ASSESSMENT OF AROMA AND YIELD POTENTIAL IN ADVANCED GENERATION (F5) OF FINE RICE

Abstract

A field experiment was conducted during aman season, 2017 at the research farm of Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh for the assessment of aroma and yield potential in advanced generation (F5) of fine rice. The experiment was carried out with thirty two aromatic rice genotypes in RCB Design with three replications. The results on analysis of variance (ANOVA) for yield and yield related characteristics of 32 F5 generation was studied and highly significant mean squares due to genotypes were observed for all traits viz. plant height(cm), productive tiller per hill, unproductive tiller per hill, fertile grain per panicle, sterile grain per panicle, 1000-grain weight (g), panicle weight (g), panicle length (cm), aroma test 1, aroma test 2, lodging percentage (%), sterility percentage (%) , days to 50% flowering, days to maturity, grain yield per hill (g) and harvest index. Low yield is a common phenomenon of aromatic rice and consequently rice breeders are trying to develop the agronomic characters to gain a better grain yield. The estimates of correlation coefficients revealed that, in general, the genotypic and the phenotypic correlation coefficients showed similar trend but genotypic correlation coefficients among F5 generation of rice yield and yield contributing traits were of higher in magnitude than the corresponding phenotypic correlation coefficients, which might be due to masking or modifying effect of environment. Very close values of genotypic and phenotypic correlations were also observed between some character combinations, such as grain yield with days to maturity, fertile grain per panicle with productive tiller per hill, which might be due to reduction in error (environmental) variance to minor proportions. Wide difference between genotypic and phenotypic correlations between two characters is due to dual nature of phenotypic correlation, which is determined by genotypic and environmental correlations and heritability of the characters. Results of correlation coefficients at genotypic and phenotypic level showed that grain yield was positively correlated with productive tillers per hill, fertile grain per plant, panicle weight, panicle length, 1000-grain weight, days to maturity, days to 50% flowering and harvest index . The findings suggest that grain yield can be improved in these rice genotypes by using these traits as selection criteria in succeeding generations. In the present study, days to 50% flowering exhibited a positive and significant association with days to maturity, productive tillers per hill, plant height and panicle length indicating a scope for simultaneous improvement of the traits. High heritability coupled with high genetic advance as percent of mean was observed for sterile grain per plant, 1000-grain weight (g), panicle weight (g), unproductive tiller per hill, aroma test 1, productive tiller per hill, fertile grain per plant and lodging percentage (%) and moderate genetic advance as percent of the mean for panicle length (cm), aroma test 2, sterility percentage (%) and grain yield per hill (g). Ranking of different characters of fine rice was done by DMRT test to make the rank of the 32F5 lines. Based on summation score value the line 3F5 stood the first position with the highest score 278, which was followed by line 18F5 with 264 and the line 25F5 with 246 values. Based on the overall performance PL 3, PL 16, PL 18, PL 25 and PL 29 might be taken under further evaluation to release new variety.