The fine structure of fern root cells showing apospory☆
[摘要] Isolatedrootsofthefern,Pteridiumaquilinumweregrownongrowth-supportingmedium(White'splus5%coconutmilk)andonapospory-promotingmedium(Knudson'sinorganicsaltswithorwithout10−7Mkinetin).Inthelattermediumgrowthoftherootceasedanddiploidgametophyteswereformedin8to10weeksfromoutercellsoftheroot.Thesebecamegreen,bulgedoutward,anddividedtoformfirstafilamentandthenatwo-dimensionalplate.Withkinetinmorerootcellsbecamegreenandmoregametophyteswereformedperroot.Thefinestructureofcellsinrootsgrowingnormallyandinrootsintheapospory-inducingmediumwascompared,concentratingontheregionseveralmillimetersbehindtheapexwheremostgametophytesformed.Nodifferencesamongthenormalrootcellswereobservedwhichwouldexplainwhyonlyafewcellswerecapableofgametophyteformation.Mostoftherootcellsdegeneratedonaposporypromotingmedium.Somecells,however,remainedviableandshowedincreasesintheinternalcomplexityandsizeoftheplastids,andinthesizeofthemitochondria.Ribosomesandendoplasmicreticulumbecamemoreconspicuous.Itisinferredthatthesecellswereregainingthecapacitytodivideandwerethesourceofthegametophytes.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
