Osmotic agents and temperature on in vitro conservation of sempre- viva/Agentes osmoticos e temperatura na conservacao in vitro de sempre- viva

The in vitro conservation is an ex situ conservation strategy that ensures the maintenance of genetic and biological integrity of species. The present study evaluated the effects of, osmotic agents and different temperature regimes on the in vitro conservation of Syngonanthus mucugensis Giul. subsp. mucugensis. The shoots were inoculated into half salt strength Murashige and Skoog culture medium (MS 1/2) containing 7g [L.sup.-1] of agar. The culture medium was supplemented with 60g [L.sup.-1] sucrose and with the sucrose concentrations 15, 30 and 45g [L.sup.-1] combined with 0 and 15g [L.sup.-1] of sorbytol or mannitol. Two different temperatures were used in these experiments (18 and 25°C). The percentage of plant survival was evaluated monthly and at 180 days were analyzed length of shoot and root, the percentage of green leaves, the percentage of explants with shoots and number of shoots per explants and shoot length. The addition of osmotic agents resulted in decreased growth of the plants and therefore reduced their viability. The averages observed in the experiments undertaken at 18°C were significantly superior to those observed at 25°C for all of the variables analyzed. S. mucugensis subsp. mucugensis can be cultured at 18°C in MS 1/2 culture medium containing 15g [L.sup.-1] of sucrose, for up to 180 days, without subculturing.