Determining the inheritance of agronomic traits in chili pepper

Cíntia S Bento,Artur M Medeiros,Cláudia P Sudré,Leandro Sa Gonçalves,Rosana Rodrigues,Vinícius As Mathias

doi:10.1590/s0102-05362016003010

Cíntia S Bento, Artur M Medeiros + Show 4 more

Open Access

https://doi.org/10.1590/s0102-05362016003010

Copy DOI

Abstract

ABSTRACT The Capsicum genus is widely studied in many countries but most of research focuses on C. annuum. Although its importance as potential genetic resource for breeding to disease resistance and fruit quality, studies on genetics and breeding in C. baccatum var. pendulum are still scarce and it still remains as an underexploited crop. This paper aimed to study the inheritance of agronomic characteristics, to estimate the genetic parameters for seven agronomic traits in C. baccatum var. pendulum, using generation mean analysis and to verify the existence of major genes and polygenes with additive and non-additive effects, using the method of maximum likelihood with the aid of Monogen software. The agronomic traits evaluated were: number of fruits per plant (NFP); average fruit mass per plant (AFM); fruit length (FRL); fruit diameter (FRD); fruit pulp thickness (FPT); soluble solids content (SSC) and fruit dry mass (FDM). There was a significant difference among generations (P1, P2, F1, F2, BC1 and BC2) for all traits evaluated. Narrow sense heritability estimates ranged from 45% for NFP to 75% for FRD. By estimating the average degree of dominance (ADD), we found that partial dominance is the gene action involved in the genetic control for FRL and FRD, while additive effect was observed for NFP, FPT and SSC, complete dominance for FDM and overdominance for AFM. The additive-dominant model was sufficient to explain the results obtained for all evaluated traits. Maximum likelihood method identified the existence of polygenes with additive and dominance effects in SSC, FPT and FDM. Major gene effect was identified for FRL and NFP characteristics. The results indicated the complexity of the inheritance of these traits with the presence of major gene involved.

Highlights

O gênero Capsicum é amplamente estudado em muitos países, porém a maioria das pesquisas se concentra em C. annuum
15 cultivars were registered in the National Registry of Cultivars (Registro Nacional de Cultivares - RNC) of the Ministry of Agriculture, Livestock and Food Supply of Brazil (MAPA, 2013), with the majority belonging to private seed companies that lack of Capsicum breeding programs in the country (Rodrigues et al, 2012)
Obtaining adequate information on the nature and magnitude of the gene effects of these characteristics is of major importance for the identification of the most suitable method to be applied in the selection and prediction of responses of segregating generations for the development of cultivars of C. baccatum var. pendulum

Summary

Introduction

O gênero Capsicum é amplamente estudado em muitos países, porém a maioria das pesquisas se concentra em C. annuum. 15 cultivars were registered in the National Registry of Cultivars (Registro Nacional de Cultivares - RNC) of the Ministry of Agriculture, Livestock and Food Supply of Brazil (MAPA, 2013), with the majority belonging to private seed companies that lack of Capsicum breeding programs in the country (Rodrigues et al, 2012). Characteristics such as productivity, resistance and/or tolerance to biotic and abiotic stresses, plant architecture, earliness, ripe fruit persistence, as well as characteristics related to fruit quality are the targets of Capsicum breeding programs (Rêgo et al, 2011; Rodrigues et al, 2012). Obtaining adequate information on the nature and magnitude of the gene effects of these characteristics is of major importance for the identification of the most suitable method to be applied in the selection and prediction of responses of segregating generations for the development of cultivars of C. baccatum var. pendulum

Objectives

Methods

Results