OPTIMIZATION OF THE EVALUATION OF RESISTANCE TO SHARKA (PLUM POX VIRUS, PPV) IN CONTROLLED GREENHOUSE CONDITIONS IN THE APRICOT BREEDING PROGRAMME OF CEBAS-CSIC IN MURCIA (SPAIN)

Abstract

In some countries like Spain or France, quarantine rules force researchers to evaluate the resistance to Sharka (Plum pox virus, PPV) in controlled isolated conditions. This method shows important limitations related to the management of plants in these controlled conditions with artificial cycles of growth in greenhouse and cold chamber alternatively. The objective of this study is to optimize the method of evaluation of PPV resistance in controlled greenhouse conditions. The steps of the method studied were the inoculation method (inoculation of rootstock or cultivar), the success in the grafting (depending on inoculation method, cultivar-rootstock combination, grafting in spring or autumn) and the efficiency of the process in each cycle of growth. Results showed that the inoculation onto the rootstock was much more efficient. As apricot rootstock, the 'GF305' and the 'Real Fino' seedlings had a similar behaviour. Differences observed in the grafting at different time periods were not related to the season (spring or autumn). Finally, the efficiency of the evaluation process was higher with the inoculation of the rootstock, mainly during the first cycle.