Sharka virus in apricot and its diagnosis

Abstract

There has been an increasing interest in apricot growing in recent years. Conseqently, a need has arisen for extending the cultivar range. Considering the susceptibility of this fruit species to sharka (PPV) virus, spread in all parts of the country, special attention has been paid to screening cultivars for resistance, as well as to diagnostic techniques due to well-known problem of the virus localization in some apricot cultivars. Screening for resistance was done in the open field by inoculation grafting a number of trees. The trials were conducted in localities with the presence of the PPV strain D, and those with the predominance of the PPV strain M, respectively. The degree of resistance was assessed by visual tests, biotests in the glasshouse, and the ELISA and PCR test. The following cultivars showed resisitance to the PPV-D: Alfred, Blenni, Farmingdale, Harcot, Riland, Stella, clone G-ČA and clone RS-ČA. The cvs Harcot and Badami were found to be susceptible to the strain M, but only Harcot develop conspicuous leaf, fruit and stone symptoms. Krupna Skopljanka manifested field resistance to D strain, but under glasshouse conditions, the infection by this strain was realized.