Effect of seed moisture content, temperature and storage period on seed germination of Saraca asoca -An endangered medicinal plant

摘要

An investigation was carried out during 2009-10 with an objective to determine the effects of seed storage and temperature on seed germination of Asoca (Saraca asoca (Roxb.) de Wilde). As there is a great demand for its bark coupled with shortage in supply, this plant is thus highly exploited and threatened. In this study a correlation between seed moisture content and seed germination was established. It was observed that the rate of moisture loss in seeds is indirectly proportional to the seed germination. Highest germination percentage (83.7%) was recorded at open nursery at 4 weeks after harvest followed by 25°C and 30°C at 3 weeks after harvest. The seed germinated immediately after harvest in open nursery whereas; at 25°C and 30°C, germination commenced only at two weeks after harvest. Under open nursery conditions, seeds failed to germinate eight weeks after harvest when the seed moisture content was below 22.8%. However, at 30°C, the seed germination continued up to nine weeks after harvest where the seed moisture content was <20%. The experimental results revealed that the seeds ofS. asoca could not tolerate drying to lower moisture content of 20-23% and might be considered as recalcitrant.