Response of the Strawberry Cv. Elsanta Micro Propagation in Vitro toDifferent Carbon Sources and Concentrations

Abstract

The study was conducted to determine the influences of carbon sources (sucrose, glucose, fructose, mannitol and sorbitol) on multiplication and rooting medium of strawberry Elsanta cv. The sugar cources were compared at a relatively wide range of concentrations (10, 30, 50, 70, and 90g l –1 ). There was a clear effect of sugar type and concentrations on the shoot multiplication rate. For each sugar added, the highest number of shoots was formed at concentration of 30g l –1 , in particular, the glucose which gave the heighest nomber of shoots. The sugars concentration lower or higher than 30 gl -1 reduce the number of shoots produced especially with concentrations of 70 and 90 g l –1 , respectively. Along with increasing sugar concentration, the height and fresh weight of shoots is reduced. Sucrose and glucose resulted in the greatest rate of proliferation, while the total number of shoots was lowest when the medium was supplemented with mannitol or sorbitol. On a rooting medium supplied with 10-90 g l –1 of mannitol or sorbitol, the explants did not grow, and subsequently they died after 2-3 weeks. In addition, there were no significant differences between glucose, fructose, and sucrose in the rooting percent, number of roots, number of leaves, and plantlet height, except in root length which showed some significant differences between these carbon sources. In contrast, there were significant differences between the concentrations of these carbon sources. The best rooting response of strawberry occurred on concentrations of 30, 50, and 70 g l –1 , respectively. At acclimatization stage, the plants cultured in fructose supplemented medium produced the highest number of leaves, fresh weight, and dry weight. Moreover, there were significant differences at the final harvest between the concentrations of sugar used. The vegetative growth of the plants was enhanced by increasing the level of sugars especially the concentration 70g l -1 which was the superior to (10, 30 gl -1 ).