Behaviour of several potato (Solanum tuberosum L.) varieties with different l ascorbic acid content to potato tuber necrotic ringspot disease.

Introduction Obtaining good quality for potato impose the improvement of identification’s techniques of pathogen agents, knowing the biochemical composition, especially the components that could affect its health status. The goal of this research was to evaluate the starch content of 10 potato samples (varieties with different resistance to potato virus Y) and the behavior of these samples to the disease caused by PVY. Material and methods The potato varieties tested were Christian, Roclas, Productiv (roumanian cv.) and Red Fantasy, Jelly, Desire, Bellarosa, Red Lady, Hermes (foreign cv.). After emergence, the material has been mechanically inoculated, using an Y source (secondary infected plants from Hermes variety). After the inoculation, disease symptoms were observed and ELISA tests have been made. The percentage of tubers with necrotic symptoms was estimated at harvesting time and after 3 months. The starch content was made using Evers method. Results Excepting the cultivars Christian and Riviera wich were very resistent and resistent to mechanical inoculation, all the other varieties presented 69-100% infected plants. After 3 months from harvesting, the frequency of tubers with symptoms was between 3.3-20.8% for varieties Roclas, Red Fantasy, Bellarosa, Jelly and for varieties Productiv, Desire, Red Lady, Hermes this percentage was higher (69-100%). Regarding the varieties Christian and Riviera, after 3 months from harvest, the stored tubers didn’t have visible tuber necrotic ringspot disease symptoms. Conclusions There is a positif correlation between the starch content of the samples and their resistance to PVY inoculation. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, CNDI-UEFISCDI, PN-II-PT-PCCA-20134-0452, project number 178/2014.