Origins of Host-Specific Populations of the Blast Pathogen Magnaporthe oryzae in Crop Domestication With Subsequent Expansion of Pandemic Clones on Rice and Weeds of Rice
- 1 June 2005
- journal article
- Published by Oxford University Press (OUP) in Genetics
- Vol. 170 (2), 613-630
- https://doi.org/10.1534/genetics.105.041780
Abstract
Rice, as a widely and intensively cultivated crop, should be a target for parasite host shifts and a source for shifts to co-occurring weeds. Magnaporthe oryzae, of the M. grisea species complex, is the most important fungal pathogen of rice, with a high degree of host specificity. On the basis of 10 loci from six of its seven linkage groups, 37 multilocus haplotypes among 497 isolates of M. oryzae from rice and other grasses were identified. Phylogenetic relationships among isolates from rice (Oryza sativa), millet (Setaria spp.), cutgrass (Leersia hexandra), and torpedo grass (Panicum repens) were predominantly tree like, consistent with a lack of recombination, but from other hosts were reticulate, consistent with recombination. The single origin of rice-infecting M. oryzae followed a host shift from a Setaria millet and was closely followed by additional shifts to weeds of rice, cutgrass, and torpedo grass. Two independent estimators of divergence time indicate that these host shifts predate the Green Revolution and could be associated with rice domestication. The rice-infecting lineage is characterized by high copy number of the transposable element MGR586 (Pot3) and, except in two haplotypes, by a loss of AVR-Co39. Both mating types have been retained in ancestral, well-distributed rice-infecting haplotypes 10 (mainly temperate) and 14 (mainly tropical), but only one mating type was recovered from several derived, geographically restricted haplotypes. There is evidence of a common origin of both ACE1 virulence genotypes in haplotype 14. Host-haplotype association is evidenced by low pathogenicity on hosts associated with other haplotypes.Keywords
This publication has 90 references indexed in Scilit:
- Fungal trunk pathogens associated with wood decay of almond trees on Mallorca (Spain)Persoonia - Molecular Phylogeny and Evolution of Fungi, 2012
- Genetic Constitution and Pathogenicity of Lolium Isolates of Magnaporthe oryzae in Comparison with Host Species-Specific Pathotypes of the Blast FungusPhytopathology®, 2004
- Green revolution: the way forwardNature Reviews Genetics, 2001
- CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choiceNucleic Acids Research, 1994
- How clonal are bacteria?Proceedings of the National Academy of Sciences of the United States of America, 1993
- The Earliest Remains of Grasses in the Fossil RecordAmerican Journal of Botany, 1991
- Production of perithecia of Magnaporthe grisea on rice plantsMycological Research, 1990
- Interactions of two strains of Magnaporthe grisea with rice, goosegrass, and weeping lovegrassCanadian Journal of Botany, 1990
- Inheritance of Resistance toPyricularia oryzaein Rice Cultivars Grown in the United StatesPhytopathology®, 1987
- Dilatory Resistance to Rice Blast in USA RicePhytopathology®, 1983