Construction Of A Bacterial Artificial Chromosome Library Of Brassica Napus And Selection Of The Clones Linked To Boron Efficiency Gene (BE1)

The bacterial artificial chromosome (BAG) library is the basic tool for the genome research. It is important for the genome physical mapping, genome sequence, and map-based gene clone.The Brassica is the most important oil crop. Brussica species are closely related to the small cruciferous plant Arabidopsis thaliana. Comparative genetics showed that the Brassica species and Arabidopsis contain conserved chromosomal regions in their genome. The sequence of Arabidopsis will provide a powerful tool for the Brassica research in the genetic map, gene cloning.As a micronutrient, boron is of important role in the structure, function and metabolic actively of plant cell. In our lab, a major boron efficiency gene named BE] was located on the LG9 between the marker pa28c and tg2h10b in one Brassica napus genetic map. In order to clone the boron efficiency gene, a BAG library was constructed for Brassica napus. The library contains 82944 clones with an average DNA insert size of 80kb, which represents 5.1 Brassica napus haploid genome equivalents. Screening the library with the DNA marker (PA28), which linked to the Boron efficiency gene (BE1), identified 13 positive clones. Hybridizing the total plant DNA with PA28, four groups in the boron-efficiency cuItivar-Ning RS-1 were detected. Three of 13 clones (13E3, 32G8, 186G20) are identified to linked to the Boron efficiency gene locus by hybridization. These clones were constructed a contig by fingerprinting. 13E3, 32G8 were selected to subclone. Some of subclones were selected randomly to sequence and the results were compared with the Arabidopsis sequence in TAIR by Blast. The collinear was found between them. It provides a proof to make use of the message of Arabidopsis for cloning the BEL...