水稻蜡质基因引导区的两个SSR序列与直链淀粉含量的相关性_英文_谈移芳

植　物　学　报　2001,43(2):146-150ActaBotanicaSinica

水稻蜡质基因引导区的两个SSR序列

与直链淀粉含量的相关性

谈移芳　张启发

＊

(华中农业大学作物遗传改良国家重点实验室,武汉430070)

摘要:　分析了蜡质基因引导区的两个简单重复序列(SSR)(CT)AATT)n和(n在74份水稻材料中的多态性及其与直链淀粉含量(AC)的关系。这些材料包括了籼稻(OryzasativaL.ssp.indica)、粳稻(O.sativassp.japonica)和普通野生稻(O.rufipogon),其AC值覆盖了栽培稻AC分布的整个范围。以(CT)n作标记检测到8个等位基因,粳稻品种趋于含有重复数目较多(n≥16)的等位基因,重复次数较少(n≤14)的等位基因只出现在籼稻中。(AATT)n检测到2个等位基因,野生稻中少数植株表现出杂合性。分析表明AC与这两个SSR序列基因型高度相关,高AC(>22.0%)品种具有(CT)重复次数较少(n≤14)的等位基因;相反,除了糯米外,所有低或者中等AC的品种都有(CT)重复数较多(n≥16)的等位基因。具有重复次数较多的(AATT)6等位基因的品种多为高AC,具有重复次数较少的(AATT)5等位基因的品种多为低或中等AC。不同SSR基因型品种间AC差异极显著。虽然目前还不能确定这两个SSR序列在直链淀粉合成中的直接功能,SSR变异与AC间近乎完全的相关性可作为分子标记直接用于水稻的品质改良。

关键词:　微卫星DNA;稻米品质;直链淀粉含量

中图分类号:Q943　　　文献标识码:A　　　文章编号:0577-7496(2001)02-0146-05

CorrelationofSimpleSequenceRepeat(SSR)VariantsintheLeaderSequence

ofthewaxyGenewithAmyloseContentoftheGraininRice

TANYi_Fang,ZHANGQi_Fa＊

(NationalKeyLaboratoryforCropGeneticImprovement,HuazhongAgriculturalUniversity,Wuhan430070,China)

Abstract:　Variationoftwosimplesequencerepeats(SSRs)intheleaderregionofthewaxygenewasana-lyzedinasampleof74accessions,includingOryzasativaL.ssp.indica,japonicaandwildrice(O.rufi-pogon)representingawidedistributionrangeofamylosecontent(AC)incultivatedrice.Eightalleleswere

detectedinthe(CT)AATT)Thedistributionoftheallelesnmotifandtwoalleleswereresolvedinthe(nmotif.ofthetwoSSRswasquiteunevenasdetectedbythe(CT)TherepeatnumbersofthetwoSSRmotifs,nmotif.(CT)AATT)nand(n,appearedtobeinverselyrelatedsuchthatthetotallengthofthisregionwasmaintained.ACofthevarietieswashighlycorrelatedwiththelengthofSSRs.DifferencesinACamongthevariousSSRgenotypeswerestatisticallyhighlysignificantasanalyzedusinggenotypesofbothSSRmotifs.AlthoughtheSSRvariationdidnotseemtohaveobviousfunctioninthesynthesisofthestarchsynthaseencodedbythewaxygene,thealmostperfectcorrelationbetweenthetwoSSRsandAClevelcouldbeusedforqualityim-provementinricebreedingprograms.Keywords:　microsatelliteDNA;ricequality;amylosecontent　　Thewaxygene(abbreviatedasWx)encodesthe

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granuleboundstarchsynthase(GBSS,EC2.4.1.11).SeveralallelesofthericeWxgenehavebeenidentified,clonedandcompletelysequenced[2,3].Ithasbeenreport-edthatthefunctionoftheWxgeneislargelyresponsiblefortheamylosecontent(AC)oftheendosperm[4,5],

whichisoneofthemaindeterminantsforcookingandeat-[6]

ingqualityofrice.

Microsatellitesaresequencesoftandemrepeats(alsoreferredtoassimplesequencerepeats(SSRs))withthelengthofrepeatsintherangeofafew(usually2to4)basepairs(bp).IthasbeenobservedthatSSRsare

Received:2000-05-25　Accepted:2000-09-04

SupportedbytheNationalProgramontheDevelopmentofBasicScience(G1998010204).＊.Phone/86_27_Emailh.hb.cn

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