Effects of water and salt stress on photosynthetic and fluorescence parameters of different cotton varieties at seedling stage
Using the main cotton varieties'Tahe 2,''Xinluzhong 56,'and'Xinluzhong 87'from the Xiao-haizi irrigation area in Xinjiang,this study set water amounts as the standard for irrigation(W1:upper limit 60％,lower limit 50％;W2:upper limit 70％,lower limit 60％;W3:upper limit 80％,lower limit 70％).The SPAD values,photosynthetic rates,and fluorescence parameters were analyzed under varying levels of soil salinity stress(S1:3 g·kg-1,S2:4.5 g·kg-1,S3:6 g·kg-1)and different irrigation thresholds.The results showed that the maximum value of 0～30 cm soil salt return was 27.44％for S1 treatment,68.44％for S2 and 64.39％for S3 treat-ment.In addition to the maximum yield of electron transfer at the cotton seedling stage,all the correlations between photosynthesis and chlorophyll fluorescence parameters showed significant differences(P＜0.01).However,soil sa-linity mainly produced significant effects on Gs,Tr and ΦPSII,qP,Y(N0),α,ETRmax,and IK.The lower limit of irrigation only had significant effects on ΦPSII and Y(N0).The Gs of'Tahe 2'cotton were significantly greater by 92.1％in W3S1 treatment than that of W3S2 treatment,and the Pn and Gs of'Xinluzhong 56'were significantly lower than W1S1 treatment by 19.2％～68.2％under S1 and S3 treatments.W3 irrigation treatment in cotton'Xin-luzhong 87'and Tr increased by 39.4％～53.1％and 10.6％～20.8％compared with other irrigation treatments.Therefore,'Tahe 2'cotton was more sensitive to salt treatment.The moisture content of'Xinluzhong 56'cotton in the soil of 50％θ(field water capacity)fields significantly reduced the improvement of photosynthetic parameters.'Xinluzhong 87'cotton was more conducive to growth under W3 irrigation treatment.
water and salt stresscottonphotosynthesischlorophyll fluorescenceseedling stage
万方数据
维普
