Genetic parameters and simultaneous selection using traits of ornamental interest in pepper plants

Abstract

Pepper plants of the genus Capsicum are widely grown worldwide. The Capsicum annuum species shows ornamental potential; nevertheless, in the state of Piauí, there has been a lack of studies on its performance, related to quality traits needed to meet market demand. The aim of this study was to estimate the genetic parameters and associations between traits of ornamental interest in C. annuum in order to indicate, by simultaneous selection of traits, accessions to start an ornamental pepper breeding program in Piauí. We evaluated 16 accessions of C. annuum under plastic house conditions at Universidade Federal do Piauí. Number of days to flowering, number of days to fruit maturation, plant height, number of fruits per plant, fruit persistence, fruit length, fruit width, leaf length and fruit weight were evaluated. A significant difference (p≤0.01) between accessions for all traits was noticed. Coefficient of genetic variation / coefficient of experimental variation [Cvg/Cve (%)] ratios were greater than 1 and the genotypic determination coefficient (H²) values were all greater than 89.95%. The estimates of the genotypic correlations were higher in relation to phenotypic correlations in most of the traits, however, according to path analysis, an effect of residual variable (0.59) was verified. According to the results, the accessions BAGC 98, 199, 207 and 236 can be used as parents to start an ornamental pepper breeding program in Piauí.

Atributos genéticos dos frutos de pimenteira ornamental para seleção

“…Estes coeficientes, possuem um papel importante nos programas de melhoramento, oferecendo uma análise da influência relativa dos fatores genéticos e ambientais na variação das características fenotípicas (KAROLINA et al, 2020). Os resultados obtidos podem direcionar a seleção dos melhores indivíduos, de forma acurada, otimizando a eficácia dos programas de melhoramento Tabela 1.…”

Genetic variability and interaction between variables of ornamental interest in a segregating pepper population

“…Low coefficient of determination (9.5%) and high residual effect (95%) were found in the trail analysis. Acevedo et al (2020) estimated direct and indirect effects of six agronomic characteristics, including number of days for maturation, fruit length and width, and number of fruits per pepper plant (C. annuum) and found high residual effect (79%). Salla et al (2015) found low coefficient of determination (12%) and high residual effect (93%) for the evaluated characteristics of Plinia cauliflora plants, with similar values to those found in the present study.…”

“…Despite of these low values, the explanatory variables did not need to be totally discarded due to low direct effect on the base variable; thus, an alternative is the use of selection indexes that can provide information on favorable gains in many characteristics (Cruz et al, 2014;Acevedo et al, 2020). Mulamba and Mock (1978) is among these selection indexes; it ranks the genotypes for each characteristic by attributing higher absolutes values to those of better performance and, then, the values attributed to each characteristic are summed, obtaining the sum of the ranks, which determines the genotype classification (Cruz & Regazzi, 2001).…”

“…Knowing the correlations between ornamental characteristics facilitates the search for new genotypes. It is important when some characteristics are difficult to measure, late expressed in the phenotype, or have low heritability, as in the case of number of pepper fruits per plant (Moreira, Kuhlcamp, Barros, Oliveira & Trindade, 2018;Acevedo et al, 2020) and plant height of ornamental pepper. Plant height present polygenic heritage, mean heritability, and late measurement; thus, other variable with high correlation with it can be used to facilitate the selection.…”

Temporal forecasting of plant height and canopy diameter from RGB images using a CNN-based regression model for ornamental pepper plants (Capsicum spp.) growing under high-temperature stress

“…high temperature) (T. dos S. Ferreira The size of the pepper plant in the pot is one of the main quality attributes observed by the ornamental plant sector and not every pepper plant can be considered ornamental. The desired ideotype includes, among other factors, the harmony between the plant and the pot given by the balance between plant height and canopy diameter in relation to the size of the pot used (Acevedo et al, 2020;do Rêgo & do Rêgo, 2018). Very tall plants with a wider crown do not adapt well to the pot, resulting mainly in the plants tipping over.…”