Shaghayegh Zolghadry - Silviculture and Forest Ecology, University of Guilan, Iran.
Mehrdad Ghodskhah Daryaee - Department of Forestry, University of Natural Resources, Guilan, Iran
Javad Torkaman - Department of Forestry, University of Natural Resources, Guilan, Iran

The survival of some elms to Dutch elm disease (DED) epidemics could be related with the resistance to disease. To test this hypothesis, there is a significant difference between species (Ulmus glabra ,ulmus carpinifolia and zelkova carpinifolia) which is cultivated in urban green space and named species cultivated outside the city. The present study aims to compare the number of hole which filled with tylose in given species at tu different place (urban green space and outside the city). To do this, some samples were randomly collected from 10 cm above the place of seedling’s inoculation. The test results showed that there was a significant difference at 1% probability level among the measured indicators in these three species. According to the result the maximum number of hole which is filled with tylose belonged to U. carpinifolia which is cultivate in urban green space where placed subject to air pollution

Dutch elm disease, Hole, Tylose, Air Pollution