ABSTRACT
Experimental conditions for efficient callus initiation from mangrove plants were investigated. As a source explant, leaf ofBruguiera sexangula was used. Mangrove plant is one of the most famous woody plants which can grow at the salty area. The initiated callus can be a suitable material for the investigation of salt tolerant mechanisms of mangrove plants.Leaf pieces cultured in an Amino Acid medium supplemented with 2 µM 2,4-dichlorophenoxyacetic acid and 2 µMN-(2-chloro-4-pyridyl)-N'-phenylurea at 30 C developed calluses. Microscopic observation suggested that the callus was initiated from the tissue in the vascular bundles in the leaf.We also examined the effect of NaCl on callus initiation and short-term culture of the calluses on the leaves. Callus initiation rate decreased with increasing NaCl concentration higher than 100 mM in the culture media. The medium containing 100 mM NaCl produced the largest callus on the leaf, compared with higher or lower concentrations of NaCl.
ABSTRACT
Calluses initiated from leaves and seedlings of the mangrove,Bruguiera sexangula, were isolated from the original tissues and subcultured. Effects of NaCl on growth and ion content of each callus were measured. The growth rate of calluses derived from leaves (leaf callus) gradually decreased as the NaCl concentration in the medium increased, while that of calluses derived from seedlings (seedling callus) was highest in the medium containing 100 mM NaCl. Concentrations of Na and Cl in both calluses increased with increasing the NaCl concentration in the culture medium. The concentration of K of leaf calluses greatly decreased at 300 mM NaCl, while the K concentration of seedling calluses decreased only slightly and remained relatively high even in the presence of 300 mM NaCl.Transient treatment of leaf calluses with media containing high concentrations of NaCl frequently induced regeneration of adventitious tissues.
