温暖化が水稲の出穂に及ぼす影響評価のための緯度の異なる地点間のTGC比較実験 Comparison of temperature-gradient chamber experiments at different latitudes for estimating the effects of global warming on the heading date of paddy rice.

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Abstract

温暖化が日本の水稲の生育に及ぼす影響を評価するためのデータ取得を目的とし,温度勾配実験装置(TGC)の緯度間連絡試験の有効性を検討した。試験実施場所は緯度の大きく異なる,すなわち日長条件の大きく異なる札幌,盛岡,熊本の3地点とし,TGCの温度勾配を2°Cに設定して早晩性の異なる8品種:きらら397,あきたこまち,ササニシキ,ひとめぼれ,コシヒカリ,日本晴,にこまる,レイホウを栽培して出穂日を調査した。さらに札幌と盛岡では+2°Cの水温上昇処理も実施した。水稲の出穂日は,高緯度ほど品種間の差が大きく,また札幌と盛岡では高温側で早まったが,熊本では高温側で出穂は早まらず,むしろ遅れる品種もあった。5葉期から出穂期までの積算気温の地域間差は,TGC内の温度勾配に基づく解析で求められた温度依存性を超えており,日長反応に起因することが明らかになり,きらら397,あきたこまち,ササニシキ,ひとめぼれは日長感応性が比較的低く,コシヒカリは日長感応性を示すが限界日長が比較的長く,日本晴やレイホウの限界日長は短いと考えられた。出穂までの生育には気温と水温の双方が関与しており,晩生の品種ほど気温の影響が大きくなることが明らかとなった。以上の結果から温暖化の影響は栽培地域の緯度(日長)や品種の特性によって変わることが確認され,またTGCによる地域間連携試験は水稲の温度と日長反応を評価する有効な実験方法である事が明らかとなった。

We designed an inter-latitudinal temperature gradient chamber (TGC) experiment to obtain data for analyzing the effects of global warming on paddy rice production in Japan. TGC experiments were carried out at three sites of different latitudes: Sapporo, Morioka and Kumamoto. The TGCs at each site were controlled to maintain an air temperature gradient of 2°C with water temperature treatment (heated +2°C and unheated, except for Kumamoto) to grow eight rice varieties: Nikomaru, Reiho, Nipponbare, Koshihikari, Hitomebore, Sasanishiki, Akitakomachi and Kirara397. The higher temperature accelerated the heading date of all varieties in Sapporo and Morioka, but not Kumamoto. The relationship between the cumulative air temperature from the 5th leaf stage to the heading stage (CAT5H) and the temperature gradient in the TGC at each site suggested that the difference in CAT5H among the regions was attributable to day length, and the fact that Kirara397, Akitakomachi, Sasanishiki and Hitomebore have little sensitivity to the photoperiod, whereas Reiho, Nikomaru and Koshihikari exhibit a greater sensitivity to the photoperiod, although the critical day length of Koshihikari was longer than that of the other two varieties. The development of the rice plant depends on both air and water temperatures and the degree of dependency is based on the type of maturity. These results confirm that the effect of global warming on the development of the rice plant and paddy rice production will differ by region (latitude) and variety. Thus, inter-latitudinal TGC experiments are useful for gathering data to estimate the effects of global warming on paddy rice production.

Journal

  • Journal of Agricultural Meteorology

    Journal of Agricultural Meteorology 66(3), 193-200, 2010

    The Society of Agricultural Meteorology of Japan

Codes

  • NII Article ID (NAID)
    130004446569
  • NII NACSIS-CAT ID (NCID)
    AA11530034
  • Text Lang
    ENG
  • Article Type
    journal article
  • ISSN
    0021-8588
  • NDL Article ID
    10836057
  • NDL Call No.
    Z18-388
  • Data Source
    NDL  J-STAGE  JASI 
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