Inheritance of grain size and its interrelationship in rice

Inheritance of grain size, nature of panide, awning and plant habit was studied in two crosses. Roti, a tall variety with normal panides having long grains was crossed with two phenotypically similar dwarf mutants with cigar shaped panides having short and round grains. Monogenic and trigenic ratios for grain size were obtained in F₂ generation. Dwarf plant habit was associated with cigar shaped panide possessing short and round grains, indicating pleiotropic gene action. Digenic and tetragenicratios were obtained for awning, indicating two and four gene interactions for expression of awns in these crosses.