蒙古冰草居群遗传多样性研究

Genetic Diversity of Agropyron mongolicum Keng Populations

应用居群生物学原理及方法,对分布于中国不同地区的 35 个蒙古冰草(Agropyron mongolicum Keng)居群的形态学性状进行了分析。结果表明,蒙古冰草居群在形态学性状上具有丰富的遗传多样性(H′=1.7779)。在遗传多样性的分布上,居群间虽存在一定程度的遗传变异(9.15%),但遗传多样性主要集中在居群内部(90.85%),这种居群内遗传变异大于居群间遗传变异是由蒙古冰草异花、风媒传粉的外繁育系统所决定的。我国蒙古冰草居群在各个分布区的遗传多样性程度也不同,从大到小依次为陕西地区(H′=1.8627)、宁夏地区(H′=1.8332)、内蒙古地区(H′=1.7232)、新疆地区(H′=1.6453)、甘肃地区(H′=1.6436);陕西与宁夏地区的蒙古冰草居群主要采集于毛乌素沙漠南缘地区,其数量占分析居群数的 68.6%。因此,对于分布于毛乌素沙漠南缘地区的蒙古冰草居群,无论从研究还是利用的角度都应给予较大关注。另外,还讨论了居群在物种定义上的意义,并提出了我国蒙古冰草居群的保护策略。

According to the population biology theories, genetic diversity of 35 populations of Agropyron mongoliucm Keng distributed over various regions in China was studied. The results showed that there was an abundant genetic diversity (H'=1.7779) among these populations in morphological characters. As for the distribution pattern of genetic diversity, the genetic variation among populations (90.85 %) was greater than that within populations (9.15%). Genetic diversity of this species distributed over every region was different, whose turn was Shaanxi region (H'=1.8627) > Ningxia region (H'=1.1.8332) > Inner Mongolia (H'=1.7232) > Xinjiang region (H'=1.6453) > Gansu region (H'=1.6436). But those of Shaanxi and Ningxia regions were collected from the southern brink of the Maowusu desert where there have abundant populations, which is about 68.6 % of the total analyzed. So high emphasis should be put on the Agropyron mongoliucm populations distributed over the southern brink of the Maowusu desert whether for the purpose of scientific research or productive application. Additionally, the significance of the population for species' definition and the effective conservation strategy to this plant were discussed.