GENETICS OF YIELD AND ITS COMPONENTS IN RICE (0. SATIVA L.)

Abstract

The components of gene effect for yield and five yield traits were studied in four crosses using a popularindigenous cultivar as one parent. The charactermeans oversix generations were subjected to scaling test. In the presence of epistasis, six-parameter model was used to detect all types of gene effects. The analysis revealed the importance of dominance and epistatic components for yield, tillers/plant, grains/panicle and lOO-grain weight in all the crosses. Additive and dominance effects were important for plant height and panicle length. Among the digenic interactions additive x additive and dominance x dominance effects contributed more in most of the characters. Additive x dominance gene effects was important for l00-grain weight in the crosses IR 50 x C 14-8 and C 14-8 x Vijaya, and for plant height inC14-8 x IR 64 andC14-8 x Vijaya. In general, most crosses revealed duplicate nonallelic interactions for majority of characters. All the crosses exhibited heterosis in Fl and inbreeding depression in F2 generation.