Abstract:Basic-cross is an approach mainly used for germplasm enhancement, which served as the basis and premise in sugarcane breeding. To establish a normative drought resistance identification system for Yunrui sugarcane parents and evaluate new blood parents from basic-crosses for drought resistance, thirty-six Yunrui sugarcane parents from basic-crossing were used as materials treated by artificial water stress, including normal water supply (as control) and water stress. Twelve indices including PMP, contents of MDA, PRO, chlorophyll fluoresence and other parameters were measured. Then drought resistance coefficient (DC), comprehensive drought resistance coefficient (CDC), drought resistance comprehensive evaluation value (D), weight drought resistance coefficient (WDC), subordinate function analysis, principal component analysis, clustering analysis, grey relational analysis and stepwise regression analysis were applied to identify the drought resistance level and screen its closely related indices. Firstly, the results indicated that moisture stress had significant effects on all indices at p value 0.0001, which suggested that drought stress was proper and all the indices selected were sensitive to drought. Secondly, the principal component analysis results revealed that seven principal components could represent 89.2686% of the original data information of sugarcane parents drought resistance. These factors could be divided into three groups and named photosynthesis factor, moisture utilization factor and physiological regulation factor. Thirdly, The clustering analysis results showed that thirty-six tested materials could be divided into five groups including high resistance to drought (groupⅠ), moderately high resistance to drought (groupⅡ), moderate resistance to drought (group Ⅲ), each accounting for 25% respectively, low resistance to drought (group Ⅳ) accounting for 13.9% and sensitive to drought (group Ⅴ) accounting for 11.1%. Nine elite materials Yunrui14-195, Yunrui15-88, Yunrui11-98, Yunrui11-256, Yunrui15-158, Yunrui14-78, Yunrui13-26, Yunrui12-137 and Yunrui15-73 were identified to have high resistance to drought. The grey relational analysis and stepwise regression analysis results further confirmed PMP, MDA, PRO and the proportion of free water and bound water were the key resistance indices with close correlation to drought, which could efficiently improve sugarcane drought resistance evaluation work. Thus, the established approach might become useful in large-scale screening for drought resistant sugarcane resources.