The development of wood decay caused by 12 major root-rot and trunk-rot fungi was investigated in vitro with sapwood extracted from nine ornamental and landscape hardwood and conifer species native to southern temperate regions of North America, Europe, and the lower Mississippi Delta. Wood decay rates based on dry weight loss for 108 host tree–wood decay fungi combinations were compared at 21 ...

Recent advances in the genetics and population biology of Heterobasidion annosum are reviewed. H. annosum is a heterothallic (outbreeding) basidiomycete with a unifactorial, multiallelic incompatibility system which regulates mating. H. annosum in western North America consists of two intersterility groups (biological species) which can be identified through mating tests and isozyme analysis. I...

The expression of gastrodianin antifungal protein (GAFP) in a form of its VNF isoform increases tolerance to Phytophthora root rot (Phytophthora cinnamomi) and the root-knot nematode (Meloidogyne incognita) in transgenic plum lines. However, nothing is known about the potential of the GAFP lectin to confer disease resistance to the ring nematode, Mesocriconema xenoplax, in plum. Three transgeni...

H. annosum was first discovered as a root pathogen of pine in western United States by E. P. Meinecke in 1909. Other early researchers reported it as a root and butt decay of nonresinous conifers in the west. Olson demonstrated its pathogenicity to western conifers and Wagener and Cave described its occurrence and role in the eastside pine forests. In the last 20 years pathologists have become ...

that 286,000 ha in Arkansas were affected by the oak decline. In 2002 and 2003, Guldin et al. (2006) established 181 field plots in Arkansas, Missouri, and Oklahoma and estimated that 33% of red oak density (trees/ha) and 30% of red oak basal area in the region were dead or dying. Kabrick et al. (2004) studied nine forested sites in southern Missouri ranging in size from 312 to 514 ha. They rep...

Individual trees of giant sequoia (Sequoia gigantea [Lindl.] Decne.) have demonstrated a capacity to attain both a long life and very large size. It is not uncommon to find old-growth giant sequoia trees in their native range that are 1,500 years old and over 15 feet in diameter at breast height. The ability of individual giant sequoia trees to survive over such long periods of time has often b...