Somatic Embryo Polarity in Dactylis Glomerata as Determined by Electron Microscopy

Abstract

Somatic embryos initiate and develop from single mesophyll cells in cultured leaf segments of orchardgrass (Dactyiis glomerata L.) genotype “Embryogen-P” (Conger et al. 1983, Conger, Manning 1991; Trigiano et al. 1989). Experiments can be designed in which segments from one half leaf can be used for a specified treatment and the corresponding “sister” or “mirror” segments from the other half of the same leaf can serve as a control. This paired half-leaf system was in a space shuttle experiment (STS-64) that flew from 9–20 September 1994. No significant differences in somatic embryogenesis were observed in leaf segments plated 21 d and 14 d prior to launch whereas, a 70% reduction was observed for segments plated 21 h before liftoff (Conger et al. 1995).