烟草赤星病菌菌种保存及致病性研究

在烟草赤星病抗性鉴定和生防菌剂筛选工作中,常因菌种在室内连续多代移植培养导致菌株的致病力衰弱,而影响测定结果的准确性和一致性。对此,本研究尝试将赤星病菌种经Richards培养液制备成菌层,置于4℃低温环境条件下长期保存,连续5年测定其培养性状和致病力,与连续转代培养方法保存的菌种进行比较,结果表明在连续5年的试验过程中,Richards法保存的菌种在培养性状和致病性上没有发生衰退,该菌种保存方法制作简单、经济、可靠,适用于烟草品种抗赤星病鉴定和生防菌剂的筛选工作。

Preservation of the pathogen of tobacco brown spot and its pathogenicity

The pathogen of tobacco brown spot,Alternaria alternate,usually degenerates as it is successively transplanted and cultivated indoors during identification of resistance and screening of antagonistic isolates,which affects the accuracy of identification.In order to maintain the pathogenicity,the pathogen was transplanted and cultivated on Richards' culture media,and then preserved in refrigerator under 4 ℃ for a long time,which was used to determine the vitality and pathogenicity by cultivating indoors and inoculating tobacco plants.The results indicated that the pathogen of tobacco brown spot on Richards' culture media could be preserved for a long time in refrigerator under 4 ℃ and keep vitality and pathogenicity for 5 years.This method of preserving pathogens was simple,economical and reliable,so it might be used for identification of resistance and screening of antagonistic isolates to tobacco brown spot.