Recently, researchers from the Genomics and Breeding Unit of the University Institute of Research on Olive Grove and Olive Oils (INUO) of the University of Jaén in collaboration with IFAPA ‘Alameda del Obispo’ and the University of Córdoba have demonstrated that three new varieties obtained from the genetic improvement programme together with others from IFAPA’s World Olive Germplasm Collection are a sure hit for obtaining high quality olive oils by avoiding Verticillium, a disease that penetrates through the roots of the plant.
Currently, Verticillium caused by the fungus Verticillium dahliae is a threat to the olive oil industry, as there is no effective treatment. Specifically, the Alert and Phytosanitary Information Network (RAIF) quantified the infection of this fungus at 2.9% in Andalusian crops in Córdoba in 2022, reaching 88.9% in Huelva.
This situation prompted the researchers to look for varieties resistant to this pathogenic fungus. To do so, they evaluated 40 different varieties, of which 31 came from the World Bank Collection of Olive Germplasm of the ‘IFAPA Alameda del Obispo’ Research Centre in Córdoba, other varieties selected were ‘Cornicabra’, ‘Changlot Real’ and ‘FS-17’ for their resistance against another olive disease caused by Xylella fastidiosa, and 6 varieties from the genetic improvement programme.
After the selection of varieties, they continued their growth stage and, after 12 months, were inoculated with the fungus to analyse their evolution. In addition, in order to classify the varieties according to their level of resistance, from highly resistant to extremely susceptible, sixteen individuals of each olive variety were included in the trials, distributed in four blocks, three infected and one control. At the end of the trials, it was determined that the first varieties to show that they remained symptom-free, despite being infected by the fungus, were ‘Frantoio’, ‘FrxAr_5’, ‘FrxAr_6’ and ‘KorOp_48’.
In short, this work has demonstrated that new varieties resistant to the disease can be obtained while maintaining high levels of productivity in the olive tree, guaranteeing the production of high quality olive oil. For this reason, the researchers are continuing to analyse the possible options for collaboration with farmers to find out how this resistance behaves in real conditions, in such a way that the agronomic values necessary for its future implementation can be confirmed.
These analyses are part of the project ‘Research and innovation in genetic improvement of the olive tree (INMEGEO)’ of the Andalusian Institute for Agricultural, Fisheries, Food and Ecological Production Research and Training (IFAPA) belonging to the Ministry of Agriculture, Fisheries, Water and Rural Development of the Andalusian Regional Government, partially financed by the European Regional Development Fund (ERDF).
Scientific publication:
Serrano, A., Rodríguez-Jurado, D., Ramírez-Tejero, J.A., Luque, F., López-Escudero, F.J., Belaj, A., Román, B., & León, L. (2023). Response to Verticillium dahliae infection in a genetically diverse set of olive cultivars. Scientia Horticulturae, 316, Article 112008. https://doi.org/10.1016/j.scienta.2023.112008
