Genetic Variation and Association Analysis for Fruit Yield, Agronomic and Quality Characters in Bell Pepper

Abstract

Knowledge of the magnitude of genetic variability for marketable fruit yield and quality traits, and relationships among these traits, is needed to improve quality breeding in bell pepper (Capsicum annuum L. var. grossum Sendt.). The study was undertaken to assess genetic variation for marketable fruit yield, fruits per plant, average fruit weight, pericarp thickness, number of lobes per fruit, TSS, and ascorbic acid and capsaicin contents and to quantify the relationship among these traits in diverse bell pepper germplasm. Significant difference among bell pepper genotypes indicated presence of significant variation for all the traits. The phenotypic coefficient of variation (PCV) indicated higher values than genotypic coefficient of variation (GCV) for all traits, indicating close association between phenotype and genotype. High heritability estimates along with high genetic advance was recorded for fruits per plant, marketable fruits per plant, pericarp thickness, and lobes per fruit, indicating the role of additive gene action for their inheritance. Days to 50% flowering, harvest duration, and ascorbic acid had high heritability estimates along with low genetic advance, indicating nonadditive gene activity, and these could be improved through hybridization. In general, genotypic correlations were higher than the corresponding phenotypic correlations, revealing inherent associations among traits. The maximum direct effect on fruit yield per plant was exhibited by fruit per plant followed by harvest duration, average fruit weight, and pericarp thickness, whereas marketable fruits per plant and days to 50% flowering had negative direct effects. This suggests that a selection procedure based on higher fruits per plant, harvest duration, and average fruit weight may be effective in improving fruit yield. Adequate genetic variability was present within available bell pepper germplasm to allow breeding improvement of marketable yield and quality traits.