几种丛生竹根际联合固氮研究

Study on Associated Nitrogen Fixation of Several Sympodial Bamboo Species

对几种丛生竹种麻竹、吊丝球竹、青皮竹、粉丹竹、马甲竹、绿竹等进行根系固氮能力调查测定 ,用直接法测定 (干根样品 )前 5个种竹种的根系最高固氮酶活性分别为 2 0 .50、2 4 .81、10 .83、7.4 9、2 .4 6nmol(C2 H4 )·g- 1·h- 1,用富集培养法测定 (鲜根样品 )前 5个种竹种的根系平均固氮酶活性分别为 2 75、4 31、169、188、79nmol(C2 H4 )·g- 1·h- 1。不同生境和不同季节丛生竹根系固氮能力的调查显示 ,充足的水分供应、较高的温度及适当施用有机肥有利于竹子固氮。对几种丛生竹种根际不同部位固氮菌数调查测定显示 ,根际固氮菌数最多的竹种是吊丝球竹 ,在根际不同部位固氮菌数由非根际土→根际土→根表→根内依次急剧递增 ,越往内部根际效应越明显。用 2 #、12 #、14#、7#菌及混合菌液对麻竹组培苗进行接种显示 ,接种固氮菌可提高苗木成活率和植株含氮量 ,14#、7#菌和混合菌接种可显著提高麻竹组培苗生物量。

Rootnitrogenfixingactivitiesofseveralsympodialbamboospecies ,namelyDendrocalamus latiflorus,Dendrocalamopsisbeecheyana ,Bambusatextilis,Bambusachungii,Bambusatulda ,Dendro calamopsisoldhamiwereinvestigatedandtested .Itisshownthatusingdirecttestingmethodstherootni trogenfixingactivityoffirstfivebamboospeciesabovementionedcanreachto 2 0 .5 0 ,2 4.81 ,1 0 .83,7. 49 ,2 .46nmol(C2 H4)·g-1·h-1respectively ,whenusingenrichmentculturemethodstherootsnitrogen fixingactivityoffirstfivebamboospeciescanreach 2 75 ,431 ,1 6 9,1 88,79nmol(C2 H4)·g-1·h-1re spectively .Therootnitrogenfixingactivityofbamboospeciesgrownindifferentenvironmentsanddiffer entseasonswereinvestigatedandtested .Itisshownthatsufficientwatersupply ,suitablehightempera tureandapplyingorganicfertilizercanmoderatelypromoterootnitrogenfixingactivity .Whencounting theamountofnitrogenfixingbacteriaatdifferentrhizosphereposition ,itisshownfromnon rhizosphere soil,rhizospheresoil,rootsurfacetorootinner,thenitrogenfixingbacteriaincreasedsharplyandfrom outsidetoinsidetherhizosphereeffectaremoreandmoreobviously .Inoculatingnitrogenfixingbacteria (2 # ,1 2 # ,1 4# ,7# ,andmixingbacteriaspecies)totissuecultureyounglingsofDendrocalamuslati florus,itisshownthatinoculatingnitrogenfixingbacteriacanpromotyounglingssurvivalrateandplant nitrogencontent.1 4# ,7# andmixingnitrogenfixingbacteriacanpromotingthebiomassoftissuecul turedyounglingsremarkable .