The study of in vitro regeneration and growth parameters in Catharanthus roseus L. under application of tryptophan.

Periwinkle (Catharanthusroseus L.) is one of the most important medicinal plants that commonly used for its anticancer alkaloids. In this investigation، the effects of different tryptophan concentrations (0، 150، 250 and 350 mg/l) under in vitro regeneration conditions have been studied. The regeneration of different explants on different media compositions in free tryptophan condition showed that the best media conditions obtained by nodal segments explants grown on MS medium containing (BAP، 0. 5 mg/l) + (NAA، 1 mg/l). Also، we achieved the rooting medial composition as half MS medium supplemented with (IBA، 0. 1 mg/l). After adding of tryptophan into this optimal medium، the maximum shooting and rooting percentages were obtained in the media containing 250 and 350 mg/l tryptophan، respectively. Furthermore، the measurement of shoot and root length، dry and fresh weight of shoot، fresh weight of root، chlorophyll a and carotenoid content and also، soluble sugars content of shoot and root، revealed the best medium in the presence of 350 mg/l tryptophan، while the maximum amount of root dry weight and chlorophyll b were obtained by 250/l mg tryptophan containing medium.. Finally، the analysis of total proteins content of shoot and root showed significant difference between all groups and the higher content of this for shoots and roots observed in 250 mg/l and 350 mg/l، respectively.