COMPARISON OF THE EFFECTIVENESS OF CHITOSAN AND AUXIN ON IN VITRO AND EX VITRO ROOTING OF Vaccinium corymbosum L.

A highly efficient micropropagation process can be achieved by using proper conditions for root initiation and growth of regenerated shoots. The efficiency of auxin and chitosan on in vitro rhizogenesis of the highbush blueberry (Vaccinium corymbosum L.) cv. Liberty was developed. After the multiplication stage, explants were transferred to Woody Plant Medium (WPM) supplemented with 0.1 mg dm–3 zeatin and 1.0 or 2.0 mg dm–3 of the auxin indole-3-butyric acid (IBA), or chitosan with a molecular weight of 800 kDa at a concentration of 20 or 40 ppm. Among the tested combinations, the maximum mean shoot and root length (6.28 and 1.73 cm, respectively) were recorded for WPM with 0.1 mg dm–3 zeatin and 2.0 mg dm–3 IBA. The higher chitosan concentration in the WPM medium increased the length of shoots and roots. The highest percentage (100%) of rooted plants was obtained on WPM with the addition of 0.1 mg dm–3 zeatin and 40 ppm chitosan. Moreover, leaves of the highbush blueberries from this medium were brighter (L* from 22% to 36%) and greener (a* -2.70 and -4.56, respectively) compared with the leaves of plants grown on WPM containing IBA.