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

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.

Effect of Meiotic Polyploidisation on Selected Morphological and Anatomical Traits in Interspecific Hybrids of Brassica oleracea × B. napus

“…The ability for seed development was better after open pollination compared to self-pollination of F 1 hybrids. Similarly, the seed development in plants of F 1 × F 2 and BC 1 × F 1 /F 2 generations of B. oleracea × B. napus after pollination by the mixture of pollen was higher than that of F 1 and BC 1 (B. oleracea) generations [30].…”

“…Hybrids FC320 and FC230 were obtained by open crosses between plants of the F 1 generation. Interspecific hybrids were pollinated following the method described by Kami ński et al [29,30].…”

Pre-fertilization Barrier, Crossability and Meiotic Behavior of Interspecific Hybrids Among Brassica Species

“…It was reported in the literature that during evolution A and C genome had evolved from the same lineage while the B genome has taken a different route. That is why the B genome has showed low a nity with both the two genome (Kaminski et al, 2020).…”

Genetic Relationship of Brassicaceae Hybrids with Various Resistance to Blackleg Is Disclosed by the Use of Molecular Markers

“…Crossing the rapeseed with different species may help to enrich the B. napus germplasm and to enable the transfer of genome fragments carrying desirable traits, which could further improve the cultivar’s characteristics. The sexual incompatibility and differences in the genome sizes of parental components may result in hybridization failure [ 6 ]. Barriers of interspecific hybridization can be overcome by implementing in vitro techniques, including ovary, ovule, and embryo rescue [ 7 ].…”