Mejora de olivo para resistencia a la verticilosis: evaluación de progenies y material ; Olive breeding for Verticillium wilt resistance: evaluation of progenies and wild materials
The Verticillium wilt of olive (Olea europaea L.), caused by the soilborne fungus Verticillium dahliae Kleb., constitutes currently the major cultivation constraint in many olive growing areas. An integrated disease management strategy is recommended for Verticillium wilt of olive with preventive and/or palliative control including the use of resistant cultivars as one of the most efficient control measures. However, only a few traditional cultivars have showed high levels of disease resistance. For this reason, a new area of work in the olive breeding program was initiated aiming at obtaining new cultivars combining high levels of resistance to the development of disease symptoms and good agronomic characteristics. The first target in this work was to obtain information about the inheritance of the main agronomic traits in olive in order to make a subsequent combined strategy for selection to the disease. For that, 26 morphological descriptors and agronomic traits were evaluated in progenies coming from open-pollination of 17 Spanish cultivars of the World Olive Germplasm Bank (WOGP) of Andalusian Institute of Agricultural Research and Training (IFAPA) of Córdoba (Spain) (Andalusian Regional Government, CAP; University of Córdoba, UCO; Andalusian Institute of Agricultural Research and Training, IFAPA) and in their corresponding parents. Significant differences among progenies were observed for all the evaluated traits and different level of heritability estimated for different characters. Resistance of olive genotypes to Verticillium wilt was, therefore, evaluated in this work at an advanced phase into the olive breeding program. Thus, the above mentioned evaluation allowed to select 52 genotypes coming from open-pollination on the basis of their favorable agronomic performance. In addition, resistance to Verticillium wilt was also evaluated in 38 genotypes from three crosses: 'Changlot Real' x 'Dolce Agogia', 'Frantoio' x 'Arbosana' and 'Koroneiki' x 'Empeltre', including all of them as parent at least one ...