蕾期低温胁迫对棉花叶绿素荧光特性的影响

Effect of Low Temperature Stress at Bud Stage on Fluorescence Characteristics of Cotton

【目的】分析棉花蕾期不同低温胁迫对不同棉花品种的叶绿素荧光特性的影响,研究棉花蕾期的抗冷响应规律,筛选棉花蕾期耐冷性相关的指标,为耐冷资源鉴定、耐冷棉花品种选育提供依据。【方法】于棉花蕾期设置3个低温梯度:T_(1)(20℃/15℃,昼/夜)、T_(2)(15℃/10℃)、T_(3)(10℃/5℃)和对CK(28℃/20℃)处理。【结果】蕾期棉花在低温胁迫条件叶绿素荧光参数Fv、Fm、Fv/Fo、qP、SPAD下降,NPQ、Fo上升。而Fv/Fm在20℃/15℃以上低温和15℃/10℃低温初期升高;10℃/5℃以下低温和15℃/10℃低温后期下降。【结论】可根据蕾期棉花的Fm、Fo等荧光参数来判断其受到的低温胁迫程度。

【Objective】To analyze the effect of different low temperature stress on chlorophyll fluorescence characteristics of different cotton varieties at bud stage,explore the cold resistance response law of cotton at bud stage,and screen the indexes related to cold resistance of cotton at bud stage,so as to provide theoretical basis and technical guidance for identification of cold resistance resources and breeding of cold resistant cotton varieties.【Methods】Three low temperature gradients were set at bud stage:T_(1)(20 ℃/15 ℃,day/night),T_(2)(15 ℃/10 ℃),T_(3)(10 ℃/5 ℃)and CK(28 ℃/20 ℃).【Result】The chlorophyll fluorescence parameters Fv,Fm,Fv/Fo,qP and SPAD decreased,while NPQ and Fo increased under low temperature stress. However,Fv/Fm increased at low temperature above 20 ℃/15 ℃ and 15 ℃/10 ℃,and decreased at low temperature below 10 ℃/5 ℃ and 15 ℃/10 ℃.【Conclusion】The degree of low temperature stress can be judged by the fluorescence parameters such as Fm and Fo of cotton in bud stage.