大顶苦瓜种质资源的形态分类及分子鉴定

Morphological Classification and Molecular Identification of Germplasm Resources in Momordica charantia L.

摘要: 结合形态学标记和分子标记技术，为综合分析大顶苦瓜种质资源遗传多样性提供解决方案。根据苦瓜形态学描述规范对供试大顶苦瓜进行形态学指标的变异和聚类分析，并采用SRAP和SSR分子标记技术进行聚类分析。结果发现，33个形态学指标中叶形的变异系数最大，其次是种皮色。结瓜习性、叶色、瓜形、单瓜重、单瓜种子数、商品瓜纵径的变异系数均大于25%，而裂片数、花柄遁形苞叶、性型、瓜面光泽、近瓜蒂端面形状和种瓜皮色等6个指标的变异系数为0，在遗传距离为18处，所有苦瓜材料被分为3大组群。采用25对SRAP引物扩增共获得282条多态性条带，在遗传相似系数阈值约0.66处可将供试材料分为4个类群；20对SSR引物扩增共获得多态性条带有58条，在遗传相似系数阈值0.64处可将大顶苦瓜供试材料分为4个类群。两种分子标记的聚类结果相似性达到92.86%，综合两种分子标记的聚类结果与SSR标记基本相同。形态标记和分子标记的聚类相似度达到78.57%。采用形态学标记结合分子标记技术综合分析大顶苦瓜种质资源的遗传多样性可靠度较高，两种分子标记的分析结果一致度非度高。种质的地理分布和第一雌花节位是大顶苦瓜种质分类中非常重要的依据，瓜形、单瓜重、种皮色、叶形等性状也很重要。

Abstract: Combined with morphological markers and molecular markers, a solution is provided for comprehensive analysis of genetic diversity of Dading bitter gourd resources. According to the morphological description standard of Momordica charantia, the variation and cluster analysis of the morphological indexes of Dading bitter gourd were carried out. And the cluster analysis was carried out based on SRAP and SSR molecular marker technology. The results showed that, among the 33 morphological indexes, the variation coefficient of leaf shape is the largest, followed by the seed skin color. The variation coefficients of melon habit, leaf color, leaf shape, single melon weight, number of seeds per melon and longitudinal diameter of commercial melon were more than 25%. However, the coefficient of variation of six indexes, such as lobes count, sexual type, hide subtending leaf of flower stalk, melon surface gloss, end face shape of proximal melon pedicel and species melon skin color, was 0. At the threshold of genetic distance of 18, all bitter gourd materials were divided into three groups. A total of 282 polymorphic bands were amplified by 25 pairs of SRAP primers, and the tested materials could be divided into 4 groups at the threshold of genetic similarity coefficient of about 0.66. A total of 58 polymorphic bands were amplified by 20 pairs of SSR primers, and at the threshold of 0.64, the tested materials of Dading bitter gourd could be divided into four groups. The similarity of the clustering results of the two markers was 92.86%, and the comprehensive clustering result based on the two markers was basically the same as those of SSR markers. The clustering similarity between morphological markers and molecular markers reached 78.57%. It is more reliable in analysing the genetic diversity of Dading bitter gourd germplasm resources than the analysis with single methodology, and the results of the two molecular markers were highly consistent with each other. The geographical distribution of germplasm and the first female flower node are very important for the classification of Dading bitter gourd germplasm, as well as melon shape, single melon weight, seed coat color and leaf shape are very important.