Elucidating Genetic Variability of Brassica napus L. Progenitors and Their Crosses for Enhanced Qualitative Traits

Abstract

Evaluation of the breeding population is crucial for the selection of a superior genotype. Hence, the present study was conducted to assess genetic variation among five Brassica napus L. parents and their diallel hybrids to identify the best-performing parents and crosses. Heterosis and inbreeding depression were also assessed for the qualitative traits. Among the parental genotypes, Ancestor 2702 was identified as the best general combiner for protein (1.41%) and oleic acid content (1.21%). 2702×DUNCLED was the best specific combiner for oil content (0.78%), while 2702×2722 was recognized as best cross for linoleic acid content (1.3%). Similarly, DUNCLED×2702 was the best reciprocal cross for oil content (2.4%) and linoleic acid content (0.4 %), while P1-801×2702 was considered the best cross for protein content (2.2%) and oleic acid (1.7%). All the qualitative traits revealed a broad sense of heritability and non-additive type of gene action, which indicated the later generation selection for further improvement. High oleic acid content, preferred negative mid and best parent heterosis for erucic acid, glucosinolate and moisture contents was reported for 2702×DUNCLED. The favorable cross combination for protein and oil content was 2702×2722, which also yielded the positive mid and best parent heterosis. Inbreeding depression for qualitative traits ranged from -20.8% to 22.9%. It was concluded that among all the genotypes, accession 2702 was the best general, specific and reciprocal combiner, and the best parent heterosis for all traits when crossed with genotypes DUNCLED, P1-119 and 2722. It is also suggested that the screened crosses be carried to further generations to improve the quality related traits of Brassica napus. L.