Rice Resistance To Bacterial Leaf Streak And The Virulence Differentiation Of Xanthomonas Oryzae Pv. Oryzicola In China

Bactenal leafs腕吹 Is an lmPOrtantbacterlal disease on rice Introplcal and subtropical rea,and also a quarantine disease In China．In oder to study the resistance varieties for the potential application In disease control,a great number of varltles were tested IOr evaluatingthe resistance to肠nthomonas ompe pv． onglcol4thlrty six of them are hybrid combinations andthelr parent lines,forty one are Xlan type(Indlca)verities,thirty four are Jing type(Japonlca)vanetles．The are as follows:(l)Resistance of mNorlty cytoplasm male sterile po and malntalnerllnestopathogen Is lowerthanthatofrecoverllnes．andresls伽e dlfferentlatlon existed 111侧 lines,meantalnerllnes and recover lines respectlvlly． BT－M lines express stronger reslstsnce than othertested CMllnes,such as W, DA etc．(2)Xlan type rice is easilier attacked by pathogenlc strains than Jing type rice and the same result Is obtained In XlantyPe hybrid rice．But thee still re some exceptions． 6 of28 varieties wlthdlfferent resistance genes were selected and comPOse a set ofdifferential varieties(IRBBS,豆RBB14,IRBB4,IRBBZI,IR24 and JG30)． Upper leaves were Inoculated with selectedstralnsby needlepuncture．The pathogenlclty of80X o．pv．o呷icola strains collected肋m different reas in China were ldentlfled based on swIn－－cultlvar Interaction．Accoding to the vlrulence against the differental var旧油 conducted,It shows that the vlrulence of these strains wasdifferentlateddlstlnctly．入厄aklmeractlonpatterns were proved mainly between psthogens and rice vanetles,some strong Interaction was discovered．It was suggested that theXo．pv．o0尸tooh can be classified Into 7 race groups or pathotypes．hey were RRRI；llllt,ItRJIRRS,MMSS,MRSSS,RRSRSS, RRSSSS and RSSSSS． In oderto compare the resistance difference of＊theence same varletlesto bactena leafNlght and leafstreak,strains ofX．o．pv．opeae andXo．pv oryZlcoh were Inoculated on 16Near－lso－lines varltles respectlvlly,on the basis oftest results during 1998—2000,tile follow conclusions re obtained:(l)．The compatlblllty among varltles and different strains Is varied．(2)．The resistance of varieties to different pathogens Is controlled by different resistant genes．(3)．There are specific 47compatibillty between the vlrulence gene InXo．pv oo厄icob ndnd山e eslstantgenein variety．O)Jingang 30 and ToToyonishlki are high susceptible to mostofthe twobacterlal psthogens,they canbe selected as susceptible standtand山d checkvane欢ies．(5)．The local epldenllc races and the variety resistant spectum should beconsidered咖n cultlvars are chosen In croPPing． ExNellulo degratlve enwmes of23 lso咖 ofXo．W．o呻oh砒ot6Sted bythe plate methods,results showed protlnase and vlrulence was notcontl咖d Intested sthelns(reo．1731 00sreo．413)．There was signlficanly conelatlon betweenestemes and vlrulence(rro·5008,r005二0·456)．Amy曲e activity was signific咖ly砒g蜘化切m阶加I！hW！印。e(0．9045,N。:目0．505)． No slgnlficantcorrelatlon was found between the motillty and viMence Intested'trains(vH2342)必...