EVALUATION OF PPV SYMPTOMS IN PLUM GERMPLASM AFTER ARTIFICIAL INFECTION

Abstract

Plum pox virus (PPV) is one of the most economically important diseases of stone fruit in the Czech Republic. PPV is currently widespread on the whole territory of the Czech Republic. Therefore, spatially isolated plantation of a broad assortment of plum cultivars (207) was established in 1990. One-year-old plant material (2 trees/cultivar) at a spacing of 6 x 4 m on myrobalan rootstock was used. The collection was planted at an altitude of 320 m. Mean annual temperature is 8.1°C and precipitation 654.7 mm. Weed-free strips are maintained under the bushes with herbicide applications. Regularly cut grass is established between the rows. After artificial infection, the PPV was detected by ELISA in 77.1% of inoculated trees. After PPV reinfection in 1996, the percentage of infected trees increased to 92.9% in 1998. The virus spread only slightly in the following years. PPV was detected in 94.2% of trees in 2000-2005 and in 95.2% of trees since 2006. Symptoms of PPV on fruits were evaluated after the beginning of fruiting. Cultivars 'Italian prune' and its clones 'Albatros', 'Bonne de Bry', 'Centenar', 'Eliasova', 'Konigsbacher Fruhzwetsche', 'Lutzelsachser', 'Vengerka Kodrinskaja', 'Zimmers Friihzwetsche' developed the most visible symptoms on fruits. Commercially important cultivars 'Anna Spath', 'Cacanska lepotica', 'Cacanska najbolja', 'Elena', 'Gabrovska', 'Hamanova', 'Hanita', 'Chrudimer', 'Opal', 'Veeblue', 'Verity' and 'Voyageur' were without symptoms of PPV on fruits.