NBS-LRR TYPE RESISTANCE GENE ANALOGS (RGAS) FROM VITIS CINEREA, V. RUPESTRIS AND V. HYBRID 'HORIZON'

Resistance gene analogs (RGAs) were cloned from V. cinerea B9, V. rupestris B38 and 'Horizon' ('Seyval' x 'Schuyler'). Degenerate primers from the nucleotide-binding site/leucine-rich repeat (NBS-LRR) class of RGAs were used for PCR amplification of genomic DNA. A total of 48, 27 and 47 putative RGA sequences were cloned from V. cinerea B9, V. rupestris B38 and 'Horizon', and subdivided into 8, 4 and 7 clusters based on nucleic acid sequence-identity of 90% or greater, respectively. Sequence analysis of representatives of the 19 clusters suggested that 13 clusters contained a TIR domain and 6 contained a non TIR domain. All RGAs cloned from the three genotypes showed similarity to nucleotide sequences of other RGA clones from grape or other plant species. These 19 RGA sequences were developed into STS markers and are being investigated for their potential as markers for resistance to downy mildew in an interspecific cross between ‘Horizon’ and Illinois 547-1 (V. rupestris B38 x V. cinerea B9).