title: Characterization of interploid hybrids from crosses between Brassica juncea and B. oleracea and the production of yellow-seeded B. napus.
abstract: Yellow-seeded Brassica napus was for the first time developed from interspecific crosses using yellow-seeded B. juncea (AABB), yellow-seeded B. oleracea (CC), and black-seeded artificial B. napus (AACC). Three different mating approaches were undertaken to eliminate B-genome chromosomes after trigenomic hexaploids (AABBCC) were generated. Hybrids (AABCC, ABCC) from crosses AABBCC × AACC, AABBCC × CC and ABCC × AACC were advanced by continuous selfing in approach 1, 2 and 3, respectively. To provide more insight into Brassica genome evolution and the cytological basis for B. napus resynthesis in each approach, B-genome chromosome pairing and segregation were intensively analyzed in AABCC and ABCC plants using genomic in situ hybridization methods. The frequencies at which B-genome chromosomes underwent autosyndesis and allosyndesis were generally higher in ABCC than in AABCC plants. The difference was statistically significant for allosyndesis but not autosyndesis. Abnormal distributions of B-genome chromosomes were encountered at anaphase I, including chromosome lagging and precocious sister centromere separation of univalents. These abnormalities were observed at a significantly higher frequency in AABCC than in ABCC plants, which resulted in more rapid B-genome chromosome elimination in the AABCC derivatives. Yellow or yellow-brown seeds were obtained in all approaches, although true-breeding yellow-seeded B. napus was developed only in approaches 2 and 3. The efficiency of the B. napus construction approaches was in the order 1 > 3 > 2 whereas this order was 3 > 2 > 1 with respect to the construction of yellow-seeded B. napus. The results are discussed in relation to Brassica genome evolution and the development and utilization of the yellow-seeded B. napus obtained here.
authors.affiliation: National Key Lab of Crop Genetic Improvement, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhu
authors.forename: Liping
authors.initials: L
authors.lastname: Qi
authors.forename: Hongmei
authors.initials: H
authors.lastname: Ke
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Ma
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
mesh_terms: D000705:Anaphase / Q000235:genetics; D001937:Brassica / Q000235:genetics*; D029688:Brassica napus / Q000235:genetics*; D023902:Chromosome Pairing; D020090:Chromosome Segregation / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics; D003433:Crosses, Genetic; D018745:Genome, Plant / Q000235:genetics; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D009149:Mustard Plant / Q000235:genetics*; D010858:Pigmentation / Q000235:genetics; D011058:Pollen / Q000235:genetics; D011123:Polyploidy; D012639:Seeds / Q000235:genetics / Q000254:growth & development*