Assessment of genetic variability, heritability and genetic advance in Indian mustard (Brassica juncea L.)

Abstract

Forty-five genotypes of Indian mustard (Brassica juncea L.) were evaluated during rabi 2021-22 under four environments
created through different dates of sowing (timely sown 20 Oct. and late sown 20 Nov.) and row to row spacing (normal
30 × 10 cm and reduced 20 × 10 cm) i.e. timely sown, normal spacing (E1), timely sown, reduced spacing (E2), late sown,
normal spacing (E3), late sown, reduced spacing (E4). Pooled analysis of variance revealed significant differences among
genotypes, environments and G × E for all the traits. Therefore, analysis of variance carried out separately for each
environment which indicated significant difference among all the genotypes for 14 traits under all environments. The
variability studies showed high phenotypic (PCV) and genotypic (GCV) coefficient of variation for number of siliquae
per plant, seed yield per plant and first branch initiation height in all the environments (except in E4 for first branch
initiation height), whereas, moderate GCV and PCV were recorded for plant height, primary branches per plant, 1000-seed
weight, number of seeds per siliqua and harvest index in all the environments. Estimate of high heritability along with
high genetic advance as per cent of mean were observed for number of siliquae per plant, seed yield per plant, first
branch initiation height, plant height, number of primary branches per plant, 1000-seed weight, number of seeds per
siliqua and harvest index in all the environments. Likewise, siliqua length had high heritability along with moderate
genetic advance as per cent of mean considered for all the four environments. Thus, these characters might be under the
control of additive gene action and direct selection based on these traits could be advantageous.