Project/Area Number |
16405021
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 海外学術 |
Research Field |
Plant pathology
|
Research Institution | Tokyo University of Agriculture and Technology |
Principal Investigator |
ARIE Tsutomu Tokyo University of Agriculture and Technology, INSTITUTE OF SYMBIOTICSCIENCEAND TECHNOLOGY, ASSOCIATE PROFESSOR (00211706)
|
Co-Investigator(Kenkyū-buntansha) |
TERAOKA Tohru TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY, INSTITUTE OF SYMBIOTIC SCIENCE AND TECHNOLOGY, PROFESSOR (60163903)
KODAMA Motoichiro TOTTORI UNIVERSITY, FACULTY OF AGRICULTURE, PROFESSOR (00183343)
|
Project Period (FY) |
2004 – 2007
|
Project Status |
Completed (Fiscal Year 2007)
|
Budget Amount *help |
¥14,270,000 (Direct Cost: ¥13,100,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2007: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2006: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2005: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2004: ¥2,700,000 (Direct Cost: ¥2,700,000)
|
Keywords | plant / fungi / evolution / plant pathology / symbiosis / pathogenicity / phylogeny / field survey / フィールド / 植物病原菌 / 宿主植物 / 共進化 / トマト / 野生種 / 育種史 / Fusarium / Alternaria |
Research Abstract |
When and where did plant pathogenic fungi generate pathogenicity?' and 'How has pathogenicity been evolved in plant pathogenic fungi?' are important questions in plant pathology. In order to give evidences to answer these questions, we focused mainly on the coevolution between Lycopersicon spp. (tomatoes) and Fusarium oxysporum, the wilt pathogen of tomato in this study. During the four research years, we visited Ecuador where we could find wild L. pimpinellifolium and L. cheesmanii, Mexico where domestication of tomato occurred more than 2000 years ago and still we can find prototype edible tomato (L. esculentum), L. esculentum vars. ceraciforme and creole, and Naples in Italy where modern breeding of edible tomatostarted in 16th century, collected tissues from symptomless Lycopersicon spp. and rhizosphere soil, and isolated Fusarium oxysporum from the tissues and the soil. All of the isolates showed no pathogenicity on tomatoes by inoculation test and were supposed to be non-pathogenic symbionts. Phylogenetic analysis against the isolates based on rDNA-IGS revealed that non-pathogenic F. oxysporum isolates from wild Lycopersicon spp. carried no phylogenetic relationship with the pathogenic strains (F. oxysporum f. sp. lycopersici). On the other hand, some of the non-pathogenic F. oxysporum isolates from Mexican prototype tomatoes and Italian edible tomatoes showed close relationship between the pathogen. These suggested that the ancient of the present wilt pathogen was the non-pathogenic symbiont which emerged during the domestication of tomato in Mexico. The non-pathogenic E oxysporum have got pathogenicity to tomato during the modern breeding and distribution after 16th century. Now, worldwide trading of tomato fruits and seeds distributes not only the symbiotic non-pathogenic E oxysporum but also F. oxysporum f. sp. lycopersici, the wilt pathogen of tomato.
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