【作者】 宋莉萍；

【导师】 崔国文；

【作者基本信息】 东北农业大学 ， 草业科学， 2007， 硕士

【摘要】 本试验以羊草、无芒雀麦、偃麦草和草地早熟禾4种根茎型禾本科牧草为试验材料，采用连续干旱的试验方法，结合温室盆栽试验与室内分析，研究了干旱胁迫下4种牧草的生理适应性，并对4种牧草的抗旱适应性进行初步的综合评价，得出结论如下：1干旱胁迫下，4种根茎型禾本科牧草植株的生长、叶片的扩展都受到了抑制，表现为相对生长率呈下降趋势，干旱程度越大，植株生长越慢；叶片长度、宽度均小于对照；地下部分表现为根系增深。2干旱胁迫下，叶片含水量随着干旱胁迫的加重而减少，但4种牧草差异不大；土壤含水量与叶片含水量呈显著正相关。3干旱胁迫下，叶绿素总量、叶绿素a含量、叶绿素b含量和叶绿素a／b的值，均随着干旱胁迫时间的延长而减少，且4种牧草间的差异显著；土壤含水量与叶绿素总量、叶绿素a含量、叶绿素b含量均呈显著正相关。4干旱胁迫下，叶片质膜相对透性随着干旱胁迫的加重而逐渐增加，4种牧草间存在显著差异；质膜相对透性与土壤含水量呈显著负相关。5干旱胁迫下，4种牧草细胞中渗透调节物质变化明显，细胞中游离脯氨酸含量与可溶性糖含量均显著增加；游离脯氨酸含量和可溶性糖含量与土壤含水量均呈显著负相关。6干旱胁迫下，4种牧草丙二醛含量都有不同程度的增加，干旱时间越长，增加量越多，4种牧草间有显著差异；土壤含水量与丙二醛含量呈显著负相关。7干旱胁迫下，超氧化物歧化酶和过氧化物酶的活性都呈先升高后下降的趋势，在干旱胁迫的整个时期二者的活性均高于对照；两种保护酶与土壤含水量的相关性不显著。8干旱胁迫下，可溶性蛋白含量表现为持续降低，4种牧草地上部可溶性蛋白含量差异显著，而地下部却没有差异；可溶性蛋白含量与土壤含水量呈显著正相关。9根据试验和前人对抗旱鉴定指标的研究，采用模糊数学的隶属函数法，通过以上各指标，对4种根茎型禾本科牧草的抗旱生理适应性进行综合评价，初步得出结论：干旱胁迫下，4种牧草中综合评价最好的为无芒雀麦，其次是偃麦草，再次是羊草，最差的是草地早熟禾。更多还原

【Abstract】 Chinese Wild-rye, Smooth Brome, Quackgrass and Kentucky Bluegrass were used as servematerial in experimentation. The method of continue drought was adapted associating pot tests andanalysis in the laborary. The study researched the effects of drought on the physical and chemicalcharacteristics,morphological characteristics of 4 rhizomatous grasses. At last, comprehensiveappraisal of drought resistance of 4 rhizomatous grass were categorized by drought resistance. Themain results were showed as following:1 The growth of plant and spread of leaves were restrained of 4 rhizomatous grasses under waterstress; the relative growth rate showed downtrend. Plants grew more slowly as drought stressaggravated; the length and width of leaves were less than CK; the length and quantity of rootincreased under drought stress.2 The moisture content of leaves of 4 grass declined with the aggravation of drought stress, but thedifference in the species was not significant. There was significant positive correlation between themoisture content of leaves and the moisture content of soil.3 The total content of chlorophyll, chlorophyll a content, chlorophyll b content and chlorophyll a/bratio declined with drought time lasting, and the varietal difference was significant; there wassignificant positive correlation between the total content of chlorophyll, chlorophyll a content,chlorophyll b content, chlorophyll a/b ratio and the moisture content of soil.4 The membrane permeability of leaves increased with the aggravation of drought stress, and thevarietal difference was significant. There was significant negative correlation between themembrane permeability and the moisture content of soil.5 Osmoregulating substance in cells changed significantly. The free praline and the soluble sugarincreased with the decline of the moisture content of soil. There was significant negative correlationbetween the free praline, the soluble sugar and the moisture content of soil.6 The MDA content increased under drought stress; the more MDA content, the longer drought time,and the varietal difference was significant. There was significant negative correlation between thefree praline and the moisture content of soil.7 The POD activity and SOD activity showed the tendency of increasing firstly and thendecreaseing under drought stress. The POD activity and SOD activity were more than the CK duringdrought time. There was no significant relation between the POD activity, SOD activity and moisture content of soil.8 The soluble protein decreased under drought stress, and the varietal difference of protein inabove-ground plant parts was significant, on the other hand, the difference of protein inunder-ground plant parts was not significant. There was significant positive correlation between thesoluble protein and the moisture content of soil.9 According to the research about the drought resistant index of the other people, comprehensiveappraisal of drought resistance of 4 rhizomatous grass were categorized by drought resistance basedon fuzzy mathematics. The elementary result was: Smooth Brome＞Quackgrass＞Chinese Wild-rye＞Kentucky Bluegrass更多还原