Effect of the gamma Radiation on Vegetative Development of the Native Grapevine (Vitis vinifera L.) in morocco

This study was conducted at the Larache experimental field, CRRA Tangier. For the discrimination of irradiated and control grapevines, 14 characters and 10 replicates for each parameter were used for this study according to the OIV code. The characters were evaluated in different organs of the plant, the twig and the mature leaves. The results showed a differentiation between irradiated and control grapevines. 23% of the irradiated grape varieties had a drop branch while only 3% of the control varieties showed this type of branch. 7% of the irradiated grape varieties showed a copper coloring of the upper face of the leaf whereas no control plant showed this coloration. 40% of the irradiated grape varieties showed a slightly longer petiole compared to the median vein in comparison with 7% of the control varieties having the same character. 43% of irradiated grape varieties showed a tooth shape with a mixture of two straight sides and two convex sides while most control grapes (57%) showed a tooth shape with two straight sides. It was also observed that some irradiated grape varieties (10%) showed the shape of the superior lateral sinus with slightly overlapping lobes and 3% of the irradiated grape varieties showed a form of the lateral sinus superior very widely open while the latter two forms are absent in groups of control grapevines. The irradiated grape varieties showed a higher density of main hairs compared with irradiated grape varieties. For the qualitative parameters it has been observed that the length of the teeth in the irradiated plants is never very short whereas in the control plants the length can be short and very short. The length of the tendrils and the length of the internodes are higher in the irradiated plants than in the control plants.