ISOLATION OF MATURE CEREAL EMBRYOS AND EMBRYONIC AXES

Numerous areas of biological research (e.g., control of seed dormancy and protein synthesis, and development of cell-free translation system s) are greatly aided by the use of large quantities of viable cereal e mbryos. The utility of a method that employs a commercial food blender for embryo isolation was assessed for mature caryopses of various gra in lots of wheat (Triticum aestivum L. em Thell.), rye (Secale cereale L.), triticale (x Triticosecale Wittmack), barley (Hordeum vulgare L. ), oat (Avena sativa L.), rice (Oryza sativa L.), pearl millet [Pennis etum glaucum (L.) R. Br.], grain sorghum [Sorghum bicolor (L.) Moench. ], and maize (Zea mays L.). The yield, physical condition, and morphol ogy of embryos and embryonic axes were characterized using light and s canning electron microscopy. Viability of embryonic axes was assessed by germination assay. Intact embryonic axes free of damage and adherin g tissues (i.e., scutellum and pericarp) were easily isolated from whe at, rye, triticale, and oat. The highest yield was obtained with wheat (almost-equal-to 10-15%). In hulless barley, pericarp always remained attached and covered the radicle portion of the embryonic axis. Embry onic axis isolation from hulled barley was poor. Rice embryos with adh ering scutellum and pericarp were isolated as a unit with 2% yield, si milar to rye, triticale, and oat. Intact axes of millet, sorghum, and maize were isolated infrequently and with difficulty. Viability of emb ryonic axes selected visually for intactness and lack of physical dama ge was similar to the viability of the parent grain lot.