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采用 RAPD技术对蒙古冰草 (Agropyron mongolicum Keng) 6个天然居群和 2个栽培品种 (系 )的 45个个体进行了遗传多样性检测。 1 7个引物共检测到 1 0 1个位点 ,其中多态位点 81个 ,占 80 .2 %。相对于其它小麦族植物 ,显示出了较高的遗传多样性。多样性指数(DC)分析的结果表明 ,遗传多样性在居群内和居群间的分布存在不均衡现象 ,但总体来看 ,居群内的遗传变异高于居群间 ,这是由蒙古冰草异花、风媒传粉的外繁育系统所决定的。在天然居群与栽培品种 (系 )间 ,前者的 DC值为 0 .2 5 0 ,后者的 DC值为 0 .1 81 ,而且前者的平均遗传距离 (0 .2 90 )也高于后者 (0 .2 1 3 ) ,表明天然居群间的遗传分化大于栽培品种 (系 ) ,这与天然居群间环境的异质性密切相关 ,同时也反映了栽培品种 (系 )间较近的亲缘关系。 UPG-MA聚类分析的结果表明 ,8个居群基本上可被分为与其生境特点及生长条件相适应的 3个类群 ,反映了自然选择及人工选择对居群间遗传分化的巨大影响
The genetic diversity of 45 individuals from 6 natural populations and 2 cultivars (lines) of Agropyron mongolicum Keng was detected by RAPD. A total of 1 0 1 loci were detected with 7 primers, of which 81 were polymorphic, accounting for 80.2%. Relative to other Triticeae plants, showing a high degree of genetic diversity. The results of diversity index (DC) analysis showed that there was an imbalance in the distribution of genetic diversity within and among populations, but overall, the genetic variation within populations was higher than that among populations, which was caused by Mongolia Flowering grass cross-species, wind pollination of the breeding system of the decision. Among the natural populations and cultivars (lines), the former has a DC value of 0.2550, the latter has a DC value of 0.111 and the mean genetic distance (0.22) of the former is also higher than that of the latter (0.21 3), indicating that the genetic differentiation among the natural populations is greater than that of the cultivars (lines), which is closely related to the heterogeneity of the environment among the natural populations, and also reflects the close proximity of cultivars (lines) The kinship. The results of UPG-MA cluster analysis showed that the eight populations could be basically divided into three groups according to their habitat characteristics and growth conditions, reflecting the great influence of natural selection and artificial selection on the genetic differentiation among the populations