DIRECT SOMATIC EMBRYOGENESIS IN CATTLEYA TIGRINA A. RICH

摘要

Cattleya tigrina A. Rich. is endemic to Brazil and is distributed in the northeast, southeast, and south regions of the country. Due to flower size and exuberance, this orchid becomes preferred by decorators, collectors, and orchid specialists, leading to the disappearance of species. This study aimed to induce somatic embryo genesis in leaf segments of C. tigrina using young leaves of in vitro plants (approximately 1 cm) as explants. The material was inoculated in MS culture medium supplemented with 2,4-D (0.0, 0.05, 0.1, 0.3, 0.5, 0.7, and 0.9 mg l(-1)). Somatic embryos of different development stages were used for histological studies. The substrates for acclimatization of somatic embryos contained pine bark, coconut coir, and/or vermiculite supplemented with limestone. The MS medium supplemented with 0.3 mg l(-1) of 2,4-D promoted direct somatic embryogenesis with higher embryo formation. Histological analyses indicated that somatic embryos were originated from cells of the leaf epidermal layer. Pine bark was the most suitable substrate for the acclimatization and survival of C. tigrina seedlings.