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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. Source

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. Source

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. Source

Salinero C.,Estacion Fitopatoloxica do Areeiro | Pinon P.,Estacion Fitopatoloxica do Areeiro | Lema M.J.,Estacion Fitopatoloxica do Areeiro | Martinez L.,Trading House Amodia
Acta Horticulturae | Year: 2010

In our latitude, expectations of the kiwifruit sector regarding kiwi productions with high yields and an adequate fruit size have been fulfilled. Thus, at present, this sector is focusing its efforts towards the quality improvement of fruit sensory properties, highly demanded by the consumer, so as to be competitive in the international market. There are several sensory properties that determine quality in kiwifruit. A kiwifruit is considered to have a good flavour quality standard, when the content rate of soluble solids (°Brix) is the highest when consumed. Dry matter is another parameter internationally accepted as an indicator of the "intrinsic" quality of kiwifruit. The acidity and the starch content play an important role on the attainment of these quality standards. The aim of the present work is to determine the effect of fertilization and training (T- bar or pergola) on content and evolution of these sensory parameters. Assays were performed during 2007 in kiwi orchards in Northern Portugal (Kiwi Ibérica S.A.), taking fruit samples every two weeks from anthesis until harvest. Sensory properties of these fruits were analyzed according to AOAC methods. Results showed that training systems influenced significantly on dry matter, soluble solids, starch content and acidity. Significant differences were also observed between both fertilization practices during the first phases of fruit development; but these differences disappeared in later stages. Source

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. Source

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