中文摘要：

为探讨早熟禾（Poa L.）不同品种根系生长状况、生物量分配与水分胁迫的关系,采用PVC管栽法,对布鲁克（Poa pratansis L. cv. Brooklawn）、英派克（Poa pratansis L. cv. Impact）和苏比纳（Poa supine Schrad. cv. SupraNova）3个品种进行干旱胁迫,测定了生物量、根冠比、根系密度、相对生长率等指标,分析了根、冠生物量分配及根系生长动态规律。结果表明：干旱胁迫对早熟禾3个品种的根、冠生物量累积和分配影响不同,3个品种通过提高根干物质重量的分配策略来提高其抗旱能力的顺序依次是布鲁克、英派克、苏比纳;轻度水分胁迫有助于根系生长;3个品种相对生长率随着干旱胁迫程度的增加而降低,其中苏比纳降低最多;干旱条件下,土壤深层根系密度、根冠比增加的顺序依次为布鲁克、英派克、苏比纳。

英文摘要：

The responses of root growth and biomass allocation of different Poa L.varieties,Poa pratansis L.cv.Brooklawn,Poa pratansis L.cv.Impact,and Poa supine Schrad.cv.SupraNova,to water stress were studied using PVC pipe cultivation method in green chamber.The indices of biomass,ratio of root to shoot,root density,and relative growth rate were measured under drought stress and the root and shoot biomass allocation and root growth characteristics were analyzed.The results show that the influence of drought stress was different on root and shoot biomass accumulation and distribution in three varieties.The order of 3 varieties in their capacity of drought resistance by biomass distribution strategy was ranked as follows： Brooklawn,Impact,SupraNova.Light water stress contributed towards the growth of roots;the relative growth rate of 3 varieties declined with the increasing of drought stress,especially for SupraNova.Under drought conditions,the order of 3 varieties in deep soil root density and the ratio increment of root to stem was ranked as follows： Brooklawn,Impact,SupraNova.