Population genetic diversity in Chinese pomegranate (Punica granatum L.) cultivars revealed by fluorescent-AFLP markers.

Eighty-five pomegranate (Punica granatum L.) cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity by means of fluorescent-AFLP markers. The results indicated that 135-185 polymorphic loci were amplified by eight pairs of primers at species level. An average of 158.25 polymorphic loci was amplified for each primer combination. The polymorphism percentage ranged from 62.5% to 86.11%, and the average polymorphism percentage was 73.26%. This indicated that there was plentiful genetic diversity in pomegranate cultivars. The genetic diversity at the species level was higher than that at the population level. The order of the genetic diversity was Henan population > Xinjiang population > Shaanxi population > Anhui population > Shandong population > Yunnan population. Variance analysis showed that there was significant difference between populations in genetic diversity. The genetic differentiation coefficient between populations (G(ST)) was 0.2018, which indicated that gene differentiation was mainly within the population, and between populations, it accounted for 20.18% of the total variation. Gene flow (Nm) between the populations measured was 1.9027 based on the genetic differentiation coefficient between populations, indicating that there was mild gene flow between populations. The UPGMA cluster analysis showed that most accessions from the same population were clustered together, but there was partly gene exchange. All genetic parameters indicated that there was plentiful genetic diversity in pomegranate cultivars in China, of which Henan population was significantly higher than the other populations, and it had wide application foreground in pomegranate breeding in China.