孟德尔--植物杂交实验论文(1865年)英文及中译

第1页共57页Mendel'sPaperinEnglishExperimentsinPlantHybridization(1865)byGregorMendelReadatthemeetingsofFebruary8th,andMarch8th,1865[1]IntroductoryRemarksExperienceofartificialfertilization,suchasiseffectedwithornamentalplantsinordertoobtainnewvariationsincolor,hasledtotheexperimentswhichwillherebediscussed.Thestrikingregularitywithwhichthesamehybridformsalwaysreappearedwheneverfertilizationtookplacebetweenthesamespeciesinducedfurtherexperimentstobeundertaken,theobjectofwhichwastofollowupthedevelopmentsofthehybridsintheirprogeny.Tothisobjectnumerouscarefulobservers,suchasKölreuter,Gärtner,Herbert,Lecoq,Wichuraandothers,havedevotedapartoftheirliveswithinexhaustibleperseverance.GärtnerespeciallyinhisworkDieBastarderzeugungimPflanzenreiche,hasrecordedveryvaluableobservations;andquiterecentlyWichurapublishedtheresultsofsomeprofoundinvestigationsintothehybridsoftheWillow.That,sofar,nogenerallyapplicablelawgoverningtheformationanddevelopmentofhybridshasbeensuccessfullyformulatedcanhardlybewonderedatbyanyonewhoisacquaintedwiththeextentofthetask,andcanappreciatethedifficultieswithwhichexperimentsofthisclasshavetocontend.Afinaldecisioncanonlybearrivedatwhenweshallhavebeforeustheresultsofdetailedexperimentsmakeonplantsbelongingtothemostdiverseorders.Thosewhosurveytheworkdoneinthisdepartmentwillarriveattheconvictionthatamongallthenumerousexperimentsmade,notonehasbeencarriedouttosuchanextentandinsuchawayastomakeitpossibletodeterminethenumberofdifferentformsunderwhichtheoffspringofthehybridsappear,ortoarrangetheseformswithcertaintyaccordingtotheirseparategenerations,ordefinitelytoascertaintheirstatisticalrelations.第2页共57页Itrequiresindeedsomecouragetoundertakealaborofsuchfar-reachingextent;thisappears,however,tobetheonlyrightwaybywhichwecanfinallyreachthesolutionofaquestiontheimportanceofwhichcannotbeoverestimatedinconnectionwiththehistoryoftheevolutionoforganicforms.Thepapernowpresentedrecordstheresultsofsuchadetailedexperiment.Thisexperimentwaspracticallyconfinedtoasmallplantgroup,andisnow,aftereightyears'pursuit,concludedinallessentials.Whethertheplanuponwhichtheseparateexperimentswereconductedandcarriedoutwasthebestsuitedtoattainthedesiredendislefttothefriendlydecisionofthereader.[2]SelectionoftheExperimentalPlantsThevalueandutilityofanyexperimentaredeterminedbythefitnessofthematerialtothepurposeforwhichitisused,andthusinthecasebeforeusitcannotbeimmaterialwhatplantsaresubjectedtoexperimentandinwhatmannersuchexperimentisconducted.Theselectionoftheplantgroupwhichshallserveforexperimentsofthiskindmustbemadewithallpossiblecareifitbedesiredtoavoidfromtheoutseteveryriskofquestionableresults.Theexperimentalplantsmustnecessarily:1.Possessconstantdifferentiatingcharacteristics.2.Thehybridsofsuchplantsmust,duringthefloweringperiod,beprotectedfromtheinfluenceofallforeignpollen,orbeeasilycapableofsuchprotection.Thehybridsandtheiroffspringshouldsuffernomarkeddisturbanceintheirfertilityinthesuccessivegenerations.Accidentalimpregnationbyforeignpollen,ifitoccurredduringtheexperimentsandwerenotrecognized,wouldleadtoentirelyerroneousconclusions.Reducedfertilityorentiresterilityofcertainforms,suchasoccursintheoffspringofmanyhybrids,wouldrendertheexperimentsverydifficultorentirelyfrustratethem.Inordertodiscovertherelationsinwhichthehybridformsstandtowardseachotherandalsotowardstheirprogenitorsitappearstobenecessarythatallmemberoftheseriesdevelopedineachsuccessivegenerationsshouldbe,withoutexception,subjectedtoobservation.第3页共57页AttheveryoutsetspecialattentionwasdevotedtotheLeguminosaeonaccountoftheirpeculiarfloralstructure.ExperimentswhichweremadewithseveralmembersofthisfamilyledtotheresultthatthegenusPisumwasfoundtopossessthenecessaryqualifications.Somethoroughlydistinctformsofthisgenuspossesscharacterswhichareconstant,andeasilyandcertainlyrecognizable,andwhentheirhybridsaremutuallycrossedtheyyieldperfectlyfertileprogeny.Furthermore,adisturbancethroughforeignpollencannoteasilyoccur,sincethefertilizingorgansarecloselypackedinsidethekeelandtheanthersburstwithinthebud,sothatthestigmabecomescoveredwithpollenevenbeforethefloweropens.Thiscircumstanceisespeciallyimportant.Asadditionaladvantagesworthmentioning,theremaybecitedtheeasycultureoftheseplantsintheopengroundandinpots,andalsotheirrelativelyshortperiodofgrowth.Artificialfertilizationiscertainlyasomewhatelaborateprocess,butnearlyalwayssucceeds.Forthispurposethebudisopenedbeforeitisperfectlydeveloped,thekeelisremoved,andeachstamencarefullyextractedbymeansofforceps,afterwhichthestigmacanatoncebedustedoverwiththeforeignpollen.Inall,34moreorlessdistinctvarietiesofPeaswereobtainedfromseveralseedsmenandsubjectedtoatwoyear'strial.Inthecaseofonevarietytherewerenoticed,amongalargernumberofplantsallalike,afewformswhichweremarkedlydifferent.These,however,didnotvaryinthefollowingyear,andagreedentirelywithanothervarietyobtainedfromthesameseedsman;theseedswerethereforedoubtlessmerelyaccidentallymixed.Alltheothervarietiesyieldedperfectlyconstantandsimilaroffspring;atanyrate,noessentialdifferencewasobservedd