Abstract
The growth and morphogenesis of cultured plant tissues can be improved by small amounts of some organic elements. In addition to being a natural source of carbon, organic additives may contain natural vitamins, phenols, fiber, hormones and also proteins. Hence, the physiological effects of apricot gum on the regeneration capacity and growth rate of three different plant species i.e. carrot (as a model plant), stevia (as an herbaceous plant), and grapevine (as a woody plant) were examined. The proliferated callus cultures of carrot and in vitro-derived microcuttings of stevia and grapevine were inoculated on their respective standardized proliferation media supplemented with 2.0-6.0 g/l apricot gum. The growth parameters of treated samples were measured and compared to gum-free medium. Earlier callus initiations with greater fresh weight, volume, as well as improved pigmentation were recorded in media fortified with apricot gum. The usefulness of gum application was also obvious in both stevia and grapevine with respect to better shoot multiplication and rooting parameters. Due to positive effects of apricot gum, longer vines with a higher number of lateral shoots, internodes and leaf area were achieved. Overall, the gum at the rate of 4.0 g/L was found to be a logical concentration with respect to encouraging response in all three species. Owing to promising results evolved in the present research, the application of gum in commercial tissue culture protocols is highly recommended. However, further studies are needed to exploit plant derived gums as an alternative carbon source in plant tissue culture media.
