棉黄萎病对棉叶脯氨酸含量及光合蒸腾作用的影响

抗病品种陕1155、陕2059与感病品种泗棉2号、冀棉11号之间,经统计分析表明,病情指数差异显著(p<0.05).用磺基水扬酸法测定不同抗性棉花叶片游离脯氨酸含量,接种后感病品种泗棉2号,冀棉11号含量显著高于抗病品种陕1155和陕2059(P<0.05).2个抗病品种之间和2个感病品种之间差异不显著.测定不同发病程度棉苗的光合与蒸腾作用表明,接菌后的棉苗即使不表现症状,净光合率也显著下降(P<0.01),病棉苗比健棉苗净光合率下降90%～96%.病棉苗的气孔传导使蒸腾速率显著下降(P<0.01),但发病程度与气孔传导和蒸腾速率之间无显著相关.叶片气孔阻力随棉苗的病情发展呈显著增加趋势(P<0.05).

EFFECTS OF Verticillium Albatrum ON PROLINE CONTENT PHOTOSYNTHESIS AND TRANSPIRATION OF COTTON LEAF

Statistical analysis showed that there was significant difference in disease indexes between resistant cultivars Shaan 1155,2059 and susceptible ones Simian 2,Jimian 11 (P<0.05).FreeProline content of cotton leaf was determined by sulfosalicylic acid method and its content of inocelated plants was much higher in susceptible cultivars than in resistant ones (P<0.05),but no significant difference between two resistant and susceptible cultivars.Examining photosynthesis and transpiration of various disease severities of seedlings showed that even inoculated plants didn''t show any symptoms,their net photosynthetic rate was significantly decreasde(P<0.01), particularly diseased plants to 90-96% compared with healthy ones.by stomatal trnsmission Transpiration rate of diseased plants was also significantly decreased (P<0.01) However,there was insignificant correlation between disease severity and stomatal transmission and transpiration.Stomatal resistance of leaf was significantly increased with disease developing.