Tissue Cultures of a Cactus

Abstract
Tissue cultures have been established from stems of Trichocereus spachianus (Riccob.) for the purpose of studying alkaloid biosynthesis in cactus tissue. On a basal inorganic medium supplemented with glucose, coconut milk, and 2,4-dichlorophenoxyacetic acid, three distinct types of callus are initiated. One is greenish, compact, and slow-growing; another is firm and yellowish, with a moderate growth rate; the third is very friable and rapid-growing. The growth habit remains constant for a given clone in successive subcultures.