Morphological Diversity and Multivariate Classification of Chile de Árbol Collections from Chihuahua and Sinaloa, México

Abstract

The objective of this study was to characterize the morphological variability of chile de árbol collections from the regions of Chihuahua and Sinaloa and to evaluate their potential for use in breeding programs. A total of 20 collections were evaluated using fourteen quantitative morphological traits, including plant height, plant width, height of the first bifurcation, stem diameter, mature leaf width and length, corolla length, fruit length and width, fruit pedicel length, fruit wall thickness, number of fruits per plant, total fresh weight, and average fruit weight, following IPGRI descriptors. Morphological data were analyzed through analysis of variance, principal component analysis, and hierarchical clustering using R software. The analysis of variance revealed highly significant differences for most variables, demonstrating substantial phenotypic variation among the collections. Principal component analysis explained 64.7% of the total variation through three components associated with plant growth and reproductive structure, fruit characteristics, and leaf traits. The biplot distinguished three functional groups of collections aligned with fruit number, vegetative vigor, and fruit size attributes. Consistently, hierarchical clustering separated the twenty collections into four morphologically distinct groups, reflecting clear structural differentiation within the germplasm. These results highlight the presence of broad morphological diversity among chile de árbol materials from Chihuahua and Sinaloa, México. Overall, these findings demonstrate considerable variability within the germplasm and highlight the value of local materials as strategic resources for chile de árbol breeding, particularly for identifying high-yielding ideotypes that can be incorporated into future breeding efforts.