水稻內(nèi)生細(xì)菌研究.pdf

1、揚州大學(xué)碩士學(xué)位論文水稻內(nèi)生細(xì)菌研究姓名：朱鳳申請學(xué)位級別：碩士專業(yè)：植物病理學(xué)指導(dǎo)教師：徐敬友20050501揚州大學(xué)碩士學(xué)位論文StudyorlendophyticbacteriaofrjceAbstract736endophyticbacteriawereobtainedfromtheroots，stemsandseedsofhealthyriceplantsinYangzhou，Nantong，ChangzhouandXuzho

2、uofJiangsuProvinceAmongtheendophyticbacteriatherewere196isolatesantagonisticagainstone，ortwoorthreepathogenssuchasPyriculariagrisea，GibberellafufikuroiRhizoctoniasolaniandXanthomonasoryzaepvoryzae，withthepercentageof2663

3、％TheantagonisticisolatesfromricestemsandrootsweremorethanfromseedsThebacteriaantagomsticagainstonepathogenweremuchmorethanthoseantagonisticagainsttwoorthinepathogensAftertheisolatesweretransferredfomtubetotubefor20times，

4、theantagonismagainstPgriseaandGfujikuroiwasmorestableandtherateofunchangedantagonisticisolatesWaS9286％and8235％respectively，wluletheantagonismagainst足so[aniandXoryzaepvoryzaeWaSeaSilydecreasedorlostIsolatesG87antagonistic

5、stronglyagainst尸grisea，Gfiffikuroi，丑oryzaepvoryzaeandJ215antagonisticstronglytoPgrisea6fujikuroiwereidentifiedasBacillussubtilis(Ehrenberg)CohnTheassociativenitrogen—fixingactivityof276endophyticbacteriawastestedbyinvitr

6、oacetylenereducedactivity(ARA)determinationand234isolatesofendophyticassociateddiazotrophswereobtainedAmongthem，therewere190isolateswitllmiddlenitrogen—fixingactivity(1≤ARA≤lOO)，accountingfor6884％and5isolateswithhighnitr

7、ogen—fixingactivity(ARA≥100)，accountingfor181％5isolateswithhighnitrogen—fixingactivitywerestableaftertransferredfomtubetotubefor20timesAccordingtomorphological，physiologicalandbiochemicalfeathers，isolatesG161(92123130umo

8、l／ml。h)andJ115(209878200umol／mlh)withstablenitrogenfixingactivitywereidentifiedasEnterobactercloacae(Jordan)Hormaeche&EdwardsThroughdippingseedlingrootsandspraying，isolatesG161andJ115withhighassociativenitrogenfixingacti