Studying on the in vitro shoot formation of Opuntia ficus – indica (L.) Mill.

Abstract

This study presented the elimination of the glochids in the areoles of Opuntia ficus-indica cladode induced the shoot formation from the explants containing the shoot apical meristem (SAM) on Murashige and Skoog medium (MS) supplemented with 6-benzylaminopurine (BA) 5 mg/L. Morphological and physiological changes in shoot formation process were analyzed. This process involved the constant stages: activation of cell division, initiating of meristematic region; formation of shoot primordium and shoot with leaves. The SAM position in the upper front of the cladode gave the highest shoot productivity. This position had the photosynthesis rate, respiration rate, endogenous indole acetic acid (IAA) and zeatin activity higher than the others. Difference of auxin concentrations increased the amount of shoots and shoot height. The maximum number of shoots per explant was obtained on MS medium supplemented with BA 5 mg/L and 1-naphthalene acetic acid (NAA) 0.5 mg/L. The elimination of SAM by removing the surface of the shoot gave the highest number of the shoot. The correlation of the glochids in the areoles, explant position, plant hormones, photosynthesis rate respiration rate and shoot formation were discussed.