荒漠植物红砂根系对干旱胁迫的生理响应_.docVIP

  荒漠植物红砂根系对干旱胁迫的生理响应?# 种培芳，李毅，李航逸　** （甘肃农业大学林学院，甘肃 兰州 730070） 5 10 15 20 25 30 35 40 摘要：以抗旱性不同的红砂 2 个种源 2 年生苗木为试材，通过盆栽实验，测定干旱胁迫后红 砂苗木根系的活力、膜透性(RPP)、脯氨酸 (Pro)、可溶性糖 (SS)、可溶性蛋白 (SP)、丙二 醛（MDA）含量和抗氧化物酶系(SOD、POD、CAT)的活性的变化,并通过灰色关联度法分 析了各指标与红砂根系抗旱性的关系。结果表明: 水分胁迫导致红砂根系活力下降，膜透性 RPP 和膜质过氧化产物 MDA 含量增加，渗透调节物质 Pro 含量、SS 含量和 SP 含量明显增 加，抗衰老酶 SOD、POD 和 CAT 活性显著升高，且抗性强的种源比抗性弱的种源对干旱胁 迫的生理生化反应更明显。红砂根系的 RPP、Pro 和根系活力的关联度虽然都大于 0.9，但 红砂根系并不是完全通过这几种机理适应干旱，而是发生了一系列适应性的生理变化，以提 高其根系的抗旱性。 关键词：红砂；根系；抗旱性；灰色关联度 中图分类号：S718.51；S728 Physiological responses of root in desert plant Reaumuria soongorica seedlings to drought stress CHONG Peifang, LI Yi, LI Hangyi (Forestry College of GanSu Agricultural University , GanSu Lanzhou 730070) Abstract: The physiological responses of root in desert plant Reaumuria soongorica seedlings among two provenances to drought stress were investigated. Under drought stress,root vigor, relative permeatbility of plasma (RPP), contents of proline (Pro),soluble sugur (SS),soluble protein(SP),malondialdehyde(MAD) and activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT)were examined.Grey correlative analysis of drought-resisitantce and its relationship with drought-resisitance indexes of root in R.soongorica were studied.The results showed that root vigor decreased significantly under drought stress,while RPP, MDA contents and osmotic adjustment substances such as Pro,SS and SP ,activities of antioxidant enzymes (SOD , POD and CAT) of root in seedlings were increased significantly. High drought resistance provenance(Wuwei) had more physiological responses to drought stress than weak drought resistance provenanc (Lanzhou). Although the grey correlative degree of root vigor, RPP and Pro of root in R. soongorica seedlings were highter than 0.9, R. soongorica increased its drought resistance through making a sireres physiological variations ,not only through the three drought resistance mechanisms. Key words: Reaumuria soongorica; root; drought resis