| Project/Area Number |
17580288
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Boundary agriculture
|
|---|
| Research Institution | Shinshu University |
|---|
Principal Investigator |
KUGA Yukari Shinshu University, Faculty of Agriculture, Associate Professor (30232747)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,710,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
|
|---|
| Keywords | Dark sentate endonhvte / Field grown lettuce / Arbuscular mvcorrhiza / Lettuce root rot / Phylozeny / Biological control / Induced systemic resistance / Colonization process / 植物根部内生糸状菌 / 誘導抵抗性 / アーバスキュラー菌根菌 / ポリリン酸 / 根部エンドファイト / 菌類 / 菌根 / Dark septate endophyte |
|---|
| Research Abstract |
Fungal root endophytes were studied with regard to their potential use as biological control agents against lettuce mot rot (pathogen: F. oxysporum f. sp. Iactucae; Fol). Studies were initiated using field-grown lettuce in Kawakami village, Nagano prefecture; where colonization rates of dark septate endophytes (DSE) were often much lower than those of arbuscular mycorrhizal fungi (AMF). Colonization frequencies of DSEs, however, were higher than those of AMF. Although AMF colonization rate was negatively correlated with the amount of available phosphorus, none of the soil chemical properties studied correlated to the colonization rate of DSEs. One dominant DSE morphotype (Type-a), was found to exist consistently in 2 experimental years examined. Phylogenetic analysis using rDNA sequence data showed type-a fungi form a sister clade with fungi in the Order Lulworthiales (Sorclariomycetes). Closely related DSE morphotypes were also isolated from Japanese pear tree roots and mountain soil baited with lettuce seedlings. A root box inoculation method showed a high affinity of type-a to lettuce roots: colonization of type-a in lettuce roots occurred 1 day after inoculation(dai), intracellular microsclemtia formation occurred 3 dai, and 100% colonization rate occurred 5 dai Papilla were formed in lettuce root tissues inoculated with either Fol, or non-pathogenic F oxysporum isolated from a lettuce root, a phenomenon which was not observed by type-a colonization. Biological control effects were different among type-α isolates used. Gene expression related to induced systemic resistance (ISR:MAPK, PDF and VSP) and systemic acquired resistance (SAR: PR1a) in lettuce plants colonized with type-a in the roots and challenge inoculated with Erwinia soft-rot bacteria on the leaves were analyzed by quantitative RTPCR. The results indicated that type-a may stimulate ISR but not SAR.
|
