Genetic variability in Brazilian Capsicum baccatum germplasm collection assessed by morphological fruit traits and AFLP markers.

Rafaella Cardoso,Leandro S A Gonçalves,Rosa L Barbieri,Eduardo A Ruas,Claudete F Ruas,Rosana Rodrigues,Renata M Giacomin,Paulo M Ruas

doi:10.1371/journal.pone.0196468

Abstract

Capsicum baccatum is one of the main pepper species grown and consumed in South America. In Brazil, it is commonly cultivated by family farmers, using mostly the genotypes bishop's hat genotypes (locally cambuci) and red chili pepper (dedo-de-moça). This study had the objective of characterizing 116 C. baccatum accessions from different regions of Brazil, based on morphological fruit descriptors and AFLP (Amplified Fragment Length Polymorphisms) markers. Broad phenotypic variability among the C. baccatum accessions was detected when using morphological fruit descriptors. The Ward modified location model (Ward-MLM) discriminated five groups, based mainly on fruit shape. Six combinations of AFLP primers detected polymorphism in 97.93% of the 2466 identified bands, indicating the high genetic variability in the accessions. The UPGMA coincided with the Bayesian clustering analysis and three large groups were formed, separating the wild variety C. baccatum var. praetermissum from the other accessions. There was no relation between genetic distance and geographical origin of the accessions, probably due to the intense exchange of fruits and seeds between farmers. Morphological descriptors used together with AFLP markers proved efficient in detecting the levels of genetic variability among the accessions maintained in the germplasm collections. These results can be used as an additional source of helpful information to be exploited in C. baccatum breeding programs.

Highlights

The genus Capsicum (Solanaceae) is native to the tropical zones of Central and South America, and was one of the first genera to be domesticated, around 6000 B.C. [1]
The center of origin of this species is Bolivia and Southern Peru [5,6], and it is divided into four botanical varieties: the domesticated C. baccatum var. pendulum and wild C. baccatum var. baccatum, C. baccatum var. praetermissum, and C. baccatum var. umbilicatum [5,7]
After 30 days, the seedlings were planted in a protected cultivation area of Universidade Estadual de Londrina (UEL), Londrina, Parana, Brazil

Summary

Introduction

The genus Capsicum (Solanaceae) is native to the tropical zones of Central and South America, and was one of the first genera to be domesticated, around 6000 B.C. [1]. The genus comprises approximately 38 described species, with great morphological variation, mainly in terms of fruit color, size, shape and levels of pungency [2]. Among the domesticated peppers species, C. baccatum is one of the most important in South America, cultivated mainly in plains and medium elevations of Argentina, Bolivia, Peru, Ecuador, Paraguay, Colombia, Chile, and in many different biomes in Brazil [4]. The center of origin of this species is Bolivia and Southern Peru [5,6], and it is divided into four botanical varieties: the domesticated C. baccatum var. The center of origin of this species is Bolivia and Southern Peru [5,6], and it is divided into four botanical varieties: the domesticated C. baccatum var. pendulum and wild C. baccatum var. baccatum, C. baccatum var. praetermissum, and C. baccatum var. umbilicatum [5,7]

Objectives

Methods

Conclusion