Abstract: 【Objective】 To screen superior Avena sativa germplasm resources introduced from Australia,providing references for A. sativa variety improvement and parental selection. 【Methods】 Fourteen A. sativa germplasm resources introduced from Australia were used as experimental materials. Nineteen traits,including grain phenotypes,root indicators,plant morphology,biomass,and root-to-shoot ratio of A. sativa,were measured. Combined with correlation analysis,principal component analysis,and related methods,genetic diversity of the Australian A. sativa germplasm resources was systematically analyzed and comprehensively evaluated. 【Results】 The coefficients of variation of 14 A. sativa germplasm resources ranged from 8.50% to 60.34%,and the diversity indices ranged from 1.43 to 1.97. Among them,root biomass exhibited the largest coefficient of variation,while thousand-grain weight showed the highest diversity index. Correlation analysis indicated that grain width was significantly positively correlated with thousand-grain weight（P<0.05）;root length,root volume,and root surface area were extremely significantly positively correlated with tiller number,root biomass,aboveground biomass,and total biomass （P<0.001）;tiller number was significantly positively correlated with leaf length（P<0.05） and extremely significantly positively correlated with root biomass,aboveground biomass,and total biomass（P<0.001）. Principal component analysis combined with the minimum data set identified grain area,grain length,root diameter,leaf width,relative chlorophyll content,root biomass,and root-to-shoot ratio as key indicators for discriminating superior A. sativa germplasm resources. Among them,Oat grata80,Oat galileo,and Oat mortlock ranked among the top three in comprehensive scores. Cluster analysis classified 14 A. sativa germplasm resources into three groups：Group Ⅰ consisted of medium-grain germplasm with large root biomass and thick root diameter,including Oat grata51,Oat grata80,Oat mortlock,Oat galileo,Oat culgoa,and Oat quoll;Group Ⅱ consisted of long-grain germplasm with long grain length,high relative chlorophyll content,and large root-to-shoot ratio,including two germplasm resources;Group Ⅲ consisted of short-grain germplasm with short grain length,small root biomass and small root-to-shoot ratio,and less developed root systems,including six germplasm resources. 【Conclusion】 Comprehensive evaluation indicated that Oat grata80,Oat galileo,and Oat mortlock exhibited outstanding comprehensive performance and can serve as important parental materials for A. sativa breeding.

Key words: Avena sativa, Germplasm resources, Genetic diversity, Phenotypic traits, Comprehensive evaluation