A complex recombination pattern in the genome of allotetraploid Brassica napus as revealed by a high-density genetic map

Guangqin Cai; Qingyong Yang; Bin Yi; Chuchuan Fan; David Edwards; Jacqueline Batley; Yongming Zhou

doi:10.1371/journal.pone.0109910

A complex recombination pattern in the genome of allotetraploid Brassica napus as revealed by a high-density genetic map

PLoS One. 2014 Oct 30;9(10):e109910. doi: 10.1371/journal.pone.0109910. eCollection 2014.

Authors

Guangqin Cai¹, Qingyong Yang², Bin Yi², Chuchuan Fan², David Edwards³, Jacqueline Batley³, Yongming Zhou¹

Affiliations

¹ National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China; Key Laboratory of Rapeseed Genetics and Breeding of Agriculture Ministry of China, Huazhong Agricultural University, Wuhan, China.
² National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
³ School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland, Australia.

Abstract

Polyploidy plays a crucial role in plant evolution. Brassica napus (2n = 38, AACC), the most important oil crop in the Brassica genus, is an allotetraploid that originated through natural doubling of chromosomes after the hybridization of its progenitor species, B. rapa (2n = 20, AA) and B. oleracea (2n = 18, CC). A better understanding of the evolutionary relationship between B. napus and B. rapa, B. oleracea, as well as Arabidopsis, which has a common ancestor with these three species, will provide valuable information about the generation and evolution of allopolyploidy. Based on a high-density genetic map with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers, we performed a comparative genomic analysis of B. napus with Arabidopsis and its progenitor species B. rapa and B. oleracea. Based on the collinear relationship of B. rapa and B. oleracea in the B. napus genetic map, the B. napus genome was found to consist of 70.1% of the skeleton components of the chromosomes of B. rapa and B. oleracea, with 17.7% of sequences derived from reciprocal translocation between homoeologous chromosomes between the A- and C-genome and 3.6% of sequences derived from reciprocal translocation between non-homologous chromosomes at both intra- and inter-genomic levels. The current study thus provides insights into the formation and evolution of the allotetraploid B. napus genome, which will allow for more accurate transfer of genomic information from B. rapa, B. oleracea and Arabidopsis to B. napus.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brassica napus / genetics*
Chromosomes, Plant / genetics*
Genome, Plant / physiology*
Polymorphism, Single Nucleotide*
Recombination, Genetic / physiology*
Tetraploidy*

Grants and funding

The work is financially supported by funding from the Ministry of Agriculture of China (nycytx-00503 and 948 project (2011-G23)), National Natural Science Foundation of China (31371659, 31171188), and Huazhong Agricultural University (STSIF 2010YB05). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.