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 (<em>Pinus sylvestris</em> 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 <em>Ophiostoma</em> cf. <em>abietinum</em> Marm. &amp; Butin, <em>Ophiostoma quercus</em> (Georgev.) Nannf., and <em>Sporothrix inflata </em>de Hoog. Seedling mortality was observed in seedlings inoculated with <em>Leptographium truncatum</em> (M.J. Wingf. &amp; Marasas) M.J. Wingf., <em>Leptographium lundbergii</em> Lagerb. &amp; Melin<em>,</em> <em>Leptographium procerum</em> (W.B. Kendr.) M.J. Wingf., <em>Grosmannia radiaticola</em> (J.J. Kim, Seifert &amp; G.H. Kim) Zipfel, Z.W. de Beer &amp; M.J. Wingf., <em>Ophiostoma floccosum</em> Math.-Käärik,<em> Ophiostoma minus</em> (Hedgc.) Syd. &amp; P. Syd., and <em>Ophiostoma piliferum </em>(Fr.) Syd. &amp; P. Syd. <em>Ophiostoma minus</em> and <em>L. truncatum</em> caused the largest lesions and sapwood blue-stain in Scots pine. <em>Grosmannia radiaticola, Ophiostoma piceae </em>(Münch) Syd. &amp; P. Syd., <em>O. floccosum</em>,<em> O. piliferum,</em> <em>L. lundbergii</em>,and<em> L. procerum </em>produced significantly smaller lesions and sapwood blue-stain than <em>O. minus</em> and <em>L. truncatum</em>, while<em> O</em>. cf. <em>abietinum</em>, <em>O. quercus</em> and <em>S. inflata</em> did not cause any lesions.