IDENTIFICATION AND CLASSIFICATION OF BER CULTIVARS BASED ON ISSR AND RAPD ANALYSIS

Abstract

Inter Simple Sequence Repeat (ISSR) and Random Amplified Polymorphic DNA (RAPD) analyses were conducted to study the genetic relationships of 22 Zizyphus accessions including nineteen ber cultivars, two Chinese date cultivars and one spine date (stock variety). A phylogenetic tree was constructed based on 533 loci amplified from 35 ISSR and RAPD primers. According to clustering analysis, the 22 accessions could be classified into three groups at the 0.845 level of genetic similarity; the first group includes sixteen ber accessions which are all just right from Taiwan province of China. The second group includes other three ber accessions that are from Burma and Vietnam. The third group includes two accessions of Chinese date and one spine date. The result of clustering analysis is completely coincident with the traditional ideology of classification. Furthermore, the dendrogram indicates a very narrow genetic background among the Taiwan accessions. In addition, two homonyms and six (in three pairs) morphologically strong resemble cultivars of Taiwan accessions are distinguished by molecular marker patterns. As a newly introduced fruit tree, ber has been cultivated and extended in South Mainland of China for about ten years. Because of the misidentifying or renaming in the course of dissemination, the nomenclature of the cultivars is very confused and the genetic relationships among the cultivars are unknown. This result would be helpful to breeding researches or germplasm utilizations of this new fruit species.