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时间:2020-06-01
《海金沙配子体发育及卵发生的显微观察.pdf》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、植物研究2014,34(2):164—169BulletinofBotanicalResearch海金沙配子体发育及卵发生的显微观察郭严冬曹建国李新国王全喜(上海师范大学生命与环境科学学院,上海200234)摘要用光镜观察海金沙(Lygodiumjaponicum)配子体发育和卵发生。海金沙孢子为四面体形,具三裂缝,孢子萌发方式为密穗蕨型(Anemia—type);配子体的发育形态多样,通常丝状体长至3~5个细胞时通过顶细胞纵分裂发育为片状体,进而发育为心形原叶体,在心形原叶体上可产生精子器和颈卵器。但在培养过程中也可
2、产生l0个细胞以上的丝状体,这种丝状体发育成的片状体和原叶体形态通常不规则,只产生精子器,不产生颈卵器。原叶体发育是铁线蕨型(Adiantum—type),性器官是薄囊蕨型(Leptosporangiate—type)。切片观察海金沙颈卵器产生于生长点下方表面细胞,经两次分裂形成了顶细胞、初生细胞和基细胞。其中初生细胞再经两次不等分裂产生卵细胞、腹沟细胞和颈沟细胞,此时三个细胞紧密相连,随发育,颈沟细胞和和腹沟细胞退化,卵周围形成了分离腔,光镜观察显示成熟卵细胞上无典型卵膜形成,未观察到受精孔的结构。关键词蕨类植物;海
3、金沙;配子体;卵发生中图分类号:Q944.33文献标志码:Adoi:10.7525/j.issn.1673—5102.2014.02.004DevelopmentofGametophyteandOogenesisoftheFernLygodiumjaponicumGUOYan—DongCAOJian—GuoLiXin-GuoWANGQuan—Xi(CollegeofLifeandEnvironmentSciences,ShanghaiNormalUniversity,Shanghai200234)AbstractGam
4、etophytedevelopmentandoogenesisofthefernLygodiumjaponicumwerestudiedusingmicroscopy.Thesporesaretetrahedralandtrilete.ThesporegerminationpatternistheAnemia-type.Thegametophytedevelopmentshowedvariousforms.Whenthefilamentslengthreached3—5cells,theycanproduceplate
5、bylongitudinaldivisionoftheapicalcell,andfinallyformedtheheart—shapedprothallus,whichcanproduceantheridia(an)andarchegonium(ar).However,thegametophytecanalsopmduce10cell·lengthedfilaments.Thesefilamentsusuallyproduceirregularprothallus,whichcanproduceantheridiaa
6、nddonotpmducearchegonia.ThedevelopmentoftheprothallusistheAdiantum-type.SexorgansaretheLeptosporangiate—type.Sectionsobservationsshowedthatthearchegoniumdevelopsfromasuperficialinitialcellunderthegrowthpoint.Twodivisionsoftheinitialcellresultinatierofthreecells,
7、i.e.theuppercell,primarycellandbasalcel1.Theprimarycellfinallydevelopsintoaneckcanalcell,aventralcanalcellandaneggbytwounequaldivisions.Thesethreecellswerecloselyassociatedwitheachother.Thentheneckcanalcellandtheventralcanaldegeneratedgradually.Aseparationcavity
8、wasformedaroundthematuredegg.Lightmicroscopeobservationshowedthatnotypicaleggenvelopewasformedinthesurfaceoftheeggandnofertilizationporewasobservedinthematuredegg.Key
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