中国沙棘(Hippophae rhamnoides ssp. Sinensis)根瘤内Frankia菌的遗传多样性

Genetic Diversity of Frankia in Nodules of Hippophae rhamnoides ssp. Sinensis

为了研究中国沙棘亚种共生菌Frankia的遗传多样性,利用PCR-RFLP分子标记方法,对从青海西宁到内蒙古库伦17个地点采集的106个中国沙棘根瘤样品进行遗传多样性分析。供试样品nifD-nifK基因间隔区（IGS）扩增产物分别用3种内切酶（HinfⅠ、HaeⅢ和MboⅠ）酶切,共产生21条酶切谱带,其中17条为多态性条带,多态位点百分比（PPL）为80.99%,所有样品可被划分为9个基因型。结果表明中国沙棘根瘤内的Frankia菌有丰富的遗传多样性,土壤质量较好地点的丰富度高于土壤质量较差地点,海拔较高地区的丰富度高于海拔较低地区,多数地点至少有2种不同基因型的Frankia菌。聚类分析显示Frankia菌不同基因型间的遗传距离在4.88%～55.96%之间,它们在不同地点的分布是不均匀的,没有发现不同基因型菌间的亲缘关系与地点有相关性。中国沙棘根瘤中Frankia菌可分为两个基因型组,组内基因型分布比较一致,而组间有明显差异。

To estimate the genetic diversity of rhamnoides ssp. Sinensis-Frankia from root nodules, PCR-RFLP molecular marker was employed to compare 106 nodule samples of H. rhamnoides ssp. Sinensis individuals collected at seventeen sites from Kulun of Inner Mongolia to Xining of Qinghai Province, China. The PCR products of nifD-nifK intergenic spacer （IGS） were digested with HinfI ,Haellland Mbo I ~ 21 discernible loci are obtained from 106 samples, and 80.99% are polymorphic of these loci （ PPL = 80.99% ）. All samples are divided into 9 IGS types. Dendrogram genotypes are found at most sites. The genetic distances among different genotypes vary 4. 88% -- 55. 96%, their distribution is nonhomogeneous, and the phylogenetic relationship among different Frankia genotypes is not found to correlate with sites. Frankia in nodules of Hippophae rhamnoides ssp. Sinensis can be divided into two genotype groups.The genotypic distribution in groups is relatively consistent, while the genotypic distribution between groups is obviously different.