不同遗传类群甘蔗黑穗病菌分离物与甘蔗互作防御酶差异的研究

为研究来源于不同遗传类群甘蔗黑穗病菌分离物侵染寄主甘蔗防御酶活性变化差异,采用注射接种法,将5个不同遗传类群的代表分离物(分离物编号依次为16,24,25,47,89号)侵染抗病甘蔗品种Q171和感病甘蔗品种ROC22,测定甘蔗与甘蔗黑穗病菌分离物互作过程中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)和多酚氧化酶(PPO)的活性变化。结果表明:5株分离物侵染引起的寄主甘蔗SOD、POD、CAT活性变化曲线中均存在2个酶峰值,抗病甘蔗品种Q171中PPO和感病甘蔗品种ROC22中PAL也存在2个酶峰值,接种后1 d出现峰值Ⅰ,接种后3~5 d出现峰值Ⅱ。其中峰值Ⅱ时期,5株分离物侵染的甘蔗上述5种防御酶活性均高于对照,但不同分离物侵染的甘蔗SOD、POD、PAL活性的峰值Ⅱ大小及出现时间表现出差异,尤其是89号分离物峰值Ⅱ比其余4个分离物峰值Ⅱ出现时间提早1~2 d且峰值差异明显。初步认为89号分离物可能代表着与其他分离物不同的致病型生理小种。

Study on the Difference of Defensive Enzyme Activities in Interaction Between Sporisorium scitamineum Isolates from Different Molecular Genetic Groups and Sugarcane

In order to investigate the changes of defensive enzyme activities in sugarcane infected by Sporisori-um scitamineum isolates originated from different molecular genetic groups.Five representative S.scitamineum isola-tions,including isolates 16,24,25,47 and 89,were injected to the resistant variety Q171 and susceptible variety ROC22 by using injected inoculation method.The activities of superoxide dismutase(SOD),peroxidase(POD),cat-alase(CAT),phenylalanine ammonialyase(PAL)and polyphenol oxidase(PPO)were determined during the interac-tions of Q171 and ROC22 sugarcane varieties with isolates of S.scitamineum.The results showed that the activities of SOD,POD and CAT existed 2 peaks,PPO of resistant variety Q171 and PAL of susceptible variety ROC22 also existed 2 peaks.PeakⅠappeared in the first day,peak Ⅱ appeared in the third to fifth days after inoculation.Dur-ing the peak Ⅱ,activities of five defensive enzymes mentioned above were higher in sugarcane plants inoculated by five isolates of S.scitamineum than those in the corresponding non-inoculated controls.However peak Ⅱ values and occurrence time of the SOD,POD and PAL showed significant difference among five isolates.Especially,peak Ⅱ of isolate 89 was earlier 1 -2 days than other four isolates in the occurrence time and its value also showed significant difference from other isolates.It was initially considered that the isolate 89 might be represent a new physiological race which was different from other four isolates.