生长期内三种结缕草对盐胁迫的响应

试验以大穗结缕草、沟叶结缕草和日本结缕草为试材,研究了不同盐浓度(0,0.2%,0.4%,0.6%,0.8%)对生长期内3种结缕草叶片膜脂过氧化及生长的影响。结果表明,3种结缕草的生物量均随着盐浓度的增加逐渐减小;随着盐浓度的提高及处理时间的延长,3种结缕草的可溶性蛋白含量逐渐降低;相对电导率和丙二醛含量增加,在低盐浓度(0.2%~0.4%)下,两者增加幅度较小,当盐浓度为0.8%时,3种结缕草的相对电导率均达最大值,分别是38.71%,41.32%,40.97%,可溶性蛋白含量均达到最小值,分别为2.08,1.15和1.33 mg/g FW。Pro含量在处理后第10天达最大值,之后逐渐下降,后期变化比较平稳。在低盐浓度(0.2%~0.4%)下,CAT和SOD活性逐渐降低,而高盐浓度(0.6%~0.8%)下,两种酶活性呈上升-下降-上升的趋势。3种结缕草相比,大穗结缕草在高盐浓度胁迫下的相对电导率和丙二醛含量最低,而保护酶活性和可溶性蛋白含量最高。试验证明大穗结缕草抗盐能力最强,沟叶结缕草次之,日本结缕草较差。

Responses of three Zoysia grass species to salt stress

The effects of salt (NaCl)on the antioxidant system and soluble protein content during growth of Zoysia macrostachys ,Z .matrella and Z .japonica was investigated.The biomass and the soluble protein con-tents of all three grasses reduced gradually with increasing salt concentration and duration of exposure,while leaf relative conductance and malondialdehyde (MDA )content increased.Under lower salt concentration (0.2%-0.4%),leaf relative conductance and MDA increased slightly,but both peaked at 0.8% salt.The proline content peaked 10 days after treatment application but subsequently declined.Under lower salt concen-trations the activities of catalase and superoxide dismutase in all three grasses reduced gradually,while under 0.6%-0.8% salt,they initially increased,declined and then increased again.Z .macrostachys had the lowest leaf relative conductance and the lowest MDA,but the highest protective enzyme activity and soluble protein content.Consequently Z .macrostachys demonstrated greater salt resistance than Z .matrella and Z .japoni-ca.