Hybrids between Brassica napus and B. nigra show frequent pairing between the B and A/C genomes and resistance to blackleg.

Autor: Gaebelein R; Department of Plant Breeding, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany., Alnajar D; Plant Pathology and Crop Protection Division, Department of Crop Sciences, Georg-August University Göttingen, Grisebachstraße 6, 37077, Göttingen, Germany., Koopmann B; Plant Pathology and Crop Protection Division, Department of Crop Sciences, Georg-August University Göttingen, Grisebachstraße 6, 37077, Göttingen, Germany., Mason AS; Department of Plant Breeding, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany. Annaliese.Mason@agrar.uni-giessen.de.
Jazyk: angličtina
Zdroj: Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology [Chromosome Res] 2019 Sep; Vol. 27 (3), pp. 221-236. Date of Electronic Publication: 2019 Jul 06.
DOI: 10.1007/s10577-019-09612-2
Abstrakt: High frequencies of homoeologous and even non-homologous chromosome recombination in Brassica hybrids can transfer useful traits between genomes, but also destabilise synthetic allopolyploids. We produced triploid hybrids (2n = 3x = ABC) from the cross B. napus (rapeseed, 2n = 4x = AACC) × B. nigra (black mustard, 2n = 2x = BB) by embryo rescue and allohexaploid hybrids (2n = 6x = AABBCC = 54) by chromosome doubling of the triploids. These hybrids demonstrated resistance to blackleg disease (causal agent: Leptosphaeria maculans) inherited from their B. nigra parent. In order to assess the possibility of transfer of this resistance between the B genome and the A and C subgenomes of B. napus, as well as to assess the genomic stability of allohexaploids from the cross B. napus × B. nigra, frequencies of non-homologous chromosome pairing in these hybrids were assessed using classical cytogenetics and genomic in-situ hybridization. Meiosis was highly irregular, and non-homologous chromosome pairing between the B genome and the A/C genomes was common in both triploid hybrids (observed in 38% of pollen mother cells) and allohexaploid hybrids (observed in 15% of pollen mother cells). Our results suggest that introgression of blackleg resistance from the B genome into the A or C genomes should be possible, but that allohexaploids from this genome combination are likely unstable.
Databáze: MEDLINE
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