Studies on wide compatibility in rice (Oryza sativa L.).

The present investigation was carried out to screen different rice sub-species for wide compatibility (WC) and to evaluate F2 populations of selected crosses to study the genetics of WC. Among the three criteria followed for screening of WCVs viz., pollen fertility per cent of hybrids, spikelet fertility per cent of hybrids and the spikelet fertility per cent of hybrids as well as tester parents, the third criteria appeared to be effective. Based on spikelet fertility per cent of hybrids as well as tester parents, seven out of 15 lines viz., Dular and ASD 16 (indicas); WCR 6, IR 65600-32-4-6-1, IR 65601-120-3-5, IR 66158-38-3-2-1 and IR 67323-46-2-1 (tropical japonica) were adjudged as WCVs. The F2 segregation in seven crosses for spikelet fertility and semi-sterility were in agreement with trigenic complementary ratio (45:19). Hence, it was concluded that the genetic basis of inter sub-specific sterility of cultivated rice is complex.