|
| ||
|
|
||
Castanea Sativa (castanea + sativa)
Selected AbstractsCharacteristics of the Cryphonectria parasitica isolated from Quercus in SlovakiaFOREST PATHOLOGY, Issue 5 2010K. Adam, íková Summary The occurrence of chestnut blight (Cryphonectria parasitica) on oaks in mixed chestnut-oak forests was studied in 2003,2008 in Slovakia. Infections on living Quercus trees were found at four of seven localities. The disease incidence on oaks ranged from 1.3% to 15.8%. The symptoms on infected oaks were similar to those on chestnut, but less conspicuous. Cankers of C. parasitica were found only on Quercus robur and Q. petraea. A total of 22 isolates of C. parasitica, all virulent, were isolated. Each site yielded only a single vc type (EU12 or EU13). Field inoculation experiments on chestnuts with seven strains of C. parasitica from oaks and an isolate from Castanea sativa showed no differences in virulence. On Quercus robur stems, the cankered area was significantly smaller than on C. sativa and the cankers developed very slowly. [source] Distribution and severity of damage by Cryphonectria parasitica in the chestnut stands in Guilan province, IranFOREST PATHOLOGY, Issue 5 2010E. Ghezi Summary Chestnut blight caused by Cryphonectria parasitica has recently been reported from Guilan province, the only region with natural chestnut (Castanea sativa) stands in Iran. During the past few years, chestnut stands in Iran have been seriously threatened by the fungus, incidence of the disease is increasing and vast canopies are reduced to sprouts. As yet, there is no report on the disease distribution and severity in this region. Six sites from three main growing regions of chestnut in Guilan province were selected for investigation. We report occurrence and evaluation of the damage of the disease caused by C. parasitica. To evaluate the scale of damage, the investigated trees were classified into six categories based on the degree of crown damage, the number of canker wounds and the presence of the fungus. Index of health condition was calculated for all sites. During this study, a total of 250 isolates of Cryphonectria species were obtained, of which 232 isolates were C. parasitica and 18 were Cryphonectria radicalis. Castanea parasitica was observed in all regions. Index of health condition was scored from 0 to 6 with 0 being disease free and six being the most severe infection. Index results in the investigated sites varied between 0.69,5.45 and 0.93,5.55 for years 2006 and 2007, respectively. The highest damage was found in Doran (IH = 5.55), which is located some 100 km away from Shahbalutmahalleh, the site with lowest damage (IH = 0.93). This is the first extended report on aspects of chestnut blight in Iran. [source] Seasonal effect on infection and development of lesions caused by Cryphonectria parasitica in Castanea sativaFOREST PATHOLOGY, Issue 4 2003L. Guérin Summary Seasonal variation in the development of chestnut blight, caused by Cryphonectria parasitica, was investigated by inoculating in situ chestnut trees and in vitro excised chestnut segments, at either monthly or 3-monthly intervals throughout 30 months. Inoculations were made with conidia and mycelium of a virulent isolate and with mycelium of a hypovirulent isolate. Conidial inoculations of living sprouts or excised segments between May and July resulted in the greatest incidence of infection whereas inoculations in autumn and winter, in vitro as well as in situ, did not reveal any visible disease. However, from these symptomless inoculated stems, C. parasitica was isolated 3 months after inoculation. Inoculations with the mycelium of the virulent isolate always resulted in lesions, except in January 1999, and the greatest rate of lesion development occurred for inoculations made in the spring and summer. There was a significant seasonal effect on lesion development. Lesions caused by the hypovirulent isolate, smaller than those caused by the virulent isolate, followed a similar seasonal pattern. The same seasonal variations were observed for inoculations in vitro of excised segments. Relative water content (RWC) of chestnut bark significantly varied with bark sampling date. The rate of lesion development in sprouts significantly correlated with average minimum (ATn) and maximum (ATx) temperatures and the sum of rainfall during inoculation period, with the rate of lesion development measured in excised segments 10 days after inoculation (R10d) and with RWC measured on the day of inoculation. In multiple regression models, variables ATx and R10d best explained variation in lesion development. Résumé La variation saisonnière du développement de la maladie du chancre causée par Cryphonectria parasitica a étéétudiée en réalisant, une fois par mois ou par trimestre pendant deux ans et demi, des inoculations de châtaigniers in situ et des inoculations in vitro de branches coupées. Les inoculations ont été réalisées avec des conidies et du mycélium d'un isolat virulent et avec du mycélium d'un isolat hypovirulent. En Mai et Juin, les inoculations conidiennes ont provoqué le taux d'infection le plus élevé, in situ et in vitro. A l'inverse, en automne et en hiver, ces inoculations n'ont pas causé de symptômes. Cependant C. parasitica a été réisolé 3 mois plus tard, sur ces tiges ne présentant aucune lésion. Les inoculations avec du mycélium ont toujours résulté en des lésions, excepté en Janvier 1999, et le développement des lésions (R1m) a été le plus rapide au printemps et en été. La date d'inoculation a eu un effet significatif sur l'extension des lésions. Le même effet saisonnier était observé sur le développement des lésions causées par l'isolat hypovirulent, plus petites que celles causées par l'isolat virulent. Les mêmes variations saisonnières de l'extension des lésions étaient observées in vitro sur tiges excisées. Un effet saisonnier significatif a été mis en évidence sur la teneur en eau relative des écorces de châtaignier (RWC). Le développement des lésions dans les tissus vivants était significativement corrélé avec les températures moyennes minimale (ATn) et maximale (ATx) et la somme des précipitations (SR) calculées sur chaque période d'incubation, avec le développement des lésions in vitro (R10d) et avec RWC. La variation saisonnière du développement des lésions était le mieux expliquée, par un modèle de régression multiple, par ATx et R10d pour l'isolat virulent, et par ATx pour l'isolat hypovirulent. Zusammenfassung Der jahreszeitlich bedingte Einfluß auf die Entstehung von Kastanienrindenkrebs, verursacht von Cryphonectria parasitica, wurde durch Inokulation von Kastanienbäumen in situ und durch Beimpfung von geschnittenen Triebsegmenten in vitro in monatlichen oder drei-monatlichen Intervallen über dreißig Monate untersucht. Zur Inokulation wurden Myzel und Konidien eines virulenten Isolates und Myzel eines hypovirulenten Isolates verwendet. Mit Konidien wurde zwischen Mai und Juni die größte Infektionshäufigkeit auf lebenden Sprossen oder Triebsegmenten erreicht, während Inokulationen im Herbst und Winter keine sichtbaren Symptome hervorriefen. Jedoch konnte C. parastica drei Monate nach Inokulation von lebenden Sprossen isoliert werden, auch wenn keine Läsion sichtbar war. Außer im Januar 1999 führte Inokulation mit Myzel des virulenten Isolates immer zu Läsionen. Am häufigsten traten Läsionen bei Inokulationen im Frühling und im Sommer auf. Der Einfluß des Inokulationszeitpunktes auf die Ausbildung von Läsionen war signifikant. Inokulationen mit dem hypovirulenten Isolat zeigten eine ähnliche jahreszeitliche Schwankung wie jene mit dem virulenten Isolat, führten aber zu kleineren Läsionen. Die gleichen jahreszeitlichen Variationen wurden bei in vitro Inokulation von Kastanientrieben beobachtet. Der relative Wassergehalt (RWC) der Borke variierte signifikant mit dem Beprobungszeitpunkt der Borke. Die Bildung von Läsionen an lebenden Sprossen korrelierte signifikant mit den durchschnittlichen Temperaturminima (ATn) und -maxima (ATx), mit der Gesamtregenmenge (SR) während der Inokulationsperiode, mit der Bildung von Läsionen an Triebsegmenten (R10d) und mit dem am Inokulationstag gemessenen RWC. In einem multiplen Regressionsanalysenmodell zeigte sich, dass die jahreszeitliche Schwankung der Ausbildung von Kastanienrindenkrebs beim virulenten Isolat am besten durch die Variablen ATx und R10d, beim hypovirulenen Isolat durch ATx erklärt wurde. [source] Vegetable and animal food sorts found in the gastric content of Sardinian Wild Boar (Sus scrofa meridionalis)JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2007W. Pinna Summary Authors report results emerging from gastric content analysis from n. 96 wild boars hunted in Sardinia isle, during the hunting tide (2001,2005), from November to January. Mean pH of the gastric content was 3.77 ± 0.69. Mean total capacity (TC) of each stomach was 1702 ± 680 g. Mean Stuff ratio (CW/TC) between the content weight (CW) and stomachs TC was 0.45. Food categories found in animal stomachs were: 19 categories of vegetal species (Allium spp., Arbutus unedo, Arisarum vulgare, Avena fatua, Avena sativa, Castanea sativa, Ceratonia siliqua, Chamaerops umilis, Cichorium intybus, Hordeum sativum, Juniperus oxycedrus, Myrtus communis, Olea europea, Pirus amygdaliformis, Pistacia lentiscus, Quercus spp., Rhamnus alaternus, Triticum durum, Zea mais); 11 categories of animal species (Agriotes lineatus, Apodemus sylvaticus dicrurus, Chalcides chalcides, Chalcides ocellatus tiligugu, Crematogaster scutellaris, Forficula auricularia, Helix aspersa, Lumbricus terrestris, Ovis aries, Podarcis tiliguerta tiliguerta, Scolopendra cingulata); three categories were identified in general terms (insects larvae, hairs of mammals, feathers of birds). Food categories found in the stomach contents of Sus scrofa meridionalis confirm observations by other researchers who report the prevalence of vegetables in spite of animal food sorts in the wild boar diet in Italian regions. [source] The umbric epipedon in the N Apennines, Italy,an example from the Vallombrosa ForestJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2005Guido Sanesi Abstract The umbric epipedon is a diagnostic surface horizon recognized by both the World Reference Base for Soil Resources and the U.S. Soil Taxonomy. It is mainly characterized by a dark color, a moderate to high content of OM, and a base saturation of less than 50%. In the N Apennines, Central Italy, forest soils over 600,700 m a.s.l. often have this epipedon. This paper stresses the morphological, chemical, and biological properties of the epipedon, specifically in the Vallombrosa Forest, where considerable work has been done in the last decade. Here, the umbric epipedon forms on sandstone, in high forests of Abies alba, Fagus sylvatica, and Castanea sativa. It does not have homogeneous properties throughout its thickness and often is divided into two distinct genetic horizons, A1 and A2. The A1 horizon is thinner, darker, and richer in OM, more base-saturated, and biologically more active than the underlying A2 horizon. The mean residence time of the bulk OM amounts to about a century in the A1 horizon, versus half a millennium in the A2. In both A1 and A2 horizons, the non-humic fraction prevails in the OM; this could account for the high susceptibility of the umbric epipedon to degrade when the forest is clear-cut or undergoes extensive uprooting due to windstorms or heavy snow loads. Significant discrepancies between the two A horizons have been found in regard to the microbial community. Umbric epipedons which developed under different tree species show minor differences, mainly concerning the microbial community. [source] Tree rings show competition dynamics in abandoned Castanea sativa coppices after land-use changesJOURNAL OF VEGETATION SCIENCE, Issue 1 2006Patrick Fonti Abstract Questions: As a consequence of socio-economic changes, many Castanea sativa coppices have been abandoned and are now developing past their usual rotation length. Do we have to expect changes in stand structure and composition of abandoned Castanea sativa coppice invaded by other species? Is a tree ring-based approach adequate to early recognise changes in inter-specific competitive interaction? Location: Lowest alpine forest belt of the southern Swiss Alps. Methods: We selected a 60-year old abandoned Castanea sativa coppice stand with sporadic Fagus sylvatica and Quercus cerris mixed in. Using tree-ring based indices we analysed differences in the species-specific response to competition. Analyses were performed by comparing how subject dominant trees (10 Castanea, 5 Fagus, 5 Quercus) have differently faced competition from their immediate Castanea coppice neighbourhood, taking into account the changes over time and space. Results: Although no species appears yet to have made a difference in the surrounding coppice mortality, there are species-specific differences in growth dominance, which indicate potential successional processes. Castanea sativa growth dominated in the early stages of stand development. However, after approximately 30,35 yr Fagus sylvatica and Quercus cerris became much more dominant, indicating a change in competitive potential that does not favour Castanea sativa. Conclusions: Without interventions this coppice will develop into a mixed stand. A tree-ring based approach allows an early recognition of forthcoming changes in stand composition and structure and is likely to be an important tool for forest landscape management. [source] In vitro leaf inoculation studies as an indication of tree foliage susceptibility to Phytophthora ramorum in the UKPLANT PATHOLOGY, Issue 4 2005S. Denman Leaves of 11 coniferous and 23 broad-leaved tree species important to UK forestry were tested for their susceptibility to the quarantine pathogen Phytophthora ramorum using a detached leaf assay. Two European and two USA isolates were used. Wounded and unwounded leaves were dipped in zoospore suspensions during summer; conifers were also tested in winter. Successful infection of tissue and amount of necrosis were assessed. Highly susceptible broad-leaved hosts included Aesculus hippocastanum, Fraxinus excelsior, Quercus ilex, Ulmus procera and, to a lesser extent, Castanea sativa, Q. cerris and Q. petraea, together with Umbellularia californica and rhododendrons. Acer pseudoplatanus, Alnus glutinosa, Carpinus betulus, Corylus avellana, Fagus sylvatica, Prunus avium, Q. robur, Q. rubra and Q. suber showed consistently low susceptibility. Conifer species including Abies procera, Picea abies, P. sitchensis, Pseudotsuga menziesii, Sequoia sempervirens and Tsuga heterophylla were also susceptible. Pseudotsuga menziesii and A. procera were severely affected. Pinus contorta, P. nigra var. maritima and P. sylvestris were virtually resistant, while Taxus baccata was only slightly affected. Increased necrosis was apparent on leaves that were wounded prior to inoculation. These results extend the known range of trees that P. ramorum is able to attack and confirm its relative host-nonspecificity. [source] Genetic characterisation of traditional chestnut varieties in Italy using microsatellites (simple sequence repeats) markersANNALS OF APPLIED BIOLOGY, Issue 1 2010M.A. Martín European chestnut (Castanea sativa) is an important multipurpose tree that has been cultivated for wood and fruit in the Mediterranean basin since ancient times. Cultivation of traditional chestnut varieties has a long tradition in Italy, where cultivars have been selected over centuries as a function of the best nut traits. In this study, 94 grafted chestnuts corresponding to 26 representative cultivars from Italy were evaluated by seven simple sequence repeat (SSR) markers to establish whether they corresponded to varieties in the narrow sense. The results allowed 20 genotypes to be identified that corresponded to the same number of clones. In total, 52 alleles were identified, eight of which were exclusive. Cases of homonymies and synonymies were detected. Moreover, our results highlighted a considerable genetic uniformity among ,Marrone-type' cultivars and, on the contrary, a high genetic diversity among the evaluated cultivars demonstrating that this is a valuable germplasm and an important genetic resource to be preserved. [source] Identification and characterisation of traditional chestnut varieties of southern Spain using morphological and simple sequence repeat (SSRs) markersANNALS OF APPLIED BIOLOGY, Issue 3 2009M.A. Martin Abstract The maintenance of plant genetic resources requires the identification of places and agroforestry systems that support high levels of genetic diversity. The aim of this work was to clarify the number and names of chestnut (Castanea sativa) cultivars in the south of Spain. Accordingly, 100 grafted chestnut trees corresponding to 34 traditional names were evaluated using 10 qualitative morphological traits and seven simple sequence repeat (SSRs) markers. We identified 38 varieties, 12 in the Huelva region and 26 in Malaga, and synonymies and homonymies were discussed. This work demonstrated that the joint use of morphological traits and SSR markers is an efficient method to evaluate the agrobiodiversity of chestnut in this region. It was also stated that chestnut production in the south of Spain is a traditional system using varieties developed ,in situ'. This constitutes a genuine system of on-farm conservation, which is now threatened. Consequently, adopting strategies for its safeguarding are urgently recommended. [source] In vivo Skin Irritation Potential of a Castanea sativa (Chestnut) Leaf Extract, a Putative Natural Antioxidant for Topical ApplicationBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2008Isabel F. Almeida However, natural products can provoke skin adverse effects, such as allergic and irritant contact dermatitis. Skin irritation potential of Castanea sativa leaf ethanol:water (7:3) extract was investigated by performing an in vivo patch test in 20 volunteers. Before performing the irritation test, the selection of the solvent and extraction method was guided by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging test and polyphenols extraction (measured by the Folin Ciocalteu assay). Iron-chelating activity and the phenolic composition (high performance liquid chromatography/diode array detection) were evaluated for the extract obtained under optimized conditions. The extraction method adopted consisted in 5 short extractions (10 min.) with ethanol:water (7:3), performed at 40°. The IC50 found for the iron chelation and DPPH scavenging assays were 132.94 ± 9.72 and 12.58 ± 0.54 µg/ml (mean ± S.E.M.), respectively. The total phenolic content was found to be 283.8 ± 8.74 mg GAE/g extract (mean ± S.E.M.). Five phenolic compounds were identified in the extract, namely, chlorogenic acid, ellagic acid, rutin, isoquercitrin and hyperoside. The patch test carried out showed that, with respect to irritant effects, this extract can be regarded as safe for topical application. [source] | |||||||||||||