水分胁迫下外源NO对苜蓿幼苗生长的影响

采用不同浓度的聚乙二醇（PEG-6000）模拟水分胁迫的方法，研究外源 NO 对水分胁迫下的不同苜蓿品种苜蓿王，德宝幼苗株高、干重、根冠比和含水量的影响。结果表明，水分胁迫能够显著降低苜蓿幼苗的株高、干重和含水量，说明苜蓿幼苗在水分胁迫下生长受到抑制。抗旱型不同的苜蓿品种表现不同，抗旱性强的苜蓿王幼苗株高、干重和含水量的降低幅度较敏感型的要低，且能够通过增加地下部分生长来提高根系对土壤水分和养分的吸收，减少胁迫对其造成的影响。添加外源 NO 后能够显著缓解水分胁迫强度对苜蓿幼苗生长的抑制作用。

Effect of exogenous nitric oxide on growth of alfalfa seedling under water stress

This paper used the different concentrations of PEG as simulate water stress to study the effect of exogenous NO on height,dry matter,root-shoot ratio and moisture content of the alfalfa seedlings of two varie-ties,Emperor and Derby.The results showed that water stress can significantly reduce the height of alfalfa seed-lings,dry matter,moisture content,as well as root shoot ratio,which prove that the growth of alfalfa seedlings was inhibited by water stress.The different alfalfa varieties with various drought resitance had the different per-formances.The reduction in plant height,dry matter and moisture content of Emperor alfalfa,the higher drought resistance variety were lower than the other variety.The higher drought resistance was due to the roots increase for absorbing water and nutrients in soil,which reduce the stress.Exogenous NO could significantly alleviate water stress on alfalfa seedling growth.