Variation in Major Agronomic Traits and its Contribution to Grain Weight per Plant in Tartary Buckwheat Germplasm

To breed high-yield buckwheat varieties with thin shells, the agronomic traits of 180 tartary buckwheat accessions were evaluated using statistical methods such as simple and partial correlation analysis and path analysis. Results showed that the variation coefficients of eight main agronomic traits ranged from 8.10% to 39.40%. Simple correlation analysis indicated that grain weight per plant (GW) was positively correlated with grain number per plant (GN) and number of primary branches (PBN). Partial correlation analysis showed that GW was positively correlated with GN and 1000-grain weight (TGW). Multiple stepwise regression and path analysis indicated that GN and TGW were the main factors affecting GW. Cluster analysis showed that the 180 tartary buckwheat accessions were classified into five groups, with 47 germplasm resources, primarily found in group Ⅲ, exhibiting excellent agronomic traits, including good stem branching capacity and high GN, GW and RGY. Therefore, 47 germplasm resources in group Ⅲ are suitable as tartary buckwheat breeding material and provide a basis for shell breeding with increased rice grain weight per plant (RGY) and milled rice rate (MR).