DEVELOPMENT OF A HIGH-YIELDING EARLY MUTANT FROM FATEMADHAN THROUGH CHEMICAL MUTAGENESIS.

The development of mutants and their further characterization offers an ample scope to isolate genes and genotypes with desire trait of interest. Ethyl methanesulphonate (EMS) is a widely used chemical mutagen applied for generating genetic variability in different crop species. This study aimed to assess the agronomic performance, genetic variability and character association of 11 EMS mutants (M3 generation) of rice derived from a promising local rice genotype (Fatemadhan). Seeds of the selected mutants, original parent and two popular varieties were grown at the field experimental farm of the Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh, Bangladesh. Significant inter-population differences for seven yield and yield contributing traits (viz., days to first flowering; days to maturity, DM; plant height, PH; number of effective tiller per plant, ET; panicle length; 100-seed weight, 100-SW; yield per plant) were observed. EMS Line 2 was found to be the most early maturing and high-yielding than those of the other mutants and check varieties. Analysis of heritability and genetic parameters revealed that all the traits are mostly controlled by genetic components while environment has little influence on them. The higher phenotypic and genotypic co-efficient of variation, heritability and genetic advance as percentage of mean confirmed the possibilities of rice yield improvement through phenotypic selection. Yield per plant showed significant positive correlation with ET whereas it showed negative correlation with DM, PH, and 100-SW. The first three components explained 81.4% of the total variation among the genotypes as revealed through principal component analysis. Thus, the promising mutant (EMS Line 2) isolated from this study can be released as an early maturing high-yielding rice variety. [ABSTRACT FROM AUTHOR]