chapter  twenty
14 Pages

Embryogenic callus and suspension cultures from leaves of orchardgrass *

ByDennis J. Gray, Robert N. Trigiano, Bob V. Conger

Somatic embryogenesis is the most common mode of regeneration for species in the Poaceae. Embryogenic culture systems are useful in the classroom, not only for illustrating plant regeneration, but also for studying embryo development and morphology. Many species require use of immature zygotic embryos as explants, which can only be obtained by careful cultivation and pollination of source plants. Other species tend to produce somatic embryos that have relatively abnormal morphologies when compared to zygotic embryos. Orchardgrass is a perennial cool-season forage species that is grown in temperate regions of the world to produce high-quality hay. It is genetically self-incompatible, which makes breeding of new varieties difficult and time consuming. This chapter discusses the successful culture establishment, observations of embryogenic callus formation, and somatic embryo development, including the gradient embryogenic response that is typical of this culture system, culture maintenance, plant regeneration, manipulation of liquid suspension cultures, and the production of model "synthetic seeds".