2019 ASHS Annual Conference

Olive (Olea europaea L.) orchards in Texas now represent the fifth highest acreage among fruit crops. However, occasional freezing events forces the trees through cycles of the acclimation-de-acclimation process damaging the orchards, especially young plants. This damage often results in severe losses in yield, oil quality, and even tree death. Most of the varieties currently used for olive production in Texas are not well adapted to survive under freezing stress. Cultivar ‘Arbequina’ dominates over 80% of the production in Texas risking the dangers of exposing monoculture genetic background to various abiotic and biotic stresses. As a step toward developing varieties adapted to the Texan climate, we evaluated the mechanism of freezing tolerance using regionally adapted varieties at four different locations. Our preliminary analysis of vegetative tissue of ten varieties grown at various orchards (Carrizo Springs, Georgetown, Dripping Springs, Moulton) indicated significant genotypic variation among primary metabolites. The differences in the N-rich amino acids are critical to the freeze tolerance response as well as nitrogen assimilation and mobilization during the development. The variety ‘Picual’ accumulated significantly higher total amino acids and N-rich amino acids (Glutamate, Glutamine, and Alanine) in leaves than the regionally popular variety; Arbequina. Identification of potential biochemical marker(s) and determination of their functional role will help in understanding the molecular mechanisms involved in freeze tolerance in olives. We are evaluating the impacts of a probiotic - Lalitha-21 (Acela BIOTEK) on the productivity and freezing tolerance of olive plants in Texas. This study will help in determining the effect of probiotics on the nutritional makeup of the plants, soil nitrogen availability and solubilization of minerals to develop long term nutrient management strategy.