Studies on the Formation of Roots and Shoots in Wheat Callus Cultures

Abstract

Callus tissues were initiated from root, embryo and inflorescence explants of wheat. These callus cultures were used to study the formation of roots and shoots in the absence and presence of selected plant hormones. On a basal medium alone, only newly-initiated embryo callus formed both roots and shoots while root callus only formed roots. Inflorescence callus showed no signs of differentiation. The regenerative capacity of root and embryo callus tissues on medium lacking hormones decreased with increasing periods of culture. Calluses which failed to differentiate in the absence of hormones were selected for studies on hormone-mediated differentiation. NAA (1 mg 1-1) was effective in inducing roots from all calluses irrespective of their origin or age. In contrast, shoot formation was elicited by incubating newly-formed callus on basal medium supplemented with kinetin (5 mg 1-1) and NAA (1 mg 1-1) but rapidly decreased with longer periods of culture. The differences observed in differentiation of the callus in the absence and presence of hormones is discussed.