茶树杂交后代的ISSR分析

ISSR标记是一种基于微卫星序列发展起来的十分有效的分子标记。采用ISSR技术利用筛选出的19个ISSR引物(ISSR prim ers)在9份茶树亲本及其杂交后代中进行遗传分析和鉴定。结果表明,9份茶树间的GS值变化范围为0.594~0.797。其中蜀永307和蜀永906之间的GS值最大、遗传相似程度最高、遗传距离最近;云南大叶茶和四川中小叶种之间的GS值最小、遗传相似程度最低、遗传学差异最大。聚类分析将9个品种划分为3个大类,云南大茶树、蜀永1号为一类;黎儿茶为一较原始的材料,单独成一类;蜀永307、蜀永906、蜀永703、蜀永808、蜀永3号与四川中小叶种为一类,显示它们具有较近的遗传关系。据此认为,ISSR标记可以有效地对杂交后代进行“亲缘跟踪”和定向选择,为杂交育种提供分子依据。

ISSR ANALYSIS OF THE HYBRID DESCENDANTS OF TEA CAMELLIAS

Inter-simple sequence repeat(ISSR) is a kind of effective molecular marker developed on the basis of microsatellite,or simple sequence repeat(SSR).In the present study,19 ISSR primers were utilized to analyze and identify the heredity in 9 parent materials of tea trees and their hybrid descendants with ISSR technology.The GS values of the tea genotypes ranged from 0.594 to 0.797.The GS was the greatest between Shuyong 307 and Shuyong 906 and they had the highest genetic similarity and the smallest genetic distance.The GS between Yunnan-Dayecha and Sichuan Zhongxiaoyezhong was the smallest and they had the lowest genetic similarity and the greatest genetic difference.Cluster analysis classified the 9 genotypes into 3 major groups.Yunnan-Dayecha and Shuyong 1 fell into one group.Liercha,a primitive form,constituted one group.The rest formed the third group,suggesting that they are close to one another genetically.The results suggest t hat ISSR markers can be used as an effective molecular technique for "genetic relationship following",directional selection of the filial generation and the study of tea cross-breeding.