To overcome the limitations of an imperfect mutagenesis breeding system for Leymus chinensis and the shortage of germplasm with high seed setting rates， this study established an efficient mutagenesis technology using a combination of spatial and atmospheric pressure room-temperature plasma （SP+ARTP）. A high-throughput， accurate phenotypic analysis of large-scale mutant populations was achieved by utilizing an automatic seed setting rate identification model based on the YOLO algorithm. The results indicated that cultivar ‘Xiwuzhumuqin’ was the most suitable material for mutagenesis； a 60-minute treatment with 20% NaOH was the optimal pretreatment method. Single-space mutagenesis significantly promoted seed germination and seedling growth. The mutagenesis efficiency of the M₁ generation using the SP+ARTP combination reached 1.20%， and 23 new germplasm lines with high seed setting rate were successfully selected. These lines exhibited a seed setting rate of 30% higher than that of the control group. The combined mutagenesis and high-throughput phenotyping system developed in this study provides key technical support and germplasm resources for the targeted breeding of high-seed-setting L. chinensis varieties and their industrial application.

Leymus chinensis  /  Mutagenesis breeding  /  Compound mutagenesis  /  YOLO  /  High seed setting rate germplasm