Development and Characteristics of Interspecific Hybrids between Brassica oleracea L. and B. napus L.

Piotr Kamiński,Elżbieta Starzycka-Korbas,Agnieszka Marasek-Ciolakowska,Michał Starzycki,Katarzyna Nowak,Małgorzata Podwyszyńska

doi:10.3390/agronomy10091339

Piotr Kamiński, Elżbieta Starzycka-Korbas + Show 4 more

Open Access

https://doi.org/10.3390/agronomy10091339

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Abstract

Interspecific hybridization between B. oleracea inbred lines of head cabbage, Brussels sprouts, kale and B. taurica and inbred lines of rapeseed (B. napus L.) were performed aiming at the development of the new sources of genetic variability of vegetable Brassicas. Using conventional crossings and the embryo-rescue techniques the following interspecific hybrids were developed: 11 genotypes of F1 generation, 18 genotypes of F2 and F1 × F2 generations (produced after self- and cross-pollination of interspecific F1 hybrids), 10 plants of the BC1 generation (resulted from crossing head cabbage cytoplasmic male-sterile lines with interspecific hybrids of the F2 and F1 generations) and 8 plants of BC1 × (F1 × F2). No viable seeds of the BC2 generation (B. oleracea) were obtained due to the strong incompatibility and high mortality of embryos. The morphological characteristics during the vegetative and generative stages, pollen characteristics, seed development and propagation, nuclear DNA contents and genome compositions of interspecific hybrids were analyzed. All the interspecific F1 hybrids were male-fertile with a majority of undeveloped and malformed pollen grains. They showed intermediate values for morphological traits and nuclear DNA contents and had nearly triploid chromosomal numbers (27 to 29) compared with parental lines. The F2 generation had a doubled nuclear DNA content, with 52 and 56 chromosomes, indicating their allohexaploid nature. F2 hybrids were characterized by a high heterosis of morphological characteristics, viable pollen and good seed development. F1 × F2 hybrids were male-fertile with a diversified DNA content and intermediate pollen viability. BC1 plants were male-sterile with an intermediate nuclear DNA content between the F2 and head cabbage, having 28 to 38 chromosomes. Plants of the BC1 × (F1 × F2) generation were in majority male-fertile with 38–46 chromosomes, high seed set, high heterosis and intermediate values for morphological traits. The obtained interspecific hybrids are valuable as new germplasm for improving Brassica-breeding programs.

Highlights

The genus Brassica includes a large number of widely distributed and economically important species that were domesticated to produce edible oil, vegetables, spices, forage crops and ornamental plants [1,2]
We aimed to develop new sources of genetic variability for the breeding of vegetable brassicas using the interspecific hybridization of B. oleracea inbred lines with rapeseed (B. napus)
Interspecific hybridization between B. oleracea and B. napus lines was performed for 10–30 opened flowers and green buds of maternal lines using the pollen of fertile paternal genotypes

Summary

Introduction

The genus Brassica includes a large number of widely distributed and economically important species that were domesticated to produce edible oil, vegetables, spices, forage crops and ornamental plants [1,2]. Many studies were reported on resynthesis of B. napus with the use of B. oleracea and B. rapa parents to expand the available gene pool [14]. Only a few studies reported improvement of B. oleracea through interspecific hybridization [15,16,17]

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