Phaeocryptopus gaeumannii, patógeno causante del “swiss needle cast” en Pseudotsuga menziesii: antecedentes de su biología, medidas de control y situación en Chile

Abstract

Phaeocryptopus gaeumannii, patógeno causante del "swiss needle cast" en Pseudotsuga menziesii: antecedentes de su biología, medidas de control y situación en Chile SUMMARYSwiss needle cast is a disease caused by Phaeocryptopus gaeumannii, a fungal pathogen causing severe defoliation in Pseudotsuga menziesii (Douglas fir) in some countries of the world, leading to losses in the volume of timber harvesting. This pathogen is distributed in the native range of P. menziesii in North America (U.S., Canada and Mexico) and has been introduced in Europe, New Zealand, Turkey and, recently, in Chile. Currently the country has an area larger than 16,000 ha of plantations of P. menziesii, which are increasing because it is a potentially productive species considered in species diversification programs. In Chile P. gaeumannii is distributed from the region of La Araucanía to Los Lagos, focusing on these areas the largest area of Douglas fir in the country (70 % approximately). The aim of this review was to examine studies related to biology and life cycle of the pathogen, epidemiology and infection processes, impact on plantations and control measures implemented in the different countries affected by this pathogen, in order to have a background take on the first studies to Chile, a referent to basic and applied research for the country. Key words: Phaeocryptopus gaeumannii, Pseudotsuga menziesii, volumetric losses timber distribution the SNC in Chile. RESUMENEl swiss needle cast o pérdida suiza de las acículas, es una enfermedad de carácter fungoso provocada por el patógeno Phaeocryptopus gaeumannii, organismo que causa severas defoliaciones en Pseudotsuga menziesii (pino oregón) en el mundo, originando pérdidas en el volumen de madera para cosechar. Este patógeno se distribuye en el rango nativo de P. menziesii en América del Norte (EE.UU., Canadá y México) y se ha introducido en Europa, Nueva Zelanda, Turquía y, recientemente en Chile. Actualmente, el país cuenta con una superficie superior a las 16.000 hectáreas de plantaciones de P. menziesii, las cuales van en aumento por tratarse de una especie con potencial productivo considerada en programas de diversificación de especies. En Chile P. gaeumannii se encuentra distribuido desde las regiones de La Araucanía a Los Lagos, concentrándose en estas zonas la mayor superficie de P. menziesii del país (70 % aproximadamente). El objetivo de esta revisión fue analizar estudios relacionados a la biología y ciclo de vida del patógeno, la epidemiología y procesos de infección, impacto en las plantaciones y medidas de control implementadas en los diferentes países afectados por este patógeno, de manera de contar con antecedentes científicos para realizar los primeros estudios en Chile, referentes a investigación básica y aplicada para el país.Palabras clave: Phaeocryptopus gaeumannii, Pseudotsuga menziesii, pérdidas volumétricas de madera, distribución de SNC en Chile.

Analysis of fungal endophytes in Scottish Sitka spruce plantations shows extensive infections, novel host partners and gives insights into origins

“…gauemannii isolated in this study at approximately 6 weeks of growth at 18°C. The dark, dense hyphal clusters are similar morphologically to cultured N. gaeumannii in recent literature (e.g., Morales et al, 2012) fungus as sister to N. gaeumannii, and also to cement its status as a common endophyte in Scottish Sitka spruce.…”

“…In addition, endophytes isolated from Scots pine in native pine forests were recorded as endophytes of Sitka spruce in the present study, although these endophyte taxa are considered to have broad host ranges (Gomes et al, 2013;U'Ren et al, 2016;Udayanga et al, 2011). The dark, dense hyphal clusters are similar morphologically to cultured N. gaeumannii in recent literature (e.g., Morales et al, 2012) fungus as sister to N. gaeumannii, and also to cement its status as a common endophyte in Scottish Sitka spruce. gauemannii isolated in this study at approximately 6 weeks of growth at 18°C.…”

“…Nothophaeocryptopus gaeumannii and R. kalkhoffii have similar ecology and some morphological similarities, which led several endophyte scientists to believe they were closely related despite some striking differences (Gregory & Redfern, 1987;Rohde, 1937;Winton, Stone, Hansen, & Shoemaker 2007). In culture, both species produce dark brown isolates, but those of N. gaeumannii produce slow, dense growth of darkly pigmented sterile hyphae on MEA (Morales et al, 2012;Stone et al, 2008) whereas R. kalkhoffii forms cultures which are fast growing, often slimy, and which sporulate abundantly (Diamandis & Minter, 1980). Although Magan and Smith (1996) report commonly collecting R. kalkhoffii as an endophyte from Sitka spruce in the UK, in the present study no isolates of R. kalkhoffii were found, while the unknown Nothophaeocryptopus aff.…”

“…Based on morphological similarities, Cannon & Minter also suggested that Lophodermium nanakii may be conspecific, but this was collected on a different host species, Cedrus deodara (Pinaceae) in India, so this appears unlikely.Nothophaeocryptopus gaeumannii is a fungal pathogen causing needle cast disease of Douglas fir (Pseudotsuga menziesii) both within and outside of the host's native range(Hansen et al, 2000;Morales, Sanfuentes, Vives, & Molina, 2012;Rodriguez et al, 2009;Winton, Stone, Hansen, & Shoemaker 2007). Based on morphological similarities, Cannon & Minter also suggested that Lophodermium nanakii may be conspecific, but this was collected on a different host species, Cedrus deodara (Pinaceae) in India, so this appears unlikely.Nothophaeocryptopus gaeumannii is a fungal pathogen causing needle cast disease of Douglas fir (Pseudotsuga menziesii) both within and outside of the host's native range(Hansen et al, 2000;Morales, Sanfuentes, Vives, & Molina, 2012;Rodriguez et al, 2009;Winton, Stone, Hansen, & Shoemaker 2007).…”

“…gaeumannii was found in high frequencies in all sites. In culture, both species produce dark brown isolates, but those of N. gaeumannii produce slow, dense growth of darkly pigmented sterile hyphae on MEA(Morales et al, 2012;Stone et al, 2008) whereas R. kalkhoffii forms cultures which are fast growing, often slimy, and which sporulate abundantly…”