Abstract

Indicas were characterised by greater values of mean, range and variance components for yield and yield characters. The GCV was the highest for grains per panicle followed by tiller number, culm length and seedling height in both indicas and japonicas. The genetic advance was also high for those characters with high variability. Both additive and non-additive gene actions were important in the expression of characters in both the botanic varieties. Days to 50 per cent flowering, tiller number and panicle length were positively correlated with plant yield in Indicas. In japonicas, days to 50 per cent flowering showed a positive association while tiller number showed a negative association with plant yield. Selection for panicle length would serve as the best criterion for plant yield in both Indicas and japonicas. Path analysis of yield components showed that seedling height and culm length had considerable direct effect in both indioas and japonicas. In addition, tiller number in indicas and days to 50 per cent flowering in japonicas had positive direct effect.

Keywords: Rice, Variability, Heritability, Correlation.