Investigation of genetic diversity of yam cultivars by SRAP markers / 中国药学杂志

ABSTRACT

OBJECTIVE: To investigate the genetic diversity of yam resources in China and provide reliable molecular evidences for cultivar identification and genetic relationship. METHODS: Sequence-related amplified polymorphism (SRAP) was applied to detect the genetic diversity of 21 yam cultivars from eight cultivated populations, Popgene software (version 1.32) was used to calculate genetic parameters, UPGMA clustering was carried out using Mega software (version 4.1), and principal component analysis was performed with the help of Ntsys-pc (Version 2.1) program. RESULTS: Three hundreds and nine bands were amplified by 20 SRAP primer combinations, of which 289 bands were polymorphic. The Nei's gene diversity index (H=0.2881), Shannon's information index (I=0.4416) and total genetic diversity (Ht=0.2891) revealed a relatively high genetic diversity level among yam populations. Within populations, HNWX population showed the highest genetic diversity (PPB= 35.92%), whereas the lowest diversity (PPB=0) was observed in FJSM and ZJRG populations. The genetic differentiation coefficient (Gst=0.8658) and genetic flow (Nm=0.0075) indicated that the genetic diversity among populations was higher than that of within populations. A well-separated groups coupling with cultivated species was formed according to the genetic distance (GD) ranging from 0.0498-0.4879 of the investigated populations. Twenty-one investigated cultivars could be distinguished and be effectively grouped into four origins, i.e., Dioscorea opposita Thunb., Dioscorea alata Linn., Dioscorea persimilis Prain et Burkill. and Dioscorea fordii Prain et Burkill.. CONCLUSION: The genetic diversity level of yam resources is high, and relatively high genetic variation exists among four yam species. SRAP marker is an effective method to identify and classify numerous yam cultivars.