Crossability and evaluation of incompatibility barriers in crosses between Capsicum species

Kellen Coutinho Martins,Rosana Rodrigues,Antônio Teixeira Do Amaral Junior,Telma Nair Santana Pereira,Sérgio Alessandro Machado Souza

doi:10.1590/1984-70332015v15n3a25

Kellen Coutinho Martins, Rosana Rodrigues + Show 3 more

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https://doi.org/10.1590/1984-70332015v15n3a25

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Abstract

The objectives of this study were to estimate the crossability rate in combinations of and assess the occurrence of incompatibility barriers between Capsicum species. The species C. annuum, C. chinense, C. frutescens, C. baccatum var. pendulum, and C. baccatum var. baccatum were crossed and the number of hand-pollinations and of resulting fruits and plants was registered. The resulting hybrids were evaluated for their pollen viability and in the crosses that produced no hybrids, the in vivo germination of pollen grains was assessed. Some crosses generated hybrids, while others produced no fruit or, despite generating fruits, no plants grew from them. The crossability rate between species of the complex C. annuumand C. baccatumranged from 2.2% to 3.7%, and was 14.6% between species of the complex C. annuum.A pre-fertilization barrier was observed in the non-germination of pollen grains, as well as post-fertilization barriers consisting of embryo death, lack of vigor and hybrid sterility

Highlights

Interspecific hybridizations allow a transfer of genes of interest between different species, especially those involved in disease resistance (Bosland and Votava 2000), allowing breeders to develop genetically superior genotypes
The crossability rate between species of the complex C. annuum and C. baccatum ranged from 2.2% to 3.7%, and was 14.6% between species of the complex C. annuum
A pre-fertilization barrier was observed in the non-germination of pollen grains, as well as post-fertilization barriers consisting of embryo death, lack of vigor and hybrid sterility

Summary

Introduction

Interspecific hybridizations allow a transfer of genes of interest between different species, especially those involved in disease resistance (Bosland and Votava 2000), allowing breeders to develop genetically superior genotypes. Incompatibility barriers in interspecific crosses may be expressed before fertilization in prezygotic barriers, and/ or after fertilization, in postzygotic barriers. Among the former we can cite the non-germination of pollen grains on the stigma of the receptor plant and a slow pollen tube growth towards the ovule, and among the latter embryo death caused by endosperm degeneration, a lack of vigor and plant sterility of the hybrid plant (Pickersgill 1991, 1992, 1997). The genus Capsicum comprises three gene complexes, formed on the basis of crossability between species: 1) Complex C. annuum, C. annuum (varieties annuum and glabriusculum): C. frutescens, C. chinense, C. chacoense and C. galapagoense (Pickersgill 1971, Zijlstra et al 1991); 2) Complex C. baccatum: C. baccatum (varieties baccatum, pendulum and praetermissum) (Pickersgill 1991, Zijlstra et al 1991) and C. tovarii (Tong and Bosland 1999); and 3) Complex C. pubescens: C. cardenasii, C. eximium and C. pubescens (Pickersgill 1991, Zijlstra et al 1991)

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