中文摘要：

为研究根瘤菌共生对干旱胁迫下紫花苜蓿（MedicagosativaL．）抗旱生理指标变化的影响，对空气干旱条件下接种根瘤菌和不接种根瘤菌的紫花苜蓿的叶片相对含水量及根、茎、叶中丙二醛（MDA）、脯氨酸（Pro）、可溶性糖、还原性谷胱甘肽的（GSH）含量及超氧化物歧化酶（SOD）和过氧化物酶（POD）活性的变化进行测定。结果表明：干旱胁迫下，根瘤菌共生紫花苜蓿叶片相对含水量在干旱前期显著高于不接种根瘤菌紫花苜蓿；不接种根瘤菌紫花苜蓿根、茎、叶中MDA含量明显高于根瘤菌共生紫花苜蓿，各胁迫时间点均差异显著（P〈0．05）。根瘤茵共生紫花苜蓿根、茎、叶中可溶性糖含量、Pro含量、GSH含量及SOD和POD活性在干旱后期明显高于不接种根瘤菌紫花苜蓿（P〈0．05）。根瘤菌共生紫花苜蓿具有更强的渗透调节能力和活性氧防御能力。

英文摘要：

The leaf relative water, malondialdehyde （MDA）, proline （Pro）, soluble sugar and reduced glu- tathione （GSH） contents, as well as the superoxide dismutase （SOD） and peroxiase （POD） activities of al- falfa inoculated rhizobium and not-inoculated rhizobium were studied in order to investigate the physiologi- cal change of alfalfa with symbiotic rhizobium under drought stress. Results showed that the leaf water content of alfalfa inoculated rhizobium was significantly higher than not-inoculated alfalfa under drought stress. The MDA content of alfalfa inoculated rhizobium was significantly higher than not-inoculated alfal- fa under drought stress. The Pro content, soluble sugar content, GSH content, SOD and POD activities of inoculated alfalfa had significant difference compared with that of not-inoculated alfalfa under drought stress. Both osmotic adjustment ability and reactive oxygen defense capability of alfalfa inoculated rhizobi- um were much better than not-inoculated alfalfa.