新疆甜瓜地方品种资源的表型遗传多样性

 通过分析121份新疆甜瓜地方品种32个形态性状的数据，对其进行遗传多样性和亲缘关系研究。结果表明：121份新疆地方品种在蔓分支数、叶片长度、主蔓粗度、果实质量和果肉厚度等5个表型性状上差异显著；不同地区的地方品种之间在叶片长度、叶柄长度、果肉质地和风味等4个表型性状上差异显著，而在其余性状上差异不显著；121个新疆地方品种表型性状Shannon’s遗传多样性指数达0.74，不同地区地方品种的遗传多样性差异明显，新疆可能与栽培甜瓜的次生起源中心有关。121个地方品种的Euclidean遗传距离的平均值为0.42 ± 0.13，其中‘哈密野瓜’与其它地方品种的亲缘关系最远，遗传距离平均为0.76 ± 0.11。聚类分析结果表明：‘哈密野瓜’被单独聚为一个类群，其可能具有完全不同的遗传背景；其余地方品种被聚为3个类群和7个亚群，不同类群或亚群间的亲缘关系较远，各类群或亚群可能具有相互独立的遗传背景。‘哈密野瓜’属于野生甜瓜亚种Cucumis melo L. ssp. agrestis，其余地方品种属于C. melo L. var. cantalupensis和C. melo L. var. inodorus两个栽培变种。

Genetic Diversity of Melon Landraces（Cucumis melo L.） in Xinjiang Based on Phenotypic Characters

The phylogenetic relationship and genetic diversity of melon germplasm in Xinjiang were investigated by comparing 32 phenotypic traits of the 121 melon landraces(Cucumis melo L.)collected from various areas of Xinjiang,China.The results showed that 121 landraces varied significantly in 5 phenotypic traits,including number of branches,leaf length,main stem thickness,fruit weight and thickness of fruit flesh.Landraces from different areas varied significantly in 4 phenotypic traits,including leaf length,petiole length,flesh texture and taste,but not in the other traits screened.Shannon’s genetic diversity index of 121 landraces reached to 0.74,and the extent of genetic diversity between areas was distinctly different,which indicated that Xinjiang would be the second diversity center of cultivated melon.The average Euclidean genetic distance(EGD)between any two pairs of all landraces was 0.42±0.13.On average,’Hami Wild Melon’was most distinct to the other landraces,with the highest EGD value of 0.76±0.11.The clustering results showed that’Hami Wild Melon’was clustered in only one branch and the other landraces were clustered in 3 groups and subsequently 7 sub-groups,which indicated that the genetic background o’fHami Wild Melon’was completely dissimilar to any landrace examined.Landraces between different groups or sub-groups showed little genetic affinity,which indicated that the genetic background of different groups or sub-groups were independent from each other.These results indicated that’Hami Wild Melon’belongs to Cucumis melo L.ssp.agrestis and all the other landraces in Xinjiang belong to two botanical varieties or groups,C.melo L.var.cantalupensis and C.melo L.var.inodorus.