Effects Of Waterlogging At Bud Stage On Plant Growth,Yield And Quality Of Cotton

Cotton is one of the important economic and agricultural crops in China,and the cotton fields in the middle and lower reaches of the Yangtze River in China are often affected by plum rain season and heavy rainfall,which has a great impact on the growth status and economic traits of cotton,especially in the flowering stage of cotton,which directly affects the yield and quality.Therefore,in this study,38 upland cottons were used as the research materials to conduct continuous 10-day waterlogging stress at the bud stage of cotton to study the effects of waterlogging stresson the growth of cotton and the yield and quality of cotton,and to analyze the correlation between waterlogging stress at the flowering stage of cotton and the formation of yield and quality,and screen out the waterlogging-tolerant cotton parents,so as to provide a theoretical basis for breeding waterlogging-tolerant cotton varieties and clarifying the physiological mechanism of waterlogging tolerance of cotton in the middle and lower reaches of the Yangtze River.The main research results are as follows :(1)Seed growth of 38 cotton varieties was blocked by waterlogging stress,Plant height decreased by an average of 11.3 cm,green leaf number of main stem decreased by an average of 10,branch number and node number decreased by 60 %-70 %.(2)Flooding delayed cotton flowering by 2 – 3 days;Compared with the control,the number of buds and bolls decreased by 15 % – 30 %,The maximum reduction of flower number per plant was 18.The average boll setting rate after flooding was only 48 %,and the maximum reduction of boll number per plant compared with the control was 19.The correlation analysis of flowering traits with yield showed that the boll setting rate was significantly correlated with seed cotton and lint cotton(P < 0.01),which was one of the main factors affecting cotton yield formation.(3)Waterlogging stress seriously reduces yield of individual cotton varieties,and the seed cotton yields of varieties NL015,NL017,NL021,NL027,NL029 and NL030 decreased by 49 %,77 %,50 %,46 %,50 % and 55 % compared with the control,respectively.The average lint yield of 38 cotton varieties was about 50 % lower than that of the control,and the lint yield of NL017 was reduced by 88 %.(4)The quality index detection and analysis showed that the average length of the upper half of the flooded cotton fiber was lower than 1.13 mm of the control.Average uniformity of cotton fiber was lower than 1.1 % of control;TThe average elongation of different cotton varieties was lower than the control 12 %,the breaking strength of cotton plants after flooding was lower than that of the control 2.42 g / tex,and the lint percentage between cotton varieties was lower than that of the control 8 %,and the clone value of flooded cotton was higher than that of the control 0.16.(5)Comprehensive all traits of cotton varieties : Zhong 053(CCRI 53 female parent),Shaan 401(Shaanmian 7),Daizimian 15 line selection,Zhong 7263,MO-3(light rare plant),Fuzimian(Foster)and Zhongmian 1279F2 have strong ability to withstand waterlogging,while the cotton variety number : Xuzhou 1818,Ejing 1,Jinmian2,Antong SP21 and King have the worst waterlogging tolerance compared with other cotton varieties.