简介:Inthisstudy,28,691genomesequencesand16,566expressedsequencetags(ESTs)ofEucalyptuswerederivedfromtheGenBankdatabase.Atotalof2292SSRlociweresoughtoutfrom1785effectivesequences.ThroughanalysesofSSRlociinformation,theSSRmotiflengthwasnegativelycorrelatedwiththeabundanceoftheSSRs.IntheESTsequencesofEucalyptus,tripletrepeatmotifswerethemostabundant,anddinucleotiderepeatsmotifshadthehighestfrequencies.Subsequently,395pairsofprimersweredesignedbasedontheSSRloci.UsingoptimizedSSR-PCRconditions,340pairsofprimersweresuccessfullyscreened,withasuccessrateof86.1%.Byconstructionofamaximumlikelihoodphylogenetictreeofsixeucalyptspecies,representedbyfivespeciesofthegenusEucalyptusandoneofthegenusCorymbia,thegeneticrelationshipsofEucalyptusurophyllaandE.camaldulensissuggestedbythistreewasfoundtodifferfromthatsuggestedbytraditionalmorphologicaltaxonomy.TheresultsprovideinsightsforevaluatinggeneticdiversityofEucalyptusandanalysisofEucalyptusphylogeneticsusingSSRmarkers.
简介:Itisprovedthatamongtheregularpolygonswithprimeedges,onlytheregularpolygonswithFermatprimeedgesareconstructablewithcompassandstraightedge.As17isaFermatprimenumber,theconstructionofheptadecagonhasbeendiscussingallthetime.Manydifferentconstructionmethodsareproposedalthoughtheyarebasedonthesametheory.Simplificationoftheconstructionisstillasensibleproblem.Here,weproposeasimplemethodforconstructingregularheptadecagonwiththefeweststeps.Theaccumulationofconstructionerrorsisalsoavoided.Thismethodismoreapplicablethanthepreviousconstruction.
简介:IntroductionTheconceptsofInertialManifold(IM)[1]andApproximateInertialManifold(AIM)[2]fordissipativepartialdifferentialequati...
简介:对4000条辣椒EST序列进行筛选,获得了119条含有SSR的EST,共设计出35对EST—SSR引物,占所有EST序列的0.87%。在所有的SSR—ESTs中,二核苷酸重复含量最高,其次是三核苷酸重复。GA和AGA分别是二,三核苷酸重复中含量最高的重复基元。以不育系(cytoplasmicmalesterility,CMS),保持系基因组DNA为模板,对EST—SSR引物进行筛选,首次获得Pe21、Pe26和Pe27等3对特异引物,并扩增出特异片段分别为CMSPe2160、CMSPe260、CMSPe27300.EST—SSR标记作为功能基因的一部分,可以直接揭示或反映相关基因功能,特异标记基因的一部分序列,它的应用将对进一步研究辣椒胞质雄性不育分子机理带来一定的促进作用。
简介:Asimplesolutionforamultilayermetallicopticalwaveguidebytransformingitintoanequivalentthree-layerslabwaveguideispresented.Thedispersionrelationoftheequivalentthree-layerslabwaveguideissolvedbyusingasimpleiterativeformula.Thismethoditselfisexactandcanapproachanyaccuracydesired.Moreover,thenumericalresultsforfour-layerandfive-layerstructuresshowthatthesecond-ordersolutionisalsoaccurateenough.ItissimpleandhasthesameformofexpressionsforTEandTMmodesandfordifferentlayerstructures.