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1.
Cryphonectria hypovirus 1 (CHV‐1) survey reveals low occurrence and diversity of subtypes in NE Spain 
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下载免费PDF全文 C. Castaño L. Bassie D. Oliach M. Gómez V. Medina B. Liu C. Colinas 《Forest Pathology》2015,45(1):51-59
Cryphonectria parasitica (Murrill.) Barr is a necrotrophic fungus that affects European chestnut populations. In Catalonia (NE Spain), this fungus is widely spread affecting chestnut stands. In addition to vegetative compatibility (VC) types of the fungus, knowledge of the Cryphonectria hypovirus (CHV) occurrence is important to implement a biocontrol programme. We confirmed the presence of hypoviruses in several chestnut subpopulations of Catalonia, and we determined the VC types of CHV‐infected isolates. We also studied the nucleotide sequences of these hypoviruses from a variable region located in the hypovirus ORF‐A. Our results show a low occurrence of hypoviruses throughout C. parasitica populations in Catalonia, except for a few localized stands. From 312 sampled cankers, we obtained 179 white, pale orange or rickety isolates. In 35 of them, we detected CHV‐1. Infected isolates belonged to 5 of the 7 sampled subpopulations. We found 12 CHV‐1 haplotypes, based on the nucleotide sequence analysis. Most of the hypoviruses have the same nucleotide sequence or show high homology at nucleotide level with isolates previously included in CHV‐1 subtype‐I. However, we found that 3 haplotypes share at least 97% of their ORF‐A nucleotide sequence with CHV‐1 subtype‐E. Phylogenetic analysis grouped these 3 isolates in a different cluster than the other hypoviruses. These results suggest that multiple introductions of CHV‐1 have occurred recently in Catalonia. Dominant VC types of hypovirus‐infected isolates are EU‐1, EU‐2 and EU‐5, which are similar to those previously reported in this region. 相似文献
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A. Olivera C. R. Fischer J. A. Bonet J. Mart��nez de Arag��n D. Oliach C. Colinas 《New Forests》2011,42(2):227-239
Interest in conversion of marginal agricultural lands to small oak woodlands for the production of black truffles (Tuber melanosporum Vittad.) is increasing in the native black truffle areas of France, Spain and Italy as well as suitable or amended sites throughout the world due to high economic returns for gastronomically valuable truffles. Successful long-term management of a perennial plantation replacing an annual crop requires understanding the system in all phases of the life cycle, and in the case of truffles this involves understanding the interactive growth of the aboveground host and the belowground symbiotic ectomycorrhizal fungus whose fruitbody is the desired truffle. Here we focus on the pre-production phase, 4 years after establishing the truffle-oak plantation and prior to truffle production. We tested the influence of weed control, irrigation and fertilizer, each at 3 levels, on plant growth and ectomycorrhizal proliferation in three truffle-oaks plantations in northeast Spain. Results show that adequate weed control improves root and shoot dry weight while fertilizer and irrigation treatments did not influence plant growth. The low dose of irrigation (50% of the estimated water deficit for the site) and glyphosate weed control both increased total root tips/plant and T. melanosporum colonized tips (ectomycorrhizae) by approximately two-fold, compared to control treatments. Distribution of the ectomycorrhizae within the soil profile was significantly influenced by the low dose irrigation treatment, with increases observed in the 10?C20 cm and the 20?C30 cm deep layers compared to the control and high irrigation treatments. Four years after planting, T. melanosporum remained the dominant fungal symbiont, despite the presence of 14 other ectomycorrhizal morphotypes from these sites. 相似文献
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Empirical models for predicting the production of wild mushrooms in Scots pine (Pinus sylvestris L.) forests in the Central Pyrenees 总被引：1，自引：0，他引：1
José Antonio Bonet Timo Pukkala Christine R. Fischer Marc Palahí Juan Martínez de Aragón Carlos Colinas 《Annals of Forest Science》2008,65(2):206-206
Mushroom picking has become a widespread autumn recreational activity in the Central Pyrenees and other regions of Spain. Predictive models that relate mushroom production or fungal species richness with forest stand and site characteristics are not available. This study used mushroom production data from 24 Scots pine plots over 3 years to develop a predictive model that could facilitate forest management decisions when comparing silvicultural options in terms of mushroom production. Mixed modelling was used to model the dependence of mushroom production on stand and site factors. The results showed that productions were greatest when stand basal area was approximately 20 m2 ha?1. Increasing elevation and northern aspect increased total mushroom production as well as the production of edible and marketed mushrooms. Increasing slope decreased productions. Marketed Lactarius spp., the most important group collected in the region, showed similar relationships. The annual variation in mushroom production correlated with autumn rainfall. Mushroom species richness was highest when the total production was highest. 相似文献
5.
Antoni Olivera José Antonio Bonet Lorena Palacio Bing Liu Carlos Colinas 《Annals of Forest Science》2014,71(4):495-504
Context
Black truffle (Tuber melanosporum) cultivation is a promising agro-forestry alternative for Mediterranean rural areas, but adequate weed control at seedling establishment still remains a challenge in black truffle plantations.Aims
The aim of this study is to evaluate the effects of several weed control strategies on early development of Quercus ilex seedlings and the symbiotic T. melanosporum.Materials and methods
In a young black truffle-inoculated holm oak plantation, we assessed for 3 years the effects of two types of mechanical weed control and five mulches in a young Q. ilex plantation inoculated with T. melanosporum. Herbaceous cover, seedling growth and abundance of T. melanosporum mycelium, based on PCR analysis of soil DNA extracts using T. melanosporum-specific primers, were estimated to determine the effectiveness of these treatments in controlling weeds and supporting the growth of both the host tree and the target fungus.Results
The amount of T. melanosporum mycelium in the soil 30 cm around the seedlings was larger under double-layer white mulch than in the rest of treatments tested. Under the white colour mulches, which had the largest light reflection, we registered the cooler soil temperature, and the best weed control was observed on the single- and double-layer black truffles and double-layer white mulch.Conclusion
The effects of double-layer white mulch on herbaceous cover, soil temperature, reflected light, and the expansion of T. melanosporum bring us closer to being able to substitute traditional tilling of truffle orchards for the less expensive mulching treatments. 相似文献6.
A comprehensive study of the population biology of Cryphonectria parasitica , the causal agent of chestnut blight, is required to understand the spread of the epidemic in Europe and its natural regulation by the Cryphonectria hypovirus-1 (CHV-1). With this objective in mind, the diversity in vegetative compatibility (vc) types and mating types of C. parasitica populations was assessed in 43 chestnut sites in western France and northern Spain. Isolates were sampled in three regions along the Pyrénées mountains (Hautes Pyrénées, Pyrénées Atlantiques and Navarra) and in two regions north of the Pyrénées (Landes and Dordogne). There were 61 vc types observed in 682 isolates sampled. Ninety-five isolates (14%) could not be assigned to any one of the previously known European vc types. The finding of 47 incompatible vc types confirmed that the genetics of vegetative compatibility could not be totally accounted for by six diallelic vic genes. The two idiomorphs of the mating type gene were detected in all regions, indicating that sexual reproduction could occur within and between vc types. In all regions except Dordogne, C. parasitica populations were dominated either by the vc type EU-66 or EU-72. Neither vc type has been reported elsewhere in Europe, which suggests that two different introductions of C. parasitica have occurred in the study area. In Dordogne, populations were dominated by EU-33 and EU-2, and to a lesser extent EU-66 and EU-72. The low diversity in vc types for most of the C. parasitica populations provides good opportunities for natural regulation in forest coppices and for biocontrol with CHV-1 in orchards. 相似文献
7.
In the last two decades, stand decline and increased mortality has affected silver fir (Abies alba) forests in the Spanish Pyrenees. Simultaneously severe occurrences of the root rot fungus Heterobasidion annosum s.l. and of the mistletoe Viscum album have been reported. We aimed to improve the understanding of the epidemiology of both pathogens in our region. All H. annosum isolates found on silver fir were typed as H. abietinum. H. abietinum was more frequently observed where cuttings had targeted fir trees rather than other species. H. abietinum fruiting bodies were observed in the most recently cut stumps. V. album was more abundant on more dominant fir trees, and in southern aspect stands. The number of V. album colonies in the stand correlated (R2 = 0.40) with silver fir mortality. Stands with a high level of V. album infection tended to have a smaller percentage of basal area in species other than silver fir, and they tended to be located on more south‐facing slopes. H. abietinum was widespread in silver fir forests of the Pyrenees. Our data suggest that, in the Pyrenees, the observed H. abietinum incidence may represent a combination of both primary and secondary spread of the pathogen. Favouring mixed forests should be tested as a potential control method for V. album. The correlation between silver fir mortality and V. album infection warrants further study, as the observed tree mortality could have occurred due to other factors than V. album, such as drought damage. 相似文献
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New Forests - Cork is a renewable resource mainly produced in Mediterranean countries thanks to sustainable management of cork oak (Quercus suber) stands. The infection caused by the ascomycete... 相似文献
9.
Environmental and stand conditions related to Fistulina hepatica heart rot attack on Castanea sativa
Castanea sativa forests in north‐eastern Spain have historically been healthy and have been good producers of timber and non‐wood forest products. In the last quarter of a century, Fistulina hepatica has gained relevance in this ecosystem and is believed to be responsible for Chestnut Red Stain (CRS), which inflicts heart rot in trees and causes severe economic losses. The fungus grows in the heartwood and produces no external symptoms that would enable early detection. With the objective of developing an inexpensive method to detect heart rot and to discover possible relationships between the severity of F. hepatica attack and the silvicultural management or site characteristics of chestnut stands, 38 pure C. sativa plots were selected, sampled and analysed for the presence of the fungus. DNA was extracted from the heartwood samples, and PCR was used to amplify target sequences with specific F. hepatica primers for non‐homologous ITS1 and ITS2 regions. Correlation analysis was used to inspect the multiple interactions among the environmental and management variables examined, and a predictive model was designed for forest managers to estimate the risk of infection. Both analyses revealed that stress variables were related to CRS severity. This result is especially relevant since temperatures are expected to rise in coming decades throughout the northern rim of the Mediterranean region, where chestnut is an important species. This study provides two tools for better managing chestnut forests in the coming years: an inexpensive and fast tool for diagnosis and a predictive model to estimate the risk of infection. 相似文献
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This paper synthesizes and reviews literature concerning climate change effects on Mediterranean forest ecology and management as well as the restorative techniques necessary to maintain forest health, forest yield and biodiversity. Climate change compounded with trends of rural abandonment are likely to diminish forested areas within the Mediterranean basin that will be replaced by fire prone shrub communities. This could be favoured by outbreaks of pathogens, fire and other large-scale disturbances. Landscape fragmentation is expected to impede species migration. Annual increments and subsequent income from forests are expected to decrease. Reafforestations are necessary to ensure the presence of propagules of forest species and their site-specific varieties best adapted to future climatic conditions even though they may be different from the present forest-plant community. Current challenges in biodiversity conservation can only be met by afforestations whose main objective is to maintain ecosystem functioning. A new silviculture must emerge encompassing these habitat displacement and economic concerns while maximizing carbon sequestration. 相似文献