Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/12/2011
Publication Date: 1/16/2012
Citation: Roberts, P.A., Ulloa, M., Wang, C., Saski, C. 2012. Sequence composition and mapping of BACs of cotton homoeologous chromosomes 11 and 21. Plant & Animal Genome XX Conference, January 14 to 18, 2012, San Diego, CA. Paper No. 2165. Interpretive Summary:
Technical Abstract: Interest in cotton chromosome 11 and its homoeologous chromosome 21 derives from the discovery of resistance (R) or pathogen-induced R genes underlying QTLs involved in root-knot nematode, reniform nematode, Fusarium wilt, Verticillium wilt, and black root rot resistance. Genetic and QTL mapping efforts of nematode and pathogen resistance trait determinants, coupled with physical alignment of genomic regions into chromosomal maps will expedite this discovery. We have been using two tetraploid cotton (Gossypium hirsutum L.) BAC libraries for genetic and physical mapping of these two chromosomes. To identify BAC clones, BAC-end derived SSR markers which mapped to this genome region were used with the root-knot nematode susceptible cv. Acala Maxxa library. Currently 26 BACs from the Acala Maxxa library have been identified, completely sequenced and the sequences annotated. For the root-knot nematode resistant N901 (cv. Acala NemX) library, we screened it with additional SSR markers associated with determinants of root-knot nematode resistance, which mapped on the two chromosomes. So far 48 N901 BAC clones have been identified and fully sequenced. The assembled BAC sequences from both libraries have been annotated with a focus on resistance and defense gene and related classes. Similarly, annotation of all the other markers which mapped to these chromosome regions has been made. The BAC clone sequence information and genetic mapping of BACs are providing an enhanced genetic and physical framework of this resistance gene-rich region of the cotton genome, which will aid resistance gene discovery and whole genome assembly efforts, as well as breeding for resistance.