Abstract

                                Heterosis and combining ability studies were made on ten grain characters viz., kernel length, kernel breadth, kernel thickness, L/B ratio, kernel length after cooking, kernel breadth after cooking, linear elogation ratio, breadth wise elongation ratio, hulling per cent and milling per cent. The study revealed that the parents IR 50 and White Ponni possessed significant per se performance and gea effect for physical grain quality characters. The parents TKM 9 and ADT 37 are best adjuded for improving the cooking quality. The hybrid combinations ADT 37/White Ponni, TKM 9/White Ponni and ADT 39/ ADT 40 can be exploited for heterosis breeding. ADT 39 proved to be a good donor for improving the hulling and milling per cent. The high GCA variance for most of the characters indicate the predominance of additive gene action

Key words : Rice, Heterosis, Combining Ability