Development of Kale Pepper Breeding Lines with Superior Agronomic Characteristics
Abstract
This study was conducted to evaluate the local genetic resources of Kale pepper in terms of agronomic characteristics and to identify superior genotypes that could be used in breeding programs. A total of 26 different genotypes were collected from Kale district. The collected genotypes were grown in 2024 and 2025 according to a Randomized Complete Block Design (RCBD) with three replications and evaluated for a total of 23 agro-morphological traits in both growing seasons. Statistically significant differences among the genotypes were detected for the majority of the traits examined in both years. Based on the data obtained in 2024, the genotypes KB15, KB18, KB9, and KB4 exhibited the highest values for vitamin C content, antioxidant activity, total phenolic content, and titratable acidity, respectively. In 2025, the highest values for the same traits were recorded in genotypes KB21, KB10, KB9, and KB29, respectively. Principal Component Analysis (PCA) of the data sets revealed eight principal components with eigenvalues greater than 1.0 in both years. These components accounted for 83.81% of the total variance in 2024 and 84.54% in 2025. Examination of the scatter plots based on the first two principal components with the highest eigenvalues showed that genotypes KB6 and KB4 were distinctly separated from the other genotypes in 2024, whereas genotypes KB27 and KB4 showed distinct separation in 2025. The high proportion of total variance explained by the principal components, together with the distinct differences in genotype distribution, indicates the presence of substantial phenotypic variation within the evaluated material. This variation is considered an important genetic resource for the identification of genotypes with superior traits, selection of parental materials, and development of appropriate crossing combinations. Therefore, the findings of this study may contribute not only to the conservation and utilization of the local genetic resources of Kale pepper but also to breeding programs aimed at developing new cultivars.