Germplasm conservation, molecular identity and morphological characterization of persimmon (Diospyros kaki Thunb.) in the NFGP of China

Abstract

Germplasm conservation and evaluation has been regarded as one of the most successful methods for preserving and utilizing genetic resources in commercial crops. However, for commercial fruit crop in East Asia, persimmon (Diospyros kaki), the understanding of its genetic diversity remains largely unclear and is of great interest both for conservation and breeding purposes. Here, we phenotyped and genotyped 495 persimmon accessions from 4 countries of origin in the National Field Genebank for Persimmon (NFGP) using both morphological and simple sequence repeat (SSR) markers. In the 495 persimmon accessions, a relatively complete morphological profile was built by twenty-five morphological markers, including tree traits, fruit appearance and inner qualities, and postharvest indexes, suggesting highly variable relationships among the indicated germplasms. The molecular profile of twelve SSR loci were used to compare genetic diversity parameters, to characterize genetic differentiation, and to examine factors responsible for the maintenance of genetic diversity and population structure in persimmon. By combining SSR and morphological markers, we successfully identified 10 synonymous groups containing 24 persimmon germplasms in the NFGP. Moreover, we also selected 52 varieties to reveal their genetic and morphological relationships, which showed potential for breeding applications due to their unique molecular and morphological characters. The overall results suggest that the diverse genetic and morphological variations in persimmon have prevented the occurrence of a genetic bottleneck. Our genetic and morphological profiles can be used to accelerate persimmon breeding by identifying potential persimmon parents exhibiting traits of agronomic interest.