| Project/Area Number |
14360028
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物保護
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| Research Institution | Kyoto University |
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Principal Investigator |
FUJISAKI Kenji Kyoto University, Graduate School of Agriculture, Prof., 農学研究科, 教授 (10228976)
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| Co-Investigator(Kenkyū-buntansha) |
TSUMUKI Hisaaki Okayama Univ., Research Institute for Bioresources, Prof., 資源生物科学研究所, 教授 (60033255)
YOSHIDA Hideya Okayama Univ., Research Institute for Bioresources, Assistant, 資源生物科学研究所, 助手 (90220665)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥9,000,000 (Direct Cost: ¥9,000,000)
Fiscal Year 2004: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2003: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2002: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Helicoverpa armigera / Helicoverpa assulta / pupal diapause / geographical cline / subtropical insects / cold hardiness / trehalose / global warming / 休眠性 / 地理的変異 / 遺伝子発現 / 発生予察 / 休眠蛹 / 亜熱帯個体群 / 気候適応 / 休眠誘導 / 日長 / 温度 / 休眠覚醒 / 地理的勾配 |
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| Research Abstract |
The pupal diapause of the cotton bollworm, Helicoverpa armigera, was investigated. The results obtained are summarized as follows.
1.Photoperiodic response of pupal diapause was investigated at lower temperature of 18℃. The diapause was induced under short day length conditions and its tendency was greater in males.
2.The diapause induction under seminatural conditions was compared between H.armigera and H.Assulta. In H.armigera, some individuals could overwinter as diapausing pupae, although many individuals died before pupation with advance in the fall season. On the other hand, in H.assulta, pupal diapause was induced even at high temperatures in summer season. These results indicated that the adaptation to temperate climate is inadequate in H.armigera.
3.No clear geographical cline in diapause tendency was detected It was supposed that pupal diapause is induced when larvae were exposed to lower temperatureds for a long time in fall season of subtropical region.
4.It was estimated that the sensitive stage to day-length in pupal diapause is the 5th instar.
5.Only the diapausing pupae are supposed to overwinter in the region where average winter temperatures are higher than 0℃. The trehalose was seemed to be responsible for the cold hardiness.
6.It was indicated that nonadditive interactions among multiple loci are influential on the diapause rate. Moreover, it was found that there is a genetic correlation between larval period and diapause.
From these results, it was concluded that H.armigera is fully possible to spread its distribution and increase its abundance in Japan with progress in the global warming.
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