内蒙古马铃薯黑胫病病原菌的分离和鉴定

Isolation and identification of the pathogen causing potato blackleg in Inner Mongolia

马铃薯是我国的第四大主粮。内蒙古是我国最大的马铃薯生产基地,马铃薯产业是当地农民收入的主要来源。2017年8月,内蒙古锡林郭勒盟部分马铃薯田块发生了一种细菌性黑胫病,发病面积约为200亩,发病率约为20%。发病初期,植株的茎基部变色、发黑,伴有臭味,严重时茎秆腐烂,植株死亡。为明确该地区马铃薯细菌性黑胫病的病原菌种类,本研究对该病原菌进行了分离,并利用生理生化测定,Biolog分析和分子生物学手段将该病原菌鉴定为胡萝卜软腐果胶杆菌巴西亚种(Pectobacterium carotovorum subsp. brasiliense)。据以往报道,我国马铃薯黑胫病主要由黑腐果胶杆菌(P. atrosepticum)和胡萝卜软腐果胶杆菌胡萝卜亚种(P. carotovorum subsp. carotovorum)两种病原菌引起,本研究是P. carotovorum subsp. brasiliense引起马铃薯黑胫病在国内的首次报道。

Potato (Solanum tuberosum L.)is the nation's fourth staple food and also as a major source of in- come for local farmers in Inner Mongolia,the largest production base of potatoes in China.In August 2017, blackleg and stem rot disease with an incidence up to 20%were recorded in a 15ha potato (cv.Helan-15)field in Xilingol league,Inner Mongolia,China.At the early stage of the disease,the mushy and black symptom with a stinking odour appeared on the stems from cuttings.Under prevailing wet and humid conditions,stems became slimy.In the late stage,the stems of the severely diseased plants got rot and wilted resulting death of the aboveground.To determinate the pathogenic species,the bacteria were isolated.Based on physiological/bio- chemical diagnostic tests,as well as molecular analysis of multilocus sequences,the causal pathogen was identi- fied as Pectobacterium carotovorum subsp,brasiliense (Pcb).In addition to the previous note of P.atrosepticum and P.carotovorum subsp,carotovorum,Pcb was the first report as a new member causing potato blackleg and stem rot in China.