Programa de mejora de Pinus pinaster frente al nematodo de la madera

The Galician breeding program of Pinus pinaster initiated in the 1980s by the Lourizán Forestry Research Centre is currently mainly focused on breeding for resistance to the nematode Bursaphelechus xylophilus, a pathogen present in Spain since 2008. Among the various studies carried out to determine the inclusion of nematode resistance as a selection trait in the program, the virulence of nematode isolates from different countries was evaluated, being the isolate detected in Galicia in 2010 one of the most aggressive and, therefore, the one used in the inoculation assays. Studies to assess nematode resistance under controlled conditions showed that there are significant differences between provenances throughout the distribution range of P. pinaster, and the provenance Coastal Galicia (from which the breeding population of the program originates) was one of the most susceptible. However, when the families of the breeding population were evaluated, significant differences were also found, which allowed us to select the most resistant (25% more resistant than the rest) and register them in the National Catalogue of Base Materials as family parents for their commercialization in nurseries. Inoculation assays are currently conducted to identify genotypes with greater resistance. In addition, work is ongoing to advance the breeding program by selecting the best individuals, using a selection index that includes, among other traits, resistance to the nematode.