Evaluation of the SILVOLIVE wild olive collection for resistance to Verticillium dahliae

Póster presentado en Olivebioteq 2018, the 6th International Conference on Olive Management and Olive Products, held in Seville, Spain, on 15th-19th October 2018.In recent years, the olive cultivation model has undergone a change from the traditional cropping model under rain-fed regime to intensive and super-intensive olive groves subjected to fertilization and irrigation. This has enhanced the proliferation of soilborne fungi like Verticillium dahliae causing verticillium wilt, currently the most threatening disease for olive crops in Spain due to the rapidity of its extension and the severity of its damage. Moreover, the most widely planted olive cultivars (Picual, Hojiblanca and Arbequina) are susceptible or very susceptible to the disease, especially under intensive conditions. We aim to take advantage of the genetic variability present in the wild subspecies of Olea europaea to identify and characterize wild olive genotypes with a high resistance to the verticillium wilt disease. The SILVOLIVE collection consists of 149 genotypes from all known subspecies of Olea europaea described so far, including the subspecies: europaea, laperrinei, cuspidata, cerasiformis, guanchica and maroccana. These genotypes were prospected from world olive germplasm collections (Córdoba and Marrakech) and different regions of Spain, continental Africa and the Macaronesian archipelago. Susceptibility to V. dahliae of 56 wild olive genotypes has been evaluated under controlled conditions inoculating six-month-old olive plants with a cotton defoliating isolate of V. dahliae (V117). After root inoculation of the fungus (107 conidia ml-1), quantification by qPCR at 35 and 120 days after inoculation, and analysis of symptoms in aerial organs, three genotypes showed high resistance/tolerance indexes. These genotypes can be used as high tolerance rootstocks as a control strategy for the growth of commercial and productive olive cultivars.Peer Reviewe