Inheritance and Relationship of Grain Size and Weight in Rice

To obtain the information on the inheritance of grain traits and their interrelationship, An experiment with two rice varieties, Daeripjong with large-size grain and ‘Manongbalay’ with small-size, along with their progenies (F1, F2, B1 and B2) was conducted. The traits studied were grain length, width, thickness, and length-width ratio, and 1,000-grain weight. Correlation between grain length and grain weight was significant in the F2 population, but grain length was not correlated with width and thickness in all populations. Scaling test and joint scaling test revealed that means of grain traits of six populations were fitted well by additive-dominance model without epistasis. Additive effects for the traits were much greater than the dominance effects in grain thickness and grain weight.