菜豆普通细菌性疫病菌在土壤和植株残体中的越冬能力

为评估菜豆普通细菌性疫病菌地毯草黄单胞杆菌菜豆致病变种或褐色黄单胞菌褐色亚种在土壤及植物残体中的越冬能力,对采自黑龙江、内蒙古、山西、河北及新疆的18块菜豆生产田的20份土壤及14份植物残体样品进行病原菌分离和鉴定。在MT选择性培养基上有12个土壤样品和13个植株残体样品提取液产生典型的类似黄单胞菌菌落。选取29个分离物进行致病性测定,有27个分离物对菜豆品种"英国红"致病。利用地毯草黄单胞杆菌菜豆致病变种和褐色黄单胞菌褐色亚种的特异性引物X4c/X4e及褐色黄单胞菌褐色亚种特异性引物Xf1/Xf2对29个分离物进行多重PCR检测,其中17个分离物为地毯草黄单胞杆菌菜豆致病变种,10个分离物为褐色黄单胞菌褐色亚种。结果表明,菜豆普通细菌性疫病菌可以在黑龙江、内蒙古、山西、河北的一些菜豆种植区的土壤及植株残体中越冬存活。

The overwintering ability of Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans in soil and plant debris

To understand the overwintering ablility of Xanthomonas axonopodis pv. phaseoli and X.fuscans subsp.fuscans causing common bacterial blight of common bean in soil and common bean plant debris, the pathogens were detected and identified in 20 soil samples and 14 plant debris samples collected from 18 common bean production fields in Heilongjiang, Inner Mongolia, Shanxi, Hebei and Xinjiang. The results showed that typical Xanthomonad-like bacteria were detected in extracts of 12 soil samples and 13 debris samples on MT selective medium. The pathogenicity of the representative isolates was confirmed by stem inoculation of young bean plants, 27 out of 29 isolates were pathogenic on bean cultivar "Yingguohong". The genomic DNA of representative isolates were amplified with the X.axonopodis pv. phaseoli and X.fuscans subsp.fuscans specific primer pair X4c/X4e and X.fuscans subsp.fuscans specific primer pair Xf1/Xf2 in a multiplex PCR, and 17 isolates were identified as X.axonopodis pv. phaseoli,while 10 isolates were X.fuscans subsp. fuscans. The study showed the pathogens of common bacterial blight can overwinter in soil and crop residues in the some bean production regions of Heilongjiang, Inner Mongolia, Shanxi and Hebei.