高倉 耕一 (タカクラ コウイチ)

TAKAKURA Koichi

写真a

職名

准教授

学内職務経歴 【 表示 / 非表示

  • 滋賀県立大学  環境科学部  生物資源管理学科  准教授   2014年04月 ~ 現在

 

論文 【 表示 / 非表示

  • Reproductive interference between two serious pests, oriental fruit flies Bactrocera carambolae and B. dorsalis (Diptera: Tephritidae), with very wide but partially overlapping host ranges

    Kitano D., Fujii N., Sujiono, Yamaue S., Kitamura T., Honma A., Tsukada M., Nishida T., Sawada H., Takakura K.

    Applied Entomology and Zoology  Applied Entomology and Zoology  53 (4)   525 ~ 533  2018年11月

    10.1007/s13355-018-0584-6  共著  

    [概要]

    © 2018, The Japanese Society of Applied Entomology and Zoology. Bactrocera carambolae and B. dorsalis (Diptera: Tephritidae) are extremely destructive pests of fruits and vegetables in the Asia-Pacific region. Earlier reports have described that B. carambolae and B. dorsalis, respectively, use mainly star fruit and mango, suggesting a certain level of host partitioning which can be ascribed neither to differences in larval food qualities nor host-specific parasitoid mortality. This study specifically examined reproductive interference (antagonistic sexual interaction) between B. carambolae and B. dorsalis as a potential factor strongly affecting their host partitioning. We observed mating behaviors, especially interspecific courtships and mating, by cohabiting the conspecific and heterospecific pairs together. Consequently, we quantified their effects on the reproductive success of females. Males of both species frequently courted their own females, but they also courted females of other species. Courtship refusal by females was not selective in males of either species. This incomplete discrimination of both sexes led to frequent occurrences of interspecific sexual interactions in both species, but only B. carambolae females showed reduced reproductive success. These results suggest that B. dorsalis, superior in reproductive interference, can occupy high-quality mango, whereas B. carambolae, inferior in reproductive interference, must use low-quality star fruit.

  • Does simultaneous and sympatric reproduction between two native spined loaches lead to reproductive interference and local extinction?

    Morii K., Nakano M., Takakura K.

    Environmental Biology of Fishes  Environmental Biology of Fishes  101 (9)   1407 ~ 1416  2018年09月

    10.1007/s10641-018-0787-2  共著  

    [概要]

    © 2018, Springer Nature B.V. Reproductive interference occurs when fitness of females of one species decreases because of misdirected courtship behaviors by males of another species. Reproductive interference strongly excludes either species in the interaction but it does not persist for long on an evolutionary time scale. Therefore, reproductive interference between a pair of co-evolved native species is difficult to observe because exclusion ends the interaction even if even the potential for reproductive interference still exists. However, anthropogenic environmental changes can bring about secondary contact between two species and trigger reproductive interference, leading to local species extinction. We demonstrated this phenomenon with two native spined loaches: Cobitis magnostriata (Cmag) and C. minamorii oumiensis (Cmio). In 2015 and 2016, we investigated the spatiotemporal dynamics of adults and juveniles of both species to estimate the effects of the relative abundance of adults on reproductive success. Additionally, we surveyed the distribution of juveniles and investigated the proportion of gravid females which failed to reproduce at the end of the spawning season. In 2016, Cmio juveniles were fewer than in 2015, although the abundances of Cmio adults were similarly low in both years and the Cmag adults were more abundant in 2016 than in 2015. The juveniles of the two species exhibited similar spatiotemporal dynamics. At the end of the spawning season, Cmag males were abundant and most Cmio females failed to reproduce. These results suggest that the two species share spawning habitats and seasons and that Cmag males exert reproductive interference on Cmio females. This report is the first of a study suggesting that anthropogenic environmental changes triggered reproductive interference between native species in the field.

  • Skewed male reproductive success and pollen transfer in a small fragmented population of the heterodichogamous tree Machilus thunbergii

    Watanabe S., Takakura K., Kaneko Y., Noma N., Nishida T.

    Journal of Plant Research  Journal of Plant Research  131 (4)   623 ~ 631  2018年07月

    10.1007/s10265-018-1018-9  共著  

    [概要]

    © 2018, The Botanical Society of Japan and Springer Japan KK, part of Springer Nature. Heterodichogamy is defined as the presence of two flower morphs that exhibit the male and female functions at different times among individuals within a population. Heterodichogamy is regarded as an adaptation to promote outcrossing through enhanced inter-morph mating, together with a 1:1 morph ratio. However, in highly fragmented populations, the morph ratio may be more likely to be biased by stochastic events. In such a situation, individuals of a minority morph within a population are expected to have higher reproductive success than those of a majority morph, which may suffer from pollen shortages of the minority morph. In this paper, we evaluated mating patterns and male reproductive success in a highly fragmented population of Machilus thunbergii, a putative heterodichogamous evergreen laurel tree. Results of paternity analysis indicated that the selfing rate was not clearly different between the two morphs. In contrast, the proportion of intra-morph mating was higher in the majority-morph (MM) mother trees than in the minority-morph (MF) mother trees. Bayesian estimated male reproductive success indicated that male reproductive success was higher in minority-morph (MF) than in majority-morph (MM) mother trees. These findings indicate that (1) the majority morph mothers, suffering a shortage of the opposite morph pollen, could partly compensate for the reduced reproductive success by intra-morph mating rather than by selfing, and (2) negative-frequency dependent selection may be involved in the maintenance of the two morphs.

  • Age class structure of spawning populations of two endangered endemic striated spined loaches in Lake Biwa river system.

    Morii K, Takakura KI

     Japanese Journal of Environmental Entomology and Zoology  29   135 ~ 141  2018年

    単著  共同(副担当)

  • Growth patterns of juveniles observed at a shared spawning site in two closely related species of spined loaches endemic to the Lake Biwa riverine system; Cobitis magnostriata and C. minamorii oumiensis

    Morii K,Nakano M, Nishida T, Takakura KI

     Japanese Journal of Environmental Entomology and Zoology    2018年

    共著  共同(副担当)

  • 滋賀県彦根市の水田地帯に生息するカヤネズミの食性分析-糞DNA分析からの推定

    畠 佐代子・高倉耕一

     環動昆  28   121 ~ 131  2017年

    共著  共同(副担当)

  • 琵琶湖につながる小規模水域におけるオオクチバスMicropterus salmoides小型個体の性成熟

    北野大輔・曽我部共生・佐竹祐亮・高倉耕一

     保全生態学研究  22   345 ~ 349  2017年

    共著  共同(副担当)

  • Skewed male reproductive success and pollen transfer in a small fragmented population of the heterodichogamous tree Machilus thunbergii.

    Shuntaro Watanabe, Koh‑Ichi Takakura, Yuko Kaneko, Naohiko Noma, Takayoshi Nishida

     Journal of Plant Research    2017年

    共著  共同(副担当)

  • A Bayesian approach for estimating hexabromocyclododecane (HBCD) diastereomer compositions in water using data below limit of quantification

    Ichihara M., A. Yamamoto, M. Sudo, K.I. Takakura

     Environmental Science and Pollution Research  24 (3)   2667 ~ 2674  2017年

    共著  共同(副担当)

  • 絶滅危惧種タチスズシロソウ(Arabidopsis kamchatica ssp. kawasakiana)個体群の個体数推定

    小杉 亜希, 高倉 耕一, 野間 直彦, 河邊 昭, 原田 英美子

     地域自然史と保全  38 (1)   51 ~ 59  2016年06月

    共著  共同(副担当)

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会議での講演 【 表示 / 非表示

  • タイワンシジミの生息と水路の物理環境との関係、およびイシガイ類への影響

    第63回日本生態学会  2016年03月

  • 琵琶湖水系産オイカワの遺伝的構造 ―”清流の女王”はなぜ止水域にも生息するのか―

    第63回日本生態学会  2016年03月

  • おいしいよ。でも食べないでーイラガのまゆ模様による捕食回避戦略ー

    日本昆虫学会第76回大会・第60回日本応用動物昆虫学会大会合同大会  2016年03月

  • 在来昆虫類が駆動する繁殖干渉と外来種問題

    日本昆虫学会第76回大会・第60回日本応用動物昆虫学会大会合同大会  2016年03月

  • 琵琶湖固有スジシマドジョウ種群の入れ替わり~希少種が希少種に脅かされる?~

    第63回日本生態学会  2016年03月

  • イモゾウムシ個体数密度の寄主植物による違い−ベイズ統計モデリングによる解析−

    第63回日本生態学会  2016年03月

  • イラガのまゆの模様とサイズは枝太さで決まる

    第63回日本生態学会  2016年03月

  • ありふれた雑草ホトケノザの送粉者はありふれていない

    第63回日本生態学会  2016年03月

  • 簡便かつ安価な環境 DNA 抽出・検出法

    第27回日本環境動物昆虫学会年次大会  2015年11月

  • インドネシア・ジャワ島における主要害虫ミバエ 2 種の寄主利用と発育パフォーマンスの関係

    第27回日本環境動物昆虫学会年次大会  2015年11月

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研究シーズ 【 表示 / 非表示

  • 生物間相互作用の視点から身近な生物相の成立要因を解き明かす

 

競争的資金(科学研究費補助金・振興調整費・JSPS等) 【 表示 / 非表示

  • シマドジョウ種群の繁殖干渉:農環境の変化による希少種間の同所的繁殖と絶滅リスク

     科学研究費基盤研究(C)   2016年04月 ~ 2019年03月

  • 自家受粉依存性を高める在来種:外来種からの繁殖干渉と遺伝的多様性低下の検証

     科学研究費基盤研究(C)   2013年04月 ~ 2016年03月

 

学部講義等担当 【 表示 / 非表示

  • 動物生態学

  • 環境フィールドワークⅢ

  • 生物資源管理学実験Ⅵ

  • 環境フィールドワークⅡ