回交能育所屬現代詞，指的是收稿日期修回日期網路版發布日期接受日期。
回交能育,鱅X(鱅X鰱)回交育種試驗報告,
回交能育
詞性及解釋
【醫】paragenesis
鱅X(鱅X鰱)回交育種試驗報告
長江水產研究所
收稿日期修回日期網路版發布日期接受日期
摘要我們自工1968-1974年對鱅♀x（鱅♀x鰱♂）回交魚進行受精過程、胚胎、形態、食性和生長等一系列生物學特性的研究,閱明了下列兩個問題：
1鱅.鰱雜交後代與親本鱅魚回交，所得到的回交魚出現雜交優勢—回交魚的（鰓耙排
列整齊者）生長速度，無論在魚種階段或成魚階段都比祖傳的良種鱅魚較快；有常規的受精細胞學程式，受精卵在水溫22-24℃的條件下，經26.5小時左右胚胎以頭部破膜孵出，畸形率低，從卵球受精開始到成色各發育階段發育良好；形態結構為鱅、鰱的中間型，更似鱅魚，但頭比鱅魚小些，且鰓耙有排列整齊和不整齊兩種個體類型；食性與鱅魚相近，但比鱅、鰱都廣，食浮遊動物及較大型的浮游植物，偏重食浮遊動物，攝食強度也較鱅魚強。
2試驗證明,鱅,鰱不但可以相互雜交，而民子代具有能育性；與縮親本回交，也能成功地
得到回交魚。從細胞學和胚胎學的研究來看，回交魚與親本間亦有很多相似之處。因此認為
縮、醚魚間的親緣關係，是否達到屬間差異的地步，似乎還有考慮的餘地。
回交魚所表現的性狀，既充分反映了結構與機能的統一，也反映出與遺傳性的關係。
關鍵字
分類號
ANEXPERIMENTALREPORTONBACKCROSSBREEDING
OFBIGHEAD(ARISTICHTHYSNOBILIS)x[BIG
HEAD(A.NOBILIS)xSILVERCARP
(HYPOPHTHALMICHTHYSMOLITRIXe)1d’
♂YangtzeRiverFisheriesResearchInstitute
Abstract
Studiesonthebiologicalcharactersofthebackerosshybrid,bighead(Aristichthysnobilis)X[bighead(A.nobilis)YXsilvercarp(Hypophthalmichthysmozitrix)includingthefertilization,embryology,morphology,foodhabits,andgrowth,werecarriedoutduring1968-1972.Accordingtothesestudies,resultsareasfollows:
(1)Thebackerosshybridsobtainedbybackerossingthehybrid,bigheadXsilvercrap了andtheparentalbigheadexhibitedapparentheterosis.Thegrowthrateofthebackerosshybridswhosearrangementsofgillrakersareregularis.fasterthanthoseoftheinheritedgoodvariety,bighead,eitherinthestageofthefingerlingsorintheadults.Thereisanormalcytologialfigureinfertilization.Thefertilizedeggshatchedoutinabout26.5hoursatthewatertemperatureof22-24’C,andthedeformitiesarelow.Thedevelopmentsarenormalinthevariousdevelopmentalstagesfromthefertilizedeggtotheadult.Themorphologicalstructuresofthebackerosshybridslieintheintermediatetypebetweenthebigheadandthesilvercarp,andaremuchmoresimilartothatofthebigheadexceptthattheheadsofthebackcrosshybridsissmallerthanoneofthebigbead.Therearetwotypesofarrangementsofgillrakers,i.e.,regularandirregular.Foodhabitsofthebackerosshybridsissimilartothatofthebighead,butitismuchmoreextentivethanthebigbeadandthesilvercarp.Thebackerosshybridsfeedmainlyonzooplanktonandalsoafewmacropbvtoplanktons.Feedingintensityisstrong.
(2)Theexperimentsshowthatthebigheadandthesilvercarpmaynotonlybehybridizedreciprocalybutalsotheirfilialgenerations(F,)arepossessingfertility.Furthermore,thebackerosshybridsmaybeobtainedbymeansofbackerossingthefilialgenerationandtheparentalbighead.
Aecordingtocytologicalandembryologicalstudies,therearemanysimilartiesbetweenthebackerosshybridsandtheparents.Therefore,whethertherelationshipsbetweenthebigheadandthesilvercarpreachtheintergenusdifferencesseemstoleaveroomforconsideration.Inconclution,thecharactersexhibitedbythebackerosshybridsnotonlyrevealsufficientlytheunityofstructuresandfunction,butalsotherelationshipsbetweencharactersandheredity.
Keywords
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