Submitted to: Plant Genome Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/14/1996
Publication Date: N/A
Technical Abstract: A Magnaporthe grisea cultivar specificity gene toward rice cultivar CO39 was previously mapped to one arm of chromosome 1 between RFLP markers CH5- 120H and 5-10-F(Smith, J.R. and S.A.Leong.1993.Theor.Appl.Genet. 88:901- 908). These RFLP markers map 11.6 and 17.2 cM respectively, on either side of AVRCO39.Using Achilles' cleavage methods CH5-120H and 5-10-F were shown to be separated by 600 kb. A chromosome walk to avrCO39 was initiated fro these flanking RFPL markers. Over 500 kb have been covered in 20 walking steps. Cosmid clones cosegregating with AVRCO39 have been identified and selected clones obtained from the walk were shown to confer avirulence on rice variety CO39 but not 51583 when introduced by transformation into the virulent M.grisea strain Guy11. The DNA conferring avirulence has been delimited to a 7.2 kb region. Preliminary hybridization studies to DNA of the virulent M. grisea strain Guy11 using portions of the 7.2 kb region suggest that an alternate allele is not present, or if present, has undergone extensive mutation.