Small tropical islands with dense human population: differences in water quality of near-shore waters are associated with distinct bacterial communities.

Water quality deterioration caused by an enrichment in inorganic and organic matter due to anthropogenic inputs is one of the major local threats to coral reefs in Indonesia. However, even though bacteria are important mediators in coral reef ecosystems, little is known about the response of individual taxa and whole bacterial communities to these anthropogenic inputs. The present study is the first to investigate how bacterial community composition responds to small-scale changes in water quality in several coral reef habitats of the Spermonde Archipelago including the water column, particles, and back-reef sediments, on a densely populated and an uninhabited island.

Bacterial Community Composition and Potential Driving Factors in Different Reef Habitats of the Spermonde Archipelago, Indonesia.

Coastal eutrophication is a key driver of shifts in bacterial communities on coral reefs. With fringing and patch reefs at varying distances from the coast the Spermonde Archipelago in southern Sulawesi, Indonesia offers ideal conditions to study the effects of coastal eutrophication along a spatially defined gradient. The present study investigated bacterial community composition of three coral reef habitats: the water column, sediments, and mucus of the hard coral genus , along that cross-shelf environmental and water quality gradient.

Investigation on the plum pox virus resistance in different apricot genotypes.

In our three-year investigation, 164 apricot trees of different old German varieties cultivated in the Mansfelder Land region were tested for the plum pox virus (PPV) resistance by double grafting in greenhouse conditions using an isolate of PPV D strain from our region. We selected 25 genotypes with quantitative resistance and two with immunity. The first results of field trials are comparable with those from greenhouse.

Some results of 50 years of research on the resistance to plum pox virus.

Over 300 references on the resistance of stone fruit species to plum pox virus (PPV) have been utilized for the summarization of relevant information in this review. Methods of testing PPV resistance, procedures of evaluation and characterization of PPV resistance as well as breeding of PPV-resistant cultivars are briefly discussed. Altogether 370 cultivars, hybrids and clones of plum, peach, apricot, nectarine and wild Prunus species are tabulated together with the authors who have reported on their immunity, resistance and tolerance.