Genotype x environment interaction in hybrid rice for yield and its component traits

The phenotypic stability for eight hybrids of rice (Oryza sativa L.) was studied during kharif 2002 and 2003 and rabi 200203 at Central Rice Research Institute, Cuttack, Orissa, India by seeding and transplanting at one month interval at four consecutive dates and exposing them to twelve growing environments. The hybrids performed differently at different environment and significant genotype (G) x environment (E) interaction was observed for plant height, leaf area index, total dry matter m⁻², panicle length, grains panicle⁻¹, spikelets fertility per cent, 1000-grain weight, harvest index and yield. Both linear and non-linear components of G x E interaction were observed. Linear components predominates for plant height, leaf area index, total dry matter m⁻², 1000-grain weight and harvest index hence performance of genotypes could be predicted over the environments for these traits. Preponderance of non-linear components was observed in panicle length, grains panicle⁻¹, spikelets fertility per cent and yield; therefore, genotypic performance under different environment may not be predicted precisely. None of the hybrid was stable for all the characters. However, hybrid CRHR 5 was stable for leaf area index and panicle length with high mean, unity bi and non-significant S²di and showed superior mean performance over environment for yield, grains panicle⁻¹, spikelets fertility per cent and 1000-grain weight and significant bi higher to unity for grains panicle⁻¹and spikelets fertility per cent indicated better performance in favorable environment also. Hybrid PHB 71 gave stable performance for leaf area index and hybrid PA 6444 was consistent its performance for total dry matter m⁻². For 1000-grain weight, KRH 2 followed by PA 6201 was more stable. The significant bi value lower to unity in CRHR 5, KRH 2 and DRRH 1 hybrids for harvest index implied that they were suitable for poorer environments.