STUDIES IN THE SEED DORMANCY OF DESERT PLANTS : 1. ABRUS PRECATORIUS L.

Abstract

The present paper deals with the analysis of the germination regulating mechanisms of Abrus precatorius L. seeds. The seeds occur in two forms viz., large and small. Dormancy in these seeds has been observed to be due to a seed coat which offers impermeability to water as well as mechanical resistance to the expansion of the embryo. One possible mechanism involved in breaking the seed coat dormancy in this plant may be desiccation to the extent of 7.31 percent, which promotes the germination up to 40 percent and 45 percent in large and small seeds respectively. Imbibition and desiccation both appear to be more critical for germination of small seeds than that of large seeds. Under light incubation sulphuric acid treatment for 120 minutes gives 80 percent germination in large seeds, and that for 90 minutes gives 90 percent germination in case of small seeds. Acid scarified seeds when subjected to continuous irradiation with red light give 100 percent germination at 25 and 30℃.