title: Extraction of the Constituent Subgenomes of the Natural Allopolyploid Rapeseed (Brassica napus L.).
abstract: As the dynamic nature of progenitor genomes accompanies the speciation by interspecific hybridization, the extraction of the constituent subgenome(s) from a natural allopolyploid species of long history and then restitution of the progenitor(s) provides the unique opportunity to study the genome evolution and interplay. Herein, the A subgenome from the allotetraploid oilseed rape (Brassica napus L., AACC) was extracted through inducing the preferential elimination of C-subgenome chromosomes in intertribal crosses and the progenitor B. rapa was restituted (RBR). Then by crossing and backcrossing RBR with B. napus donor, the C subgenome was in situ dissected by adding each of its nine chromosomes to the extracted A subgenome and establishing the whole set of monosonic alien addition lines (MAALs). RBR from spring-type B. napus genotype "Oro" expressed a phenotype resembling some type of B. rapa never observed before, but showed a winter-type flowering habit. This RBR had weaker growth vigor and suffered more seriously from biotic and abiotic stresses compared with Oro. The phenotypes specific for these MAALs showed the location of the related genes on the particular C-subgenome chromosomes. These MAALs exhibited obviously different frequencies in homeologous pairing and transmission of additional C-subgenome chromosomes, which were associated with the distinct degrees of their relatedness, and even with the possible genetic regulation for meiotic pairing evolved in B. napus Finally, large scaffolds undetermined for sequence assembly of B. napus were anchored to specific C-subgenome chromosomes using MAALs.
authors.affiliation: National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Crop Research Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, People's Republic of China.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Tu
authors.affiliation: National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
authors.forename: Pan
authors.initials: P
authors.lastname: Zeng
authors.affiliation: National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
authors.forename: Xianhong
authors.initials: X
authors.lastname: Ge
authors.affiliation: National Key Lab of Crop Genetic Improvement, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China lizaiyun@mail.hzau.edu.cn.
authors.forename: Zaiyun
authors.initials: Z
authors.lastname: Li
mesh_terms: D029741:Brassica rapa / Q000235:genetics*; D018745:Genome, Plant; D007178:Inbreeding; D010641:Phenotype; D011123:Polyploidy
keywords: B. rapa; Brassica napus; alien additional lines; allopolyploid; aneuploid