Determination of the activity of Cryphoneectria hypovirus in different ultraviolet light exposed cultures

Cryphonectria parasitica (Murill) Barr causes cankers by progressing under the bark of chestnut trees. For the most effective fight against chestnut canker, it is recommended to apply cultural measures (mechanical measures) and biological measures together. Biological control is to try to reduce the virulence of the pathogenic fungus by using hypovirulent strains. The success of biological control depends on the hypovirus. However, it is thought that there are many different factors that affect the state of the hypovirus in the fungus. The effect of light on the development of hypovirus was the subject of this study. In biological control studies, hypovirus-containing C. parasitica isolates, that is, hypovirulent isolates, are applied to the canckerous bark with appropriate methods. In the study, hypovirulent isolates obtained from Sinop province, which is included in the European compatibility group EU-1, and a hypovirulent isolate of Macedonian origin, which entered EU-12, and EU-12 (BU06) isolates from Bursa origin, which were transferred hypovirus, were used. Hypovirulent isolates were kept under 5 different light combinations and the development of hypovirus was evaluated according to their cultural characteristics. All isolates subjected to light were also included in the Bavendamm test. It was observed that different light lengths adversely affected virus development, and the virus did not develop in hypovirulent isolates kept under ultraviolet light.