Analysis of agronomic traits in recombinant inbred line population of tartary buckwheat (Fagopyrm tataricum)

Objective  To study the genetic variation in major agronomic traits of tartary buckwheat (Fagopyrm tataricum), reveal the major factors influencing grain weight per plant, select excellent lines, and provide a theoretical basis and materials for high-yield tartary buckwheat breeding.

Method  Using 399 recombinant inbred lines (RILs) derived from the cross of ‘Xiaomiqiao’ and ‘Jinqiao2’, we studied the genetic variations of eight agronomic traits including plant height (PH), branch number of main stem (BN), branch number with double-bifurcation on main inflorescence (BND), grain number of the top-three-branch (GNT), grain number per plant (GN), grain weight per plant (GW), 1 000-grain weight (TGW) and grain yield (GY) and did correlation analysis. Multiple regression and path analysis were conducted to detect the traits mostly affected GW. Cluster analysis for the RIL population was carried out based on the phenotypic data of invested traits, and the excellent lines were selected by variance analysis among groups.

Result  The coefficient variation of the traits ranged from 13.1% to 42.4%. Excepting BN, tremendous transgressive segregation for all traits was observed. PH, BND and GN were significantly positively correlated with GW and GY, respectively (P<0.01). GN, BND and TGW were the traits mostly affected GW. GN had the most direct and overall effects on GW. The RIL population could be divided into ten groups at the Euclidean distance of 22.0. Group C5 had the highest GY and group C1 had fine performance in GW, GN, BND and GY.

Conclusion  GN can be used as a reference index for high-yield tartary buckwheat breeding, and lines from group C1 and C5 are recommended as materials for breeding.