Stability analysis and GxE interactions in lowland rice promising genotypes

Genotype x environment interactions and stability parameter analysis are of major importance to sort out high yielding and stable promising genotypes. 48 diverse rice genotypes were evaluated in four different environments created by presence and absence of inoculation pressure for rice blast disease during wet season 2012 and wet season 2013 seasons to identifystability for grain yield per plant in rice. G x E (linear) and G x E (non-linear) were found significant for grain yield per plant. The preponderance of linear component noticed would help in predicting the performance of the genotypes across the environments with great precision. Three genotypes viz., GR-7 x NWGR-2002 (2-3-1-1-1), GR-7 x NWGR-3003 (3-1-2-1-1) and GR-7 x NWGR-3003 (4-1-1-1-1) were identified as most promising as it yielded higher than population mean performance coupled with unit regression coefficient and non-significant deviation from regression and therefore they should be recommended for wider cultivation after necessary testing. The genotypes, GR-7 x Ratna(1-1-1-1-1), GR-7 x IET-17429 (1-1-1-1-1-1), Gurjari x IR-72 (2-1-1-1-1) and Pankhali-203 due to mean value higher than overall mean, bi>1, and nonsignificant deviation from regression, hence considered as “genotypes with below average stability”. Apart from these, Gurjari x IR-72 (4-1-2-3-1) was found with high mean performance than population mean, regression coefficient less than unity and non-significant deviation from regression was regarded as genotype with “above average stability and better adaptability to unfavourable environments”.