Genetic variability of wild apricot (Prunus armeniaca L.) populations in the Ili Valley as revealed by ISSR markers

The genetic variability of 14 wild Prunus armeniaca populations was investigated using morphological analysis and inter-simple sequence repeat markers. 10 morphological characters revealed a high level variation, especially Fruit number, Fruit weight, Seed weight and Tree height. Totally, 15 selected primers generated 155 loci, with an average of 10.3 bands per primer. Nei's gene diversity (H-e) and Shannon's index of diversity (I) were fairly high at the species level (H-e = 0.2741, I = 0.4220). High molecular and morphological variability indicated that wild apricots in the Ili Valley still maintained a relatively high level of diversity. The G(ST) of 0.2275 revealed a low level of genetic differentiation among populations, and genetic variation mainly resided within populations (81.51 %), which was identified with the moderate gene flow value (N-m = 1.6974). The relatively high intraspecific genetic diversity and low inter-population genetic differentiation was largely attributed to long-distance dispersal of pollen, continuous distribution of populations and the self-incompatible breeding system.