EARLY DEVELOPMENT AND VIABILITY TESTING OF EMBRYOS OF SCRIPUS-ACUTUS MUHL

Scirpus acutus Muhl. is a hardstem bulrush found throughout North Amer ican wetlands. The seeds of most species of Scirpus have a relatively low germination potential. Seed viability and the developmental morpho logy of the embryo upon germination were studied using standard tetraz olium (TZ) testing, scanning electron microscopy (SEM), and standard l ight microscopy techniques. TZ indicates the majority of seeds are via ble. Upon germination, a leaf is the first structure to elongate, emer ge from the seed coat, and finally break through the pericarp. Followi ng this stage, the radicle develops from an extension of the embryo ax is located between the scutellum and the shoot tip of the embryo. The next leaf eventually arises at the junction of the sheath of the first leaf. The pericarp may act as a physical barrier and be a factor cont ributing to low germination in Scripus acutus.