NaCl胁迫下外源水杨酸对棉花幼苗叶片光合特性的影响

Effects of Exogenous Salicylic Acid on Photosynthetic Characteristics of Cotton Seedlings Leaves under Salt Stress

为研究NaCl胁迫下外源水杨酸(SA)对棉花光合特性的影响,以"中棉所41号"和"中棉所49号"为材料,采用室内盆栽培养法,设置NaCl浓度为0.60%,以SA浸种+叶面喷施复合处理为缓解方式,分别从光合色素、光合气体交换参数以及叶绿素荧光动力学三方面探讨SA的缓解作用。结果表明:SA处理可提高NaCl胁迫下叶绿素a、叶绿素b以及类胡萝卜素含量,同时调节叶片气孔的闭合程度,改变光合机构,提高光合吸收、耗散以及捕获的能量,使中棉所41号的净光合速率(Pn)提高8.32%~18.76%,中棉所49号提高14.29%~25.19%,其中以0.05 mmol·L-1浸种+0.2 mmol·L-1叶面喷施为最优,可促使Pn提高18.76%~25.19%。

In order to study the effects of exogenous SA on the photosynthetic characters of cotton seedlings under NaC1 stress, the ＂Zhongmiansuo 41＂ and ＂Zhongmiansuo 49＂ were incubated in pot culture under NaC1 concentra- tion of 0.60% with the way of SA soaking ＋ foliar application so as to relieve from the photosynthetic pigment, photosynthetic gas exchange and chlorophyll fluorescence parameters. The results showed that the contents of chlo- rophyll a, chlorophyll b and carotenoid could be increased by the SA treatment under NaC1 stress, SA treatment could be used to regulate the stomatal closure degree, change the photosynthetic mechanism, and improve the photo- synthetic absorption, dissipation and energy captured. Finally, the net photosynthetic rates （Pn） of Zhongmiansuo 41 and Zhongmiansuo 49 were increased by 8.32% - 18.76% and 14.29% - 25.19% ,the 0.05 mmol·L-1 ＋ 0.2mmol·L-1 soaking spraying was the best,and Pn could be increased by 18.76% -25.19%.