Studies on Seed Morphometry of Epiphytic Orchids from Western Ghats of Karnataka

Abstract

Seed morphometry and Scanning Electron Microscopic studies on 10 species of epiphytic orchids from Western ghats of Karnataka are presented. All the presently investigated taxa are different in their seed surface characters including size, shape, visibility of embryo, testa cells and structure, curvature and ridges. Seed colours range from pale yellow to yellow, brown and white. Variation between maximum and minimum in the length/width ratio of seed is discussed. Data on the seed volume show that higher seed volume is the result of both greater length and width. Maximum width of testa cell and seed volume are found in Cymbidium bicolor. Variations in seed and embryo volume and percent air space could exist among the different taxa of orchids. The volume of the embryo changes during its developments from zygote to seedling. Increase in the percentage of air space is due to increase in the cell length of the testa. Seeds with higher percentage of air space get dispersed over wide geographical areas.