Abstract

Heritability is an important genetic parameter of the trait under selection. 193 F_2:3families of a cross between 'MousaTarom' and '304' were evaluated under field conditions. The studied traits were seedling height, plant height, culm length, panicle length, penultimate leaf length and width, brown rice length, width, and shape. The parameter m, was highly significant for all traits. The additive component of means and variance were highly significant for all the traits except for the additive component of means of seedling height, panicle length, and leaf length. Special environmental component of variance was not significant only for brown rice shape. Culm number and panicle length showed the lowest (<0.19), and brown rice characters showed the highest (>0.78) narrow sense heritability. Common environmental component was not statistically significant for any of the corresponding traits even for those with low heritability estimates and hence means of variances of 'between replication of each non-segregating genotype', including parents and checks used to estimate the common environmental component instead of its deletion, and to estimate heritability with more confidence. Thus, for generations with high environmental component of variance, such as F₂s, this method could be used to find good information about environmental variation components.

Key words: Rice (Oryza sativa L.), F_2:3 families, heritability, environmental variance.