The Application of ISSR Technology in Genetic Diversity Detection of Capsicum

The genetic diversity and relationship of 30 pepper materials including Capsicum annuum L. and Capsicum chinense Jacquin were analyzed with ISSR markers. The results showed that 16 primers from 44 ISSR primers for amplified the gene DNA of peppers. Totally 293 ISSR loci including 245 polymorphic loci were produced, with a polymorphism rate of 83.62%. All of the materials could be separated into two groups at about 0.68 similarity value with UPGMA, including a group of Capsicum chinense Jacquin from America (N.11, 12, 13, 14, 15, and 17), a group of Capsicum annuum L. from America (N.26) and Asia (the other materials of 30). And principal coordinate analysis confirmed the results of clustering analysis basically. However, the percentage of polymorphic loci (P) and Shannon information index (I) of Capsicum annuum L. (73.04%, 0.3392) were much higher than those of Capsicum chinense Jacquin (59.39%, 0.3210). We deduced that there was a narrow genetic base for Capsicum chinense Jacquin. Nei's genetic identity (0.8579) and the genetic variation (Gst=0.2019) between species of Capsicum annuum L. and Capsicum chinense Jacquin showed that this may be related with cross-compatibility between the two species and fertility of the F1 hybrids.