GENETIC VARIATION AND CHARACTER ASSOCIATION IN F4 POPULATIONS OF BORO RICE (Oryza saliva L.)

Abstract

A field experiment was conducted with 25 F4 materials and 4 parents of Oryza sativa L. at the experimental field of Sher-e-Iangla Agricultural University, Dhaka to study the genetic variability, correlation and path coefficient analysis during December 2013 to May 2014. Fourteen characters were studied to find out the suitable traits for the improvement of rice yield. The selected genotypes were found significantly variable for most of the characters. Comparatively phenotypic variances were higher than the genotypic variances for all the characters studied. Also PCV were higher than the CCV for all the characters studied. All characters showed high heritability. All characters except days to flowering and days to maturity showed moderate to high genetic advance in percent mean. High heritability coupled with moderate to high genetic advance in percent mean is governed by additive gene action which is better for selection. On the other hand, the significant positive correlation with seed yield per hectare was found in days to maturity, number of secondary branches per panicle, number of filled grains per panicle, total number of spikelet per panicle and yield per plant. Path coefficient analysis revealed that plant height, number of total tillers per plant, number of effective tillers per plant, number of secondary branches per panicle, number of filled grains per panicle and 1000-seed weight had the posilive direct effect on yield per hectare. The residual effect was found 0.164 which indicated that 83.6% of the variability was accounted for fourteen yield and yield contributing traits in the present studies. Rest 16.4% variability might be controlled by other yield contributed traits that was not included in the present investigation. So direct selection based on these traits would be effective for improvement of these F4 materials. l'wenty six plants were selected from (18 (BR 26 XBRRI dhan29, SIPS), 69 (BR 26XBRRI dhan 29, SIPIO), 610 (BR 26XBRRI dhan 36, S7PI), 015 (BRRI dhan 28xBRRI dhan 29, S2P2), 0l6 (BRRI dhan 28xBRRI dhan 29, S2P3). 617 (BRRI dhan 28xBRRI dhan 29, S2P4), 618 (BRRI dhan 28xBRRI dhan 29. S2P5), 019 (BRRI dhan 28xBRRI dhan 29, S2P6), 020 (BRRI dhan 28xBRRI dhan 36, 57P1). 022 (BRRI dhan 28xBRRI dhan 36, S7P6), 623 (BRRI dhan 28xBRRI dhan 36, S7P8), 024 (BRRI dhan 28xBRRI dhan 36, S7P9) and 626 (BRRI dhan 29XBRRI dhan 36. S5P5) on the basis of days to maturity, total number of spikelet and yield per plant.