The tuber necrotic strain of Potato Virus Y
(PVYNTN) is considered the most aggressive
strain of PVY. Effects of PVYNTN on some
metabolic
activities
and
cytological
characteristics of three potato cultivars Lady
Rosetta,
Mondial
and
Santana
were
investigated. Virus concentration, infection
percentage and disease severity were also
estimated. Potato cultivars differed in their
susceptibilities to PVYNTN infection, whereas
various levels of apical necrosis with different
disease severity 30, 60, and 100% were
recorded for Mondial, Santana and Lady
Rosetta cultivars respectively. The lowest
amount of leaf pigments was found in PVYNTN
infected potato cv. Santana. Total phenolic
and total soluble sugars contents were highly
accumulated in PVYNTN-infected leaves
compared to healthy ones. A noticeable
increased level of sodium cation was detected
in PVYNTN-infected leaves of potato cv. Lady
Rosetta. Electron microscopy analysis showed
changes in nuclei, mitochondria, cell walls,
and chloroplasts in PVYNTN-infected cells of
potato cultivars compared with healthy.
Genetic variations among potato cultivars
under PVYNTN infection were detected by Inter
Simple Sequence Repeat-Polymerase Chain
Reaction (ISSR-PCR) analysis. The ISSR
primers amplified 57 bands, and 52 showed
polymorphism (91.23%). According to the
obtained results, potato cvs. Lady Rosetta
and Santana were highly susceptible to
PVYNTN infection while, Mondial was
moderately resistant. |
