Journal article

Publication year: 2021

Pages: 1242-1257

Journal: New Phytologist

Volume number: 230

Issue number: 3

ISSN: 0028-646X

eISSN: 1469-8137

DOI Link: https://doi.org/10.1111/nph.17225

Publisher: Wiley

Abstract: 

Many flowering plant taxa contain allopolyploids that share one or more genomes in common. In the Brassica genus, crop species Brassica juncea and Brassica carinata share the B genome, with 2n = AABB and 2n = BBCC genome complements, respectively. Hybridization results in 2n = BBAC hybrids, but the fate of these hybrids over generations of self-pollination has never been reported.

We produced and characterized B. juncea x B. carinata (2n = BBAC) interspecific hybrids over six generations of self-pollination under selection for high fertility using a combination of genotyping, fertility phenotyping, and cytogenetics techniques.

Meiotic pairing behaviour improved from 68% bivalents in the F-1 to 98% in the S-5/S-6 generations, and initially low hybrid fertility also increased to parent species levels. The S-5/S-6 hybrids contained an intact B genome (16 chromosomes) plus a new, stable A/C genome (18-20 chromosomes) resulting from recombination and restructuring of A and C-genome chromosomes.

Our results provide the first experimental evidence that two genomes can come together to form a new, restructured genome in hybridization events between two allotetraploid species that share a common genome. This mechanism should be considered in interpreting phylogenies in taxa with multiple allopolyploid species.

Harvard Citation style: Katche, E., Gaebelein, R., Idris, Z., Vasquez-Teuber, P., Lo, Y., Nugent, D., et al. (2021) Stable, fertile lines produced by hybridization between allotetraploids Brassica juncea (AABB) and Brassica carinata (BBCC) have merged the A and C genomes, New Phytologist, 230(3), pp. 1242-1257. https://doi.org/10.1111/nph.17225

APA Citation style: Katche, E., Gaebelein, R., Idris, Z., Vasquez-Teuber, P., Lo, Y., Nugent, D., Batley, J., & Mason, A. (2021). Stable, fertile lines produced by hybridization between allotetraploids Brassica juncea (AABB) and Brassica carinata (BBCC) have merged the A and C genomes. New Phytologist. 230(3), 1242-1257. https://doi.org/10.1111/nph.17225