Fine structure of the oocyst of Nematopsis mytella (apicomplexa, porosporidae),a parasite of the mussel Mitella falcata andof the oyster crassostrea rizophorae (Mollusca, Bivalvia)from the northeastern atlantic coast of Brasil

Oocystsof Nematopsis mytella, an apicomplexa gregarine parasite of the mussel Mytella falcata (fam. Mytelidae) and of the oyster Crassostrea rizophorae (fam. Ostreidae). Were collected from Itamaracá Island and Suape, two distinct zones in the estuarine region of the northeastern coast of Brazil, near the city of Recife. The oocysts were examined by light and transmission electron microscopy. No morphological and ultrastructural differences were observed between oocysts the two host species. The oocysts were engulfed by the cytoplasm of host phagocytes, with each phagocyte containing 1-19 oocysts (usually 3-5). Each oocyst was located in the center of a spherical to ellipsoidal parasitophorous vacuole (PV) 20-25 um in diameter. The oocyst (13.2 um long and 8.4 um wide) consisted of an external wall 0.6 um thich surrounded by an internal, uninucleated sporozoit. The apical region of the wall of each oocyst contained a circular micropyle 0.8 um in diameter covered by an operculum. The oocyst wall was connected to the PV membrane by a complex network of anastomosed microfibrils. The PV matrix contained 1-2 dense bodies and the periphery was occupied by numerous glycogen particles. This is the first record of a Nematopsis sp. from the northeastern coast of Brazil and only the second from Brazil as a country.

Biocontrole pós-colheita da podridäo de Lasiodiplodia em frutos de manga por leveduras saprofíticas / Postharvest biocontrol of Lasiodiploidia rot of mango fruits by saprophytic yeasts

Among eigtheen yeast isolates studied as potential agents for biocontrol of stem-end rot on mango fruits caused by Lasiodiplodia theobromae, five were selected for testing in relation to three pathogen concentrations (1x10ü, 1x10 elevada à quarta and 1x10 elevada à quinta conidia/ml). The isolate LM-5 (Candida maritima) showed high control level at all pathogen concentrations. When tested against five pathogen isolates, LM-5 again demonstrated high control efficiency, and at in vitro test, highlyinhibited L.theobromae spore germination. The isolate LM-5 demonstrated great potential as agent for postharvest biocontrol of mango rot