報告書番号

481014

タイトル（和文）

ハツカダイコンおよびインゲンの酸性雨による表皮形態と無機成分濃度の変化

タイトル（英文）

CRYO-SCANNING ELECTRON MICROSCOPIC OBSERVATIONS AND CONCENTRATIONS OF INORGANIC ELEMENTS IN RADISH AND KIDNEY BEAN EXPOSED TO ACID RAIN

概要 （図表や脚注は「報告書全文」に掲載しております）

ハツカダイコンとインゲンに，純水で希釈調製した硫酸水溶液を毎日噴霧処理し，凍結走査電子顕微鏡で葉表皮の観察を行なうとともに，植物体のＳ，Ｃａ，Ｍｇ，Ｋ，Ｎａの濃度について検討を行った。１）ハツカダイコンおよびインゲンともｐＨ３．０では可視害はみられず，ｐＨ２．０で陥没型の壊死斑が多数観察された。ハツカダイコンの場合には気孔を取り巻く副細胞が影響を受けている像もみられた。インゲンの場合には，葉上に結晶状物質の析出あるいは沈着が観察され，この結晶状物質の主成分はＣａとＳであることが明らかとなった。２）インゲン葉におけるＳおよびＣａの濃度は経時的に増大したが，ｐＨ４．０およびｐＨ５．８区（対照区）よりもｐＨ２．０区とｐＨ３．０区の方が濃度は高かった。

概要 （英文）

THIS REPORT DESCRIBES THAT FRESH LEAVES OF RADISH AND BUSH BEAN PLANTS EXPOSED TO SULFURIC ACID SOLUTION AS AN ACIDRAIN WERE RAPIDLY FROZEN AND LEAF SURFACE PERTURBATION WAS OBSERVED BYCRYOSCANNING ELECTRON MICROSCOPE WITHOUT ANY FIXATION AND DEHYDRATION PROCEDURES FOR SPECIMENS. MANY NECROTIC LESIONS WERE OBSERVED ON THE LEAVES EXPOSED TO PH 2.0,HOWEVER,NO VISIBLE INJURY IN BOTH PLANTS WAS OBSERVED AT PH 3.0.EPIDERMAL CELLS WERE AFFECTED AND SLIGHTLY FLACCID.IN NECROTIC LESIONS COMPOSED OF COLLAPSED EPIDERMAL CELLS,ONLY TRACES OF GUARD CELLS OR STOMA WERE OBSERVED.THEREFORE,INJURED AREAS WERE CLEARLY SEPARATED FROM APPARENTLY UNINJURED AREAS. BUSH BEAN LEAVES EXPOSED TO SULFUIC ACID SHOWED FLACCID NECROTIC LESIONS AS WELL AS RADISH,HOWEVER,STOMATAL DENSITY IN ADAXIAL LEAVES WAS APPARENTLY LOWER THAN THAT OF RADISH.NECROTIC LESIONS ON BUSH BEAN LEAVES WERE OBSERVED IN BOTH AREA NEAR AND AWAY FROM STOMA;IT WAS DIFFICULT TO FIND THE CORRELATION BETWEEN THE DISTRIBUTION OF STOMA AND DEVELOPMENT OF NECROTIC LESIONS IN THIS EXPERIMENT. ABOUT FIVE WEEKS AFTER THE INITIATION OF THE EXPOSURE,DEPOSITION OF WHITSH CRYSTALLINE SUBSTANCES WERE OBSERVED ON THE LEAF SURFACE.QUANTITATIVE X-RAY ANALYSIS USING CRYO-SEM EQUIPPED WITH ENERGY DISPERSIVE X-RAY ANALYZER REVEALED THAT THEY WERE PILLAR-AND NEEDLE-SHAPED AND WERE COMPOSED OF CA AND S.THESE SUBSTANCES APPEARED TO BE NEUTRALIZEDDERIVATIVES;CA WITHIN A LEAF SURFACE TISSUE WAS ACCERELATED TO BE LEACHED OUT THROUGH CATION-ANION EXCHANGE PROCESSES BY EXPOSURE OF SULFURICACID SOLUTION.

報告者

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