79份陆地棉种质资源抗旱性鉴定与综合评价OA

In order to comprehensively evaluate the drought resistance of upland cotton germplasm resources,79 upland cotton germplasm resources were used as materials.2 treatmetns were set including normal irrigation and drought stress during flowering and boll stage.The drought resistance was evaluated by descriptive statistics,drought resistance coefficient(DC),drought resistance index(DI),drought resistance comprehensive evaluation values(D)and principal component,grey correlation degree and cluster analysis.The results showed that drought stress had significant effects on 12 traits(P<0.05)except for the first fruiting node,height of the first branch and uniformity index.For the coefficient of variation,the number of bolls per plant and the number of fruit branches were greatly affected by drought stress.For the DC and DI,the number of bolls per plant,short fiber index and effective branch number were greatly affected by drought stress.Principal component analysis transformed 15 traits into 5 independent comprehensive indexes,which could cover 68.275％of the original traits,and were mainly determined by fiber length,short fiber index,uniformity index,single boll weight,height of the first branch,plant height,elongation and fruit branch number.The results of grey correlation analysis showed that fiber length,uniformity index,plant height and fruit branch number were closely related to D value and weighted drought resistance coefficient.According to the results of principal component analysis and grey correlation analysis,fiber length,uniformity index,plant height and fruit branch number could be used as important indexes for drought resistance evaluation of cotton.The clustering analysis classified 79 cotton germplasms into 4 groups.Group Ⅰ belonged to high drought-resistant type,including Xinluzao 63,Xinluzao 62,Xinluzhong 78 and Xinluzhong 81.Group Ⅱ belonged to drought resistant type,including Xinluzhong 82,Z1112,Xinluzhong 84 and other 23 cotton germplasm resources.Group Ⅲ belonged to rather drought-sensitive type,including Xinluzao 82,y7-1,Zhonghua 4108 and other 40 cotton germplasm resources.Group Ⅳ belonged to drought sensitive type,including 993,Lumian 343,Xinluzao 46 and other 12 cotton germplasm resources.Above results not only provided theoretical basis and germplasm resources for screening and breeding drought-resistant cotton varieties,but also laid important foundation for addressing climate change,enhancing the sustainability of cotton production,and ensuring the stable development of the industry.