Seed Viability and Morphology Evaluation of Three Mexican Orchid Species

Here we studied some aspects of morphology and seed viability of three Mexican orchid species with different life forms, two epiphytes Cuitlauzina pendula and Laelia anceps and one terrestrial Epidendrum radicans, evaluating its viability with a modification of triphenyl tetrazolium chloride (TTC) test, applying pretreatment of 10% sucrose. Initial red staining was observed on viable seeds Laelia anceps 88.89%, Cuitlauzina pendula 44.44% and Epidendrum radicans 24.44%, which diminished after 30-, 60-days storage. Orchid seed morphology was measured in length, width and volume, with Toupview software. Seeds from the two epiphytes showed similar size: testa 0.48- and 0.45-mm length, 0.18; 0.11mm width, its embryo 0.26, 0.23mm length 0.16; 0.09-mm width, embryo volume 0.856; 0.684 mm3. The terrestrial Epidendrum radicans had the largest size testa 0.24 length 0.48 mm width: small embryo 0.60 mm. The use of viability bioassays might help on orchid conservation and on the in vitro germination procedures.