低温对棉花主要生育期危害机理初探

Primary Study on Damage of Low Temperature toCcotton Growth at Seedling and Flower Stage

温度是影响棉花生长的重要因子。本文模拟田间棉花苗期及花铃期温度的异常变化 ,结合土壤主要病原菌及冰核细菌与温度之间的互作 ,初步研究了温度对棉花主要生育期的危害能力 ,结果表明 ,在 - 3～ 15℃的范围内 ,真正造成棉花烂根烂种的温度范围应当在 3～ 10℃ ,病情指数高达 90 0 0 %。将处于花铃期的棉花植株置于人工气候箱中 ,设立 3个降温梯度处理棉株 ,32～ 2 0℃降至 2 0～ 16℃ ,棉株未表现出不良症状 ;32～ 2 0℃降至 16～ 3℃ ,仅造成棉叶螨和棉蚜危害叶片萎焉、干枯 ,叶柄干枯 ,危害较轻的叶片仅边缘卷曲干枯 ,其他叶片表现正常 ;32～ 2 0℃降至 16～ 3℃ ,棉花整株受害 ,叶片似水烫状 ,失水透明 ,叶片及植株顶端干枯 ,至室温后干枯死亡。INA、立枯丝核菌和低温 (15～ 10℃ )互作可加重棉花受害程度。

Temperature is one of important effect factors to cotton growth.This paper is showed that damage of abnormal change of air temperature to cotton growth at seedling and flower stage was assessed in Lab,combining with inoculating Rhizoctonia solani, INA.The result showed that cotton seed and seedling were easy to be damaged at 3～10℃,causing seed rot and damping off of seedling.Cotton plants at flower and boll stage were treated at three temperature range in Lab.The growth of cotton plant was normal at 32～20℃ to 20～16℃,but the leaves of cotton plant damaged by insect and mite only became wilt and dry rot,its leave edge became curl at 32～20℃ to 16～3℃,other leaves were normal.Cotton plants were damaged at 32℃～20℃ to 16℃～-3℃,like waterlogging,leaves and top of plant became dry rot, if return it normal temperature, plant became death at once.The interaction of low temperature,INA,and .Rhizoctonia solani would aggravate the damage of low temperature to cotton growth.