1,720,996 research outputs found
Fuoco e funghi. Impatto degli incendi boschivi sulle comunità fungine
No full textLe modificazioni dell’ecosistema bosco in seguito ad un evento fortemente perturbante quale l’incendio, sono strettamente connesse a delicati dinamismi nei quali la componente fungina assume un ruolo fondamentale
A sampling method to describe the Norway spruce ectomycorrhizal community at plant level.
No full textTo verify the possibility of developing a sampling method to accurately describe the Norway spruce ectomycorrhizal community at plant level, research was conducted in four comparable monospecific forests on healthy, mature and coeval Norway spruce trees. The results showed that the lowest number of tips per root core can characterize the community changes from site to site, with tree species, age and sampling design being constant. This highlights the importance of ectomycorrhizal species distribution, which is not an intrinsic character of ectomycorrhizal species, and probably changes with the environmental and fungal community features. The research demonstrated, in accordance with a theoretical ectomycorrhizal distribution, the effectiveness of an encoded geometrical sampling design consisting of the collection of 24 root samples from each of the four unrelated plants, along four perpendicular directions and at six fixed distances from the collar, and with the observation of 10 randomly selected ectomycorrhizal tips per sample
First report of damping-off of Common oak plantlets caused by Cylindrocladiella parva in Italy
No full textIn April 2006, damping-off of common oak (Quercus robur L.) plantlets as much as 3-years-old was observed in a typically declining Q. robur L. forest located in northeastern Italy (Cessalto, VE). Among a variety of microorganisms, Cylindrocladiella parva (P.J. Anderson) Boesewinkel was isolated from 12 plants. The pathogenicity test was repeated twice with the same results. C. parva is the known causal agent of seedling blight, damping-off, and root rots on a broad host range of monocots and dicots
Lophodermium piceae and Rhizosphaera kalkhoffii in Norway spruce: correlations with host age and climatic features.
No full textThe study was carried out in 4 similar Norway spruce stands and it demonstrated that the spreading structures produced by Lophodermium piceae and Rhizosphaera kalkhoffii are not correlated. The two fungi were always detected with opposite growth trends, probably due to different needle colonization and spreading strategies, and this was most likely also why they were able to co-exist, colonizing different parts of the needle. Independently of the year, site, sampling period and amount of precipitation, the two fungi were significantly less common in saplings and more common in mature trees, with frequencies also depending on both the minimum and the maximum temperatures
Ramaria flavo-saponarea R. H. Petersen + Fagus sylvatica L.
No full textThe ectomycorrhizae of Ramaria flavo-saponarea display most features of Ramaria mycorrhizae described so far: dense, nest-like clusters of silvery-white mycorrhizae surrounded by a veil of emanating hyphae and abundant slightly differentiated rhizomorphs, commonly also with short, blunt-ending rhizomorphs formed as obtuse mycorrhiza-like outgrowths, a plectenchymatous mantle in all layers, outer mantle and rhizomorphs with ampullate hyphae, acanthocystidia (or acanthohyphae) and globular cells containing yellowish to brownish droplets. The hyphae bear clamps as well as simple septa. Very characteristic for this species are acanthocystidia with an irregular shape from partially lobed to inflated
Ectomycorrhizal community associated to Pinus radiata D. Don plantations in the Western Cape, South Africa: preliminary results.
No full textThe ectomycorrhizal (ECM) symbiosis involves a large number of plant and fungal taxa worldwide, dominating woodland and forest communities in boreal, temperate and Mediterranean forests, as well as savanna and rain forest habitats.
ECM fungi are one of the most important elements of forest ecosystems, connecting, transferring and stocking water and nutrients through a complex system of hyphal networks and also creating a defense barrier for the root tips against soil pathogens. The benefits that ECM fungi grant on their associated plants are: increased survival, improved growth, greater drought tolerance and resistance to disease.
Until now, ECM research has not received much attention in South Africa, in forests and in plantations, in terms of understanding the ECM species and the functional community composition.
The main goal of this study was to describe the ECM fungal community present belowground in 4 Pinus radiata D. Don plantations in the Western Cape, South Africa.
ECM species were identified using morpho-anatomical and molecular (restriction fragment length polymorphism and DNA sequencing) analyses.
The preliminary results showed 28 ECM anatomotypes identified.
Further studies in these Western Cape pine plantations are being developed to investigate the ECM community according to a gradient of water stress, to verify a change in species diversity or shift in species composition and to determine the ECM species most resistant to drought.
The results obtained from this study are completely new and relevant to South African forestry, showing high potential applications in the industry throughout southern Africa, especially prospecting new applications in the forestry nurser
A geostatistical model to describe root vitality and ectomycorrhization in Norway spruce.
No full textThe spatial distribution of vital root tips and ectomycorrhizal (ECM) communities in forest soils is characterized by patchiness at a microscale level, mostly related to the distribution patterns of biotic and abiotic factors. A geostatistical model was applied to verify if spatial analyses could be useful in identifying an appropriate sampling method to study root tip vitality, ectomycorrhization and the ECM community. Root samples were collected from two high mountain Norway spruce forests (Trentino province, Italy) following a geometrical design. Laboratory microscopic and geostatistical ordinary kriging analyses were used to map tip vitality and ectomycorrhization degree, ECM richness and distribution grouped in exploration types (amount of emanating hyphae or presence and differentiation of rhizomorphs). Spatial gradients of the examined features existed at plant level, associated to the up-downslope direction (root tip vitality and ectomycorrhization, ECM richness) and distance from the stem base (ECM exploration types). The effectiveness of the geostatistical model used demonstrates that a geometrical sampling design, associated to spatial mapping techniques, can be useful in research where the tree, and not the forest, is the subject (mycological and phytopathological studies)
Dormouse injuries predispose beech to infection by Neonectria ditissima.
No full textAfter awaking from winter hibernation, the Edible dormouse begins to feed by stripping the bark and the outer part of the xylem from the branches of both broadleaves and conifers. Natural or artificial wounds are essential for the penetration and colonisation of the tissues by the fungal pathogen Neonectria ditissima. This pathogen creates open cankers on beech branches and other broadleaves, which are frequently later infected by wood-decaying fungi. Because of the high frequencies of both dormouse injuries and branch cankers in a large monospecific beech forest in northern Italy, field and laboratory investigations were conducted to verify whether rodent-inflicted injuries on beech were a preferred infection point for the pathogen. These studies also examined the susceptibility to infection of the dormouse-inflicted wounds over time, and the relationships between dormouse damage, Neonectria infection, and wood decay. The results showed a significant direct correlation between the percentage of infections and their proximity to the wounds, indicating that the parasite localises to sites where there are receptive dormouse injuries. In addition, the susceptibility of the wound was found to diminish with increasing age, disappearing in 120-150 days. The association between dormouse injuries, Neonectria cankers and wood decay was also found to cause approximately half of the frequent beech branch breakages during intense weather events
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