No abstract

Resumo -O crescimento de Eucalyptus é favorecido por fungos ectomicorrízicos (FECM).De ocorrência comum nas plantações florestais, os FECM diferem, entretanto, em infectividade e eficiência. O objetivo deste estudo foi testar a compatibilidade e a eficiência do inoculante ectomicorrízico produzido por fermentação semi-sólida, em relação a Eucalyptus dunnii Maiden. Neste sentido, o inoculante de Pisolithus sp., produzido por fermentação semi-sólida em vermiculita-solução nutritiva, foi aplicado ao substrato turfa-vermiculita (30:70, v/v) nas concentrações de 0, 1, 3, 5 e 10% (v/v) que foi semeado com E. dunnii, e mantido em casa de vegetação. A inoculação proporcionou colonização radicular e aumento da matéria seca da parte aérea e do conteúdo de P em razão da concentração do inoculante. O peso da matéria seca das plantas com 1% de inoculante não diferiu do peso das testemunhas. A 3% e 5%, a matéria seca aumentou 62%. O maior valor foi obtido com 10% de inoculante, onde o peso das plantas foi 73% superior ao das testemunhas, e o teor de P, 130%. Resultados semelhantes foram obtidos em relação à raiz. Altura e diâmetro foram positivamente afetados pela inoculação, mas não a relação raiz/parte aérea. As doses mais eficientes de inoculante foram aquelas de 3% ou superiores. Este método de produção deverá ser testado com outros FECM, e sua eficiência, avaliada em viveiro e no campo.Termos para indexação: Pisolithus, inoculação, eficácia, fósforo, absorção. Effect of ectomycorrhizal inoculum produced by solid state fermentation on growth of Eucalyptus dunnii MaidenAbstract -Growth of Eucalyptus can be improved by ectomycorrhizal fungi (ECMF). Although widespread in forest plantations, ECMF differ in infectivity and effectiveness, hence the need of selection of compatible and efficient ECMF and the establishment of inoculum production methods. The objective of this study was to test compatibility and efficiency of the ectomycorrizal inoculum produced by solid state fermentation, in relation to Eucalyptus dunnii Maiden. For this purpose, inoculum of Pisolithus sp. was produced by solid state fermentation in vermiculite + nutrient solution and applied to peat:vermiculite (30:70 v/v) at 0, 1, 3, 5 and 10% (v/v). Seeds of E. dunnii were sown and kept in a glasshouse. Inoculation promoted root colonization, plant growth and phosphorus (P) uptake depending upon inoculum concentration. Plant dry matter with 1% inoculum did not differ from that of the controls. At 3% and 5%, plants had 60% more dry matter than the controls. At 10%, inoculum shoot dry weight (dw) was 70% higher, and P content was 130% higher than that of the controls. Similar results were obtained in relation to root dw. Height and diameter were also positively affected by inoculation. Root:shoot ratios were not influenced. The most efficient doses were those at 3% inoculum or higher. This method of inoculum production needs to be tested with other ECMF and its efficiency must be evaluated in the nursery and in the field.

Resumo -O potencial de fungos ectomicorrízicos na promoção do crescimento das plantas e o controle da micorrização podem alavancar a exploração comercial desses fungos. O objetivo deste trabalho foi avaliar a eficiência de isolados de fungos ectomicorrízicos na colonização radicular, absorção de P e no crescimento de mudas de Eucalyptus dunnii, sob diferentes doses de fósforo. O inóculo dos isolados fúngicos INRA-Cou (Paxillus involutus), UFSC-Hg93 (Hysterangium gardneri), UFSC-Pt116 (Pisolithus microcarpus) e UFSC-Ch163 (Chondrogaster angustisporus) foi produzido assepticamente numa mistura turfa-vermiculitameio de cultura. As plantas foram cultivadas num substrato de igual composição, suplementado com macro e micronutrientes, e diferentes doses de fósforo: 0, 0,25, 0,50, 1,00, 2,00, 4,00 e 8,00 mg por planta. Os isolados UFSC-Pt116 e UFSC-Ch163 promoveram maior colonização radicular, absorção de P e crescimento das plantas, medido pela altura e massa de matéria seca. A colonização micorrízica foi inibida pelo aumento das doses de fósforo. As doses de 0,50 e 1,00 mg de P por planta mostraram-se mais adequadas em compatibilizar a colonização radicular com um bom crescimento das mudas. Os isolados UFSC-Ch163 e UFSC-Pt116 são promissores em um programa de micorrização controlada de E. dunnii. Termos para indexação: Eucalyptus dunnii, Pisolithus microcarpus, Chondrogaster angustisporus, ectomicorrizas, inoculação. Efficiency of ectomycorrhizal fungi on phosporus uptake and eucalypt growth promotionAbstract -The potential of ectomycorrhizal fungi to promote plant growth and the mycorrhization control may contribute to important progress towards the exploitation of these fungi commercially. The objective of this work was to evaluate the efficiency of ectomycorrhizal isolates on root colonization, P uptake and growth of Eucalyptus dunnii seedlings under different levels of phosphorus applied. Inocula of the ectomycorrhizal isolates, INRA-Cou (Paxillus involutus), UFSC-Hg93 (Hysterangium gardneri), UFSC-Pt116 (Pisolithus microcarpus) and UFSC-Ch163 (Chondrogaster angustisporus), were aseptically produced in a peat-vermiculite mixture supplemented with liquid culture medium. Plants were grown in a similar substrate supplemented with macroand micronutrients, under different levels of phosphorus: 0, 0.25, 0.50, 1.00, 2.00, 4.00, and 8.00 mg per plant. The isolates UFSC-Pt116 and UFSC-Ch163 promoted higher root colonization, higher P uptake and plant growth, as determined by plant height and dry matter. Levels of 0.50 and 1.00 mg of P per plant promoted a significant mycorrhizal colonization and an adequate plant growth. The isolates UFSC-Ch163 and UFSC-Pt116 represent a promising alternative for a controlled mycorrhization programme of E. dunnii.

The abundance and diversity of ectomycorrhizal fungi (EMF) was assessed based on the collection of basidiocarps during 12 months comprising the spring of 1995, and the summer, autumn, and winter of 1996, in three stands of young, middle-aged, and rotation age plantations of Pinus taeda and Eucalyptus dunnii, in the state of Santa Catarina, southern Brazil. A total of 3,085 collections yielded 34 presumed EMF taxa in ten genera, including mushroom-like and sequestrate species. Fruiting patterns of EMF differed with host and season, and host specificity was apparent in some. The overall relative importance (RI) and the Shannon diversity index (H) suggested that stands of E. dunnii had a more diverse aboveground EMF community than those of P. taeda. Overall, species of Scleroderma and Laccaria were not only the most abundant but also had the highest biomass values. The results show that a small number of species of abundant biomass and a larger number of species of less-abundant biomass characterize each forest class.

No abstract

No abstract

The utilization of rocks as fertilizers is limited by their low solubility. However, solubilization may be achieved by some micro-organisms, such as ectomycorrhizal fungi (ECMf). The aim of this study was to evaluate the potential of seven isolates of ECMf to solubilize two rocks, alkaline breccia and granite, and to liberate potassium and phosphorus for Eucalyptus dunnii seedlings under greenhouse conditions. Fungal inoculants were produced in a peat-vermiculite-liquid medium mixture and added to the planting substrate at 10 %. Rocks were ground up and added at 0.500 mg and 16.0 mg per plant, as a source of phosphorus and potassium, respectively. Other nutrients were added and E. dunnii seeds were sown.Control plants, non-inoculated, were fertilized with the same amount of phosphorus and potassium using soluble forms. After 90 days, the plant height, shoot dry weight, root length, phosphorus and potassium contents, and mycorrhizal colonization were evaluated. Alkaline breccia was more efficient than granite as

Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4 ',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from C. limon.Key words: polymethoxylated flavonoids -antibiosis -pathogens -fungi -bacteria Citrus spp. are considered an important source of polymethoxylated flavonoids (PMF), a class of secondary plant metabolites (Afek et al. 1986). PMF's are generally found bound to sugar moieties (glycosides) or in exceptional circumstances as free aglycones (Robards et al. 1997). They are often used to establish phylogenetic relationships among plants (Mizuno et al. 2001). However, flavonoids are known to have physiological effects on other organisms. They have been shown to reduce erythrocyte aggregation and sedimentation rates in human blood (Robbins 1976), as well as to exhibit antiviral (Brinkworth et al. 2002), antimutagenic (Iwasse et al. 2001), and antimicrobial properties (Afek et al. 1986, Cushinie & Lamb 2005. Some studies have indicated that foods containing high amounts of flavonoids may reduce the risk of heart diseases, due to their antioxidant properties (Young et al. 1999, Arts et al. 2001, Tripoli et al. 2007).Studies of the antimicrobial activities of flavonoids have become important because of the increasing occurrence of opportunistic systemic mycosis, as well as the rising prevalence of drug resistance in human pathogenic bacteria (Afek et al. 1986). Drug-resistant bacteria and fungi have complicated the treatment of infectious diseases in immunocompromised AIDS and cancer patients. The evolution of multiple drug resistant human pathogenic microorganisms, has driven the search for new sources of antimicrobial substances, including plant metabolites (Nostro et al. 2002).The dramatic increase in the resistance of plant pathogens to chemical fungicides has led to the use of repeated applications of chemical fungicides to control plant diseases. As a consequence, public concern has increased the demand for safer and less environmentally harmful agrochemicals (Wedge & Nagle 2000). New antifungal and antibacterial agents are necessary to address this situation.PMFs with their lipophylic properties, are usually present in vacuoles or in the wax cuticle of plants. Several studies have detected their presence in the wax epicuticular layer on plants where they play a role in protecting these regions against UV radiation and microbial ...