简介:A2×2factorialcrossbetweentwopopulationsofPacificabaloneHaliotisdiscushannaiIno,collectedseparatelyfromDalian(D)inChinaandMiyagi(M)inJapan,wasconductedtocompareperformancesinfertilizationrate,hatchingrate,metamorphosisrateandgrowthatdays20,43,160and330betweenpurebreds(DDandMM)andcrossbreds(DMandMD)andinvestigatethemagnitudeofheterobeltiosis(betterparent)andheterosis(mid-parent).HeterobeltiosisandheterosisforallthetraitsanalyzedwereevidentlydifferentbetweencrossbredsDMandMD.HeterobeltiosisinthecrossbredDMvariedamongtraits,withvaluesof2.5%forthefertilizationrate,2.2%forthehatchingrate,-1.9%forthemetamorphosisrateand7.4%forthegrowthattheday330.ThecrossbredDMdisplayedpositiveheteroticvaluesforfertilizationrate(5.4%),hatchingrate(7.4%),metamorphosisrate(7.6%)andgrowth(12.0%)attheday330.However,bothheterobeltiosisandheterosisforallthetraitsinthecrossbredMDwerenegativeexceptthoseforthegrowthatdays20and43.TheresultsindicatetheimportanceofselectingsuperiorhybridvarietiesiftheexploitationofhybridvigorisconsideredinthePacificabalonebreedingprogram.
简介:【解题指导】(一)thenumberof...与anumberof...的判定技巧thenumberof+名词,表示'……的数量',作主语时,谓语动词要用单数形式;anumberof+名词,其名词是复数形式,表示'许多……',作主语时,谓语动词要用复数形式。(二)so的倒装句式与so的强调句式的辨析
简介:彝语被动句在各方言间有不同的表现形式。大体可分为屈折形式和分析形式两大类。屈折形式是通过动词、代词本调变次高调表示主动态,本调表示被动态来体现.次高调在凉山彝语中多数情况下属于临时变调,不区别词汇意义,但在上述语法关系中它却具有语法意义。分析形式一种是通过语序表达主动句和被动句,即主语和宾语通过变换位置来体现主动句和被动句的对立形式.但部分方言如凉山彝语被动句型只有0+S+VP一种而没有与之对应的主动句型S+0+VP。一种是通过一些被动标志词来体现主动句和被动句的关系,彝语各方言间被动句及其标志词和位置也不一样。有关彝语被动标志词的形式和来源问题,从其句中位置和功能来看,它可能来源于彝语使动范畴分析形式的前缀词素.