外源调节物质对棉花幼苗耐寒生理特性的效应

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

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。

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 con- ductivity; 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 solu- ble 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 sali- cylic 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.