Genetic divergence between pepper accessions based on quantitative fruit traits

Abstract

The development of new Capsicum cultivars aiming to meet market requirements will depend, above all, on the genetic diversity of the study population. To quantify this genetic divergence, several multivariate techniques assessing quantitative traits have been employed. This study aimed to: i. estimate the genetic diversity among Capsicum chinense accessions from the Active Germplasm Bank of Plants of the Federal University of Viçosa (BGH-UFV); ii. indicate promising accessions for prospective studies of specific market niches; iii. evaluate the disposal of redundant traits. The experiment was conducted in a completely randomized design with four replicates, in which 11 C. chinense accessions were evaluated, based on 11 quantitative fruit traits. The data were subjected to cluster analysis by the UPGMA and Tocher methods, based on the quadratic Euclidean distance, to assess diversity. Afterwards, we used principal component analysis, Jolliffe's method and procrustes analysis for the disposal of traits. The highest genetic dissimilarity was obtained between accessions 2 and 10. The phenotypic correlation coefficients obtained were 0.75 (UPGMA) and 0.91 (Tocher), the latter being significant by the Mantel test (p < 0.05). Six clusters were formed by using the Tocher method, four of which were composed by a single accession. Regarding the disposal of variables, traits TFDW, TFFW, PUN, %DM, FW, PT, and FL were shown to be disposable, and do not affect diversity prediction in terms of graphic dispersion. Accessions 9, 10, and 11 are indicated for in natura consumption, while accessions 2 and 3 are indicated for industrial purposes. These accessions showed the best results among the evaluated traits for the mentioned niches.

Morpho-Agronomic Characterization, Sample Size, and Plot Size for the Evaluation of Capsicum chinense Genotypes

“…The PCA results showed that among the variables analyzed those with the most significance greater than 5% were FTSh (6.32%), MFC (7.41%), FSH (10.51%), CCS (11.56%) and IFC (49.49%). For Capsicum breeding, crosses between genetically divergent genotypes are recommended and it is desirable that both parents are high yielding and complementary in terms of fruit quality traits [15,30]. In this case, the characterization of "pimenta-de-cheiro" C. chinense genotypes and their allocation in different clusters, based on multivariate analyses will be important to guide future crosses.…”

“…For an effective use of genetic resources, genes of interest for genetic breeding, their adequate characterization, evaluation, and documentation are essential, as are studies that elucidate the genetic basis of the selection target trait directed towards the establishment of efficient strategies in breeding programs [14][15][16][17]. The characterization of genotypes with recommended descriptors can provide studies of sampling, selection, and hybridization to define adequate strategies for the conservation and genetic breeding of C. chinense.…”