R. Mafacioli

Variabilidade patogênica e efeito de carboidratos no crescimento micelial, esporulação e agressividade de Colletotrichum gloeosporioides da pupunheira

The aggressiveness of 17 Colletotrichum gloeosporioides isolates associated with anthracnose on leaves of peach palm (Bactris gasiapes) from Northern, Southeastern and Southern States of Brazil was evaluated through a bioassay using detached leaves of peach palm, at three stages: young, intermediate and fully expanded leaves. Differences on aggressiveness among isolates were significant only on fully expanded and intermediate leaves. Different sources of carbohydrates such as glucose, maltose and starch, added to potato-agar medium affected mycelial growth and sporulation of some isolates. Among five isolates tested, only two had their aggressiveness increased when conidia were produced on potato-agar medium supplemented with starch.

Colletrotrichum gloeosporioides causando antracnose em frutos de pupunheira nos estados de Minas Gerais e Paraná

The cultivation of peach palm (Bactris gasipaes) for production of palm heart has increased in Southeast and Southern Brazil, in areas of domain of Atlantic Forest. Adult peach palm plants kept for seed production have suffered severe rot damages on fruits, resulting from coalescence of spots. The fungus Colletotrichum gloeosporioides was isolated from the damaged tissues and its pathogenicity to peach palm fruits was confirmed under controlled conditions. This is the first report of this disease damaging peach palm fruits in the Minas Gerais and Parana States.

Caracterização morfo-fisiológica e patogenicidade de Colletotrichum gloeosporioides da pupunheira

Isolates of Colletotrichum sp. obtained from leaves of peach palm (Bactris gasipaes) showing symptoms of anthracnosis from several regions of Brazil were characterized and identified based on their phenotypic traits. A total of 17 isolates collected from the states of Acre and Rondonia, where the peach palm is originated as well as from Southern States such as Espirito Santo, Sao Paulo and Parana, where peach palm has been introduced for the production of palm heart, were studied. Disease symptoms were characterized and the isolates were compared based on form and size of conidia and apressoria, color of the colony, mycelial growth and sporulation in vitro. The pathogenicity of all isolates was confirmed based on a detached leaf of peach palm assay. All isolates were characterized as Colletotrichum gloeosporioides and the occurrence of the meiosporic stage (Glomerella cingulata) was observed only for one isolate.