Somatic embryogenesis in longleaf pine (Pinus palustris)

Isolated zygotic embryos and female gametophytes containing zygotic embryos were cultured on MSG and DCR basal media, supplemented with three different carbon sources added individually to the medium at four levels each. The media also contained various levels of 2,4-dichlorophenoxy acetic acid (2,4-D) and N6-benzyladenine (BA). Embryogenic tissue extruded from female gametophytes during 4 weeks in culture on media containing either glucose or maltose or sucrose. Embryogenic tissue initiation was most frequently from explants collected on July 14, 1992, when the zygotic embryos within the female gametophytes were precotyledonary. A total of 33 embryogenic cultures were initiated from 944 explants cultured. One of 192 explants cultured on basal media with no growth regulators produced embryogenic tissue. The embryogenic tissue showed numerous somatic embryos at stages 1 and 2 of development, corresponding to their zygotic embryo counterparts.