Pathogenicity of Leptographium Species Associated with Loblolly Pine Decline

Abstract

Freshly lifted seedlings and 21-year-old trees of loblolly pine were wound-inoculated with Leptographium species recovered from the soil and/or roots of trees with loblolly decline symptoms in central Alabama. Seedlings inoculated with L. procerum in the greenhouse produced significantly fewer root initials and a smaller root mass than control seedlings. Vertical lesions produced in seedlings by L. serpens and L. terebrantis were significantly longer than in controls. Lesions produced in mature trees by L. serpens and L. lundbergii were significantly longer than in controls. Of the fungi tested, L. serpens, L. terebrantis, and L. lundbergii were the most aggressive and may pose the greatest threat to loblolly pines.

Simulated Summer Rainfall Variability Effects on Loblolly Pine (Pinus taeda) Seedling Physiology and Susceptibility to Root-Infecting Ophiostomatoid Fungi

“…Results from this study should be reviewed with caution as the experimental duration (13 weeks) was short, while the impact of changed precipitation patterns could have effects over longer periods. In addition, root-infecting ophiostomatoid fungi associated with SPD affect mature trees; however, the use of seedlings to screen families for tolerance has been useful in predicting the response of mature trees (Eckhardt et al, 2004).…”

“…Predisposing abiotic factors include resource stress (nutrient deficiencies, edaphic factors, and moisture stress), management strategies such as overstocking, mechanical injury and prescribed burning [4]. Studies have shown that when loblolly pine (P. taeda) is inoculated with L. terebrantis, the fungus can result in the development of lesions in the phloem and resin-soaking in the xylem [5][6][7]. Grosmannia huntii, a non-indigenous species, is a related fungal pathogen and has been reported to be more virulent in young pine seedlings when compared to L. terebrantis [7].…”

Phylogeny and taxonomy of species in theGrosmannia serpenscomplex

“…Grosmannia serpens was isolated from symptomatic P. pinea trees with a root disease in Italy (Lorenzini and Gambogi 1976) and G. alacris was isolated from diseased roots of P. pinaster and P. radiata in South Africa (Wingfield andKnoxDavies 1980, Wingfield andMarasas 1980). Studies also showed that G. alacris can cause lesions when inoculated in pine seedlings and mature trees (Eckhardt et al 2004, Zhou et al 2002. None of these authors suggested that this fungus is a serious primary pathogen (Eckhardt et al 2004, Matusick et al 2008, Zhou et al 2002).…”

“…Studies also showed that G. alacris can cause lesions when inoculated in pine seedlings and mature trees (Eckhardt et al 2004, Zhou et al 2002. None of these authors suggested that this fungus is a serious primary pathogen (Eckhardt et al 2004, Matusick et al 2008, Zhou et al 2002). Yet among the fungi associated with conifer root-infesting bark beetles those in the G. serpens complex are among the most pathogenic.…”

Do novel genotypes drive the success of an invasive bark beetle–fungus complex? Implications for potential reinvasion

“…B1). Some studies have shown good correlation between responses from mass-inoculated mature trees and lesion length in wound-inoculated seedlings (Krokene and Solheim 1998, Eckhardt et al 2004, Lieutier et al 2004). We have also recently shown a strong correlation between the pathogenicity of L. procerum isolates on mature pines with that on seedlings (B. Wang, M. Lu, and J.…”