Abstract: 【Objective】The present study analyzed the genetic variation of phenotypic traits and genetic diversity of sorghum breeding materials. Additionally, the study explored a comprehensive method for the evaluation of germplasm materials and screening of excellent sorghum germplasm to provide an important basis for sorghum germplasm innovation and variety selection.【Method】In total, 263 sorghum germplasms from different sources were used as the test materials, and 17 phenotypic traits were identified under different environments for two years. Genetic diversity of the phenotypic traits was calculated based on the Shannon-weaver information diversity index. The sorghum germplasms were comprehensively evaluated using the correlation analysis, principal component analysis, cluster analysis, and stepwise regression. Excellent sorghum germplasms were screened according to the phenotypic comprehensive evaluation value (F value) and target traits.【Result】Sorghum breeding materials exhibited high genetic diversity. The diversity index distribution of different traits ranged from 0.497 to 2.075, with the diversity index of spike shape being the smallest and that of spike stalk length being the largest. The coefficient of variation of seven plant height, stem diameter, panicle length, panicle stalk length, grain weight per spike, thousand grain weight, period of duration varied in different years; the smallest variation was observed in the period of duration, followed by the panicle stalk length, whereas the largest variation was observed in stem diameter, followed by plant height. A comprehensive evaluation of the breeding materials showed that when the cumulative contribution percentage was >80%, the number of the total principal components was 11. F value of the sorghum breeding materials was calculated using the membership function method. The average F value was found to be 0.464, with the restorer line L28 having the highest F value (0.581) and the maintainer line 72B/DORADO having the lowest the F value (0.330). Through stepwise regression, a regression equation was established, with 12 traits (main vein color, ear type, ear shape, awn character, glume coating degree, grain shape, plant type, stem diameter, ear length, grain weight per ear, 1000-grain weight, and growth period) as independent variables. The equation could be used for a comprehensive evaluation of the phenotypic traits of breeding materials of sorghum breeding materials. Based on F value clustering, 263 materials were divided into six groups. Among these, 34 materials in group Ⅲ exhibited excellent agronomic characteristics and high F value, which could be used as parent materials for material innovation and cross breeding.【Conclusion】Sorghum phenotypic traits exhibit rich genetic variation and high genetic diversity. A total of 34 excellent germplasms were obtained. Using multivariate statistical analysis is a feasible approach to comprehensively evaluate sorghum germplasm.

Key words: Sorghum, phenotypic traits, genetic diversity, comprehensive evaluation