内蒙古中东部草原不同地理种群克氏针茅种子萌发对渗透胁迫的响应

利用聚乙二醇-6000（PEG-6000）模拟水分胁迫,研究了内蒙古典型草原不同地理种群克氏针茅种子对渗透胁迫的响应,并以相对发芽率、萌发抗旱指数、活力指数为指标采用模糊隶属法对为种群克氏针茅种子的耐旱性进行了综合评价.结果表明：不同浓度PEG处理的克氏针茅种子均存在萌发高峰期;50 g/L低浓度PEG-6000的渗透胁迫使克氏针茅萌发的整齐性提高;来源于典型草原东部相对湿润生境的巴彦乌拉克氏针茅种子比典型草原中部和西部相对干旱生境的锡林浩特西与新浩特克氏针茅种子对渗透胁迫更敏感;3个种群克氏针茅种子的耐旱能力依次为新浩特种子〉锡林浩特西种子〉巴彦乌拉种子;不同种群克氏针茅种子萌发的耐旱能力与生境有密切关系.

Response of seeds germination of different geographical Stipa krylovii Roshev. populations to osmotic stress in middle and eastern of Inner Mongolia steppe

The response to osmotic stress of three different geographical Stipa krylovii Roshev. populations seeds in typical grassland of Inner Mongolia steppe are studied by simulated water stress using polyethylene glycol （PEG-6000）, and the drought resistance of the seeds is comprehensively evaluated using the fussy subordinate method with three indicators includingrelative germination rate, promptness index and vigor index. The results show that there is germination fastigium of Stipa krylovii Roshev. seeds which are processed by PEG solution with different concentration, the germination uniformity of the seeds which are processed by 50 g/L PEG is improved, the Bayanwula seeds grow in typical east of Inner Mongolia steppe which is relative humid habitat are more sensitive to the osmotic stress than that grow in typical middle and west of Inner Mongolia steppe which are relative drought habitats. The relationship of the drought resistance abilities of three Stipa krylovii Roshev. population seeds is Xinhot〉West Xilinhot〉Bayanwula, and their drought resistance abilities are closely related with their own habitats.