杨树水泡型溃疡病菌的致病性研究

 从杨树病斑上分离所得的水泡型溃疡病病原菌(Dothiorella gregaria Sacc.),经室内外的人工接种试验,均能诱致发病,产生与自然罹病相同的典型症状。室内人工接种保湿时间以10~14天较为适宜,接种最适温度为24℃~28℃,温度低于13℃不发病。该菌对阔叶树中的柳树、刺槐、核桃均有致病性。不同杨树种及品种对该菌的抗病性测定结果,白杨派的种及品种较抗病,其中尤以新疆杨最抗病;青杨派、黑杨派×青杨派、青杨派×黑杨派的派间杂种最易感病,其中尤以青杨、小青杨、北京杨感病最重;黑杨派的品种为中等感病。

ON THE PATHOGENSIS OF THE CAUSAL ORGANISM(Dothiorella gregaria Sacc.)OF THE BLISTER-TYPE CANKER ON POPLAR

Dothiorella gregaria Sacc. isolated from the blister type canker on poplar tree has been demondstrated as a causal fungus of the disease,through artificial inoculation both in laboratory and in the field tests.The symptoms induced are just as typical as those shown in the field.Keeping moisture 10-14 days after inoculation are suitable. The optimal temperature for disease development is 24℃ to 28℃.If the temperature is below 13℃, it does not cause any disease at all. The fungus infects the broad leaf trees such as Salix sp.,Lobinia pseudocacta, Juglan regia.Examinations show that resistance are different among species and va-rieties of poplar to the fungus. The varieties of Sect.Leuce Duby are fairly resistant,in which P. bolleana Lauche is the most resistant. The hybrids of Sect.Tacamahaca Spach of Sect.Aigeiros Duby×Sect. Ta-macahaca Spach and of Sect.Tacamahaca Spach×Sect.Aigeiros Duby are the most susceptible.P.cathayana Rehd.,P. pseudo-simonii K itag.,P. peki-nensts Hsu are the most susceptible while Sect.Aigeiros Duby the median susceptible.