The pathogen Mycosphaerella dearnessii Barr. (syn. Scirrhia acicola; anamorph Lecanosticta acicol... more The pathogen Mycosphaerella dearnessii Barr. (syn. Scirrhia acicola; anamorph Lecanosticta acicola), the causal agent of brown spot needle blight, was observed on Pinus mugo in the Botanical Garden in Gardone (Brescia), on the western side of Garda Lake in northeastern Italy. Symptoms were first noticed in the spring of 1997 by Klaus Lang (University of Freising, Germany). Two years later, all 12 of the P. mugo present in the Garden exhibited extensive necrosis, and defoliation of the crown starting from the bottom upward was more prevalent on the shaded portion of infected trees. The trees were about 50 years old and 2.0 to 2.5 m in height. Symptomatic needles were confined to the 2- and 3-year old internodes. Infected needles had several dark to purplish-brown spots surrounded by green tissue and usually had dead tips. Pycnidia and conidia of Lecanosticta acicola were observed. Conidia were 4-celled, curved, pointed at one end and blunt at the other, pale olive-brown and 20 to 30 ...
... 179 isolats ont ete rassem-bles a partir d'A. alba et 81 a partir d&... more ... 179 isolats ont ete rassem-bles a partir d'A. alba et 81 a partir d'autres especes, dans 26 localites. ... CAPRETTI, P.; MORIONDO, F., 1983: Danni in alcuni impianti di conifere associati alia presenza d\ Heterobasidion annosum {Tomes annosus). Phytopath. medit. ...
Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2012
Abstract The development of new tools able to select specific plant tissue is crucial for gene ex... more Abstract The development of new tools able to select specific plant tissue is crucial for gene expression studies. During the last years, the use of laser microdissection, mainly tested on herbaceous plant tissue, has been found to be a useful technique for these purposes. This method is poorly tested on woody species, and so far no studies of gene expression have been applied on forest trees. For this reason the present work proposes the optimization of a functional protocol using laser microdissection pressure catapulting (LMPC) and real-time ...
Inoculation tests were carried out in the greenhouse on wild cherry (Prunus avium) and Italian al... more Inoculation tests were carried out in the greenhouse on wild cherry (Prunus avium) and Italian alder (Alnus cordata) seedlings, to determine their susceptibility to certain Phytophthora species (P. citrophthora, P. alni, P. megasperma and P. cinnamomi) that are commonly present in the soil. Host susceptibility was evaluated in accordance with a disease index, with the lesion length after stem inoculation, and with a root system disease index. Wild cherry was found to be highly susceptible to P. citrophthora, and was also found to be susceptible to P. alni, although to a lesser extent. Italian alder was very susceptible to P. alni, but had only low susceptibility to P. citrophthora. The other Phytophthora species caused only modest symptoms. The danger to alder and wild cherry is all the greater because these trees not only share the same pathogens, but also commonly planted together in mixed stands. The results will now have to be confirmed by using a more natural inoculation method.
Se ha determinado el número de genotipos fúngicos (genets) presentes en dos parcelas de pinsapar ... more Se ha determinado el número de genotipos fúngicos (genets) presentes en dos parcelas de pinsapar afectadas por la podredumbre radical causada por Heterobasidion abietinum en el Parque Natural de la Sierra de las Nieves. El mayor genet identificado se encontró colonizando 10 árboles a lo largo de una distancia de 57 m. El gran tamaño de los principales genets implica que H. abietinum se está diseminando preferentemente mediante contactos o injertos radicales a partir de viejos focos de infección establecidos antes de la creación del Parque Natural en 1989. Los veranos excepcionalmente largos y secos que se registran en la zona desde hace dos décadas pueden haber debilitado al pinsapar y favorecido la diseminación de la enfermedad.
La podredumbre radical causada por Heterobasidion es una grave enfermedad que afecta a las masas ... more La podredumbre radical causada por Heterobasidion es una grave enfermedad que afecta a las masas de Abies pinsapo en el sur de España. Para la identificación específica del patógeno que causa esta enfermedad, se recogieron muestras de árboles sintomáticos en siete localizaciones del Parque Natural de la Sierra de las Nieves (Málaga). Los aislados monobasidiospóricos obtenidos se identificaron mediante tests de apareamiento con aislados de referencia de grupo de interesterilidad conocido. Todos los aislados conocidos de A. pinsapo pertenecen al grupo de interesterilidad F. también identificado como la especie Heterobasidion abietinum.
The proceedings are organized under seven headings: Genomics and plant-pathogen interactions; Sys... more The proceedings are organized under seven headings: Genomics and plant-pathogen interactions; Systematics, taxonomy and phylogeography; Ecology; Population genetics; Etiology and epidemiology; Disease management and control; New reports, diagnostics and research on the application of new diagnostic methods. Following the custom of the IUFRO WP 07.02.01, most presentations dealt with the root rot caused by Heterobasidion annosum, the main agent of root rot in Europe. Molecular studies on the H. annosum species complex, its pathogenicity, the host resistance response, the production of secondary metabolites by various host species, and the use of biochemical markers in selection and breeding for resistance, were the subject of extensive discussion. Participants also directed their attention to other, related topics, such as the new species of Heterobasidion that have been found in Europe, and their relationship with other fungal pathogens. and they discussed climate change. __________...
Plants experiencing drought stress are frequently more susceptible to pathogens, likely via alter... more Plants experiencing drought stress are frequently more susceptible to pathogens, likely via alterations in physiology that create favorable conditions for pathogens. Common plant responses to drought include the production of reactive oxygen species (ROS) and the accumulation of free amino acids (AAs), particularly proline. These same phenomena also frequently occur during pathogenic attack. Therefore, drought-induced perturbations in AA and ROS metabolism could potentially contribute to the observed enhanced susceptibility. Furthermore, nitrogen (N) availability can influence AA accumulation and affect plant resistance, but its contributions to drought-induced susceptibility are largely unexplored. Here we show that drought induces accumulation of hydrogen peroxide (H2O2) in Austrian pine (Pinus nigra Arnold) shoots, but that shoot infection by the blight and canker pathogen Diplodia sapinea (Fr.) Fuckel leads to large reductions in H2O2 levels in droughted plants. In in vitro assa...
The pathogen Mycosphaerella dearnessii Barr. (syn. Scirrhia acicola; anamorph Lecanosticta acicol... more The pathogen Mycosphaerella dearnessii Barr. (syn. Scirrhia acicola; anamorph Lecanosticta acicola), the causal agent of brown spot needle blight, was observed on Pinus mugo in the Botanical Garden in Gardone (Brescia), on the western side of Garda Lake in northeastern Italy. Symptoms were first noticed in the spring of 1997 by Klaus Lang (University of Freising, Germany). Two years later, all 12 of the P. mugo present in the Garden exhibited extensive necrosis, and defoliation of the crown starting from the bottom upward was more prevalent on the shaded portion of infected trees. The trees were about 50 years old and 2.0 to 2.5 m in height. Symptomatic needles were confined to the 2- and 3-year old internodes. Infected needles had several dark to purplish-brown spots surrounded by green tissue and usually had dead tips. Pycnidia and conidia of Lecanosticta acicola were observed. Conidia were 4-celled, curved, pointed at one end and blunt at the other, pale olive-brown and 20 to 30 ...
... 179 isolats ont ete rassem-bles a partir d'A. alba et 81 a partir d&... more ... 179 isolats ont ete rassem-bles a partir d'A. alba et 81 a partir d'autres especes, dans 26 localites. ... CAPRETTI, P.; MORIONDO, F., 1983: Danni in alcuni impianti di conifere associati alia presenza d\ Heterobasidion annosum {Tomes annosus). Phytopath. medit. ...
Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2012
Abstract The development of new tools able to select specific plant tissue is crucial for gene ex... more Abstract The development of new tools able to select specific plant tissue is crucial for gene expression studies. During the last years, the use of laser microdissection, mainly tested on herbaceous plant tissue, has been found to be a useful technique for these purposes. This method is poorly tested on woody species, and so far no studies of gene expression have been applied on forest trees. For this reason the present work proposes the optimization of a functional protocol using laser microdissection pressure catapulting (LMPC) and real-time ...
Inoculation tests were carried out in the greenhouse on wild cherry (Prunus avium) and Italian al... more Inoculation tests were carried out in the greenhouse on wild cherry (Prunus avium) and Italian alder (Alnus cordata) seedlings, to determine their susceptibility to certain Phytophthora species (P. citrophthora, P. alni, P. megasperma and P. cinnamomi) that are commonly present in the soil. Host susceptibility was evaluated in accordance with a disease index, with the lesion length after stem inoculation, and with a root system disease index. Wild cherry was found to be highly susceptible to P. citrophthora, and was also found to be susceptible to P. alni, although to a lesser extent. Italian alder was very susceptible to P. alni, but had only low susceptibility to P. citrophthora. The other Phytophthora species caused only modest symptoms. The danger to alder and wild cherry is all the greater because these trees not only share the same pathogens, but also commonly planted together in mixed stands. The results will now have to be confirmed by using a more natural inoculation method.
Se ha determinado el número de genotipos fúngicos (genets) presentes en dos parcelas de pinsapar ... more Se ha determinado el número de genotipos fúngicos (genets) presentes en dos parcelas de pinsapar afectadas por la podredumbre radical causada por Heterobasidion abietinum en el Parque Natural de la Sierra de las Nieves. El mayor genet identificado se encontró colonizando 10 árboles a lo largo de una distancia de 57 m. El gran tamaño de los principales genets implica que H. abietinum se está diseminando preferentemente mediante contactos o injertos radicales a partir de viejos focos de infección establecidos antes de la creación del Parque Natural en 1989. Los veranos excepcionalmente largos y secos que se registran en la zona desde hace dos décadas pueden haber debilitado al pinsapar y favorecido la diseminación de la enfermedad.
La podredumbre radical causada por Heterobasidion es una grave enfermedad que afecta a las masas ... more La podredumbre radical causada por Heterobasidion es una grave enfermedad que afecta a las masas de Abies pinsapo en el sur de España. Para la identificación específica del patógeno que causa esta enfermedad, se recogieron muestras de árboles sintomáticos en siete localizaciones del Parque Natural de la Sierra de las Nieves (Málaga). Los aislados monobasidiospóricos obtenidos se identificaron mediante tests de apareamiento con aislados de referencia de grupo de interesterilidad conocido. Todos los aislados conocidos de A. pinsapo pertenecen al grupo de interesterilidad F. también identificado como la especie Heterobasidion abietinum.
The proceedings are organized under seven headings: Genomics and plant-pathogen interactions; Sys... more The proceedings are organized under seven headings: Genomics and plant-pathogen interactions; Systematics, taxonomy and phylogeography; Ecology; Population genetics; Etiology and epidemiology; Disease management and control; New reports, diagnostics and research on the application of new diagnostic methods. Following the custom of the IUFRO WP 07.02.01, most presentations dealt with the root rot caused by Heterobasidion annosum, the main agent of root rot in Europe. Molecular studies on the H. annosum species complex, its pathogenicity, the host resistance response, the production of secondary metabolites by various host species, and the use of biochemical markers in selection and breeding for resistance, were the subject of extensive discussion. Participants also directed their attention to other, related topics, such as the new species of Heterobasidion that have been found in Europe, and their relationship with other fungal pathogens. and they discussed climate change. __________...
Plants experiencing drought stress are frequently more susceptible to pathogens, likely via alter... more Plants experiencing drought stress are frequently more susceptible to pathogens, likely via alterations in physiology that create favorable conditions for pathogens. Common plant responses to drought include the production of reactive oxygen species (ROS) and the accumulation of free amino acids (AAs), particularly proline. These same phenomena also frequently occur during pathogenic attack. Therefore, drought-induced perturbations in AA and ROS metabolism could potentially contribute to the observed enhanced susceptibility. Furthermore, nitrogen (N) availability can influence AA accumulation and affect plant resistance, but its contributions to drought-induced susceptibility are largely unexplored. Here we show that drought induces accumulation of hydrogen peroxide (H2O2) in Austrian pine (Pinus nigra Arnold) shoots, but that shoot infection by the blight and canker pathogen Diplodia sapinea (Fr.) Fuckel leads to large reductions in H2O2 levels in droughted plants. In in vitro assa...
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