INST. DE BIOTEC. DE LAS PLANTAS. CUBA.
Elisa Quiala1, M—nica Meij—n2, Mar’a Jesśs Ca–al2, Roberto Rodr’guez2, MaitŽ Ch‡vez1, Luis Valledor2 y Raśl Barb—n1.
RESUMEN (ABSTRACT)
The presence of cytokinins in culture media increases the multiplication rate in in vitro Tectona grandis L. shoots cultured in temporary immersion systems (TIS). Shoots cultured with Benzylaminopurine (BAP) exhibited a high multiplication rate and a 100% of plants with root were observed in cytokinin-free medium (control). However, shoot water content increase with the concentration of BAP, proportionally and severe hyperhidric shoots were developed when 6.66 µM of BAP was used. The morphometric analysis by scanning microscopy revealed that the increment of BAP dose was accompanied by an increase in size and area of the whole stomatal complex. Stomata were often found to be elliptical shape, always closed and sunken in the control and with 2.22 µM of BAP. Abnormal stomata with broken epidermis in the guard cells were observed when the highest concentration (6.66 µM of BAP) was applied. Phloroglucinol-HCl staining showed that gradual increment of BAP affected the deposition of lignin in the vascular cells. In the control well organized xylem with homogeneous lignin deposition pattern were observed. Whereas, in the treatment with 6.66 µM of BAP xylem organization was poor and phloroglucinol-possitive material was amorphous, with no identifiable or consistent pattern of deposition. Shoots from control accumulated from two to three times more phenolic than BAP treatments. TIS were successfully applied to improve teak propagation; this semiautomatic system enhances both shoot proliferation and rooting. It was also demonstrated that BAP concentration gradually affected the morpho-physiological characteristics of harvested shoot.