干旱对甜菜叶丛期光系统Ⅱ及光合作用的影响  

Effects of drought stress on photosystem Ⅱ and photosynthesis in Beta vulgaris during the vegetative development period

作　　者：李思忠 高卫时[1] 张立明[1] 白晓山[1] 刘军[1] 董心久[1] 杨洪泽[1] 沙红[1] 高燕[1] LI Sizhong;GAO Weishi;ZHANG Liming;BAI Xiaoshan;LIU Jun;DONG Xinjiu;YANG Hongze;SHA Hong;GAO Yan(Research Institute of Economic Crops,Xinjiang Academy of Agricultural Sciences,Urumqi 830091,Xinjiang,China)

机构地区：[1]新疆农业科学院经济作物研究所,新疆乌鲁木齐830091

出　　处：《草业科学》2021年第8期1548-1558,共11页Pratacultural Science

基　　金：农业部国家糖料产业技术体系“甜菜高产高糖品种改良”(CARS-170108)。

摘　　要：为探索甜菜(Beta vulgaris)叶丛期叶片光合机构和功能对干旱胁迫的响应机制,以抗旱性相对不同的品种"XJT9907"(旱敏感型)和"XJT9916"(耐旱型)为材料,在甜菜叶丛期控水为45%~50%田间持水量持续7 d时,利用植物效率分析仪(Handy-PEA)测定各处理叶片的叶绿素a荧光诱导动力学曲线(OJIP曲线),同时通过JIP-test数据分析方法,获得有关光系统Ⅱ(PSⅡ)标准化数据、比活性参数、性能指数、总性能指数和能量分配比率。结果表明:1)干旱胁迫增加了XJT9907和XJT9916叶片可变荧光强度,降低叶片电子传递效率(ΨEO,φEO,φRO);2)降低单位面积光能的吸收、捕获、耗散和传递(ABS/CSO,DIO/CSO,ETO/CSO,REO/CSO),其中对耐旱型品种XJT9916的影响较小;3)降低了PSⅡ单元之间的能量连通性和光系统之间的电子传递能力;4) PSⅡ放氧复合体(OEC)失活和PSⅡ受体侧与供体侧电子之间的不平衡;5) XJT9907和XJT9916叶片净光合速率分别降低32.2%和10.3%;6)耐旱型品种XJT9916通过较强的能量耗散(DIO/CSO,DIO/RC)防止了能量被过度激发,致使叶片的净光合速率降低幅度低于旱敏感型XJT9907。XJT9907和XJT9916甜菜叶丛期土壤含水量为45%~50%田间持水量时,叶片光合系统光化学活性降低,电子传递反应和Calvin-Benson循环之间平衡失调,光合机构稳定性和光能利用效率降低,导致叶片光抑制,从而降低了叶片的光合能力。由此可知,干旱胁迫下甜菜光合能力的降低与PSⅡ功能下调有关,与Fv/Fm相比,性能指数PItotal可作为筛选抗旱基因型品种的敏感性指标。In order to explore the response mechanism of the photosynthetic apparatus and function in sugar beet leaves to drought stress, cultivars ’XJT9907’(drought sensitive type), and ’XJT9916’(drought tolerant type) were used to determine the chlorophyll a fluorescence induction curve of each treatment using a plant efficiency analyzer(Handy-PEA) when the field water capacity was 45%~50% at the sugar beet leaf cluster stage over seven days. The chlorophyll a fluorescence induction curve in each treatment was measured simultaneously using the OJIP-test data analysis method. The standardized data, specific activity parameters, performance index, total performance index, and energy distribution ratio of the related optical system Ⅱ(PSⅡ) were obtained. The results showed that drought stress: 1) increased the variable fluorescence intensity and decreased the electron transfer efficiency of leaves(ΨEO, φEO, φRO);2) decreased the absorption, capture,dissipation, and transfer of light energy per unit area(ABS/CSO, DIO/CSO, ETO/CSO, REO/CSO), but had little effect on drought tolerant varieties;3) decreased the energy connectivity between PSⅡ units and electron transfer between these photosystems;4) led to the(oxygen-evolving complex, OEC) inactivation of the PSⅡ oxygen evolution complex and imbalance of electron transfer between the PSⅡ acceptor and donor sides;5) The net photosynthetic rate of leaves of XJT9907 and XJT9916 decreased by 32.2% and 10.3%, respectively;6) the drought-tolerant cultivar, XJT9916, prevented over-excitation of energy by strong energy dissipation(DIO/CSO, DIO/RC), resulting in a lower reduction in the net photosynthetic rate of the leaves than in the drought-sensitive cultivar, XJT9907. When the soil water content of XJT9907 and XJT9916 beet leaf clusters was 45%~50% of the field water holding capacity, the photochemical activity of the leaf photosynthetic system was reduced, the electron transfer reaction and the Calvin-Benson cycle was out of balance, and the photosynthetic mecha

关 键 词：甜菜 荧光 干旱胁迫 光合能力 光系统Ⅱ 净光合速率 光抑制 

分 类 号：S566.3[农业科学—作物学]