Growth and physiological responses of Catharanthus roseus (L.) shoot cultures to salinity stress

In vitro shoots of the Catharanthus roseus L. c vs. Rosea ( pink flowered) and Alba (white flowered) were subjected to satinity stresses using different NaCI levels (0 to 100 m M) in a shoot proliferating medium composed of the Murashige and Skoog (MS) basal medium supplemented with 2 mu g glycine, 1 mg L-1 kinetin and 30 g L-1 sucrose. The cultivar Rosea was the more tolerant genotype. As the level of NaCI increased, there were corresponding linear increases in the levels of total phenol, pro line and sugar, while the leaf chlorophyll con tent showed am arked decline. The foliar m literal contents showed distinct patterns between the satinity to lerant and susceptible cultivars. The level of Na+ in creased in the foliar tissue with increases in NaCI, while K+ showed a slow decrease. The results of this Study on shoot cultures suggest that C. roseus (L.) cv. Rosea may be a candidate cultivar that can be used in selecting for salt tolerance.