光皮桦和青冈栎茎的比较解剖

Anatomical Observations on Stems of Seedlings of Shining leaf Birch and Blue Japanese Oak

光皮桦和青冈栎一年生苗茎的解剖比较表明,前者茎的构造更具有适应速生生长的特征:茎上部的初生生长持续时间长;茎的输导组织较青冈栎发达;形成层细胞分裂次数多,分裂速度快,因而形成的次生木质部径向厚度大,而青冈栎茎中机械组织较发达,材质更坚硬。

ThispaperdealswithMorphologicalanatomyofstemsofyearlingseedlingsofBetulaluminiferaHWin kl.andCyclobalanopsisglauca(Thunb.)Oerst.Thepreliminaryresultshowsthattheanatomicalfeaturesofstemof Betulaluminiferaadapttofastgrowing.ThreeimportantdifferencesofanatomybetweenBetulaluminiferaandCy clobalanopsisglaucaare:1)primarystructureoftheupperstemofNovember,resultinginthelongperiodandrapid speedofshootheightgrowth;2 )conductingtissueofBetulaluminiferaisadvancedanddispersesrandomly ,with greatnumberandlargediameter,leadingtohigherratetowaterandinogranicsaltconduction .Incontrastconducting tissueofCyclobalanopsisglauca ,accompaniedbyxylemraybundles,representsradioactiveshapewithsmallnumber anditsmechanicaltissueisadvancedwithgreatnumberandhighlymaturedpholemfiberandxylemfiber,which limitsthegrowthofitsshootheightandcollardiameter;3)radialthicknessofsecondaryxylemofBetulaluminifera is3 .2timesthatofCyclobalanopsisglauca,duetoitsactivecambiumfission .Thattherearemuchmorenon ligni factedcelllayersofBetulaluminiferaistheresultthatxylemcellsdonotlignificatasquicklyasactivesofcambium fissiondo .