PAG-II Plant Genome II Conference

Town & Country Conference Center, San Diego, CA, January, 1994.


PG-II: MICROSATELLITE LENGTH POLYMORPHISM WITHIN ANCIENT WINE GRAPE CULTIVARS (VITIS VINIFERA L.)

MICROSATELLITE LENGTH POLYMORPHISM WITHIN ANCIENT WINE GRAPE CULTIVARS (VITIS VINIFERA L.)

John E. Bowers and Carole P. Meredith, Department of Viticulture and Enology, University of California, Davis, CA 95616.


Many of the classic wine varieties of Vitis vinifera L. are ancient. Within these varieties, sub-types ("clones") have been identified and maintained that possess distinct and desirable attributes. Because environmental and systemic virus effects have in most cases been ruled out, these differences are attributed to genetic divergence due to the accumulation of somatic mutations. Regions of the genome particularly amenable to a search for such divergence include microsatellite sequences, simple sequence repeats subject to length polymorphisms due to polymerase slippage during DNA replication. A genomic library of V. vinifera cv. Pinot noir was constructed and screened for poly-CT regions by hybridization with a synthetic CT, probe. Positive clones were sub-cloned if necessary to obtain inserts less than 700 bp. Positive clones were then sequenced and PCR primers were designed based on the sequences flanking the repeat region. The primers were then used to amplify genomic DNA from selected wine grapes. Forty-two positive clones were obtained and are now being sequenced and characterized. Of the first 11, the number of CT repeats ranged from 8 to 23. Six contained perfect repeats and two were compound repeats that included AT sequences. Primers flanking a (CT)13 locus were used to amplify genomic DNA of 11 varieties, revealing 8 alleles. Preliminary analyses of several clones each of the varieties Cabernet Sauvignon, Chardonnay, Zinfandel and Pinot noir revealed a single putative intra-variety polymorphism.


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