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Solla A.,University of Extremadura | Aguin O.,Estacion Fitopatoloxica do Areeiro | Cubera E.,University of Extremadura | Mansilla J.P.,Estacion Fitopatoloxica do Areeiro | Zas R.,Mision Biologica de Galicia
European Journal of Plant Pathology | Year: 2011

Results of a greenhouse Armillaria ostoyae inoculation experiment, designed for screening resistant Pinus pinaster genotypes and for exploring the role of different phenotypic traits in seedling susceptibility, are reported. The experiment included 39 open-pollinated pine families that comprised a random subset of the breeding population of P. pinaster in Galicia (NW Spain). We employed a non-parametric survival-time analysis to analyze patterns of survival times during 14 months after inoculation with a local A. ostoyae strain. Results indicate (i) a significant correlation between seed weight and tree susceptibility, with seedlings originating from large seeds being more susceptible, (ii) a positive family mean correlation between secondary root weight and size and median life expectancy, and (iii) genetic variation of tree tolerance to A. ostoyae, with some families surviving significantly longer than others. Less susceptible families could be used in breeding programmes or directly in forest plantations to reduce the losses caused by A. ostoyae. Large within-family variation in tolerance to the disease was also observed, suggesting that non additive genetic variance was also important. Although being infected, 32 out of the 1200 inoculated trees survived the fungus infection. These tolerant genotypes comprise an attractive collection to further investigate genetic, phenotypic and environmental factors affecting pine susceptibility to Armillaria root rot. © 2011 KNPV.


Aguin O.,Estacion Fitopatoloxica do Areeiro | Abuin M.,Centro Tecnologico Agroalimentario Of Lugo Cetal | Lozano F.,Centro Tecnologico Agroalimentario Of Lugo Cetal | Ferreiroa V.,Estacion Fitopatoloxica do Areeiro | And 2 more authors.
Revista Iberoamericana de Micologia | Year: 2015

Blackground: The genus Armillaria, specifically Armillaria mellea, is an important phytopathological problem in the wine sector in Galicia (NW Spain), having caused yield reductions in vineyards for the last 15 years. The fungus attacks the root system, resulting in a decrease in vigour, and eventually in the death of the plant. Up to now, there is no chemical or biological method really effective against the pathogen once it has infected the plant. Aims: The main objective of this work was to study the incidence and distribution of the genus Armillaria across the five Galician protected designation of origin (DO) wines (namely Rías Baixas, Ribeiro, Ribeira Sacra, Valdeorras and Monterrei) through the application of molecular techniques. Methods: A total of 624 samples (483 soils and 141 symptomatic vines) were analyzed by nested-PCR/RFLP, PCR-RFLP and phylogeny. Results: Armillaria mellea is widely distributed in vineyards of the five DO wines, with the highest incidence in the Ribeiro DO. Conclusions: Preventive control measures against Armillaria mellea must be established in the five DO wines of Galicia, in order to reduce the advance of white root rot. © 2013 Revista Iberoamericana de Micología.


Aguin O.,Estacion Fitopatoloxica do Areeiro | Sainz M.J.,University of Santiago de Compostela | Ares A.,Estacion Fitopatoloxica do Areeiro | Ares A.,University of Santiago de Compostela | And 3 more authors.
Forest Ecology and Management | Year: 2013

The incidence and diversity of fungal species causing Mycosphaerella Diseases (MD) and Teratosphaeria Diseases (TD), and the disease severity, were studied in 190 stands of Eucalyptus globulus, 17 of Eucalyptus nitens, 3 of Eucalyptus viminalis and 1 of Eucalyptus obliqua in NW Spain. Results showed that MD and especially TD were present in practically all E. globulus plantations, in many of them with a high severity, suggesting they might be suffering important wood yield reductions, and extended with low severity to E. nitens, E. viminalis and E. obliqua stands. Eleven species were identified, namely Mycosphaerella aurantia, Mycosphaerella madeirae, Mycosphaerella marksii, Pseudocercospora pseudoeucalyptorum, Teratosphaeria africana, Teratosphaeria molleriana, Teratosphaeria nubilosa, Teratosphaeria parva, Teratosphaeria readeriellophora, Uwebraunia commune and Uwebraunia dekkeri. All species were found in juvenile foliage, and most also in adult leaves, in E. globulus stands. Less fungal diversity was recorded for E. nitens, E. obliqua and E. viminalis plantations. T. africana on E. globulus is a new record for Spain. M. aurantia on E. globulus, P. pseudoeucalyptorum and U. commune on E. nitens, M. madeirae and T. molleriana on E. obliqua, and T. nubilosa and T. parva on E. viminalis are first records in Europe. The most frequently isolated species was T. nubilosa, followed by T. parva and T. molleriana. These three fungi were responsible for the highest levels of disease severity. © 2013 Elsevier B.V.


Cao A.,Mision Biologica de Galicia CSIC | Santiago R.,Mision Biologica de Galicia CSIC | Ramos A.J.,University of Lleida | Souto X.C.,University of Vigo | And 3 more authors.
International Journal of Food Microbiology | Year: 2014

In northwestern Spain, where weather is rainy and mild throughout the year, Fusarium verticillioides is the most prevalent fungus in kernels and a significant risk of fumonisin contamination has been exposed. In this study, detailed information about environmental and maize genotypic factors affecting F. verticillioides infection, fungal growth and fumonisin content in maize kernels was obtained in order to establish control points to reduce fumonisin contamination. Evaluations were conducted in a total of 36 environments and factorial regression analyses were performed to determine the contribution of each factor to variability among environments, genotypes, and genotype. ×. environment interactions for F. verticillioides infection, fungal growth and fumonisin content. Flowering and kernel drying were the most critical periods throughout the growing season for F. verticillioides infection and fumonisin contamination. Around flowering, wetter and cooler conditions limited F. verticillioides infection and growth, and high temperatures increased fumonisin contents. During kernel drying, increased damaged kernels favored fungal growth, and higher ear damage by corn borers and hard rainfall favored fumonisin accumulation. Later planting dates and especially earlier harvest dates reduced the risk of fumonisin contamination, possibly due to reduced incidence of insects and accumulation of rainfall during the kernel drying period. The use of maize varieties resistant to Sitotroga cerealella, with good husk coverage and non-excessive pericarp thickness could also be useful to reduce fumonisin contamination of maize kernels. © 2014 Elsevier B.V.


Pintos Varela C.,Estacion Fitopatoloxica Do Areeiro | Aguin Casal O.,Estacion Fitopatoloxica Do Areeiro | Chaves Padin M.,Estacion Fitopatoloxica Do Areeiro | Ferreiroa Martinez V.,Estacion Fitopatoloxica Do Areeiro | And 6 more authors.
Plant Disease | Year: 2013

In Europe, several diseases of maize (Zea mays L.) including seedling blight and stalk rot are caused by different Fusarium species, mainly Fusarium graminearum, F. verticillioides, F. subglutinans, and F. proliferatum (3). In recent years, these Fusarium spp. have received significant attention not only because of their impact on yield and grain quality, but also for their association with mycotoxin contamination of maize kernels (1,4). From October 2011 to October 2012, surveys were conducted in a maize plantation located in Galicia (northwest Spain). In each sampling, 100 kernels and 10 maize stalks were collected from plants exhibiting symptoms of ear and stalk rot. Dried kernels and small stalk pieces (1 to 2 cm near the nodes) were placed onto potato dextrose agar medium and incubated in the dark for 7 days. Fungal colonies displaying morphological characteristics of Fusarium spp. (2) were subcultured as single conidia onto SNA (Spezieller Nahrstoffarmer agar) (2) and identified by morphological characteristics, as well as by DNA sequence analysis. A large number of Fusarium species (F. verticillioides, F. subglutinans, F. graminearum, and F. avenaceum) (1,2) were identified. These Fusarium species often cause ear and stalk rot on maize. In addition, a new species, F. temperatum, recently described in Belgium (3), was also identified. F. temperatum is within the Gibberella fujikuroi species complex and is morphologically and phylogenetically closely related to F. subglutinans (2,3). Similar to previous studies (3), our isolates were characterized based on the presence of white cottony mycelium, becoming pinkish white. Conidiophores were erect, branched, and terminating in 1 to 3 phialides. Microconidia were abundant, hyaline, 0 to 2 septa; ellipsoidal to oval, produced singly or in false heads, and on monophialides, intercalary phialides, and polyphialides. Microconidia were not produced in chains. No chlamydospores were observed (3). Macroconidia in carnation leaf agar medium (2) were hyaline, 3 to 6 septate, mostly 4, falcate, with a distinct foot-like basal cell (2,3). DNA was amplified with primers ITS1/ITS4 and EF1/EF2 (3). Partial sequences of gene EF-1α showed 100% homology with F. temperatum (3) (GenBank Accession Nos. HM067687 and HM067688). DNA sequences of EF-1α gene and ITS region obtained were deposited in GenBank (KC179824, KC179825, KC179826, and KC179827). Pathogenicity of one representative isolate was confirmed using a soil inoculation method adapted from Scauflaire et al., 2012 (4). F. temperatum isolate was cultured on sterile wheat grains. Colonized wheat grains (10 g) were mixed with sterilized sand in 10 cm diameter pots. Ten kernels per pot were surface disinfected in 2% sodium hypochlorite for 10 min, rinsed with sterilized water, drained (4), placed on the soil surface, and covered with a 2 cm layer of sterilized sand. Five pots were inoculated and five uninoculated controls were included. Pots were maintained at 22 to 24°C and 80% humidity for 30 days. Seedling malformations, chlorosis, shoot reduction, and stalk rot were observed on maize growing in inoculated soil and not from controls. F. temperatum was reisolated from the inoculated seedlings but not from the controls. © The American Phytopathological Society.


Abelleira A.,Estacion Fitopatoloxica do Areeiro | Ares A.,Estacion Fitopatoloxica do Areeiro | Aguin O.,Estacion Fitopatoloxica do Areeiro | Picoaga A.,Estacion Fitopatoloxica do Areeiro | And 2 more authors.
Plant Pathology | Year: 2014

Bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae (Psa), is a disease that is spreading rapidly in several kiwifruit-producing countries, causing significant economic losses. In 2011, it was detected for the first time in Spain, in the south of Galicia (northwest Spain). Kiwifruit orchards were therefore inspected and sampled in 2011 and 2012 to determine the pathogen distribution, and the isolates obtained were characterized by morphology, fatty acids profile, biochemical tests and molecular techniques. Isolates were obtained from Actinidia deliciosa 'Hayward' (from leaves, canes, flower buds, fruits and roots), from A. deliciosa 'Summer', from Actinidia chinensis 'Jin Tao' (from canes and leaves) and from A. chinensis pollinator 'Belén' (from canes). Results of the analysis of the cfl gene (phytotoxin production-related), the tox-argK gene cluster and phylogenetic analysis of the cts gene demonstrated that all Psa isolates from northwest Spain correspond to the Psa3 population, which includes strains of haplotype 2. This is the first record of Psa3 and haplotype 2 in Spain. © 2013 British Society for Plant Pathology.


Vela P.,Estacion Fitopatoloxica Do Areeiro | Salinero C.,Estacion Fitopatoloxica Do Areeiro | Sainz M.J.,University of Santiago de Compostela
Annals of Applied Biology | Year: 2013

Camellia japonica is the most important ornamental species within the genus Camellia, with over 32 000 cultivars. On the basis of data from 72 cultivars maintained in a live camellia germplasm bank in Pontevedra (NW Spain), the phenological growth stages of C. japonica are described using the Biologische Bundesantalt and Chemische scale. The main stages of development for buds, leaves, shoots, harvestable vegetative plant parts, flowers and fruits are given. Eight main stages were defined, with a total of 42 secondary stages. This scale provides growers and researchers with uniform criteria on the selection and description of phenological stages for best management and study of C. japonica. © 2012 Association of Applied Biologists.


Abelleira A.,Estacion Fitopatoloxica Do Areeiro | Ares A.,Estacion Fitopatoloxica Do Areeiro | Aguin O.,Estacion Fitopatoloxica Do Areeiro | Mansilla P.,Estacion Fitopatoloxica Do Areeiro | Lopez M.,Instituto Valenciano Of Investigaciones Agrarias Ivia
Acta Horticulturae | Year: 2015

seudomonas syringae pv. Actinidiae (Psa) was detected for the first time in a kiwifruit orchard in Galicia (NW Spain) in 2011. About 83% of the Spanish kiwifruit are produced in this region. Surveys were performed in Actinidia orchards in Galicia during 2011-2013. Symptomatic and asymptomatic leaves, canes, flower buds, fruit, sap and roots were collected from plants of Actinidia deliciosa, A. chinensis, A. arguta and A. kolomikta. Characterization of isolates showed that 94% corresponded to the Psa biovar 3 population, highly virulent and currently widespread in many countries. Nevertheless, some isolates that show different biochemical and molecular characteristics were also recently found. They could be close to the Psa biovar 4 population of low virulence reported in New Zealand, although confirmation of their type or biovar will require evaluation of their behavior in kiwifruit cultivars and further work.


Aguin O.,Estacion Fitopatoloxica Do Areeiro | Ares A.,Estacion Fitopatoloxica Do Areeiro | Abelleira A.,Estacion Fitopatoloxica Do Areeiro | Mansilla P.,Estacion Fitopatoloxica Do Areeiro
Acta Horticulturae | Year: 2015

In Galicia (NW Spain), Pseudomonas syringae pv. Actinidiae was first detected on Actinidia deliciosa and A. chinensis in 2011. The region is characterized by high annual rainfall and mild temperatures. These climatic characteristics might favour the persistence of the bacteria in leaves that have fallen on orchard soils during the senescence period. The knowledge of the survival period of Psa would allow developing better strategies for the control of the pathogen. The aim of the present work was to study the survival of Psa in fallen leaves until the plant was completely defoliated. The study was carried out in an orchard of A. deliciosa 'Hayward'. Sixteen symptomatic plants were monitored. One plastic box was placed below each plant. Leaves fallen in boxes were collected weekly and processed by three methods: dilacerations, crushing and washing to study the presence of viable colonies of Psa. The three methods were successful in detecting Psa colonies. The bacteria remained active in the leaf litter for more than two months, representing a potential inoculum source for infection in the orchard.


PubMed | University of Santiago de Compostela, Instituto Valenciano Of Investigaciones Agrarias Ivia and Estacion Fitopatoloxica do Areeiro
Type: Journal Article | Journal: Journal of applied microbiology | Year: 2016

Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is currently the major threat to its commercial production worldwide. In 2011, the most virulent type (Psa3) was detected for the first time in Northwest-Spain, in the province of Pontevedra. In 2013 surveys, leaves and flower buds with mild symptoms were observed in Actinidia deliciosa Hayward vines in an orchard at the province of A Corua, suggesting the presence of P. syringae pv. actinidifoliorum (Psaf).Isolates obtained from such orchard were characterized by morphological, biochemical and physiological tests, fatty acids (FA) profile and molecular tests (PCR, BOX-PCR, duplex PCR, multiplex PCR, real-time PCR, PCR-C, phytotoxins, housekeeping and effector genes). Pathogenicity tests were also carried out on plants and fruits of A. deliciosa Hayward and on different cultivated plants and fruits. Results demonstrated the presence of P.syringae pv. actinidifoliorum in Spain.The work provides new information on the pathovar P. syringae pv. actinidifoliorum, which has only been found previously in New Zealand, Australia and France.The results are relevant for taxonomy of isolates of P. syringae from kiwifruit, especially those of low virulence not belonging to pathovar actinidiae.

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