ESTIMATION OF GENETIC VARIABILITY AND INTERRELATIONSHIP BETWEEN YIELD AND YIELD CONTRIBUTING CHARACTERS OF BC 1 F 7 POPULATION IN Brassica napus L.

Abstract

Thirty genotypes from BC 1 F 7 populations of Brassica napus L. were evaluated to study the genetic variability, heritability with genetic advanced, correlation and path analysis based on yield and yield component traits. The experiment was conducted at the experimental field of Sher-e-Bangla Agricultural University, Dhaka during midNovember

2018 to mid-March 2019. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Analysis of variance revealed significant variations among the genotypes for all the traits studied. Mean difference studies showed significant values for all the traits among the genotypes. Comparatively phenotypic variances and PCV (Phenotypic Coefficient of Variation) were higher than the genotypic variances and GCV (Genotypic Coefficient of Variation) for all the characters studied. The highest PCV value was observed followed by seed yield per plant (31.20%) number of secondary branches per plant (25.39%) and 1000 seed weight (21.96%) and GCV values were followed by seed yield per plant (23.97%), number of secondary branches per plant (17.68%) and thousand seed weight (12.18%). High heritability values coupled with high genetic advances as percent of mean was noticed for seed yield per plant (37.94%) with heritability (59.04%) and secondary branches per plant (25.36%) with heritability (48.49%). The significant positive correlation with seed yield per plant was found in primary branches per plant (G=0.297, P=0.283), secondary branches per plant (G=0.260 P=0.293), siliqua per plan (G=0.589, P=0.489), seeds per siliqua (G=0.325, P=0.403) and 1000 seed weight (G=0.277, P=0.278). On the other hand, path analysis was exhibited the positive direct effects towards days to 50 % flowering (5.806), plant height (cm) (1.838), primary branches (3.067), siliqua length (cm) (0.789), seeds per siliqua (1.385) and 1000 seed weight (g) (1.102) where negative direct effect was recorded in days to 1 st flowering (-5.490), secondary branches per plant (-2.497), siliqua per plant (0.279).

Based on the result of the study, according to seeds yield per plant and other agronomic performance genotypes G 13 (19.59), G 24 (17.20), G 19 (14.05), G 30

(13.19) and G 29 (15.13) can be used further for varietal improvement programs and development of higher-yielding variety.