Studying domesticated species and their wild relatives allows understanding of the mechanisms of population divergence and adaptation, and identifying valuable genetic resources. Apricot is an important fruit in the Northern hemisphere, where it is threatened by the Plum pox virus (PPV), causing the sharka disease. The histories of apricot domestication and of its resistance to sharka are however still poorly understood. We used 18 microsatellite markers to genotype a collection of 230 wild trees from Central Asia and 142 cultivated apricots as representatives of the worldwide cultivated apricot germplasm; we also performed experimental PPV inoculation tests. The genetic markers revealed highest levels of diversity in Central Asian and Chinese wild and cultivated apricots, confirming an origin in this region. In cultivated apricots, Chinese accessions were differentiated from more Western accessions, while cultivated apricots were differentiated from wild apricots. An approximate Bayesian approach indicated that apricots likely underwent two independent domestication events, with bottlenecks, from the same wild population. Central Asian native apricots exhibited genetic subdivision and high frequency of resistance to sharka. Altogether, our results contribute to the understanding of the domestication history of cultivated apricot and point to valuable genetic diversity in the extant genetic resources of wild apricots.

Random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) markers were used for comparative analysis of genetic variation in 42 sugar beet accessions. A total of 24 polymorphic primers (12 RAPD and 12 ISSR) were used. The RAPD primers generated 204 amplification products and the ISSR primers produced 178 fragments, 190 and 173 of which were polymorphic, respectively. The average polymorphism level with the ISSR markers (97.2%) was higher than that with the RAPD primers (93%). High genetic diversity indices for both marker types (0.86 for RAPD and 0.91 for ISSR) suggested that these methods were equally effective in determining genetic variation in sugar beet accessions. Cluster analysis of the RAPD, ISSR, and combined datasets revealed similar grouping patterns. However, the dendrogram created from analysis of the combined RAPD+ISSR data was more similar to the RAPDonly dendrogram than the ISSR-only analysis, indicating that RAPD could determine genetic diversity with higher resolution than ISSR in the cultivars tested. High correlation between the RAPD and ISSR marker systems was shown using a Mantel test (r = 0.92). Screening a higher number of anonymous loci in sugar beet using these molecular markers will enable the selection of the best parent cultivars for the development of novel varieties.

Diversity analysis was performed among 39 cultivated lentil (Lens culinaris Medik.) accessions of Central Asia and Caucasian origin using five highly polymorphic microsatellite markers. A total of 33 alleles determined ranging from 3 to 8 per locus. Estimated gene diversity value for 33 loci was 0.66. Genetic similarity indices among 39 accessions ranged from 0.24 to 1.0. Cluster analysis using the unweighted pair group method with arithmetic mean method classified accessions into six major groups at 0.5 similarity coefficient. More than half accessions from Tajikistan formed large cluster. On the other hand, a few accessions from each country showed unique genotypes. Overall, most of the accessions, except ones with closely related origin, were distinguished by the present high quality DNA fingerprinting. This molecular diversity information gives important basis for conservation strategy in gene bank and exotic germplasm introduction in breeding programs in Central Asia and Caucasian countries.

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Genetic diversity of 62 chickpea accessions was studied using 8 ISSR and 11 RAPD primers. In the study RAPD primers detected more polymorphism (98%) than the ISSR primers (80%). Genetic diversity index was high (0.73 for ISSR and 0.85 for RAPD) for each of these marker systems. Cluster analysis performed from both separate and combined data of RAPD and ISSR markers using SPSS software package. Jaccard?s similarity coefficient for 62 chickpea genotypes was 0.65. Cluster analyses based on combined data generated a dendrogram that separated genotypes into 11 clusters. Four clusters contained only one genotype showing the genetic uniqueness of these accessions. The studied chickpea collection has been proved to constitute a rich source of biodiversity as revealed by RAPD and ISSR markers. Crossing between distantly related genotypes is expected to yield more vigorous plants constituting much of the different traits contained in the two parental lines.