萎锈灵杀菌剂对提高棉花耐低温冷害胁迫能力的影响

【目的】研究冷胁迫条件下萎锈灵杀菌剂对棉花种子发芽率、保苗率及幼苗耐低温冷害胁迫能力的影响,为萎锈灵杀菌剂应用于棉花生产提供依据。【方法】在室内制备5种不同浓度(4.2%、5.7%、7.2%,8.7%和10.2%)的萎锈灵,以裸种子不包衣处理作为空白对照,以基础杀菌剂包衣处理作为参比对照,按药种比1∶100进行种子包衣处理,测定在冷胁迫条件下萎锈灵杀菌剂对棉种的发芽率、出苗率、保苗率、棉苗株高、叶片数、干鲜重和光合参数,并采用主成分分析法,综合评价萎锈灵对棉花耐低温胁迫的影响。【结果】8.7%萎锈灵处理的种子发芽率较空白对照分别增加7.0%(25℃)、12.0%(18℃)、18.0%(15℃)和20.5%(12℃),较参比对照分别增加5.0%(25℃)、9.0%(18℃)、12.0%(15℃)和16.4%(12℃)。7.2%萎锈灵处理的出苗率较空白对照增加10.1%,较参比对照增加13.0%、8.7%萎锈灵处理的保苗率较空白对照增加9.1%,较参比对照增加13.2%。7.2%萎锈灵处理的幼苗株高、茎粗、鲜重和干重分别较空白对照增加8.9%、9.7%、7.4%和25.4%,较参比对照分别增加10.8%、10.7%、8.3%和27.5%。7.2%萎锈灵处理提高了在冷胁迫条件下的棉花幼苗叶片净光合速率、气孔导度、胞间CO₂浓度指标,较空白对照分别增加11.0%、17.0%和9.0%,较参比对照分别增加6.0%、6.0%和5.0%,这些指标差异均达显著水平。7.2%萎锈灵杀菌剂处理增强棉花耐低温冷害胁迫能力的作用效果最好,其次为8.7%萎锈灵杀菌剂。【结论】萎锈灵杀菌剂处理能够增强棉花种子活力,提高了发芽率、出苗率和保苗效果,提高了棉苗耐低温冷害胁迫能力,可促进棉苗光合作用和生长。

Effects of the Carhoxin Fungicide on the Chilling Stress of Cotton Seedlings

【Objective】 To study the effect of carhoxin Fungicide on the germination and seedling of cotton under chilling stress, the Optimum concentration to improve the germination rate, seedling preservation rate and seedling chilling tolerance were explored in the hope of providing theoretical basis and technical support for the application of seed film coating carhoxin Fungicide in cotton production.【Methods】 Five kinds of seed coating agents with different concentrations (4.2%, 5.7%, 7.2%, 8.7% and 10.2%) of carhoxin were prepared in the laboratory. The naked seeds as control and the basic seed coating as control reference, and the seed coating treatment was carried out according to the drug/seed ratio of 1:100; Under the chilling stress, the germination rate and other characters were investigated and the synthetic effects were evaluated by principal component analysis through the data of the germination rate, etc.【Results】 Compared with the control, the germination rate of seeds treated with 8.7% carhoxin increased by 7.0% (25℃), 12.0% (18℃), 18.0% (15℃) , 20.5% (12℃), respectively. Compared with the control reference, the germination rate of seeds treated with 7.2% carhoxin increased by 5.0% (25℃), 9.0% (18℃), 12.0% (15℃) , 16.4% (12℃), respectively. The seedling rate of seeds treated with 7.2% carhoxin increased by 10.1% compared with the control, 13.0% compared with the reference. The seedling rate of seeds treated with 8.7% carhoxin increased by 9.1% compared with the control, 13.2% compared with the control reference. Compared with the control, the seedling height, stem diameter, fresh weight and dry weight of seeds treated with 7.2% carhoxin increased by 8.9%, 9.7%, 7.4% and 25.4%, respectively. Compared with the control reference, these indicators increased by 10.8%, 10.7%, 8.3% and 7.5%, respectively. Compared with the control, the indexes of net photosynthetic rate, stomatal conductance and intercellular CO₂ concentration of cotton seedling leaves of seeds treated with 7.2% carhoxin under chilling stress increased by 11.0%, 17.0% and 9.0%, respectively. Compared with the control reference, these indicators increased by 6.0%, 6.0% and 5.0%, respectively. Comprehensive analysis showed that seed treated with 7.2% carhoxin had the optimum effect on enhancing the ability of cotton to resist chilling stress, followed by 8.7% carhoxin.【Conclusion】 The carhoxin fungicide can enhance the vigor of cotton seed, increase the germination rate, emergence rate and seedling protection effect, improve the ability of cotton seedling to withstand chilling stress, and promote the photosynthesis and growth of cotton seedling.