Effect of Chitosan and Meta-Topolin in Micropropagation of Vaccinium Corymbosum

The culture medium is often optimised to improve growth and morphogenesis in vitro. The efficiency of chitosan (CH) and meta-topolin (mT) on in vitro growth of blueberries (Vaccinium corymbosum) cv Liberty was investigated. The explants were grown on Woody Plant Medium (WPM) supplemented with mT at a concentration of 0.2, 0.4, and 0.6 mg l^-1 and WPM with chitosan with a molecular weight 3.33 kDa at 10, 20, and 40 ppm. WPM with the addition of 0.1 mg l^-1 zeatin was used as a control. Among the tested combinations, the maximum mean shoot length (23.81 cm), the number of new shoots (1.34), fresh mass (42.29 g), and dry mass (14.24 g) were recorded on the control medium. The addition of lower concentrations of chitosan (10 and 20 ppm) to the WPM medium decreased shoot length (23%-24.5% of control), fresh mass (30%-40% of control), and dry mass (20%-29% of control). However, blueberries treated with 40 ppm chitosan had similar shoot lengths, but darker (112% of control) and greener (139% of control) leaves compared with the control. In contrast, mT had a negative effect on the studied traits of Liberty blueberries, regardless of the concentration.