Work

Combining ability, gene action and heterosis studies for yield improvement in rapeseed (Brassica napus L.)

Year: 2026

Type: article

Abstract: Rapeseed ( Brassica napus L.) is a key oilseed crop in Bangladesh, yet its yield remains below the global average. This study investigated combining ability, gene action, and heterosis for yield and related traits using a 5 × 5 full diallel among five parental lines. Significant genotypic variation was observed across all seven traits, confirming broad genetic diversity. Specific combining ability variance (σ 2 sca ) exceeded general combining ability variance (σ 2 gca ) for all traits, with σ 2 A /σ 2 D ratios below unity, confirming the predomination of dominance effects. Among the parents, NAP-0721-1 and BD-10109 emerged as strong general combiners for yield and its components. The hybrids BD-6951 × BD-7118 and NAP-0724 - 2 × NAP-0721 - 1 showed favorable GCA of parents, strong SCA effects, and superior per se performance for seed yield per plant (SY/P). Heterosis breeding proved effective, with crosses such as NAP-0724 - 2 × NAP-0721 - 1 , NAP-0724-2 × BD-7118 , and BD-10109 × NAP-0724–2 exhibiting significant positive heterosis over mid-parent, better-parent, and check variety means for SY/P. Overall, the findings provide critical insights into the genetic control of yield-related traits in B. napus , supporting targeted breeding strategies for yield enhancement and hybrid development.

Source: Discover Plants.

DOI: 10.1007/s44372-026-00584-2

Authors: Jaber Bin Azim, Noushin Chowdhury, Arif Hasan Khan Robin

Institution: Bangladesh Agricultural University

Language: English

Topic: Agricultural Practices and Plant Genetics

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: diamond

Funder: Bangladesh Agricultural University Research System