Occurrence of Platypus mutatus Chapuis (Coleoptera: Platypodidae) in a brazilwood experimental plantation in Southeastern Brazil

The hardwood of Caesalpinia echinata Lam. (brazilwood, Pernambuco, ibirapitanga) is currently the most profitable material used for violin bow due to the unique vibrational properties and dimensional stability. Although this species is resistant to the wood decay caused by termites and rot fungi, an experimental plantation in Southeastern Brazil has been attacked by the ambrosia beetle Platypus mutatus Chapuis (= Megaplatypus mutatus and P. sulcatus). This species invaded ca. 3 percent of the individuals, mainly in the central part of the plantation. Infestation by larvae and adults was higher during the dry season (winter) when compared to the rainy period (spring and summer).

O cerne da madeira de Caesalpinia echinata Lam. (pau-brasil, Pernambuco, ibirapitanga) é considerado o material mais adequado para a construção de arcos de violinos devido às suas propriedades vibracionais e a estabilidade. Embora a madeira dessa leguminosa seja resistente à deterioração causada por fungos apodrecedores e cupins, um bosque experimental de pau-brasil no Sudeste do Brasil vem sendo atacado pelo besouro de ambrosia Platypus mutatus Chapuis (= Megaplatypus mutatus e P. sulcatus). Esse coleóptero invadiu cerca de 3 por cento das árvores, principalmente na região central do bosque. A infestação por larvas e insetos adultos foi maior durante a estação seca (inverno) quando comparada ao período chuvoso (primavera e verão).

Woronin bodies in Penicillium Janczewskii Zaleski

Penicillium janczewskii Zaleski is an efficient microorganism for the production of extracellular inulinases and grows rapidly on medium containing sucrose or inulin as carbon source. Maintenance of this filamentous fungus on inulin medium induces secretion of large amounts of inulinases, but the resulting mycelium has thinner cell walls that easily collapse and break. Woronin bodies in hyphae of P. janczewskii grown on sucrose and inulin substrates were observed. No significant differences in the number, location, size and shape of Woronin bodies and level of plugging were observed in cultures of the fungus grown on the two carbon sources. The data indicate that the presence of Woronin bodies in P. janczewskii could not be associated with more easily damaged hyphae, although the function of these organelles in pore plugging has been confirmed.

Involvement of active oxygen species and peroxidases in phytoalexin production induced in soybean hypocotyls by an elicitor from a saprophytic fungus

The involvement of active oxygen species and apoplastic peroxidases in the mechanism of phytoalexin induction were evaluated in soybean hypocotyls using an eliciting extract from the saprophytic fungus Mucor ramosissimus. Hydrogen peroxide and ferric chloride-ascorbic acid a .OH radical generating system, promoted glyceollin production and increase in peroxidase activity similar to those observed with the fungal elicitor. Addition of catalase or potassium ferrocyanide (an inhibitor of peroxidase) inhibited both processes. It is suggested that there is a cause-effect relationship between peroxidase activity and phytoalexin induction both triggered by oxidative processes.