JOURNAL OF PLANT GENETIC RESEARCH
Year:2018 | Volume:5 | Issue:2|Papers Count:7

Sunflower (Helianthus annuus L. ) is an important crop that its oil has nutritional and high economic value. Basal stem rot, caused by Sclerotinia sclerotiorum and S. minor, is one of the important and devastating disease of sunflower. The use of resistant cultivars is considered as the most important and effective method to control the disease. In this study, the reaction of 100 oily sunflower lines to three isolates of S. sclerotiorum and three isolates of S. minor was studied. Identification of gene loci associated with resistance to disease was done with markers produced with 30 SSR primers pairs. The results showed that some of sunflower genotypes had well resistant to Sclerotinia disease. Population structure analysis using Structure software identified 2 subpopulations (K=2). Association analysis using TASEEL software with general and mixed linear models (GLM and MLM) identified 14 and 12 loci, respectively that have significant association with resistant genes related to Sclerotinia. ORS617 locus was commonly related to genes associated with resistance to M1 from S. minor and J1 from S. sclerotiorum. The common markers are important in sunflower breeding programs making possible simultaneously selection for several traits and producing resistant cultivars to Sclerotinia disease.

Phylogenetic relations among 12 wild species of almonds, one cultivated almond and one species of peach were investigated by using of ITS1-5. 8S rDNA-ITS2 sequences and trnL region of chloroplast DNA. To do this, maximum-parsimony and neighbor joining analysis adopted. Results of ITS data showed that studied species of Prunus only divided in two groups but incapable to separate different sections. P. tenella showed more diverse genetic distance in compare to other studied species and it seems that this species does not belong to Amygdalus. Also, by using the ITS data it can be reported that Prunus is monophyletic. In this research, the genetic distances for each pair of species were determined and the average genetic distance between species shows only the lowest genetic distance within the genus. Therefore, Prunus is a single genus. Regarding its high similarity of trnL region in wild almond species, it can be reported that maternal ancestor of Prunus is the same and trnL is not optimum marker to separate species of almond.

Fungal diseases, especially leaf and stripe rusts are wheat yield reducing factors in Iran and the world. In this study, genetic diversity of 20 wheat varieties with different response to leaf and stripe rusts were studied using primers designed based on the conserved regions of plant disease resistance genes. The banding patterns of polymorphic markers were scored as dominant and number of amplified bands and percentage of polymorphism were determined. In addition, for each primer combination, polymorphic information content (PIC) and marker index (MI) were calculated. Out of the 11 used single primers and primer combinations, five primer combinations and a single primer produced scorable amplification. The maximum and minimum of PIC were observed for LLOOP-1 and H2016-H2020 primer combination with mean value of 0. 50 and 0. 28, respectively. The primer combinations of H2016-H1146 and H2016-H2020 with mean values of 4. 80 and of 2. 84, had minimum and maximum of MI, respectively. Cluster analysis based on Neighbor-Joining algorithm and evolutionary P-distance coefficient assigned the varieties into four groups which were in agreement with their response to yellow rust. In principal coordinate analysis, the scatter plot of varieties based on two first coordinates confirmed the groups obtained from cluster analysis.

Genetic diversity among Russian olive genotypes in three different regions of East-Azerbaijan province (includes Tabriz, Maragheh and Malekan) were assessed using morphological and molecular (AFLP) markers. Results of the quantitative and qualitative traits statistics showed a significant genetic variation among studied germplasm and categorized them in five distinguished groups. The most number of genotypes from Maragheh region were in group 1, while, the group 3 consisted of the majority of genotypes from Tabriz region. All genotypes were analyzed with 14 EcoRI-MseI primer combinations. A total of 439 informative and polymorph AFLP markers was generated and analyzed. Based on Jaccard Similarity Index, the minimum genetic similarity was observed between genotype 19 (from Malekan region) and 27 (from Maragheh). The principal coordinate analysis (PCoA) showed the suitable genomic distribution of AFLP markers among individuals. The highest (0. 83 %) and lowest (0. 33 %) polymorphic information content achieved by primers combination MTTT-EGA and MGTETA, respectively. Cluster analysis using molecular data and UPGMA algorithm, classified the studied genotypes in three distinguished groups. The genotypes at the same geographical region did not classify in the same group based on clustering by molecular data. However, this achieved to a large extent when they were classified groups using morphological traits. This result might be explained in terms of convergent evolution and some in part due to asexual propagation of Russian olive from the limited maternal genotypes and distribution across the different geographical regions.

Drought is a threaded factor in the world production and application of breeding methods could improve the tolerant and adapted cultivators under drought stress condition. In order to evaluate and determine the stress tolerance indices and identifion of tolerant genotypes to drought stress, 15 safflower genotypes were evaluated in a randomized complete block design with three replications in two conditions (stress and nonstress). Analysis of variance showed significant differences among genotypes for all traits, stress tolerance indices and yield in both conditions. Significant positive correlation was found between grain yield in the stress condition with indicators stress tolerance index, harmonic mean and geometric mean productivity indicating that these indices are suitable criteria for screening drought tolerant genotypes. No significant correlation was observed between Ys with tolerance index and mean productivity, hence they can be discarded as the desirable markers for identifying drought tolerant genotypes. In conclusion, using a graphical approach of three dimensional scatter plots, Principal component analysis and biplot analysis, two tolerant genotype (Syrian and Kino-76) were selected for future programs in stress and non-stress condition.

In order to select the best parents for crossings, plant breeders seek varieties or genotypes with highest genetic dissimilarities. This can be achieved by measuring the similarities among genotypes, using multivariate analysis methods such as cluster analysis. This study aimed to group 50 aerobic and lowland rice genotypes based on biochemical characteristics including Iron, Zinc, Manganese and protein, and their linked DNA markers. According to the cluster analysis results using Ward method, the genotypes were assigned to four groups. The third group, as the smallest group including three genotypes (IR82635-B-B-82-2, Caiapo, and Gohar), had the highest value for these micronutrients. Their mean value for Iron, Zinc, Manganese, and protein were 32. 39, 34. 15, 25. 66 mg/kg and 6. 71%, respectively. Also, all genotypes were classified into two main groups based on microsatellite markers information, that according to QTL mapping studies these markers were identified as linked to elements. So, the most of non-local genotypes and aerobic rice cultivars were assigned in a separate group. The correlation between Euclidean distance of elements and protein matrix and genetic similarity matrix (Nie) using Mental correlation test was estimated significant (p<0. 01) that can be evidence of a genetic relationship between the SSR markers and genome controlling regions of elements in this population.

This experiment was conducted to evaluate genetic diversity in 72 peanut accessions (Arachis hypogaea L. ), which introduced from seed bank of Australia in training and seed production research center of oilseeds company, Iran. Twelve major morphological traits recorded during 2013 growing season using a randomized complete block design with three replications. The results showed that the difference between genotypes for all traits was significant. In addition, coefficient of phenotypic variation was greater than coefficient of genotypic variation for all traits, indicating the effect of environment on recorded traits. The broad-sense heritability ranged from 80. 25% (for seed width) to 99. 54% (for 100 seed weight) and was 96. 85% for grain yield. The highest phenotypic and genotypic coefficients of variation obtained for the pod weight, thus, it is possible to improve this trait by selection method and this trait could use as a selection index to improve grain yield. Genetic correlation indicated a high significant correlation between grain yield with grain weight and pod yield. The studied genotypes divided to four groups by cluster analysis based on Ward method.