Conservation strategy for Hopea parviflora Bedd. species through storage of seeds using cryopreservation techniques

Abstract

A detailed study was conducted at College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala during 1998-2000 to standardize the conservation strategy for Hopea parviflora Bedd. species through storage of seeds using cryopreservation. Diameter of seeds collected at seven weeks after anthesis was found to be higher than that at sixth week. Physiological maturity of the propagules is attained between five and six weeks after anthesis. The propagules were subjected to different relative humidities, vacuum and dry air for different durations as a pretreatment for cryopreservation studies. In 100 to 46.6 per cent relative humidities, the moisture content and the leachate conductivity of the propagules were found to increase with duration compared to the initial value. Equilibrium moisture content of Hopea parviflora propagules was found to lie between 75.6 to 30 per cent relative humidities. Germination parameters of seed and seed without seed coat were not decreased significantly due to desiccation by relative humidities, vacuum or dry air, but that of embryonic axes was considerably reduced as rapid drying might have been effected due to 30 and 20 per cent relative humidities and also due to vacuum and dry air with duration. High culture contamination was observed in vacuum and dry air treatments. After cryopreservation techniques, the propagules invariably failed to regenerate but could retain green colour for two to three days.