THE INCIDENCE AND DISTRIBUTION OF RACES OF VERTICILLIUM-DAHLIAE IN CRETE

In a survey of verticillium wilt of cultivated and weed hosts in Crete in 1988-89, Verticillium dahliae was the only species isolated. The pathogen was found in 84 out of 231 vegetable crops, and six out of 14 olive orchards. It was also found in two locations on the weed Solanum nigrum. Hosts belonged to 12 plant species in six different botanical families. Natural infection of Vicia faba by V. dahliae is reported for the first time. The physiological races of 92 isolates of V. dahliae were identified using two differential tomato cultivars. Of these isolates, 89 were race 1, one was race 2, and the remaining two were non-pathogenic. Virulence of the various isolates to tomato varied from slightly to highly pathogenic and was independent of the hosts from which they originated.