国外甜瓜种质资源形态性状遗传多样性分析

对250份国外甜瓜(Cucumis melo)种质资源的19个形态性状多样性进行研究。结果表明, 国外甜瓜种质资源具有丰富的形态多样性, 平均遗传多样性指数为1.378。9个质量性状(果实形状、果皮底色、覆纹颜色、覆纹形状、网纹密度、网纹粗度、果肉颜色、果肉质地和种子颜色)和4个数量性状(单果鲜重、果肉厚度、可溶性固形物含量和种子千粒重)变异明显, 其Shannon’s指数分别大于1.0和1.9。不同生态区间种质资源遗传多样性差异明显, 多样性指数由高到低依次为: 南亚(1.512)、东北欧(1.404)、西欧(1.372)、北美(1.340)和东亚(1.281)。通过聚类分析将所有甜瓜种质划分为四大组群, 即南亚组群、东北欧组群、西欧北美组群和东亚北美组群。以印度为代表的南亚甜瓜种质形态多样性水平较高, 支持了印度次生大陆为甜瓜起源中心的观点。

Genetic Diversity of Foreign Melon (Cucumis melo) Germplasm Resources by Morphological Characters

We studied the morphological diversity of 250 foreign melon germplasm by examining 19 morphological characters. The foreign melon germplasm was rich in morphological diversity, with mean diversity index (Shannon’s index, H′) of 1.378. We found great variety in 9 qualitative characters (fruit shape, ground color of fruit skin, vein color of fruit skin, vein shape of fruit skin, density of net, thickness of net, flesh color, flesh texture, and seed coat color) and 4 quantitative characters (fresh weight of single fruit, thickness of fruit flesh, soluble solid content, and 1 000-seed weight), with H′ greater than 1.0 and 1.9, respectively. The degree of genetic diversity between various regions differed greatly. The upper-to-lower order of H′ for the various regions was south Asia (H′=1.512), northeast Europe (H′=1.404), west Europe (H′=1.372), north America (H′=1.340), and east Asia (H′=1.281). Cluster analysis divided the melon germplasm into four groups; south Asia, northeastern Europe, west Europe-North America, and east Asia-North America. The melon germplasm in south Asia (mainly represented by India) were rich in morphological diversity, which supports the Indian subcontinent as the original center of melon.