Abstract:In order to explore the response of flower organ traits and Lint percentage to high temperature, and to evaluation the breeding materials of Gossypium barbadense L. with high temperature tolerance, this study evaluated 5 traits (including 4 flower organ traits and Lint percentage traits) of 534 Gossypium barbadense L. resources in Awati County in 2022, and then selected 36 materials with extreme traits.Descriptive statistical analysis showed that the variation coefficient of 534 Gossypium barbadense L. resources ranged from 8.57% to 26.56%, the variation coefficient of Lint percentage was the smallest (8.57%), and the variation coefficient of stigma length was the largest (26.56%).Correlation analysis revealed that style length was positively correlated with the other 4 traits (stigma length, stamen length, anther length, Lint percentage), stigma length was negatively correlated with stamen length, stamen length was positively correlated with anther length, and anther length was positively correlated with Lint percentage.In 2023, we conducted an enhanced temperature shed heat stress test on 36 previously selected Gossypium barbadense L. resources with extreme traits in the same location (Awati County), and measured the performance of 23 phenotypic traits.The results showed that the 36 extreme resources showed different degrees of variation in agronomic traits. Descriptive statistical analysis showed that the variation coefficient of each trait increased under high temperature treatment, and 14 traits showed obvious difference compared with the control.Principal component analysis identified 6 principal components, which accounted for 85.34% of the total variance, covering yield composition, photosynthesis, fiber quality and many other aspects.The materials were classified into four categories of heat resistance, medium resistance, sensitive and high sensitivity by cluster analysis. The correlation analysis confirmed the positive correlation between the properties of effective boll number, effective fruit branch number and heat resistance.Fitting regression analysis further showed that there was no significant correlation between flower organ traits, Lint percentage and pollen activity and comprehensive evaluation value.This study provided important theoretical basis and germplasm resources for Gossypium barbadense L. breeding for high temperature tolerance.