engleski

Biological control of chestnut blight

One of the most aggressive plant pathogens, chestnut blight fungus Cryphonectria parasitica, is present in all chestnut-growing regions in Croatia, causing decay of chestnut trees. Disease caused by this fungus can be controlled by naturally-occurring hypovirus. To characterize the populations of C. parasitica and asses the possibilities for biological control of chestnut blight in Croatia, vegetative compatibility (vc) types and mating types of the fungus were determined, as well as hypovirus distribution in C. parasitica populations, and it's genetic variation. Eighteen vc types were identified, revealing high genetic diversity of C. parasitica populations. The vc type EU-1 was the most common type comprising 42.9% of the isolates followed by EU-2 (21%) and EU-12 (14.2%). Both mating types of C. parasitica in approximately 1:1 ratio were found in all populations indicating sexual reproduction in all C. parasitica populations in Croatia. Although a high diversity of vc types has been observed, natural biological control was recorded in all 10 populations with incidence of white-hypovirulent isolates varying from 12.7% to 66.6%. All white C. parasitica isolates and some intermediate isolates contained subtype I of Cryphonectria hypovirus 1. Phylogenetic analysis of Croatian CHV-1, subtype I isolates revealed that the viruses were closely related to those of other European countries.

chestnut; Cryphonectria hypovirus 1; Cryphonectria parasitica; hypovirulence; phylogenetic analysis

nije evidentirano