干旱胁迫对海岛棉叶绿素荧光参数及产量的影响OA

To study the changes of chlorophyll fluorescence parameters of island cotton varieties with different drought tolerance under drought stress,and to reveal the relationship between chlorophyll fluorescence parameters and yield formation of island cotton under different water treatments,the drought-resistant variety Xin 78(X78)and the drought-sensitive variety Lutai 700Q(LT700Q)were used as materials.A two-factor fissure zone experimental design was adopted,and 3 irrigation amount treatments were set including 3 150(W1),3 825(W2)and 4 500 m3·hm-2(W3,conventional irrigation amount).The effects of different irrigation amount treatments on chlorophyll fluorescence parameters and yield of different varieties with different drought resistances were studied.The results showed that the leaf SPAD value of island cotton increased with the decrease of drip irrigation amount,the relative water content of leaves and the fluorescence parameters of chlorophyll decreased with the decrease of drip irrigation amount.The yield of drought-resistant variety X78 decreased by 6.87%～20.55%under drought stress,and the yield of drought-sensitive variety LT700Q decreased by 10.32%～29.40%.It indicated that drought stress would cause photoinhibition damage of reaction center in photosystem Ⅱ,which affected the photosynthesis efficiency of island cotton and then leaded to decrease of yield.The decreased range of physiological indexes of drought-resistant variety X78 under drought conditions was small,which indicated that it had strong drought adaptability and could reduce the negative impact of drought on photosynthesis by maintaining chlorophyll function,stabilizing water status and photochemical efficiency.Mantel analysis showed that the cottonseed yield of island cotton was greatly affected by maximum fluorescence(Fm),variable fluorescence(Fv)and Fv/Fo,and Fm had strong correlation with yield and yield components under drought stress.