High performance liquid chromatography determination of ergosterolas a measure of ectomycorrhiza infection in Scots pine     

By B. Salmanowicz  J.-E. Nylund 《Forest Pathology》1988,18(5):291-298

A technique for determining the ergosterol content in mycorrhizal pine roots using HPLC was developed. Pure cultures of different my corrhizal fungi contained very similar and constant amounts of ergosterol, and calculations of fungal biomass in mycorrhizal roots based on ergosterol readings agreed well with results using other methods. The extraction and sample purification were simple and reliable. Consequently, the technique is considered practical wherever accurate estimates of the intensity of mycorrhizal infection are required.  相似文献   

Simple diagnosis of ectomycorrhiza formation and demonstration of the architecture of the Hartig net by means of a clearing technique     

J.-E. Nylund  Asa Kasimir  Agneta Strandberg Arveby  T. Unestam 《Forest Pathology》1982,12(2):103-107

Coniferous ectomycorrhiza was cleared in KOH and bleached in H₂ 0₂ . After the treatment, the structure of the Hartig net and inner mantle could be studied in detail in entire mycorrhizal short roots. The Hartig net and inner mantle were found to be formed by the same type of labyrinthic tissue, a result of morphogenetic processes during mycorrhiza formation. Even early phases of mycorrhizal infection could easily be detected, which makes the method very suitable for diagnosticating mycorrhiza formation accurately.  相似文献   

Episodic Events in Water Chemistry and Metals in Streams in Northern Sweden during Spring Flood     

Frida Edberg  Hans Borg  Jan-Erik Åslund 《Water, air, and soil pollution》2001,130(1-4):1697-1702

Thirteen streams in the province of Jämtland in northern Sweden were monitored during spring in 1995 (December 94 – July 95) to study changes in water chemistry and metal concentrations during snow melt. The brooks are not treated with lime, with one exception, and can be approximately divided into three groups according to watershed characteristics; A) > 65% above tree line, B) > 65 % wetland, C) > 55% forested. During peak flow, pH dropped 0.5–2.5 units and alkalinity generally to zero. The brooks above tree line were lowest in base cations and reached the lowest pH-values (4.4–4.6) during peak flow, while sulphate levels were about the same as in the forested watersheds. During peak flow, organic anions showed the highest increase in the wetland and forested catchments. Compared to base flow, Al, Zn, Pb and to some extent Mn was enriched during peak flow. The results also illustrate the difficulties in generalising the reasons for alkalinity losses during spring flood in this kind of streams. In some of the brooks, the use of either base cations or silica, when calculating dilution effects, gave deviating results concerning the relative contribution of strong acids in the snow pack.  相似文献   

Thoracoscopic‐assisted lung lobectomy in cat cadavers using a resorbable self‐locking ligation device     

Adam M. Nylund  Odd V. Hglund  Boel A. Fransson 《Veterinary surgery : VS》2019,48(4):563-569

  相似文献   

Mechanizsed microsite preparation and direct seeding of Pinus sylvestris in boreal forests — a way to create desired spacing at low cost     

Wennström  Ulfstand  Bergsten  Urban  Nilsson  Jan-Erik 《New Forests》1999,18(2):179-198

The main objective of this study was to examine the cost, flexibility, and appropriate scale of mechanized microsite preparation (MP), in combination with mechanical direct seeding of Pinus sylvestris L. with orchard seed. This technique was tested at four boreal forest sites in Northern Sweden. Orchard and stand seeds were sown with and without MP. The use of orchard seed increased seedling establishment by 41% and the use of MP increased seedling establishment by 47%, respectively, after two years. The best substrates for sowing when using MP were OA_h-, E- and BC-horizon, in ranked order. The use of orchard seed compared to stand seed increased mean seedling height by 25% after four years. These trials suggest that to obtain a density of 5,000 stems ha^-1 four years after seeding, 61,000 viable stand seeds or 41,000 orchard seeds ha^-1 should be sown if MP is not used. If MP is used, seeding rate could be reduced by about 32%. By using MP, and by further improving scarification technique so that all scarified area is thin OA_h-horizon, we predict that only 32,000 stand seeds or 22,000 orchard seeds ha^-1, i.e., half the dosage, should be needed. Under these optimal conditions, it would be necessary to sow about six and four germinable stand and orchard seeds, respectively, to ensure one seedling after four years. Furthermore, regeneration cost would be less than a third that of planting.  相似文献   

The influence of mist irrigation on the potato IV. Tuber quality factors     

D. C. Sanders  R. E. Nylund  E. C. Quisumbing  K. V. P. Shetty 《American Journal of Potato Research》1972,49(7):243-254

The influence of irrigation method on tuber quality factors was assessed during three seasons. Low volume “mist” irrigation (M), furrow irrigation (F), mist plus furrow (MF) and no irrigation (NI) were compared. Tubers from misted treatments (M and MF) tended to be lower in dry matter, had a high incidence of secondary growth and hollowheart, yielded darker chips, required more time to condition, were less mature, and contained more reducing sugars than those from NI treatments. Further the tubers from misted treatments tended to contain more P, Mg, Ca, Fe, Al, B and Mn, than those from NI plots at various times during the latter part of the season.  相似文献   

Effects of slash retention and wood ash addition on fine root biomass and production and fungal mycelium in a Norway spruce stand in SW Sweden     

Hooshang Majdi  Laimi Truus  Ulf Johansson  Jan-Erik Nylund  Håkan Wallander 《Forest Ecology and Management》2008

In the study reported here we examined the short-term effects (1–3 years) of slash retention (SR) and the long-term effects (13–15 years) of wood-ash application (A) on fine roots and mycorrhizae in a 40-year-old Norway spruce forest in southwest Sweden. Soil cores were used to obtain estimates of the biomass (g m⁻²) of roots in three diameter classes (<0.5, 0.5–1 and 1–2 mm), root length density (RLD), specific root length (SRL) and mycorrhizal root tip density (RTD). Fine root (<1 mm) length production and mortality, and mycelium production, were estimated using minirhizotron and mesh bag techniques, respectively. Compared with the control plots (C), the biomass of fine roots in diameter classes <0.5 mm and 0.5–1 mm was significantly higher in A plots, but lower in SR plots. In addition, RLD was significantly lower in the humus layer of SR plots than in the humus layers of C and A plots, but not in the other layers. None of the treatments affected the SRL. In all soil layers, the SR treatment resulted in significant reductions in the number of ectomycorrhizal root tips, and the mycelia production of fungi in mesh bags, relative to the C treatment, but the C and A treatments induced no significant changes in these variables. Fine root length production in the C, A and SR plots amounted to 94, 87 and 70 mm tube⁻¹ during the 2003 growing season, respectively. Fine root mortality in treated plots did not change over the course of the study. We suggest that leaving logging residues on fertile sites may result in nitrogen mineralisation, which may in turn induce reductions in root biomass, and both root and mycelium production, and consequently affect nutrient uptake and the accumulation of organic carbon in soil derived from roots and mycorrhizae.  相似文献   

Further studies on the influence of sprout-inhibiting and sprout-inducing treatments on the growth and yields of potatoes     

Humberto Gandarillas  R. E. Nylund 《American Journal of Potato Research》1949,26(1):7-16

  相似文献   

Evaluation of a resorbable self‐locking ligation device for performing peripheral lung biopsies in a caprine cadaveric model     

Adam M. Nylund  Chi‐Ya Chen  Odd V. Hglund  Bonnie G. Campbell  Boel A. Fransson 《Veterinary surgery : VS》2019,48(5):845-849

  相似文献   

Echinococcus granulosus in Finland     

Hirvelä-Koski V  Haukisalmi V  Kilpelä SS  Nylund M  Koski P 《Veterinary parasitology》2003,111(2-3):175-192

Echinococcus granulosus is shown to occur in eastern Finland in a sylvatic cycle involving wolves (Canis lupus) as the definitive host and reindeer (Rangifer tarandus tarandus) and probably also elk (Alces alces) and the wild forest reindeer (Rangifer tarandus fennicus) as intermediate hosts. Even though the prevalence of E. granulosus in reindeer has increased in recent years, it is still very low (<0.013%). The results suggest, however, that the reindeer is a good sentinel animal to show the contamination of soil with Echinococcus eggs. This is the first report of wolves acting as a definitive host for E. granulosus in northern Europe. The parasite seems to be quite common in the Finnish wolf population, with a prevalence of approximately 30% in both intestinal and faecal samples. The present results and previous ones indicate that E. granulosus infection has not spread to dogs in the reindeer herding area.  相似文献