抽穗期高温胁迫对水稻花药花粉和光合特性的影响

Effects of high temperature stress at heading stage on pollen and photosynthetic characteristics of rice anthers

以热钝感品种创两优丰占、中间型品种Y两优1号和热敏感品种农香32为试验材料,于抽穗期利用人工气候室进行高温处理(最高温度39.0℃、相对湿度75%~80%、光照度5.0×10^(5)lx),通过测定高温处理与对照处理(大田栽培)花粉、花药的性状与光合特性及外观品质等,分析抽穗期高温胁迫对水稻花粉、花药及光合特性的影响。结果表明:与对照相比,高温胁迫下创两优丰占、Y两优1号、农香32花药长分别增加了7.93%、10.96%、106.56%,花药宽增加了30.99%、56.79%、106.54%,花药体积分别增加了84.62%、167.92%、764.00%;花粉直径分别增加了5.83、3.50、2.60μm;可育花粉率分别下降19.97%、23.12%、29.19%,柱头着粉数分别减少了10、8、9个,柱头花粉萌发率分别下降39.09%、39.83%、41.47%;3个品种整精米长分别降低4.59%、5.66%、13.12%,宽分别降低2.01%、3.18%、10.42%,长宽比分别降低了2.44%、2.55%、3.33%,结实率分别下降了23.39%、24.59%、49.49%,千粒质量分别下降了8.92%、16.86%、17.79%;3个水稻品种在高温胁迫下叶绿素荧光参数Fv/Fm分别下降了7.87%、8.24%、17.98%,ΦPSII分别下降了19.05%、20.00%、24.14%,qL分别下降了30.00%、33.33%、40.00%,YNO平均上升了5.33%、7.46%、11.27%,表明其有效光能利用率、光反应中心活性和热耗散调节能力下降,胁迫解除后,Fv/Fm、ΦPSII、qL缓慢升高,YNO缓慢降低。综上可知,高温胁迫下水稻花药和花粉膨大,花粉活力和柱头花粉萌发率降低,有效光能利用率降低;在高温胁迫下,热钝感品种较热敏感品种具有较好的花粉活性和散落特性以及光合特性,这可能是水稻耐高温的关键因素。

The heat-insensitive cultivar Chuangliangyou fengzhan,the intermediate cultivar Y liangyou 1 and the heat-sensitive cultivar Nongxiang 32 were used as experimental materials,and an artificial climate chamber was used for high temperature treatment at the heading stage(the maximum treatment temperature was 39.0°C;relative humidity 75%-80%;light intensity 5.0×10^(5)lx).The effects of high temperature stress at heading stage on pollen,anther and photosynthetic characteristics of rice were analyzed by measuring the characteristics,photosynthetic characteristics and appearance quality of pollen and anther under high temperature treatment and control treatment(field cultivation).The results showed that under high temperature stress,anther length of three rice varieties increased by 7.93%,10.96%and 106.56%,and anther width increased by 30.99%,56.79%and 106.54%,respectively.The anther volume increased by 84.62%,167.92%and 764.00%,respectively.The pollen diameter increased by 5.83μm,3.50μm and 2.60μm,respectively.The fertile pollen rate decreased by 19.97%,23.12%and 29.19%,stigma pollen number decreased by 10,8 and 9,and stigma pollen germination rate decreased by 39.09%,39.83%and 41.47%,respectively.The whole rice length of three varieties decreased by 4.59%,5.66%,13.12%,and width decreased by 2.01%,3.18%,10.42%,respectively.The length-width ratio decreased by 2.44%,2.55%and 3.33%,respectively.The seed setting rate decreased by 23.39%,24.59%and 49.49%,and the thousand grain weight decreased by 8.92%,16.86%and 17.79%,respectively.Under high temperature stress,the chlorophyll fluorescence parameters of three rice varieties Fv/Fm decreased by 7.87%,8.24%,17.98%,ΦPSII decreased by 19.05%,20.00%,24.14%,qL decreased by 30.00%,33.33%,40.00%,respectively.YNO increased by 5.33%,7.46%and 11.27%,respectively,indicating that its effective light energy utilization rate,photoreaction center activity and heat dissipation regulation ability decreased.With the stress relieved,Fv/Fm,ΦPSII,qL slowly increased,YNO slowly decreased,indicating that the effective light energy utilization rate,light reaction center activity and heat dissipation regulation ability slowly recovered.In conclusion,heat-insensitive cultivars had better pollen activity,scatter characteristics and photosynthetic characteristics than that of heat-sensitive cultivars,which may be the key factors of rice height tolerance.