Assessing the virulence of ophiostomatoid fungi associated with the pine-infesting weevils to scots pine Pinus sylvestris L. seedlings

Abstract

The pine-infesting weevils are known to be effective vectors of ophiostomatoid fungi. To understand more about fungal virulence of these fungi, inoculation studies were conducted on Scots pine ( Pinus sylvestris L.). Two-year-old seedlings were wound-inoculated with one of eleven ophiostomatoid fungi associated with pine-infesting weevils. After 11 weeks, a darkened lesion, extending from the point of inoculation, was observed in all species, except for Ophiostoma cf. abietinum Marm. & Butin, Ophiostoma quercus (Georgev.) Nannf., and Sporothrix inflata de Hoog. Seedling mortality was observed in seedlings inoculated with Leptographium truncatum (M.J. Wingf. & Marasas) M.J. Wingf., Leptographium lundbergii Lagerb. & Melin, Leptographium procerum (W.B. Kendr.) M.J. Wingf., Grosmannia radiaticola (J.J. Kim, Seifert & G.H. Kim) Zipfel, Z.W. de Beer & M.J. Wingf., Ophiostoma floccosum Math.-Käärik, Ophiostoma minus (Hedgc.) Syd. & P. Syd., and Ophiostoma piliferum (Fr.) Syd. & P. Syd. Ophiostoma minus and L. truncatum caused the largest lesions and sapwood blue-stain in Scots pine. Grosmannia radiaticola, Ophiostoma piceae (Münch) Syd. & P. Syd., O. floccosum, O. piliferum, L. lundbergii,and L. procerum produced significantly smaller lesions and sapwood blue-stain than O. minus and L. truncatum, while O. cf. abietinum, O. quercus and S. inflata did not cause any lesions.