Name: JANIL FERREIRA DA FONSECA
Type: MSc dissertation
Publication date: 28/06/2013
Advisor:
Name |
Role |
|---|---|
| Viviana Borges Corte | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Emilio de Castro Miguel | Co advisor * |
| Geraldo Rogério Faustini Cuzzuol | Internal Examiner * |
| Viviana Borges Corte | Advisor * |
Summary: The Rubiaceae family is the largest among the four Angiosperms families, considering the number of species. In Brazil, comprising approximately 118 genera, highlighting for commercial species of Coffea Lgenus. Among these species Coffea arabica and Coffea canephora Pierre ex Froehner are those of greatest economic importance. Coffeas canephora accountable for much of the coffee production of Espírito Santo, however, much attacked by pathogens, especially fungi. On the other hand, no significant diseases are noted in apical meristems, region full of the secretion of secretory structures named colleters. The aim of thisstudy was to describe the micromorphology and anatomy of colleters of Coffea canephora Pierre ex Froehner, as well as investigating the allelopathic and antifungal potential of secretion. Thus, we used basic techniques of optical microscopy and scanning electron microscopy, as well as germination test with organic seeds of Phaseolus vulgaris L., subjected to treatments with Coffea canephora aqueous and alcoholic extracts of shoot apex and leaves. Colleters, present in the base of the adaxial side of the stipules, are secretory structures consisting of an elongated central axis, formed by fundamental parenchyma, surrounded by a palisade epidermal cells. Germination tests showed a decrease in the rate of germination of seeds treated with alcoholic extract of the apex, which was not observed for the aqueous extract. Aqueous and alcoholic leaf extracts did not affect Phaseolus vulgaris L. germination. The shoot apex alcoholic extract inhibited fungi spores the growty, once presented atypical morphology, similar to the control with sodium hypochlorite. Colleters presented typical structure of Rubiaceae and its secretion has allelopathic and antifungal effect. However, more studies are needed to elucidate the ultrastructure of the colleters, as well full characterization of allelopathic and antifungal secretion activity.
