Rice inheritance of resistance to mechanical damage caused by sogata

Abstract

The inheritance of resistance to mechanical damage in rice caused by sogata, Tagosodes orizicolus (Muir), was studied in cultivars with this resistance. Evaluation of F1 and F3 generations suggests that resistance to mechanical damage is controlled by a single dominant gene (A). This gene, present in cultivars Makalioka and Mudgo, is homozygous. The gene confers resistance, but its expression is modified by another gene (B). The action of the modifier gene is dependent on the genotype and the exposure to insect attack. For Mudgo, the modifier gene is in the homozygous form (bb), which accelerates the expression of the susceptible phenotype. In Makalioka, the dominant homozygous form (BB) retards the expression of susceptibility.