Heritability of Morphological and Yield Traits in F2 Populations of Jalapeño Pepper

Abstract

Aims: The objective of this study was to evaluate F₂ populations of jalapeño peppers by estimating genetic parameters for morphological and yield characteristics. Study Design: Seven jalapeño pepper entries were evaluated using a randomized complete block design with four replications. Statistical analyses were conducted in R. Genetic parameters were estimated from phenotypic and genotypic variances, coefficients of variation, and broad-sense heritability. Genetic correlations among quantitative traits were determined using linear mixed models, with block as a fixed effect and genotype as a random effect. Models were fitted by the REML method to obtain Best Linear Unbiased Predictors, from which correlations were calculated. Place and Duration of Study: The experiment was conducted at the experimental fields of the Universidad Autónoma Agraria Antonio Narro. The study was carried out from March to September 2024. Methodology: Seeds from seven jalapeño pepper genotypes collected in Chihuahua, Mexico, were disinfected and sown in trays using a peat moss–perlite–humus substrate before transplantation. Results: The results show genetic variability among jalapeño genotypes for most fruit traits. Fruit length, width, and wall thickness showed high heritability, indicating strong genetic control, while fruit number, weight, and yield per plant had low heritability, reflecting environmental influence. The genotype Ori had the highest yield, Bal produced the most fruits, and Mix had the widest, heaviest fruits with thicker walls. Strong positive correlations were found between fruit width and wall thickness and between wall thickness and fruit weight, while negative correlations were observed between fruit width and fruit number. Conclusion: The F₂ jalapeño populations showed genetic variability, with Bal, Mix, and Ori standing out for fruit size and yield. High heritability in fruit traits and strong environmental effects on yield indicate good potential for developing new genotypes.