Genetic stability of Magnaporthe oryzae during successive passages through rice plants and on artificial medium

Sook Young Park, Myoung Hwan Chi, Michael G. Milgroom, Hyojung Kim, Seong Sook Han, Seogchan Kang, Yong Hwan Lee

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Genetic instability of the rice blast fungus Magnaporthe oryzae has been suggested as a major factor underlying the rapid breakdown of host resistance in the field. However, little information is available on the mechanism of genetic instability. In this study, we assessed the stability of repetitive DNA elements and several key phenotypic traits important for pathogenesis after serially transferring two isolates though rice plants and an artificial medium. Using isolate 70-15, we obtained a total of 176 single-spore isolates from 10 successive rounds of culturing on artificial medium. Another 20 isolates were obtained from germ tubes formed at the basal and apical cells of 10 three-celled conidia. Additionally, 60 isolates were obtained from isolate KJ201 after serial transfers through rice plants and an artificial medium. No apparent differences in phenotypes, including mycelial growth, conidial morphologies, conidiation, conidial germination, appressorium formation, and virulence, or in DNA fingerprints using MGR586, MAGGY, Pot2, LINE, MG-SINE and PWL2 as probes were observed among isolates from the same parent isolate. Southern hybridization and sequence analysis of two avirulence genes, AVR-Pita1 and AVR-Pikm, showed that both genes were also maintained stably during 10 successive generations on medium and plants. However, one reversible loss of restriction fragments was found in the telomere-linked helicase gene (TLH1) family, suggesting some telomere regions may be more unstable than the rest of the genome. Taken together, our results suggest that phenotype and genotype of M. oryzae isolates do not noticeably change, at least up to 10 successive generations on a cultural medium and in host plants.

Original languageEnglish (US)
Pages (from-to)313-320
Number of pages8
JournalPlant Pathology Journal
Volume26
Issue number4
DOIs
StatePublished - Dec 1 2010

Fingerprint

Magnaporthe oryzae
genetic stability
telomeres
rice
phenotype
appressoria
blast disease
genes
germ tube
DNA fingerprinting
Southern blotting
conidia
virulence
host plants
pathogenesis
sequence analysis
spores
germination
fungi
genome

All Science Journal Classification (ASJC) codes

  • Agronomy and Crop Science

Cite this

Park, Sook Young ; Chi, Myoung Hwan ; Milgroom, Michael G. ; Kim, Hyojung ; Han, Seong Sook ; Kang, Seogchan ; Lee, Yong Hwan. / Genetic stability of Magnaporthe oryzae during successive passages through rice plants and on artificial medium. In: Plant Pathology Journal. 2010 ; Vol. 26, No. 4. pp. 313-320.
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Genetic stability of Magnaporthe oryzae during successive passages through rice plants and on artificial medium. / Park, Sook Young; Chi, Myoung Hwan; Milgroom, Michael G.; Kim, Hyojung; Han, Seong Sook; Kang, Seogchan; Lee, Yong Hwan.

In: Plant Pathology Journal, Vol. 26, No. 4, 01.12.2010, p. 313-320.

Research output: Contribution to journalArticle

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