RESUMO
Introduction: Wood is a natural resource used for construction and the manufacture of many products. This material is exposed to damage due to biotic and abiotic factors. An important biotic factor is wood-degrading fungi that generate large economic losses. The objectives of this study were to determine the effect of xylophagous fungi (Coniophora puteana and Trametes versicolor) on the natural durability of six timber species in southern Durango, Mexico, and to establish differences between fungal effects on each tree species. Materials and Methods: Samples of Pinus durangensis, P. cooperi, P. strobiformis, Juniperus deppeana, Quercus sideroxyla, and Alnus acuminata were exposed to fungi for 4 months under laboratory conditions according to European Standard EN350-1. Samples of Fagus sylvatica were used as control. Durability was determined as the percentage of wood mass loss for each species. Welch ANOVA tests were performed to establish differences among tree species. Welch t-tests were used to prove loss mass differences between fungi for each tree species. Results: The most resistant species to C. puteana were P. durangensis, J. deppeana, P. cooperi and P. strobiformis, showing mean mass losses lower than 8.08%. The most resistant species to T. versicolor were J. deppeana, P. strobiformis and P. durangensis (mean mass losses lower than 7.39%). Pinus strobiformis and Q. sideroxyla were more susceptible to C. puteana effect; in contrast, P. durangensis and P. cooperi showed more damage due to T. versicolor degradation. Conclusions: Woods of P. durangensis, P. cooperi, P. strobiformis and Juniperus deppeana are well adapted to infection by these xylophagous fungi and are therefore highly recommended for commercial use in southern Durango, Mexico.
Assuntos
Fagus , Pinus , Trametes/metabolismo , México , Madeira/metabolismo , Pinus/metabolismo , Fagus/microbiologiaRESUMO
This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest-Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin-like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin-like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern-Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold-temperate regions.
Assuntos
Basidiomycota/metabolismo , Candida/metabolismo , Fagus/microbiologia , Fusarium/crescimento & desenvolvimento , Pythium/crescimento & desenvolvimento , Saccharomycetales/metabolismo , Vaccinium/microbiologia , Verticillium/crescimento & desenvolvimento , Argentina , Basidiomycota/isolamento & purificação , Agentes de Controle Biológico , Candida/isolamento & purificação , Ácidos Indolacéticos/metabolismo , Saccharomycetales/isolamento & purificação , Sideróforos/metabolismo , Microbiologia do SoloAssuntos
Ascomicetos/citologia , Ascomicetos/classificação , Fagus/microbiologia , Árvores , Argentina , Chile , Ecossistema , FungosRESUMO
A population of Fagus grandifolia var. mexicana (covering ca. 4.7 ha) is established in a montane cloud forest refuge at Acatlan Volcano in eastern Mexico (Veracruz State), and it represents one of only ten populations of this species known to occur in the country (each stand covers ca. 2-35 ha in extension) and one of the southernmost in the continent. Sporocarps of several ectomycorrhizal macrofungi have been observed in the area, and among them, individuals of the genus Lactarius are common in the forest. However, the morphological and molecular characterization of ectomycorrhizae is still in development. Currently, two species of Lactarius have been previously documented in the area. Through the phylogenetic analysis of the internal transcribed spacer (ITS) region from basidiomes and ectomycorrhizae, we identified the Lactarius fumosibrunneus ectomycorrhiza. The host, F. grandifolia var. mexicana, was determined comparing the amplified ITS sequence from ectomycorrhizal root tips in the GenBank database with Basic Local Alignment Search Tool. The mycorrhizal system of L. fumosibrunneus is monopodial-pyramidal, characterized by its shiny, white to silver and pruinose surface, secreting a white latex when damaged, composed of three plectenchymatous mantle layers, with diverticulated terminal elements at the outer mantle. It lacks emanating hyphae, rhizomorphs, and sclerotia. A detailed morphological and anatomical description, illustrations, and photographs of the ectomycorrhiza are presented. The comparison of L. fumosibrunneus and other Lactarius belonging to subgenus Plinthogalus is presented.
Assuntos
Basidiomycota/isolamento & purificação , Fagus/microbiologia , Micorrizas/isolamento & purificação , Sequência de Bases , Basidiomycota/classificação , Basidiomycota/citologia , Basidiomycota/genética , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Fagus/citologia , Carpóforos , Hifas , México , Dados de Sequência Molecular , Micorrizas/classificação , Micorrizas/citologia , Micorrizas/genética , Filogenia , Raízes de Plantas/citologia , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Simbiose , ÁrvoresRESUMO
A new milkcap species, Lactarius fuscomarginatus, was found in the subtropical region of central Veracruz (eastern Mexico) associated with two relict populations of Fagus grandifolia var. mexicana. The species is characterized macroscopically by its dark pileus and stipe and by its distant and whitish lamellae with blackish to blackish brown edges. A molecular phylogenetic analyses based on ITS and LSU nucDNA sequences confirms the delimitation of this new taxon and places L. fuscomarginatus in subgenus Gerardii. A detailed morphological comparison is given with similar species.
Assuntos
Agaricales/classificação , Fagus/microbiologia , Agaricales/genética , Agaricales/ultraestrutura , Sequência de Bases , DNA Fúngico , DNA Espaçador Ribossômico , México , Dados de Sequência Molecular , Micorrizas/classificação , Micorrizas/citologia , Filogenia , Análise de Sequência de DNA , Esporos Fúngicos/ultraestrutura , Árvores/microbiologia , Clima TropicalRESUMO
Ectomycorrhizal (EM) fleshy fungi are being monitored in a population of Fagus grandifolia var. mexicana persisting in a montane cloud forest refuge on a volcano in a subtropical region of central Veracruz (eastern Mexico). The population of Fagus studied represents one of the 10 recognized forest fragments still housing this tree genus in Mexico. This is the first attempt to document EM fungi associated with this tree species in Mexico. We present evidence of the ectomycorrhizal symbiosis for Lactarius badiopallescens and L. cinereus with this endemic tree. Species identification of Lactarius on Fagus grandifolia var. mexicana was based on the comparison of DNAsequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). The occurrence of Lactarius badiopallescens and L. cinereus populations in the area of study represent the southernmost record known to date of these two species in North America and are new for the Neotropical Lactarius mycota. Descriptions coupled with illustrations of macro- and micromorphological features of basidiomes as well as photographs of ectomycorrhizas are presented.
Assuntos
Basidiomycota/classificação , Fagus/microbiologia , Micorrizas/classificação , Árvores , Basidiomycota/genética , Basidiomycota/crescimento & desenvolvimento , Basidiomycota/isolamento & purificação , DNA Fúngico/análise , DNA Espaçador Ribossômico/análise , México , Dados de Sequência Molecular , Micorrizas/genética , Filogenia , Reação em Cadeia da Polimerase , Ribulose-Bifosfato Carboxilase/genética , Análise de Sequência de DNA , Especificidade da Espécie , Esporos FúngicosRESUMO
Axenically germinated seedlings of two species of Southern beech (Nothofagus obliqua, N. glauca) from Chile were inoculated with spores of the Périgord black truffle (Tuber melanosporum). Ectomycorrhizal development was monitored for 6 months in the greenhouse and compared to the performance of the natural host species Quercus ilex and Quercus robur. Seedling survival and mycorrhization showed major differences in both Nothofagus species: T. melanosporum readily formed ectomycorrhizae with seedlings of N. obliqua, although at a lower rate than with Q. ilex but at a proportion very similar to Q. robur; survival and colonization rates were high, and seedling growth was not visibly affected by the high soil pH required by T. melanosporum. In contrast, more than 50% of N. glauca seedlings died after inoculation, and mycorrhiza formation was very sparse. In both species, no colonization by adventive ectomycorrhizal fungi could be observed, whereas both species of Quercus showed minor colonization by another fungus, probably Inocybe or Hebeloma. Our results show that it is possible to infect N. obliqua with the Périgord black truffle under greenhouse conditions, which opens up the possibility of cultivating this truffle as a secondary crop during reforestation with N. obliqua in Chile.