Acta Botanica Croatica, Vol. 40 No. 1, 1981.
Original scientific paper
Effect of Senescence on Lesion Formation and the Level of Induced Resistance in Samsun NN Plants Infected with TMV. II. Topography of TMV Resistance in Samsun NN Leaves
Kazimierz A. Miczyński
; Poljska
Abstract
Mechanical inoculation of leaves of Samsun NN tobacco with a TMV suspension causes the formation of necrotic lesions, the number and size of which depends on the physiological age of infected tissues. Lesions at the periphery of the leaf blade are usually much larger than those which are formed closer to the main vein. This difference reflects a natural decrease in TMV resistance, directed from the centre of the leaf to its margins. TMV infection of the one half of the leaf induces a certain level of resistance against viral invasion in the other half. This induction is much stronger in the area situated in direct vicinity of the main vein of the leaf, than in its marginal parts. It is also more pronounced in the young leaves as compared with the older ones. As a consequence, a gradual shift in the repartition of the necrotized tissues occurs, proceeding from the
centre of the leaf-blade to its periphery, parallelly to the increasing level of induced resistance. Reinfection of “resistant” half-leaves with TMV results in the formation of a great number of minute necrotic lesions. This decreases the calculated values of average lesion sizes, and causes their strongly skew distribution around the mean.
Keywords
Hrčak ID:
158407
URI
Publication date:
31.12.1981.
Visits: 1.192 *