SYMPTOM EXPRESSION AND ACCUMULATION OF POTATO VIRUS-Y (PVY(O)) AND POTATO LEAF ROLL VIRUS IN 13 POTATO CULTIVARS

Necrotic local lesions developed in cvs. Matilda, Ostara, Record, Satu rna, Stina, Hank-kija's (Hjan) Tanu and Hjan Timo and local ring spots in Olympia and Sieglinde (Siikli) following sap inoculation with the ordinary strain of potato virus Y (PVY(O)). Secondarily infected cvs. Ostara, Pito, Siikli and Hjan Timo developed leaf drop. No infected pr ogeny was produced by Matilda, Satuma and Hjan Tanu. In contrast, Bint je, Puikula and Sabina developed neither local lesions nor systemic ne crosis, but showed mosaic symptoms following primary and secondary inf ection by PVY(O). The ELISA absorbance values for potato leaf roll vir us (PLRV) in Ostara, Pito and Satuma were less than 10% of those in th e PLRV-infected Siikli. The ELISA values for PLRV in Olympia, Stina, H jan Tanu and Hjan Timo were not significantly different from those of Siikli. The severity of die symptoms did not correlate with die concen tration of PLRV in the potatoes.