite interval mapping, regarding traits such as germination rate (GR), germination percentage (GP), radicle length (RL), plumule length (PL), coleorhiza length (COL) and coleoptile length (CL), totally 13 QTLs were detected under pole drought stress (−8 MPa poly ethylene glycol 6000) and 9 QTLs under non-stress conditions. Of the QTLs identified under non-stress conditions, QTLs associated with COL (qCOL-5) and GR (qGR-1) explained 21.28% and 19.73% of the total phenotypic variations, respectively. Under drought stress conditions, QTLs associated with COL (qCOL-3) and PL (qPL-5) explained 18.34% and 18.22% of the total phenotypic variations, respectively. A few drought-tolerance-related QTLs identified in previous studies are near the QTLs detected in this study, and several QTLs in this study are novel alleles. The major QTLs like qGR-1, qGP-4, qRL-12 and qCL-4 identified in both conditions for traits GR, GP, RL and CL, respectively, should be considered as the important and stable trait-controlling QTLs in rice seed germination. Those major or minor QTLs could be used to significantly improve drought tolerance by marker-assisted selection in rice.