Genetic mapping and chromosomal assignment of Magnaporthe oryzae avirulence genes AvrPik, AvrPiz, and AvrPiz-t controlling cultivar specificity on rice

• Published in: Phytopathology Vol. 95; no. 6; pp. 640 - 647
• Main Authors: Luo, C.X, Yin, L.F, Koyanagi, S, Farman, M.L, Kusaba, M, Yaegashi, H
• Format: Journal Article
• Language: English
• Published: St. Paul, MN American Phytopathological Society 01.06.2005
• Subjects: Biological and medical sciences; chromosome mapping; cultivars; Fundamental and applied biological sciences. Psychology; fungal diseases of plants; Fungal plant pathogens; genes; genetic markers; host specificity; Magnaporthe; Magnaporthe oryzae; Oryza sativa; pathogenicity; Phytopathology. Animal pests. Plant and forest protection; plant pathogenic fungi; random amplified polymorphic DNA technique; rice; strain differences; virulence; Genetic mapping; Monocotyledones; Plant pathology; Microbiology; Plant pathogen; Chromosome; avirulence; Random amplified polymorphic DNA marker; Cereal crop; Fungi; Magnaporthe; Oryza sativa; Specificity; Gene; Gramineae; Angiospermae; Genetics; Isolate; Ascomycetes; Spermatophyta; Southern blotting; Thallophyta; Cultivar
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/PHYTO-95-0640

A genetic map including three avirulence (Avr) genes, AvrPik, AvrPiz, and AvrPiz-t, was constructed in a genetic cross of two rice field isolates, 84R-62B and Y93-245c-2. The chromosomal locations of the Avr genes were determined by using selected markers to probe Southern blots of the parental chromosomes that had been separated by contour-clamped homogenous electric fields electrophoresis. Electrophoretic karyotyping showed that both parental isolates 84R-62B and Y93-245c-2 contained seven chromosomes greater than 3.5 megabases (Mb) in size and 84R-62B possessed a small chromosome of approximately equal to 1.6 Mb. The linkage groups containing AvrPiz and AvrPiz-t were assigned to chromosomes 3 and 7, respectively. Some markers from the linkage group that contained AvrPik hybridized with chromosome 1 and the 1.6-Mb chromosome, yet all of the cloned RAPD markers that were closely linked to AvrPik hybridized exclusively to the 1.6-Mb chromosome in 84R-62B, the parent that possesses AvrPik. Thus, we conclude that AvrPik is located on the 1.6-Mb chromosome in 84R-62B.