Open Access

ARTICLE

Phenotypic Variation among and within Three Peppers Species (Capsicum) from Mexico

Carlos Eduardo Ornelas-Ramírez¹, Sergio Hernández-Verdugo^1,*, Jesús Enrique Retes-Manjarrez¹, Angel Valdez-Ortiz², Antonio Pacheco-Olvera¹, Tomás Osuna-Enciso³, Flor Porras¹

1 Facultad de Agronomía, Universidad Autónoma de Sinaloa, Culiacán, Sinaloa, 80000, México
2 Programa Regional de Posgrado en Biotecnología, Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Sinaloa, Culiacán, Sinaloa, 80030, México
3 Centro de Investigación en Alimentación y Desarrollo A.C. Unidad Culiacán, Culiacán, Sinaloa, 80110, México

* Corresponding Author: Sergio Hernández-Verdugo. Email:

Phyton-International Journal of Experimental Botany 2021, 90(1), 259-275. https://doi.org/10.32604/phyton.2020.012476

Received 01 July 2020; Accepted 31 August 2020; Issue published 20 November 2020

Abstract

The phenotypic variation and its distribution among species, morphotypes, and among and within populations was estimated in 71 populations pertaining to 15 morphotypes of three domesticated species of Capsicum from Mexico. Collections were made in the states of Sinaloa, Nayarit, Oaxaca, Tabasco, and Yucatán in two agroecosystems: Backyard-garden and monoculture. Fifteen phenotypic characteristics were analyzed through one-way variance analysis and multivariate analyses of principal components analysis (PCA) and hierarchical clustering using Ward’s method. The study was performed in a uniform greenhouse experiment. A high variation was found among and within populations in all the measured characteristics. Of the total variation, 13.0% was distributed among species, 27.9% among morphotypes, 8.1% among populations, and 51.0% within populations. Because plants grew in a uniform environment, these results indicate that the differences observed among and within species, morphotypes, and populations have a genetic basis. Univariate and multivariate analyses clearly differentiated morphotypes, suggesting that the category of morphotypes must be used to nominate the infraspecific variation in the domesticated Capsicum. The principal components analysis identified a total of 15 principal components that contributed to explain the total variation. The first two components explained 59.64% of the total variation and seven components explained more than 90% of the total variation. Among the measured characteristics, number of seed per fruit, weight of the fruit, width of the fruit, length of the fruit, stem diameter, days to flowering, and height of the plant contributed to component 1 variation, whereas width of the leaf, length of the leaf, and number of locules, number of fruits and number of seeds per plant contributed to component 2. The hierarchical clustering separated the populations and the morphotypes in two large different groups. One group consisted of populations collected in monoculture conditions and the other group corresponded to population collected from backyard-garden conditions. The monoculture populations were characterized mainly by their longer, wider, and higher weight fruits, plants were of less height, had smaller stem diameters, and lower number of fruits than the populations collected from the backyard-garden conditions. The backyard-garden populations of the Capsicum annuum and Capsicum frutescens species, considered wild or semi-domesticated, constituted a non-differentiated phenotypic group that does not allow dividing them in different species.

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