Studies on Seed Germination, Seedling Growth, and In Vitro Shoot Induction of Aloe ferox Mill., a Commercially Important Species

A study was done to investigate the effects of some physical and chemical factors on growth and development of Aloe ferox ex vitro and in vitro. The effects of light, temperature, and smoke-water on seed germination, ex vitro seedling growth requirements, and effect of germination medium and cytokinins on shoot induction and multiplication in vitro were investigated. The highest germination percentage of A. ferox seeds was recorded between 15 and 30 degrees C. Seed germination was inhibited at 10 and 35 degrees C. There was a nonsignificant increase in germination percentage (78%) for seeds that were germinated under constant dark conditions. Smoke-water-treated seeds showed significant improvement in percentage germination (80%) over the control (66%) at 25 degrees C with a 16-h photoperiod. Seedlings of A. ferox subjected to alternating temperatures (30115 degrees C) or being irrigated three times weekly at 25 degrees C showed better seedling growth. In an in vitro experiment, seedlings germinated in distilled water and one-tenth strength Murashige and Skoog medium had superior shoot induction competence compared with the other germination media. The cytokinins meta-Topolin (mT) and meta-Topolin riboside (mTR) at 5 mu M gave significantly higher shoot multiplication rates compared with the control and benzyladenine (BA)-treated plants. A higher abnormality index was recorded for BA-treated plants. The findings of this study will be beneficial for commercial propagation of Aloe ferox.