報告書番号

485028

タイトル（和文）

アマモへの温度の影響１．発芽と発芽体の生長

タイトル（英文）

EFFECTS OF TEMPERATURE ON ZOSTERAMARINA L. I.SEED GERMINATION AND SEEDLING DEVELOPMENT

概要 （図表や脚注は「報告書全文」に掲載しております）

アマモ場の季節的消長と温度との関係についての基礎的知見を得るため，アマモ種子の発芽と発芽体の生長に及ぼす温度の影響について明らかにした。その結果は以下の通りであった。１．１０℃以下では覆土すると発芽が促進された。２．発芽好適温度は５～１０℃であり，１４℃以上では発芽率が低かった。３．発芽体の生育下限温度は５℃より低く，生育上限温度は２８℃付近であった。４．発芽体の生育に適した温度は部位によって異なっていた。５．葉の伸長速度は５～２０℃の間で温度に比例しており，２０～２６℃で最も大きかった。また，出葉周期は５～２６℃の間で温度が高い程短くなる傾向を示した。

概要 （英文）

ZOSTERA MARINA L.(EELGRASS)BEDS ARE VERY IMPORTANT PLACES FOR LARVAE AND JUVENILE OF FISH AND SHELLFISHES AS NURSARY AREAS. THE AREA OF ZOSTERA BEDS IS BEING GRADUALLY DECREASED BY RECLAMATION,DREDGING AND DECREASE OF WATER TRANSPARENCY CAUSED BY WATER POLLUTION IN JAPAN. MANY RESEARCHERS ARE TRYING TO CREATE OR RECOVER EELGRASS BEDS. IT IS VERY IMPORTANT TO CLEARIFY THE RELATIONSHIP BETWEEN SEASONAL CHANGE OF EELGRASS BEDS AND ENVIRONMENTAL FACTORS FOR THIS PURPOSE. TEMPERATURE IS ONE OF THE MOST IMPORTANT FACTORS WHICH CONTROL THE SEASONAL CHANGE OF PLANTS. BUT,THE RELATIONSHIP BETWEEN TEMPERATURE AND EELGRASS HAS NOT BEEN THOROUGHLY CLARIFIED. SO,WE HAVE EXAMINED THE EFFECT OF TEMPERATURE ON SEED GERMINATION AND SEEDLING DEVELOPMENT OF EELGRASS IN LABORATORY EXPERIMENT TO DEFINE THE RELATIONSHIP BETWEEN SEASONAL CHANGE OF EELGRASS AND TEMPERATURE.RESULTS 1.SEED GERMINATION SEED GERMINATION WAS PROMOTED BY COVERING THE SEEDS WITH SEDIMENT FROM ODAWA BAY. THE OPTIMUM TEMPERATURE FOR SEED GERMINATION WAS 5 10GRADIENT AND GERMINATION RATE OF THE SEEDS WAS LOW (0 23%) AT 14 35GRADIENT. 2.SEED DEVELOPMENT THE LOWER AND UPPER TEMPERATURE LIMITS FOR SEEDLING GROWTH WERE BELOW 5GRADIENT AND ABOUT 28 GRADIENT RESPECTIVELY AND MOST SEEDLINGS DIED WITH IN 10 DAYS AT 30 35GRADIENT. THE OPTIMUM TEMPERATURES FOR SHOOT LENGTH,NUMBER OF LEAVES PER SHOOT,AND THE LENGTH OF THE LONGEST ROOT OF SEEDLINGS WERE OBSERVED AT 15 20GRADIENT,20 25GRADIENT,AND 15GRADIENT RESPECTIVELY.THE LEAF ELONGATION RATES FOR SEEDLINGS WERE INCREASED WITH INCREASING TEMPERATURE FROM 5GRADIENT TO 20GRADIENT AND WERE HIGHEST AT 20 26GRADIENT.THE TIME INTERVALS BETWEEN LEAF FORMATION WERE DECRESED WITH INCREASING TEMPERATURE UP TO 26GRADIENT.FROM THESE RESULTS,WE INFERRED THAT EELGRASS SEEDS WOULD BEGIN TO GERMINATE WHEN TEMPERATURE DECREASED BELOW 14GRADIENT AND GROWTH RATE FOR LEAVES OF SEEDLINGS WOULD BE ACCELERATED WITH INCREASING TEMPERATURE UP TO 20GRADIENT FOR ODAWA BAY EELGRASS.

報告者

キーワード