Incidence of decay in creosote-treated Scots pine poles in Ireland

Air-seasoning is a simple method for moisture management in utility poles prior to treatment, but it involves the risk of fungal invasion during drying. These fungi can be eliminated by heat treatment, but fungi surviving in the installed poles are a quality problem. In this context, the incidence of decay fungi was investigated in 963 creosote-treated Scots pine (Pinus sylvestris) poles of varying ages in a utility system in Ireland. Thirty-seven percent of increment cores removed from the poles contained at least one viable basidiomycete. There was no relationship between pole age or distance above the groundline and fungal isolations.Phlebiopsis gigantea, a white rot fungus, was the most common isolate followed byNeolentinus lepideusandSistotrema brinkmannii. The results highlight the importance of including a sterilizing process during treatment and maintaining quality controls when purchasing large numbers of poles.

PRIMARY HOMOTHALLISM—RELATION TO HETEROTHALLISM IN THE REGULATION OF SEXUAL MORPHOGENESIS IN SISTOTREMA

ABSTRACT The wood-rotting basidiomycete, Sistotrema brinkmannii, is an aggregate of biological species possessing several variations—homothallism, bipolar heterothallism and tetrapolar heterothallism—on the genetic regulation of a critical phase of development. Nutritionally forced intra- and interspecific matings provide genetic information about the relatedness of homothallic isolates, the relation of the various species to one another, the genetic basis of homothallism, and its relationship to heterothallism. Most homothallic isolates are interfertile when nutritionally forced. Successful hybridization between species is restricted to particular combinations of homothallic × bipolar isolates. Significant findings of these studies include: (1) documentation of hybridization of biological species in the Homobasidiomycetes, (2) documentation of the relatedness of two naturally occurring, variant systems, homothallism and bipolar heterothallism, that regulate sexual morphogenesis in the higher fungi, (3) evidence for definite, but limited, evolutionary divergence of the polygenic, regulated components of the respective systems, and (4) indication that the genetic basis of homothallism in this system is essentially due to constitutive function and consequently is fundamentally different from presently understood mechanisms in other self-fertile systems.