Assessment of Hybrid Vigour for Qualitative and Quantitative Traits in Rice (Oryza sativa L.)

The present investigations were undertaken to estimate the extent of average heterosis and inbreeding depression for grain yield and yield contributing traits. The F1 hybrid recorded higher grain yield per plant compared with both the parents, but in the F2 segregating populations, grain yield per plant were intermediate than non segregating populations. Significant average heterosis were observed for all traits studied except panicle length, test weight, kernel width, kernel width after cooking and disease severity at 14, 21 and 28 days after inoculation. The significant inbreeding depression was observed for most of the traits under studied. A high degree of inbreeding depression was observed for grain yield per plant (12.69%) indicated the utilization of cross combinations in early generation selection i.e. exploitation of heterosis in F1 generation. The traits spikelet fertility, test weight, kernel length, kernel breadth, kernel length after cooking, kernel breadth after cooking and grain yield per plant showed significant positive inbreeding depression in F2 generation, indicating inbreeding resulted in loss of hybrid vigour.