Path analysis for kernel traits associated with grain mould resistance in food type sorghum

Abstract

This study was carried out with the following objectives: (1) to determine the correlation and compensatory effects among seed and grain traits under grain mould incidence (GMI) and (2) to determine the direct and indirect effect of these kernel traits on seed germination and seedling vigour through the use of path-coefficient analysis. This analysis was applied to data from the cross between RT × 430 and Sureño, grain mould susceptible and resistant lines respectively. Seeds from six generations (P1, P2, F1, F2, BC1P1 and BC1P2) were planted at four Texan locations. Results indicate that an increase of GMI led directly to a decrease of grain size, grain density, seed germination, seedling vigour and test weight. Grain density had the highest negative and floury endosperm the highest positive correlation with GMI. Breeding and management practices that maximize grain density should enhance grain mould resistance and improve seed germination and seedling vigour.