In summer 2003 a first search was done whit the goal of finding adult walnut seedlings with leafs free of Xanthomonas arboricola pv. juglandis (Xaj) spots. During that year about 150 walnut trees were pre-selected. However in successive years they had been discarded a number of genotypes that had shown some Xaj spots on leaves. At present they remain selected only 25 genotypes that year-after-year were keeping their leaves and nuts free of Xaj spots.
In February 2007 some thin shoot tips out of the 25 genotypes had been removed and set to IMIDA of Murcia to be evaluated.
En el verano de 2003 se realizó una primera investigación con el fin de localizar semillas de nogales adultos con hojas libres de Xanthomonas arborÃcola pv. juglandis (Xaj) spots. Durante ese año se preseleccionaron 150 nogales. Sin embargo, en años sucesivos se descartaron los genotipos que presentaban alguna mancha en sus hojas. En la actualidad, la selección consta de 25 genotipos cuyas hojas y nueces han permanecido cada año limpias de Xaj spots. En febrero de 2007 se enviaron muestras de 25 genotipos al IMIDA de Murcia para su evaluación.
