PAG-X  Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Large Insert Libraries
            

CONSTRUCTION AND CHARACTERIZATION OF FIVE LARGE-INSERT BAC AND BIBAC LIBRARIES OF Aegilops tauschii, THE DIPLOID DONOR OF THE WHEAT D GENOME

ZHANYOU XU1* , Karin R. Deal2* , Wanlong Li3* , Lina Covaleda1 , Yueh-Long Chang1 , Jan Dvorak2 , Ming-Cheng Luo2 , Bikram S. Gill3 , Olin D. Anderson4 , Hong-Bin Zhang1

1 Department of Soil and Crop Sciences and Institute for Plant Genomics and Biotechnology, 2123 TAMUS, Texas A & M University, College Station, TX 77843-2123, USA
2 Department of Agronomy and Range Sciences, University of California, Davis, CA 95616, USA
3 Department of Plant Pathology, Kansas State University, 4024 Throckmorton Plant Sciences Center, Manhattan, KS 66506, USA
4 USDA/ARS, 800 Buchanan St., Albany, CA 94710, USA
* Co-senior authors

Common wheat, Triticum aestivum, is an allohexaploid (genomes AABBDD). The D genome is the smallest of the three, about 4,000 Mb/1C. The D genome was contributed by the diploid Aegilops tauschii. Cytogenetic studies showed that the chromosomes of Aegilops tauschii are completely homologues with those of the wheat D genome. Nei's genetic distances between the D genome of T. aestivum `Chinese Spring' and 165 accessions of Ae. tauschii were computed. Accession AL8/78 of ssp. strangulata collected in Armenia was found to be the most closely related to the D genome of `Chinese Spring' and was selected for the construction of large DNA fragment libraries and physical mapping of the D-genome. DNA fragments were inserted into the Hind III, Bam HI and Eco RI sites of BAC vector pECBAC1 and Hind III and Bam HI sites of Agrobacterium-transformation ready BIBAC vector pCLD04541. The Eco RI BAC library contains ca. 54,000 clones, Hind III BAC library ca. 59,000 clones, Hind III BIBAC library ca. 52,000 clones, Bam HI BAC library ca. 59,000 clones, and Bam HI BIBAC library ca. 76,000 clones with average sizes of inserts 167, 189, 190, 149, and 174 kb, respectively. The combined five libraries contain a total of ca. 300,000 clones, equivalent to >13x haploid D genomes. A total of 200,000 clones are being fingerprinted to construct BAC contigs and physical maps of the D-genome chromosomes and 80,000 clones are being used for integration of wheat ESTs and other mapped markers into the contigs.

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