Efeito de inoculante ectomicorrízico produzido por fermentação semi-sólida sobre o crescimento de Eucalyptus dunnii Maiden

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.

Growth and Nutrition of Eucalypt Rooted Cuttings Promoted by Ectomycorrhizal Fungi in Commercial Nurseries

“…The increase in eucalypt CD, SH, and SDM promoted by inoculation with increasing application rates of different EMF species (Figures 1a, 1b, 1c) was also observed by other authors in eucalypt seedlings (Alves et al, 2001;Souza et al, 2004Souza et al, , 2008. E. dunnii seedlings had greater CD (1.4 times), SH (1.3 times), and SDM (1.7 times) levels when inoculated with Pisolithus sp.…”

“…Ectomycorrhizal fungi species differed in their capacity to increase leaf P concentration and content ( Figures 2a, 2b); however, they did not differ in terms of growth promotion (Figures 1a, 1b, 1c) and root colonization ability (Figure 1d), and they also raised leaf K and N concentration and content (Figures 2c, 2d, 2e, 2f). This similar behavior among EMF species observed in growth promotion, root colonization, and plant nutrition for some nutrients differs from most studies found in the literature (Alves et al, 2001;Silva et al, 2003;Souza et al, 2004Souza et al, , 2008Chen et al, 2006c).…”

“…In E. dunnii seedlings inoculated with Pisolithus sp. (UFSC-pT24) and cultivated for 100 days, the largest CD (2.5 mm) and SH (26.2 cm) were observed in seedlings that received 3 % inoculum produced in a mixture of a vermiculite-peat culture medium (Alves et al, 2001). This difference may be due to different types of inocula used in this study.…”

“…Chondrogaster angustisporus and Pisolithus microcarpus vegetative inoculum in Eucalyptus dunnii increased the percent colonized root length, P uptake and shoot dry mass (SDM) of colonized plants (Souza et al, 2004). E. dunnii inoculated with Pisolithus sp., grown in a mixture with vermiculitepeat culture medium, had greater colonization at the highest inoculum rate (10 % in sapling substrate), whereas shoot height, diameter, and SDM increases were observed as of a 3 % inoculum rate and greater P concentrations as of 1 % (Alves et al, 2001). …”

“…especially in greenhouses (Courty et al, 2010) and with seminal saplings (Alves et al, 2001;Souza et al, 2004;Chen et al, 2006c). The development of this biotechnology for routine inoculation in commercial nurseries may increase the sustainability of planted forests in Brazil, making the already competitive forestry sector even more competitive.…”