Investigation And Pathogen Identification Of Powdery Mildews On Woody Plants In Hohhot

In order to find out the incidence and types of powdery mildews of woody plants in Hohhot,this study investigated the major parks and other places around Hohhot in detail by means of traveling along the road.More than 300 specimens were collected and the pathogen of powdery mildew of woody plants in Hohhot was identified by morphological classification method.The main results are as follows:(1)Through the investigation of Xiaojinggou,Nantianmen,Manduhai Park,Chilechuan Park,Qingcheng Park,Arboretum,Genghis Khan Park,Ulanf Memorial Hall and the surrounding campuses in Hohhot,44 species of woody plants belonging to 27 genera and 17 families were found to suffer from powdery mildews.In the process of collecting and investigating diseases,9 kinds of woody plants,such as Morus alba L.?Morus mongolica Schneid.and Prunus davidiana(Carr.)Franch.were found to have a serious incidence of powdery mildews.There were 25 kinds of host plants,such as Acer truncatum Bunge.?Toona sinensis(A.Juss.)Roem.?Pyrus bretschneideri Rehd and others had a moderate incidence.While 10 kinds of plants,such as Caragana rosea Turcz.?Catalpa ovata G.Don?Koelreuteria paniculata Laxm.and others had a mild incidence of powdery mildews.Only a few leaves were susceptible to diseases,which were difficult to observe under normal circumstances.(2)A total of 32 species of powdery mildew fungi belonging to 4 families,5 genera were identified.There are 18 species of Erysiphe,1 specy of Arthrocladiella,5 species of Podosphaera,4 species of Sawadaea and 4 species of Phyllactinia.There are two new species which parasitized on Sorbarria kirilowii(Regel)Maxim.and Cotoneaster multiflonis Bunge.respectively.One new recorded species in Inner Mongolia,which is Uncinula cedrelae.(3)Three new recorded host plants of powdery mildews fungi were found in China,they are Lonicera ruprechtiana Regel?Lonicera nigra L.var.barbinervis(kom.)Nakai and Sorbarria kirilowii(Regel)Maxim,respectively.Furthermore,there are 4 new recorded host plants of Inner Mongolia,they are Toona sinensis(A.Juss.)Roem.?Cotoneaster multiflorus Bunge.?Syringa microphylla Diels?Populus tomentosa Carr.and Malus spectabilis(Ait.)Borkh..