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microscopicsystem，weobservedthediferenceinextracelularandintracelular企ezingbehaviourand intracelularpHforplanttisueduetoelectriccurentload.Consequently，wefoundthatelectriccurentload causedslowericecrystalprogresandfinericegrain[2]andthatitsupresedthedropofintracelularpH thatisthesignofcel'sweakening[3].Here，crepingsaxifrage(Sax~斤αgα stoloni戸ra Mei'b.)wasusedfor plantforthereasonofeasetoobtainsinglelayertisuewithliving.Further，fromthemorepracticalviewpoint， theinvestigationwascariedouttoclarifシwhetherornotthereisalsothedamagedecreaseefectforleafthat isscaled-upedthantisueduetoelectriccurentload[4].However，because，atpresentthereisnoestablished reliablemeasuretoevaluatethedamageofleaf，thetemporaryestimationforleafdamagewasperformedby usingmicroscopicobservationandweightchangeratiobetwenbeforeandafterdamageexposure.Then，we discusedusingspectruminformation.Normalizeddiferencevegetationindex(herea丘er，NDVI)takinguse ofspectruminformationofphotosynthesisoftenusedinthefieldofremotesensingwastriedfortransientnon- destructivemeasure.Asaresult，itwasfoundthatNDVIcanotalwaysmeasuretransientleafdamage acurately.However，fromourdepinspectionofspectrumresults，wenoticedthattherearethecharacteristic changesinwavelengthfrom50nmto630nmwiththeprogresofcoling.Payingspecialatentiontothis characteristic spectrum change，this research proposed new index to estimate transit leaf damage and investigatedthevalidityofnewproposedindexforleafdamagebycorespondingnewindextovariousleaf damage.Leafdamagewasmadebyvaryingitsexposuretimeandtemperature. Thekindofplantwasalso varied.Further，tounderstandleafdamagedeply，chemicalsubstancesrelatedtophotosynthesis;chlorophyl aandscarotene，wasmeasuredforleafthatsufereddamagebyhighperformanceliquidchromatography (hereafterHPLC). Consequently，itwasfoundthatnewmeasurewasmoresuitablethanNDVIforestimation ofleafdamage.
2.EXPERIMENTALAPPRUSTUSANDPRODUCERS
Theexperimentwasperformedbysetingleafinthelowtemperaturechamberof64Lthatcanbecontroled 企om-850Cto+1800CwithlOCofvariationinchamber.Leafwascoveredwithpartitionofacrylicresinto avoidwind'shitingitdirectly. Exposedtemperaturewas25，久ー170C.Exposedtimewas80daysinthe longestcase.Strawber ryGeranium(Saxij均 gestolon旅 rα)，Kamchatkastonecrop(Phedimus arizonL. 'tHart)， Komatsuna(BrasicarapαL.vαr.perviridisL._HBailey)andSpinach(命einαciaoleraceaL.)wereusedfor plantlea王Thepurposeofthisresearchwastofindnewtransitnon-destructivemeasureforleafdamageusing spectrum information. Normalized diference vegetation index caled NDVI taking use ofspectrum informationis0丘enusedasmeasureofdamageestimation.NDVItakesuseofthecharacteristicsthatleaf showshighref1ectionatwavelengthofnearinfraredrayandhighabsorptionatthatofredrayinphotosynthesis andisoftenusedintheremotesensing[5].
NDVIisdefinedas
Here，IRistheintensityatIRwavelength(765四 775nm)andRth剖 ofRedwavelength(65-65nm).Inthis research，hyper-spectrum camera with resolution of 5nm of 350nm to 1050nm was used to obtain such spectruminformation，Halogenlumphaving1.5kWof300to1700nmwasusedaslightforiradiatingleaf. Thisresearchdiscusedleafdamage.Therefore，leafdamagewasverifiedbychangeofchemicalsubstances relatedtophotosynthesis. Chlorophylaofmainphotosyntheticpigmentandscaroteneofacesorypigment weremeasuredbyusingHPLCwithlowpresureunitaschemicalsubstances[6].ColumnwasShim-pack GWSC18.Detectionwavelengthwas450nm.
3.EXPERIMENTALRESULTSANDDISCUSSIONS
3.1NDVI Figure1showsthetransientrelationshipbetwenwavelengthandNormalizedreflectancewiththeprogres ofdamage.PlantleafwasKamchatkastonecrop(Phedimus arizonL. 'tHart).Se eingthephotographsfrom1 to5inFig.(b)，leafcolorchanges企omgrentored-brownwiththeprogresofleafdamage.NDVIvalue requiredfromtransientspectrumdistributionshowsconstantvaluefrom1to3inspiteofcolorchangeand subsequentlyrapiddecrease. ThechangeofNDVIvaluedoesn'tseemtomatchleafdamage.Therefore，we
2
IR-R' NDVI=一 一 一 一
IR+R'
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