The damage and symptoms of jujube fruit soft rot in Xinzheng,Henan Province,were investigated from 2006 to 2008,and the pathogen was identified based on the morphological characteristics and the ITS se-quence of ribosome DNA. The results showed that the aerial mycelium of colony was white in color in the first four days,then turned gray after incubation on PDA for5 -6 d at25℃ and became black two weeks later.The mycelia grew luxuriantly with velvet character. The pycnidium was flask-shaped with a height of 196.9μm and a width of 213.3μm on the avereage. The conidium was colorless with single cell and had the shape of spindle,its size was (15.0 -20.0)μm ×(4.5 -6.5)μm. The conidiophore was fastigiate. The homology of ITS sequence of ribosome DNA between the tested strain NXK and Botryosphaeria dothidea(GenBank ac-cession number:AJ938005) reached 99.87%,with a difference of only two base pairs. Based on the results of both morphological characters and molecular identification,the pathogen of jujube fruit soft rot in Xinzheng was identified as B. dothidea(Moug. ex Fr.) Ces. et de Not..
枣树缩果病的病原菌(Frwinia jujubovoraWang.Cai.Feng et Gao)为肠杆菌科,欧文氏菌属的一个新种。经多年研究,此病发生与气温、湿度和枣果发育期密切相关。在新郑枣区,8月中旬至9月中旬,旬平均气温22—26℃时,是此病主要发生期。通过小区试验,使用链霉素70—140单位/毫升、50%DT 600倍液、卡那霉素140单位/毫升、土霉素210单位/毫升等药剂喷药3次,保果率在90%以上。1986年以来,在新郑等三县示范防治6.1万株,病果率降至7%以下,纯经济收入57.95万元。
