Heterosis and path analysis for grain yield and chocolate spot disease resistance in faba bean (Vicia faba L.)

Abstract

This study was conducted to estimate better-parent and mid-parent heterosis for grain yield and chocolate spot resistance and to determine the direct and indirect effects of yield components on yield of faba bean (Vicia faba L.) in Ethiopia. Ten genetically diverse inbred lines were crossed in a full diallel to produce 90 F1 progenies. The parents and their 90 F1 progenies were evaluated in a 10 x 10 alpha lattice design with two replications at three locations. Data were analyzed using the Gardner and Eberhart's analysis II and PATHSAS using SAS program. The maximum heterosis for grain yield (t ha-1) was 162.3% for mid-parent and 133.9% over the better parent. Six crosses; NC58 × ILB-4726, ILB-4726 × Kasa, NC58 × BPL-710, ILB-938 × CS-20-DK, ILB-938 × CS-20-DK and CS-20-DK × BPL-710 are recommended for grain yield breeding. Similarly, crosses ILB-4726 × Kasa, ILB-4726 × Bulga-70, CS-20-DK × Gebelcho, NC58 × ILB-4726, Kasa × BPL-710 and ILB-938 × Kasa are recommended for chocolate spot resistance breeding. Three crosses ILB-4726 × Kasa, ILB-4726 × Bulga-070, NC58 × ILB-4726 are recommended for both grain yield and chocolate spot disease resistance breeding in faba bean. Path coefficient analysis showed a significant direct effect of the number of nodes that had pods, plant height and total biomass on grain yield. However, general chocolate spot disease score (GDS) and relative area under disease progress curve (rAUDPC) had negative direct effect and significant negative correlation with grain yield. These results are useful to faba bean breeders for indirect selection of grain yield during the early segregating generation when yield tests cannot be conducted.