Diversity analysis and comprehensive evaluation of phenotypic traits in 53 populations of Agropyron in Xinjiang, China

Agropyron is a type of perennial forage grass with strong resistance and a high forage value that has significant economic potential for the establishment of artificial grasslands and the restoration of natural grasslands. This study focused on 53 populations of Agropyron cristatum var. pectinatum and A. mongolicum distributed in Xinjiang, China. Under homogeneous garden conditions, 32 phenotypic traits of these populations were measured. The phenotypic variation patterns of Agropyron populations in Xinjiang were analyzed using analysis methods, including coefficient of variation, genetic diversity index, cluster analysis, and comprehensive evaluation based on principal component analysis. The results showed that the coefficient of variation of 24 quantitative traits among Agropyron species ranged from 5.76% to 53.23%. The variation of eight qualitative traits among Agropyron species was reflected within the population of A. mongolicum, which had a genetic diversity index ranging from 0.00 to 0.66. Correlation analysis showed that there were significant or extremely significant correlations among the traits of 53 Agropyron populations. Principal component analysis transformed 24 quantitative traits into eight principal components, with a cumulative contribution rate of 74.00%. Cluster analysis divided the materials into three categories: category I had thick upright stems, small flag leaves, and small spikelets; category II had tall plants, many flowers, and large spikelets; and category III had short plants, few flowers, and large spikelets. The comprehensive scores of the 53 Agropyron populations ranged from –1.18 to 1.24, identifying the top 10 populations with the best trait performance, including seven populations of A. mongolicum and three populations of A. cristatum var. pectinatum. In summary, the phenotypic variation of the Agropyron populations in Xinjiang was relatively abundant, with a high genetic diversity, providing a theoretical basis for the protection and utilization of Agropyron germplasm resources.