Morphological and yield trait-based evaluation and selection of chili (Capsicum annuum L.) genotypes suitable for both summer and winter seasons

Abstract

Chili (Capsicum annuum L.) is one of the most important vegetable cum spice crops grown throughout the world. Evaluation of genotypes based on morphological and yield contributing traits provides the opportunity to assess variability and select superior genotypes. The present investigation was carried out from April 2018 to November 2018 in the summer season and from December 2018 to June 2019 in the winter season in a net house and field, respectively, in the Department of Genetics and Plant Breeding, Patuakhali Science and Technology University, Patuakhali, Bangladesh. A set of 30 qualitative and 13 quantitative characteristics developed by Biodiversity International were recorded to evaluate the genotypes for morphological and yield-contributing traits. The estimated Shannon–Weaver diversity for qualitative traits ranged from 0 to 1.334, where the maximum diversity was recorded for fruit color at an intermediate stage, stem color after transplanting, fruit surface, stigma position, calyx margin shape, and fruit set, while the minimum diversity (H′ = 0) was observed for the traits corolla shape and anthocyanin spots, indicating no diversity of these traits. Thirteen quantitative traits were also analyzed for the selection of the genotypes with the greatest yield. The quantitative traits also exhibited a wide range of variability according to descriptive statistics and analysis of variance. Moreover, the present study revealed a high heritability for almost all of the quantitative traits, which was confirmed by the values of genotypic coefficient of variation, phenotypic coefficient of variation, h 2 b, and GA for both the summer and winter seasons. This suggests that these traits are predominantly governed by additive genes, making them highly amenable to effective selection. The heatmap analysis based on the morphological quantitative traits revealed five clusters for both the summer and winter seasons for the studied chili genotypes, four distinct clusters in the summer season, and three distinct clusters in the winter season for the parameters studied. Using the multi-trait genotype–ideotype distance index based on multiple trait information, the genotypes R-06, R-07, C0525-2, BARI (Bangladesh Agricultural Research Institute) Morich-2, Tengakhali, and Rcy 002 were selected as promising for both the summer and winter seasons. Hence, they are recommended for commercial cultivation or use as parent materials in future breeding for the development of new cultivars adaptable to climate change.