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

Abstract

The diversity in the Capsicum genus and the low number of ornamental pepper cultivars available have stimulate the development of breeding programs for this species. The study of segregating populations is important to obtain ornamental pepper cultivars. The objective of this work was to detect the variability in a F2 pepper population through principal component analysis (PCA) considering characters of interest of ornamental peppers and identify which variables affect the height of these ornamental plants through trail analysis. A crossing between two contrasting materials followed by self-fertilization of the F1 population was carried out and seven variables of ornamental interest were evaluated in 333 plants of the F2 generation. The evaluated variables were: mean fruit weight (MFW), mean fruit length (MFL), mean fruit diameter (MFD), mean peduncle length (MPL), mean pericarp thickness (MPT), plant height (PH), and flowering cycle (FC). The results were subjected to principal component analysis and trail analysis using PH as the base characteristic. The two first components explained 90% of the genetic variability of the population; PH and FC together reached 96.9%; and FC alone was responsible for 62.1%. The trail analysis showed that PH is more affected by the FC (24.35%) and MPL (16.6%); increases in these variables may increase PH. MFD presented a low-magnitude negative effect on the base variable (-1.99%). MFW, MFL, and MPT presented low effect on PH, 0.35%, 0.76%, and 7.06%, respectively. A genetic variability that can be explored in breeding programs was detected in the segregating population of ornamental pepper evaluated, mainly for FC and PH. Despite FC and MPL affect positively the plant height, this effect has a low magnitude.