新疆甜瓜地方品种资源核心种质构建

新疆甜瓜地方种质资源具有丰富的遗传多样性,是新疆哈密瓜遗传改良的重要基因库。以121份新疆甜瓜地方品种为研究对象,结合按来源分组和系统聚类选择的方法,通过多重比较29个表型性状数据确定适宜的取样比例,筛选出25份地方品种为初选核心种质。在初选核心种质取样量上,人工定向补充5份优异种质和极值材料确定了核心种质,约占地方品种总数量的25%。对表型保留比例、遗传多样性指数、变异系数、表型频率方差、极差符合率、均值符合率、标准差符合率等检验参数进行了检验和评价。结果表明:调整后的核心种质除标准差符合率降低外,其余参数均优于或等于初选核心种质,更能代表原始样品;所构建的核心种质很好地保留了所有地方品种资源的遗传多样性和变异幅度。

Construction of Core Collection of Melon Landraces in Xinjiang

Local melon germplasm in Xinjiang is the most important resources for hami-melon genetic improvement because of its abundant genetic diversity. By combining source grouping and systematic cluster selection, an optimal sampling scale was determined after multiple comparisons of 29 phenotypic traits of the 121 melon landraces (Cucumis melo L.) in Xinjiang, and 25 landraces were selected as preliminary core collection then. Supplemented 5 landraces with elite, rare and extreme traits by hand, the core collection of total landraces was conformed, and the sampling scale was about 25% lastly. 7 parameters, such as ratio of phenotype retained, genetic diversity, coefficient of variance, variance of phenotypic frequency, and conformity of extreme difference, average and standard deviation were examined between preliminary and confirmed core collection, core collection and total landraces. The results showed that except conformity of standard deviation all parameters of confirmed core collection were more suitable than or the same as that of preliminary one, and representation of confirmed core collection was better than that of the preliminary one. The genetic diversity and variation in the core collection obtained were well presented in the total landraces.