Evaluating the persistence of Phlebiopsis gigantea (Fr.: Fr.) Jülich mycelium and fruiting bodies in pine stumps after root-rot protection treatments

Abstract

Ocena wystêpowania grzybni i owocnikówAbstract. Commercial preparations Rotstop and PgSuspension, used in Scandinavia and the United Kingdom, are EUlicensed biocontrol agents against root rot that contain isolates of the fungus Phlebiopsis gigantea. The composition of these two products differs from that of PgIBL, previously use in Poland, hence the need to verify their effectiveness under Polish site and stand conditions. Stumps were treated with the commercial products and subsequently checked after one year for the persistence of mycelia and fruiting bodies. Molecular methods were used on the mycelia present in the stumps to confirm that their genetic identity was consistent with fungal isolates from the preparations. Treatments with EU-licensed preparations gave satisfactory results -in about 70-80% of the stumps mycelia were present under the bark. Inoculation with Rotstop preparations was most effective during autumn 2008 (effectiveness of 82%), while PgSuspension application was most effective during spring 2008 (effectiveness of 77%). The development of the mycelia in pine stumps from the two preparations investigated (containing preserved dormant spores) was similar to that of preparation PgIBL (formulated from living mycelium within a growing medium), in terms of their relative effectiveness measured as the percentage of stumps supporting under-bark mycelia (which ranged between 70-90%, depending on the treatment term).

What Is Important in Selecting Phlebiopsis gigantea Strain for Commercial Use?

“…Li et al [23] suggested that local Chinese strains of P. gigantea were better to control H. parviporum than Rotstop. However, this remark was not confirmed by Małecka et al [24] during studies carried out under the environmental conditions of Polish forests.…”

“…The results obtained under different site conditions in Poland (i.e., climate, density of forests, age of trees, treatment timing, season of application, etc. ), both in Scots pine and Norway spruce stands indicated high but differentiated efficacy of the products used in protective treatments [24]. Those results suggest that in the first years after application the effectiveness of P. gigantea inoculation on spruce stumps is lower than that on pine stumps.…”

“…Specificity of forest location, environmental conditions as well as resultant differentiation in genetic and physiological features of coniferous stands in Poland encourage undertaking studies on P. gigantea strains effectiveness and their practical usefulness at a local level, in view of different climatic, habitat and management conditions [17,24]. Since it is possible that the registered strains (active in tests performed in the country of their origin) can show the other kind of activity under different habitat conditions in another country.…”

Colonization of Fungi and Bacteria in Stumps and Roots of Scots Pine after Thinning and Treatment with Rotstop

“…; Małecka et al. ), the developing P. gigantea mycelium can grow deep in the root system of Scots pine and decrease secondary infection risk (root‐by‐root) (Sierota ). This is especially of importance in regard to Rotstop registration in Poland in 2015 and its use in the Central B zone of European countries (Art.…”

Fibroporia gossypium in northeastern Poland – a preliminary study

“…At present, a saprotrophic fungus Phlebiopsis gigantea, a protective agent against Heterobasidion spp., is commercially used [18][19][20]. However, studies performed by Żółciak et al [21] and Małecka et al [22,23] showed that in the case of spruce stumps, the prophylactic effect of P. gigantea is not always satisfactory over a short period of time. Hence, it is important to search for other saprotrophic species that could be more effective in the decay of spruce stumps and roots under natural conditions and could therefore find practical application.…”