茶树‘黄山种’自然杂交后代遗传多样性分析

 通过ISSR标记结合形态学性状，分析了茶树‘黄山种’自然杂交后代的遗传多样性。所调查形态学性状的平均变异系数为20.5%（12.5% ~ 33.2%），Shannon-weave指数平均为1.89（1.60 ~ 2.07）。22条ISSR引物在供试样品中共扩增出402条带，其中多态性条带396条，多态性比率为98.5%，引物的多态性信息指数（PIC）平均达0.90，供试样品的基因多样性（H）和Shannon信息指数（I）分别为0.32和0.49。充分表明‘黄山种’通过自然杂交，发生了基因的分离和重组，产生了丰富的遗传变异。Mantel检测基于形态学与基因型估算的遗传距离矩阵间，存在极显著正相关（r = 0.61，P = 0.01）。基于形态学性状和ISSR标记的聚类结果显示，大多数‘黄山种’自然杂交后代的单株可聚成一大类群，只有少数单株遗传距离较远，单独聚为一类。这些单株一芽三叶长、百芽质量较大，可为今后‘黄山种’系统选种提供优异种质材料。

Analysis of Genetic Diversity Among Natural Hybrid Progenies of Camellia sinensis 'Huangshanzhong'

Genetic diversity among natural hybrid progenies of Camellia sinensis ‘Huangshanzhong’was studied，using some morphological traits and ISSR markers. The average coefficient of variation and Shannon-weave index were 20.5%（ranged between 12.5% and 33.2%）and 1.89（ranged between 1.60 and 2.07）respectively，based on investigation of morphological traits. Using 22 ISSR primers，402 discernible DNA fragments were generated，among which 396（98.5%）were polymorphic. The mean of poly- morphism information content（PIC）for the ISSR primers was 0.90. The mean of Nei’s genetic diversity（H） and Shannon’s information index（I） were 0.32 and 0.49 respectively，among all tested individuals. The results showed that genetic variation was high among those progenies of C. sinensis‘Huangshan- zhong’. The relationship between morphological and ISSR-based distance was significant positively correlated（r = 0.61，P = 0.01）by Mantel testing. It indicate that ISSR is a useful tool for relationship analysis of tea germplasm resources. Based on morphological and ISSR data，several plants were cluserted into a major group，and only few individual plants were divided into single group. These special plants would be of great help to the tea breeding in future.