Genetic variability of the 'bark canker resistance' character in several natural provenances of Cupressus sempervirens

Several Aegean (Greece) and Anatolian (Turkey) cypress provenances were studied for resistance variability to bark canker, a disease caused by the fungal pathogen Seiridium cardinale. The investigation also examined whether the low disease rate within the natural area of cypress was due to genetic or geographic-climatic reasons. Results demonstrated strong variability for the 'bark canker resistance' character, in particular for trees within families. As trees from the provenances studied were not found to have genetic superiority for bark canker resistance, the above-mentioned low disease rate could be due to geographic-climatic barriers that inhibit the development of the fungus or its ability to infect the host. Several half-sib progenies exhibited high resistance, suggesting that this character is totally inherited through the maternal line. Should this finding be confirmed by further research, it would facilitate the task of genetic improvement for resistance, allowing progenies of resistant trees to be obtained.