Comprehensive Evaluation of Ecological Functional Traits and Screening of Key Indicators of Leymus chinensis Germplasm Resources from Northern China and Mongolia

Leymus chinensis is important for ecological restoration and stock farming in Eurasia. In the context of climate change, excavating L. chinensis germplasm resources with excellent ecological functional traits is important to resist grassland degradation and promote the restoration of degraded grassland ecosystems. In this study, we used 42 L. chinensis germplasm resources (LC01–LC42) from different geographical sources to perform a multidimensional comprehensive evaluation of drought tolerance, rhizome space expansion, and soil improvement abilities. (1) LC07, LC15, LC18, and LC19 exhibited excellent ecological functional traits and could be used in breeding for ecological restoration. They were mainly from eastern and central Mongolia and central Inner Mongolia. (2) Principal component analysis showed that eight principal components with eigenvalues ≥1 were extracted from 26 traits of L. chinensis. The cumulative contribution rate was 80.551%. (3) There was a significant positive correlation between the F value and longitude and a significant negative correlation of the F value with latitude. L. chinensis germplasms from high longitudes and low altitudes may exhibit better comprehensive performance. (4) Plant height, leaf number, tiller number, malonaldehyde, chlorophyll content, dry weight on the ground, maximum one-direction extended distance, and organic matter can be used as key indices to comprehensively evaluate L. chinensis germplasm resources.