In a cross of Begunbuchi and IRAT 102 varieties of rice having extreme variations for number of grains and 1000-grain weight, additive and additive x additive interaction effects were found important in the inheritance of grains/panicle and 100 D-grain weight. However, grain yield was predominantly governed by dominance effects and additive Xdominance and dominance X dominance interaction effects. Complementary type epistasis was observed for grains/panicle and 1000-grain weight, while duplicate type epistasis was prominent for grain yield. The midparent heterosis was maximum (29.3%) for grain yield/plant. Appropriate breeding methodologies for the exploitation of various type of gene effects observed in the present study are discussed.
Genetics, grain number, grain weight, grain yield, rice
