短命植物小瘡菊的果實(shí)異形性及其生態(tài)適應(yīng)對(duì)策.pdf

1、新疆農(nóng)業(yè)大學(xué)碩士學(xué)位論文短命植物小瘡菊的果實(shí)異形性及其生態(tài)適應(yīng)對(duì)策姓名：孫華之申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：植物學(xué)指導(dǎo)教師：譚敦炎20080601AbstractGarhadioluspapposusBoissetBuhseisoneoftheverycommonephemeralAsteraceaespeciesthatgerminatesinearlyspringintheJunggarDesertItproducesthreetypes

2、ofachenes(peripheral，intermediate，andcentral)thatdifferinmorphology，dispersalorgerminationbehaviorinoneheadInthispaperthemorphological，dispersal，germinationanddormancycharacteristicsofthetheremorphswereobservedandanalyze

3、dbothinfieldandindoors，andtheecologicaladaptivestrategyofthespecieswasdiscussedThemainresultsare硒follows：(1)Thethreetypesofachenesdiffersignificantlyinthenumbershape，colormass，lengthanddensityofpappusandembryosizePeriphe

4、ralachenes，whicharesubtendedbytheinnerinvolucralbracts(phyllaries)，aresmooth，I1810M30mg(meanS士SE)per100achenes，columnarandarcuate，yelloworyellowwhitish，667士010mminlengthandhaveascarcelydevelopedpappusCentralacheneswithnu

5、merousconspicuouslongitudinalthinribsare6900士060ragper100achenescolumnarandarcuateorstraight，brownelongated(withalengthof974：L014ram)，andhaveawelldevelopedpappusIntermediateachenesrepresentarangeofmorphologiesbetweenthe“

6、pure”centralandperipheraltypesInonehead，thecentralandintermediateachenesaremorenumerousthanperipheralones(577士013VS539士014kS524：L005)Inaddition，centralandintermediateacheneshaveathinnerandanatomicallydifferentpericarp(ha

7、lfasmuchbiomass)comparedtoperipheralachenes(697pmⅧ821ItrnⅧ15671tm)，andembryosinperipheralachenesareheavierthanthoseincentralandintermediateachenes(46701050mgV苫3680士030mgVs3690士030mgper100embryos)(2)Thethreemorphsdifferin

8、dispersalInthelaboratorydispersaldistanceWasgreaterforcentralthanforintermediateachenesandgreaterforintermediatethanperipheralachenesInthefield，centralachenescalleasilybedispersedalongdistancebywind，whereasperipheralache

9、nes，whicharecoveredbylignifiedphyllaries，remainonthecapitulumaftermaturationandaredispersed，closetothemotherplants，onlywhenthecapitulumbreaksapartDispersalfeaturesofintermediateachenesliemidwaybetweenthoseofcentralandper

10、ipheralachenes(3)ThethreemorphsdifferingerminationrequirementsFreshcentralachenesgerminatedto1021％inlightat15／2’Cand20／10。C，whileintermediateandperipheralachenesgerminatedto5％GerminationWasenhancedbyexcisingtheembryoinpe