我国核桃组(Sect.Juglans)种质资源的SSR标记分析

为从基因水平对我国核桃组资源的遗传多样性进行分析,用9对SSR引物对核桃组中29份核桃(Juglansregia L.)样品、2份铁核桃(J.sigillata D.)样品、4份J.sigillataD.×J.regiaL.样品进行扩增,共检测出等位基因47个,每个位点扩增3～9个等位基因,平均5.2个。9个SSR位点的PIC值在0.3188～0.7902,平均为0.6357。35个样品在9个SSR位点上有杂合位点1～6个,样品的杂合度在0.11～0.67,平均0.35。采用UPGMA方法进行聚类分析,35个样品可以分为4组。其中陕西晚实核桃与华北核桃聚为一类,陕西早实核桃聚为一类再与新疆核桃聚为一组,表明秦巴山地核桃可能属于华北和新疆2个地理生态型。铁核桃与西藏核桃聚为一组,说明铁核桃与西藏核桃的亲缘关系较近,认为铁核桃和西藏核桃作为核桃种下的一个生态类型可能更为合适。

Analysis of Sect. Juglans germplasm in China by using SSR marker

In order to analyze the genetic diversity of germplasm of Sect. Juglans in China, 9 SSR(Simple sequence repeats) primer pairs originally designed in black walnut (J. nigra L.) were used to amplify SSR fragments for 35 samples of Sect. Juglans, including 29 samples of J. regia, 2 samples of J. sigillata and 4 hybrids of J. sigillata×J. regia. The 9 pairs of SSR primers generated a total of 47 alleles. The number of alleles per locus ranged from 3 to 9, and averaged 5.2. The value of allelic polymorphism information content (PIC) ranged from 0.318 8 to 0.790 2, and averaged 0.635 7. In 9 SSR loci, the number of heterozygosis locus per sample ranged from 1 to 6, and the heterozygosity per sample ranged from 0.11 to 0.67. The 35 germplasm samples of Sect. Juglans could be clustered into 4 groups with UPGMA method. In one group, Shaanxi late-bearing walnut sample being as Qinba (West China) walnut clustered together with Huabei (North China) walnut. And Shaanxi early-bearing walnut samples being as Qinba walnut clustered together with Xinjiang walnut. It indicated that, Qinba walnut, probably belongs to Huabei and Xinjiang ecological type. In the dendrogram, the 2 samples of J. sigillata clustered in the same group with Tibet walnuts, which identified that the J. sigillata and Tibet walnuts have close relationship. Possibly, it is more proper for the J. sigillata and Tibet walnuts to be one ecological type in J. regia.