Gram-Positive Bacteria Associated with Rice in China and Their Antagonists Against the Pathogens of Sheath Blight and Bakanae Disease in Rice

(整期优先)网络出版时间:2005-03-13
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Itisnecessarytounderstandthebacterialpopulationsassociatedwithricesoastoprovidemoreinformationandnaturalresourcesforeffectivemanagementofmajordiseasesinrice.Asurveyonscreeningandidentificationofgram-positivebacteriawasconductedduring1998-2004.Sevenhundredandfifty-sixricesampleswerecollectedfromZhejiang,Jiangsu,FujianandYunnanProvinces,China.Over1000bacterialisolateswereisolatedandtestedforcolonymorphology,pathogenicity,andsomecharacteristicsofbacteriologyincludingGramstaining,fluorescentpigmentonKingsmediumBandmicroscopicobservationforendospore.Togetherwithfivestandardreferencestrains,74representativegram-positivebacterialisolateswereconfirmedbyBiologandgaschromatographicanalysisoffattyacidmethylesters.FivebacterialspeciesofBacillusandotherthreegenerawereidentifiedandisolatesfromBacillussublitisandBacillusmegaterium,exhibitedthemosteffectiveinhibitionagainstthepathogensofsheathblightandbakanaediseaseofrice.AfewisolatesfromBacilluspumilusandBacillusmegateriumshowedweakvirulentonricetogetherwithsomevirulentisolates,dskshouldbeconsideredwhenisolatesfromthesespecieswerescreenedforbiocontrolagents.