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1、热带亚热带植物学报2011,19(1):26~32JournalofTropicalandSubtropicalBotany黄顶菊的大孢子发生、雌配子体与胚胎发育**江莎,郑书馨,刘龙会,赵娜,高玉葆,古松(南开大学生命科学学院,天津300071)摘要:用常规石蜡制片对黄顶菊(Flaveriabidentis(L.)Kuntze)大孢子发生、雌配子体和胚胎的发育过程进行了观察。黄顶菊雌蕊柱头二裂,2心皮,1室,单胚珠,基生胎座,单珠被,薄珠心,倒生胚珠,具发达的珠被绒毡层。珠心表皮下分化出孢原细胞,孢原细胞直接发育为大孢子母细胞,大孢子母细胞减数分裂形成直列四分体,珠孔
2、端的1个大孢子发育为功能大孢子,其余3个退化,胚囊发育为单孢型。单核胚囊经过3次连续有丝分裂,形成八核胚囊,成熟胚囊珠孔端有2个助细胞和1个卵细胞,胚囊中央有1个双核中央细胞,合点端3个反足细胞。胚胎发育过程分为球形胚、心形胚、鱼雷胚和成熟胚4个阶段。胚乳发育为细胞型,胚胎发育属紫菀型。在成熟种子中存在胚乳外套层。在种皮、苞片、胎座中观察到分泌结构和分泌物。关键词:黄顶菊;大孢子;雌配子体;胚胎;分泌结构中图分类号:Q944.4文献标识码:A文章编号1005-3395(2011)01-0026-07do:i10.3969/.jissn.1005-3395.2011.01
3、.003Megasporogenesis,DevelopmentofMegagametophyteandEmbryoinFlaveriabidentis(L.)Kuntze**JIANGSha,ZHENGShu-xin,LIULong-hu,iZHAONa,GAOYu-bao,GUSong(CollegeofLifeSciences,NankaiUniversity,Tianjin300071,China)Abstract:Themegasporogenesis,megagametophyteandembryodevelopmentinFlaveriabidentis(
4、L.)Kuntzewereobservedbyusingparaffinsectionmethod.Theresultsshowedthatthestigmahad2spli,tovarywasunilocularwithbicarpellate,oneovule,basalplacenta,unitegmic,tenuinucellate,anatropousovule,anddevelopedintegumentarytapetum.Archesporialcelldifferentiatedbelowthenucellarepidermisdevelopedint
5、omegasporemothercel,lwhichformedalineartetradbymeitoticdivison,onemegasporeatmicropylarenddevelopedintoafunctionalmegaspore,andtheothersdegraded.ThedevelopmentofembryosacwasMonosporicType.Themononucleateembryosacunderwentthreesuccessivemitosistoformmatureembryosacwithsevencells,eggcellan
6、dtwosynergidsnearthemicropyle,acentralcellinthecenterofembryosac,threeantipodalcellsinthechalaza.lTheembryodevelopmentcouldbedividedintofourstages,suchasglobularembryo,hear-tshapedembryo,torpedoembryoandmaturecotyledonembryo.ThedevelopmentoftheendospermwasCellType,andthatofembryobelonged
7、toAsteradType.Thematureseedhadanendospermjacketlayer,andthesecretorystructureandsecretionswereobservedinseedcapsule,placentaandbrac.tKeywords:Flaveriabidentis(L.)Kuntze;Megaspore;Megagametophyte;Embryo;Secretorystructure[1]黄顶菊;Flaveriabidentis(L.)Kuntze]隶属菊是一种外来入侵的杂草,它喜光喜
