30份野牛草种质的遗传多样性

以从美国及中国收集的30份野牛草（Buchloe dactyloides）种质为研究对象，对供试材料的基本坪用性状如叶长、叶宽、株高、茎粗、分蘖数、匍匐茎数量、匍匐茎长度、匍匐茎节数、叶色、叶片枯黄程度等进行田间观测。利用简单重复序列（ISSR）分子标记技术，对供试野牛草的遗传多样性进行分析。研究结果显示，1）供试材料的叶色呈现显著差异（P<0.05），叶长、叶宽、茎粗、株高、匍匐茎长度和匍匐茎节数差异极显著（P<0.01），分蘖数、匍匐茎数目和叶片枯黄程度没有显著差异；2）7个ISSR引物对30份不同地理来源的野牛草进行扩增，共检测到108个扩增位点，其中多态性位点90个，多态性比率（PPB）为82.6%，平均每条引物可以扩增出15.6条带，说明供试的野牛草材料间遗传差异较大；3）30份野牛草的遗传相似系数（GS）值变化范围为0.546~0.880，表明了供试材料具有丰富的遗传多样性；4）在遗传距离的基础上进行UPGMA聚类分析，30份野牛草可被分为5组，该结果表明遗传距离的差异是导致供试野牛草材料整体遗传差异较大的主要原因。

A study on genetic diversity of Buchloe dactyloides with different geographical origin

30 Buchloe dactyloides collected from different geographical origins were put into this research. The basic turf characters, including leafblade length, leafblade width, height, diameter, number of tillers, number of stolon, length of stolon inter node, length of stolon, leaf color, extent of leaf turning yellow were measured and the genetic diversity was analyzed using the ISSR technique. The following results were obtained: 1) The difference of leaf color among these germplasm was significant (P<0.05）, and the difference of leafblade length, leafblade width, height, diameter, length of stolon, number of stolon was very significant (P<0.01). 2) Seven primers produced 108 polymorphic bands, with an average of 15.6 bands per primer. The percentage of polymorphic bands in average was 82.6%. 3) The Nei’s genetic similarity coefficient (GS) of the tested accessions ranged from 0.546 to 0.88, which suggested that there was rich genetic diversity among the germplasm of B. dactyloides. 4）These accessions were clustered into five groups. Moreover, there was the positive correlation between the geographical distance and the genetic distance.