GENETIC PARAMETERS AND CHARACTER ASSOCIATION STUDIES IN CHEMICALLY INDUCED MUTANTS OF UPLAND COTTON (Gossypium hirsutum L.)

Abstract

The experiment was carried out at the Cotton Research, Development, Training, and Seed Multiplication Farm, Sadarpur, in 2022-2023 cropping season. The chemical mutagen, sodium azide (NaN3) was used to treat the seeds of five varieties, namely CB15. CB16, CB17, CB18 and CB19. Three concentrations viz. 10Mm/L, 15Mm/L and 25Mm/L were employed to create mutant lines. According to RCBD design, the treated seeds were sown on July, 13, 2022. Ten characters were studied to assess variations present in the mutants. Before, the first boll was picked 230 suspected mutant plants had been found. In both varieties and the mutant plants the selected characters were measured. The variety, CB18 produced the highest number of suspected mutants (51), whereas CB15 was refractory to changing its genetic makeup as produced the lowest number of mutants (37). The highest seed cotton yield was obtained from the genotype CM 13 with 232.733 g followed by CM 14, CM 9, and CB 17 and the highest lint fiber yield was recorded CM 13 with 213.2g followed by CM 14, CM 7, CM 9, and CB 17. The important characters, like the lowest plant stature (112.53 cm) and the highest sympodial branches/plant (23.133) were recorded in the mutants of CB 17. The highest bolls/plant (47.6) and the highest seeds/boll (31.866) were obtained from CM 7 and CM 11 mutants, respectively. Hence, a complicated mechanism including genetic interaction and the environment was responsible for developing early boll-picking bur short-duration cotton varieties. Last but not least, it may be suggested that early generation may not be effective, so the mutants must advance with a view to rapid fixation of heterozygous alleles which ultimately might promote the breeding exercise to develop high lint fiber yielding, short duration, and compact canopy structured cotton varieties that would eventually meet up the demand of the cotton growers in the northern belt of Bangladesh.