Abstract
A genetic cross between a Triticum isolate (pathogenic on wheat) and a Setaria isolate (pathogenic on foxtail millet) of Magnaporthe oryzae yielded several F1 cultures that were virulent on both wheat and foxtail millet at the primary leaf stage. To estimate whether these cultures survive in nature, they were sprayed onto 1-, 2-, and 3-week-old wheat and foxtail millet. As the age of the inoculated plants increased, the lesion number and size were greatly reduced. The F1 cultures were almost nonpathogenic on both wheat and foxtail millet at the 3-week-old stage. Cytological analysis revealed that the low pathogenicity of the F1 cultures on older plants was primarily associated with a reduced ability to penetrate the cuticle. When placed on wounded leaf surfaces, the F1 cultures produced large lesions on 4-week-old wheat and foxtail millet. These results indicate that hybridization between species-specific pathotypes results in a reduction of aggressiveness. We therefore suggest that, even if such hybrids were produced in nature, they might not survive in the natural environment.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
I Chuma Y Tosa M Taga H Nakayashiki S Mayama (2003) ArticleTitleMeiotic behavior of a supernumerary chromosome in Magnaporthe oryzae Curr Genet 43 191–198 Occurrence Handle12764669 Occurrence Handle1:CAS:528:DC%2BD3sXjvFClurg%3D
FG Chumley B Valent (1990) ArticleTitleGenetic analysis of melanin-deficient, nonpathogenic mutants of Magnaporthe grisea Mol Plant Microbe Interact 3 135–143 Occurrence Handle1:CAS:528:DyaK3MXmslGmtL4%3D
BC Couch LM Kohn (2002) ArticleTitleA multilocus gene genealogy concordant with host preference indicates segregation of a new species, Magnaporthe oryzae, from M. grisea Mycologia 94 683–693 Occurrence Handle1:CAS:528:DC%2BD38XmsVWlsLk%3D
JC de Jong BJ McCormack N Smirnoff NJ Talbot (1997) ArticleTitleGlycerol generates turgor in rice blast Nature 389 244–245 Occurrence Handle1:CAS:528:DyaK2sXmtFGjt7c%3D Occurrence Handle10.1038/38418
N Hayashi H Kato (1998) ArticleTitleViability and aggressiveness of Pyricularia cultures preserved by silica gel-drying grain method (in Japanese) Proc Kanto-Tosan Plant Prot Soc 35 12–13
U Hiura (1978) Genetic basis of formae speciales in Erysiphe graminis DC DM Spencer (Eds) The powdery mildews Academic London 101–128
RJ Howard MA Ferrari (1989) ArticleTitleRole of melanin in appressorium formation Exp Mycol 13 403–418 Occurrence Handle1:CAS:528:DyaK3cXntlCqsA%3D%3D Occurrence Handle10.1016/0147-5975(89)90036-4
RJ Howard MA Ferrari DH Roach NP Money (1991) ArticleTitlePenetration of hard substrates by a fungus employing enormous turgor pressures Proc Natl Acad Sci USA 88 11281–11284 Occurrence Handle1837147 Occurrence Handle1:CAS:528:DyaK38XhtVamurY%3D Occurrence Handle10.1073/pnas.88.24.11281
K Ikeda H Nakayashiki T Kataoka H Tamba Y Hashimoto Y Tosa S Mayama (2002) ArticleTitleRepeat-induced point mutation (RIP) in Magnaporthe grisea: implications for its sexual cycle in the natural field context Mol Microbiol 45 1355–1364 Occurrence Handle12207702 Occurrence Handle1:CAS:528:DC%2BD38XntFGktbg%3D Occurrence Handle10.1046/j.1365-2958.2002.03101.x
S Kang JA Sweigard B Valent (1995) ArticleTitleThe PWL host specificity gene family in the blast fungus Magnaporthe grisea Mol Plant Microbe Interact 8 939–948 Occurrence Handle8664503 Occurrence Handle1:CAS:528:DyaK28XitFahsg%3D%3D
H Kato M Yamamoto T Yamaguchi-Ozaki H Kadouchi Y Iwamoto H Nakayashiki Y Tosa S Mayama N Mori (2000) ArticleTitlePathogenicity, mating ability and DNA restriction fragment length polymorphisms of Pyricularia populations isolated from Gramineae, Bambusideae, and Zingiberaceae plants J Gen Plant Pathol 66 30–47 Occurrence Handle1:CAS:528:DC%2BD3cXktFSgsrs%3D Occurrence Handle10.1007/PL00012919
J Kumar RJ Nelson RS Zeigler (1999) ArticleTitlePopulation structure and dynamics of Magnaporthe grisea in the Indian Himalayas Genetics 152 971–984 Occurrence Handle10388817 Occurrence Handle1:STN:280:DyaK1MzhvVygsQ%3D%3D
J Murakami Y Tosa T Kataoka R Tomita J Kawasaki I Chuma Y Sesumi M Kusaba H Nakayashiki S Mayama (2000) ArticleTitleAnalysis of host species specificity of Magnaporthe grisea toward wheat using a genetic cross between isolates from wheat and foxtail millet Phytopathology 90 1060–1067
J Murakami R Tomita H Nakayashiki Y Tosa S Mayama (2003) ArticleTitleAnalysis of host species specificity of Magnaporthe grisea toward foxtail millet using a genetic cross between isolates from wheat and foxtail millet Phytopathology 93 42–45 Occurrence Handle1:CAS:528:DC%2BD3sXksV2jtw%3D%3D
H Nakayashiki N Nishimoto K Ikeda Y Tosa S Mayama (1999) ArticleTitleDegenerate MAGGY elements in a subgroup of Pyricularia grisea: a possible example of successful capture of a genetic invader by a fungal genome Mol Gen Genet 261 958–966 Occurrence Handle10485287 Occurrence Handle1:CAS:528:DyaK1MXlvFyiur8%3D Occurrence Handle10.1007/s004380051044
H Nakayashiki H Matsuo I Chuma K Ikeda S Betsuyaku M Kusaba Y Tosa S Mayama (2001) ArticleTitlePyret, a Ty3/Gypsy retrotoransposon in Magnaporthe grisea contains an extra domain between the nucleocapsid and protease domains Nucleic Acids Res 29 4106–4113 Occurrence Handle11600699 Occurrence Handle1:CAS:528:DC%2BD3MXotlWgsL8%3D Occurrence Handle10.1093/nar/29.20.4106
HS Oh Y Tosa N Takabayashi S Nakagawa R Tomita LD Don M Kusaba H Nakayashiki S Mayama (2002) ArticleTitleCharacterization of an Avena isolate of Magnaporthe grisea and identification of a locus conditioning its specificity on oat Can J Bot 80 1088–1095 Occurrence Handle10.1139/b02-101
MJ Orbach FG Chumley B Valent (1996) ArticleTitleElectrophoretic karyotypes of Magnaporthe grisea pathogens of diverse grasses Mol Plant Microbe Interact 9 261–271 Occurrence Handle1:CAS:528:DyaK28XivVaitrw%3D
EU Selker (1997) ArticleTitleEpigenetic phenomena in filamentous fungi: useful paradigms or repeat-induced confusion Trends Genet 13 296–301 Occurrence Handle9260514 Occurrence Handle1:CAS:528:DyaK2sXlt1Gguro%3D Occurrence Handle10.1016/S0168-9525(97)01201-8
T Sone T Abe N Yoshida M Suto F Tomita (1997) ArticleTitleDNA fingerprinting and electrophoretic karyotyping of Japanese isolates of rice blast fungus Ann Phytopathol Soc Jpn 63 155–163 Occurrence Handle1:CAS:528:DyaK2sXmsF2ju7k%3D
JA Sweigard AM Carroll S Kang L Farrall FG Chumley B Valent (1995) ArticleTitleIdentification, cloning, and characterization of PWL2, a gene for host species specificity in the rice blast fungus Plant Cell 7 1221–1233 Occurrence Handle7549480 Occurrence Handle1:CAS:528:DyaK2MXnvVWnuro%3D Occurrence Handle10.1105/tpc.7.8.1221
N Takabayashi Y Tosa HS Oh S Mayama (2002) ArticleTitleA gene-for-gene relationship underlying the species-specific parasitism of Avena/Triticum isolates of Magnaporthe grisea on wheat cultivars Phytopathology 92 1182–1188
NJ Talbot (2003) ArticleTitleOn the trail of a cereal killer: exploring the biology of Magnaporthe grisea Annu Rev Microbiol 57 1575–1588 Occurrence Handle10.1146/annurev.micro.57.030502.090957
NJ Talbot YP Salch M Ma JE Hamer (1993) ArticleTitleKaryotypic variation within clonal lineages of the rice blast fungus, Magnaporthe grisea Appl Env Micro 59 585–593 Occurrence Handle1:CAS:528:DyaK3sXhsVehsbo%3D
Y Tosa K Hirata H Tamba S Nakagawa I Chuma C Isobe J Osue AS Urashima LD Don M Kusaba H Nakayashiki A Tanaka T Tani N Mori S Mayama (2004) ArticleTitleGenetic constitution and pathogenicity of Lolium isolates of Magnaporthe oryzae in comparison with host species-specific pathotypes of blast fungus Phytopathology 94 454–462 Occurrence Handle1:CAS:528:DC%2BD2cXkt1Sitr8%3D
B Valent FG Chumley (1991) ArticleTitleMolecular genetic analysis of the rice blast fungus, Magnaporthe grisea Annu Rev Phytopathol 29 443–467 Occurrence Handle1:CAS:528:DyaK38XlsFWmsg%3D%3D Occurrence Handle10.1146/annurev.py.29.090191.002303
JE Vanderplank (1984) Disease resistance in plants EditionNumber2nd edn Academic London
H Yaegashi (1978) ArticleTitleInheritance of pathogenicity in crosses of Pyricularia isolates from weeping lovegrass and finger millet Ann Phytopathol Soc Jpn 44 626–632
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Murakami, J., Thi, V., Hau, B. et al. Reduction in aggressiveness among hybrids between host-specific pathotypes of Magnaporthe oryzae is caused by reduced ability to overcome adult resistance at the level of penetration. J Gen Plant Pathol 72, 284–291 (2006). https://doi.org/10.1007/s10327-006-0284-x
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s10327-006-0284-x