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

One of the most widespread and destructive disease of the elm family is Dutch Elm Disease. The present study aims to compare the diameter size of vessels and the number of xylary rays in four species: Ulmus carpinifolia, Ulmus glabra, Zelkova carpinifolia and Celtis australis as important factors in host resistance to elm disease. Based on result, there was a significant difference at 1% probability level among the measured indicators in these four species, the maximum diameter of vessel and the maximum number of xylary rays belonged to U. carpinifolia.

Dutch elm disease, xylary rays, vessel, resistance