In the present study, in order to evaluate the drought tolerance indices and their relationship with ISSR markers, 12 rapeseed genotypes were studied using a factorial experiment based on completely randomized block design under the three irrigation treatments (control and irrigation after drainage of 60 and 85% moisture content) in the greenhouse of Mohaghegh Ardabili University, Iran. Drought tolerance genotypes were evaluated by quantitative indices including MP, GMP, SSI, STI and TOL. Cultivars in all five of indices at two levels of stress exhibited significant differences. Regarding the results of the mean comparison at both levels of stress, SLMO46 was identified as the most resistant cultivar with the highest amount of MP and STI, and Karun was the most sensitive one with the highest amount of SSI index. According to the results of factor analysis, in the first level of stress, Sarigol32 and Karun were sensitive, and in the second level of stress, Talaye and Sarigol32 were sensitive as well. SLMO46 was known to be resistant to stress in both levels of stress. Phenotypic correlation of grain yield under stress and non-stress conditions was investigated in two levels of stress with 5 drought indices. In first level of stress condition, grain yield had a positive and significant correlation with mean productivity, geometric mean of productivity and stress tolerance index. In the second level of stress condition, the same correlation was observed with the difference that there was no significant correlation between drought tolerance and tolerance indices. Canonical correlation analysis was performed between drought indices and molecular markers. Five ISSR primers (5, 9, 11, 14 and 19) with the highest polymorphic percentages were used for calculation using the first factor coefficients. ISSR-PCR was used to identify some of the molecular markers associated with drought tolerance indices. A total of 106 clear and score-able loci were amplified by 18 ISSR primers, of which 60 bands (56.6%) were polymorphic. Finally, according to the results, these markers can be used in rapeseed breeding programs for drought tolerance.

In breeding programs, it is necessary having knowledge of the relatedness and genetic diversity in germplasm pools. The spread of cultivated regions and the high levels of production indicates citrus importance in the global economy. Therefore, 110 citrus genotypes were evaluated using 12 ISSR markers. Overall, 154 polymorphic bands were scored with an average of 12.8 alleles per primer. The polymorphism percentage ranged from 57 for the ISSR1 to 82 for the ISSR9. Averages of polymorphic information content (PIC), marker index (MI), gene diversity index (Nei), Shannon index (I) and number of effective alleles (Ne) were 0.48 ± 0.002, 6.14 ± 1.17, 0.42 ± 0.11, 0.61 ± 0.12 and 1.78 ± 0.27, respectively. Based on genetic diversity statistics, the studied population had high genetic diversity, and four markers (ISSR11, ISSR9, ISSR4, and ISSR5) had more potential for differentiation of genotypes. Cluster analysis and model-based structure analysis, divided the genotypes into five groups and four subpopulations based on the Neighbor-Joining method (NJ) and Bayesian approach, respectively. Based on both analyses, grouping of unknown genotypes and control cultivars in the same group probably confirms the assumption of a common genetic background between these genotypes. Results from the two analyses showed that Pummelo (C. maxima), Mandarin (C. reticulate), and Citron (C. medica), as three true citrus species, separated in different groups. In addition to the three true species, at least one species or another genus of citrus relatives is involved in the genetic makeup of the studied population. In this study, although both used analyses were effective in completing each other's information, by considering the degree of genetic mixing and the information of the origin of the genotypes, the effectiveness of model-based structure analysis in evaluating genetic relationships could be achieved.

Twenty-two G. glabra populations were used to study the genetic diversity of ISSR molecular markers. 12 primers were used to amplification of genomic DNA fragments of G. glabra populations. High genetic diversity based on ISSR markers was observed among individuals. A total of 130 bands were formed and 105 bands were polymorphic. The mean polymorphism percentage among studied populations was 80.47. The highest polymorphic percentages were assigned to IS23, IS21, IS9, IS13 and IS15 primers. The mean of PIC and MI were 0.347 and 2.47, respectively. The Shannon index (I) varied between 0.207-0.393 and the Nei genetic variation index (h) from 0.140 to 0.026. Darab and Solataniyeh populations showed the lowest and highest genetic diversity, respectively. The percentage of polymorphic loci was varied between 35.224 to 65.71%. The observe allele number and effective alleles number was 1.46 and 1.34, respectively. Based on the genetic distance Nei, populations Bardsir and Baft had the highest genetic similarity (0.888) and populations Bardsir and Solataniyeh had the least genetic similarity (0.132). The studied populations were grouped into three main groups by cluster analysis using UPGAM and Jaccard's similarity coefficient. The results showed that the ISSR marker is a reliable marker system for revealing a high level of polymorphism and can be used to study genetic diversity and further examinations as a subset of breeding programs in G. glabra.