Aftermath of the Long-Term Application of Sludge and Water from a Sewage Treatment Plant to an Olive Tree (Olea europaea L.) Plantation

Anthropogenic changes detected in the sediment of a shallow (~1.6 m) billabong (Horseshoe Lagoon) are the result of a Sewage Treatment Plant (STP) connection in 1958 and catchment urbanization around 1974. Nutrient-rich water caused the collapse of macrophyte populations, algal blooms became common, and urbanization increased sediment deposition (~1 cm year −1 ). Changes in P retention were investigated by using dated cores, pore-water element profiles, and water quality records. The lagoon is the last of three STP holding ponds. Ponds 1 and 2 were sand-mining pits; they receive no sediment input and have negligible P adsorption. The Fe:P ratios in sediments from three Australian rivers have a common slope and this relationship was used to examine Fe:P ratios in the anoxic bottom sediments of the lagoon. A potential for effluent P adsorption developed in the lagoon through Fe mobilization and enrichment in the upper sediments and a strong clay–Fe–P association. The mean long- term P adsorption in the lagoon (35±18%) was the result of maintaining clay input to an oxic waterbody. Bacterial sulfate reduction is the main process decreasing available Fe for effluent P adsorption. Appropriately designed systems could expect to maintain effluent P adsorption efficiencies of around 70%.

Download Full-text

Genetic Resources of Olea europaea L. in the Garda Trentino Olive Groves Revealed by Ancient Trees Genotyping and Parentage Analysis of Drupe Embryos

Genes ◽

10.3390/genes11101171 ◽

2020 ◽

Vol 11 (10) ◽

pp. 1171

Author(s):

Paula Moreno-Sanz ◽

Luca Lombardo ◽

Silvia Lorenzi ◽

Franco Michelotti ◽

Maria Stella Grando

Keyword(s):

Genetic Resources ◽

Olea Europaea ◽

Virgin Olive Oil ◽

Olive Tree ◽

Extra Virgin Olive Oil ◽

Parentage Analysis ◽

Fruit Production ◽

Olea Europaea L ◽

Genetic Profiles ◽

Olea Europaéa

The area of the Garda Lake within the Trentino province (north of Italy) is the northernmost part of Europe where the Mediterranean species Olea europaea L. is traditionally cultivated. ‘Casaliva’ is claimed as the main variety traditionally grown in the Garda Trentino area (GT) from which a world renowned niche extra virgin olive oil is produced. Since a dominant presence of ‘Casaliva’ would link the fruit set success and yield to a self-pollination compatibility system, a deep genetic survey of the olive tree population in the GT has been performed with the aim of establishing the actual varietal composition and of understanding from which pollen donor the ‘Casaliva’ olives originate. Forty-four different genetic profiles were observed among the 205 leaf samples collected from 106 ancient trees through the analysis of 20 nuclear microsatellite markers. The varietal composition in modern orchards was also explored and the vast majority of the additional 151 trees analyzed showed the same genotype as the ancient accessions of ‘Casaliva’. The results support the long historical link of ‘Casaliva’ with the GT and, besides a high varietal homogeneity, they also revealed the presence of olive genetic resources essential to fruit production. In fact, the parentage analysis of 550 embryos from drupes of ‘Casaliva’ evidenced that a cross-fertilization system is favored and a list of candidate cultivars most suitable as local pollinizers of ‘Casaliva’ was identified.

Download Full-text