Phyllactinia mali . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Phyllactinia mali . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Powdery mildew of different arboreal Rosaceae, including important cultivated species. Mycelium, conidiophores, conidia and ascomata develop on lower part of leaves without any visible damage. This disease is dangerous for pear seedlings in nurseries only. HOSTS: Amelanchier canadensis, A. ovalis ( A. vulgaris ), Cotoneaster bacillaris (?), Crataegus brevispina, C. curvisepala ( C. kyrtostyla, C. oxycantha ), C. douglasii, C. laevigata, C. lindmanii ( C. calycina), C. meyeri, C. monogyna, C. nigra, C. orientalis ( C. laciniata ), C. pallasii, C. parviflora, C. pentagyna, C. sanguinea, C. scabrifolius, C. taurica, Cydonia oblonga, Malus domestica, M. pumila, M. sylvestris, Mespilus germanica, Prunus avium ( Cerasus avium [Prunus avium] ) (?), P. cerasus ( Cerasus vulgaris [Prunus cerasus] ) (?), P. padus ( Padus avium [Prunus padus] ) (?), P. spinosa (?), Pyrus caucasica, P. communis, P. cordata, P. elaeagnifolia, P . lindleyi, P. pashia, P. pyraster, P. pyrifolia , ( 'P. sativa Fakirova'), P. zangezura, Rosa canina (?), Sorbus aucuparia (?), S. torminalis (?). [Type host - Malus sp.] GEOGRAPHICAL DISTRIBUTION: Africa: Algeria, Morocco. Asia (temperate areas only): Armenia, Azerbaijan, China, Cyprus, Republic of Georgia, India, Iran, Israel, Japan, Korea, Lebanon, Nepal, Pakistan, Russia (western Siberia), Taiwan, Turkey, Turkmenistan. Europe: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Rumania, Slovakia, Spain, Sweden, Switzerland, Turkey (European part), Ukraine, former Yugoslavia. North America: Canada, USA. TRANSMISSION: By wind-dispersed conidia. The rôle of ascospores in disease transmission is unknown, although it has been supposed that they can cause the initial stage of the disease.