CHITOSAN AND META-TOPOLIN SUPPLEMENTATION OF THE MULTIPLICATION MEDIA OF VITIS VINIFERA L.

We investigated the efficiency of chitosan (CH) and meta-topolin (mT) on in vitro growth and adaptation to greenhouse conditions of Vitis vinifera cv. Johanniter and cv. Hibernal. After the initiation stage, we transferred explants to Woody Plant Media (WPM) with chitosan (molecular weight 3.33 kDa) at a concentration of 10, 20, and 40 ppm or to WPM with mT at a concentration of 0.5, 1.0, and 2.0 mg l–1. WPM without CH or mT served as a control. Among the tested combinations, WPM with 10 ppm of CH led to the maximum mean root length (12.18 cm and 12.65 cm for the Hibernal and Johanniter cultivars, respectively) and the number of new leaves (5.9 and 8.15 for the Hibernal and Johanniter cultivars, respectively). As the CH concentration in the medium increased, the length of shoots and roots decreased. We found the highest percentage of acclimatised plants on WPM (cv. Hibernal) and WPM with 40 ppm of CH (cv. Johanniter). The addition of mT had a negative effect on the morphological traits we measured, regardless of the concentration. Leaves of explants from WPM with mT were yellower and redder compared with the control. None of the explants obtained on this medium produced roots.