Origin and early developmental patterns of somatic embryos from freely suspended cell culture of enicostemma hysopifolium (willd.) verd. - A vulnerable medicinal plant

Early somatic embryogenesis from single cells or a multi cells differentiated into embryos from Enicostemma hyssopifolium (Willd.) Verd. cell suspension culture were obtained by fractionation through sieving, using iron mesh and centrifugation. These cells differentiated to embryos when they were cultured on a Murashige and skoog’s medium containing 0.5 mgl 1 α-Napthaleneacetic acid (NAA) + 1.0 mgl 1 Zeatin (Ze) for 14 days, followed by transfer to a medium containing 1.0 mgl 1 Ze lacking auxin. This indicates that there are at least two phases in the differentiation of embryos. The progression of the first phase required exogenous auxin, whereas that of the second phase was inhibited by the same growth regulator. The embyrogenic cells were richly cytoplasmic, contained numerous starch grains and were about 30 µm. Proembryo like structures with few cells and having mainly transverse or longitudinal division was observed among many elongated and vacuolated non embryogenic single cells (50-200 µm). From serial observations of the pre-embryo like structures after transfer to a micro chamber, it was confirmed that they are developed in to successive stages of somatic embryos. Therefore, a study of the origin and pattern of development will provide a better understanding of the order-generating processes.