外源调节物质对棉花幼苗耐寒生理特性的效应

以棉花幼苗为试材,叶面分别喷施外源调节物质水杨酸(SA)、壳聚糖(CTS)、水杨酸+壳聚糖(SCM)、水杨酸+壳聚糖+硝酸钙(SCCa M)后,在5℃低温下进行处理,分别于0、24 h、48 h及恢复处理24 h时测定相对电导率、MDA含量、叶绿素含量,SOD、POD、CAT的活性和可溶性蛋白、可溶性糖、脯氨酸的含量。结果表明:低温胁迫前用0.7 mmol·L-1水杨酸、0.6 mmol·L-1壳聚糖及复配制剂处理棉花幼苗,其叶片的SOD、POD、CAT活性和叶绿素、可溶性蛋白、可溶性糖、脯氨酸含量与对照相比均有不同程度的提高,相对电导率和MDA含量有所降低;复配制剂处理效果优于水杨酸和壳聚糖单独施用的效果,而水杨酸、壳聚糖、硝酸钙三元复配的效果比水杨酸和壳聚糖两元复配的效果好。表明水杨酸、壳聚糖和硝酸钙在诱导棉花幼苗耐寒性中具有协同效应。

Effects of Exogenous Regulating Substances on Physiological Traits of Cold Tolerance in Cotton Seedlings

We studied the effects of exogenous regulating substances on the physiological traits of cold tolerance(5 ℃) in cotton seedlings by spraying them with SA, CTS, SCM(SA+CTS) and SCCaM(SA+CTS+Ca), respectively. Indicators of relative conductivity; MDA content; chlorophyll content; SOD, POD and CAT activity; soluble protein; soluble sugar; and proline content were measured at 0 h, 24 h and 48 h. The results showed that if the cotton seedlings were treated with a compound preparation of 0.7 mmol·L^－1 salicylic acid and 0.6 mmol·L^－1 chitosan before stressing, then the SOD, POD and CAT activity and the soluble protein, soluble sugar and proline content of the seedlings improved in varying degrees compared with untreated seedlings. The effect of treating with a mixture of salicylic acid and chitosan was better than using just one of these. Treatment with salicylic acid, chitosan and calcium nitrate ternary compound was superior to that with a binary compound. This shows that salicylic acid, chitosan and calcium nitrate have a synergistic effect in inducing cold tolerance in cotton seedlings.