Establecimiento de un protocolo óptimo para la introducción en cultivo in vitro de las especies endémicas: Phaedranassa schizantha y Phaedranassa tunguraguae, en peligro de extinción.

Abstract

It was established optimal protocol for the in vitro cultivation of endemic species in danger of extinction: Phaedranassa schizantha and Phaedranassa tunguraguae, at the vegetal Biotechnology Laboratory-Natural Resources Faculty-ESPOCH. A literature review of studies was conducted about the Amaryllidaceae Family. Planting and sampling were carried out in the cities of Riobamba (P. schizantha) and Baños (P. tunguraguae). Later, the disinfection of the vegetal material departed with a rinse with tap water, followed buy the cut of: steams, leaves and roots. The resulting bulbs were immersed in various solutions in order to ensure adequate disinfection in the following order: liquid soap (10%), ethanol (70%), Benomyl® (10%), NaClO (3%) and Tween® 20. The basal medium (MB) consisting of Murashigue & Skoog medium (4,32 g/L), Sacarosa (30 g/L), Agar (10 g/L) and adjusted to pH 5,6. Four treatments (T0, T1, T2, T3) were used with 15 repetitions (P. schizantha) and 10 repetitions (P. tunguraguae), respectively. The control treatment (T0) constituted by MB; T1: MB + BAP 0,5 ppm + ANA 0,1 ppm; T2: MB + BAP 1 ppm + ANA 0,1 ppm; y T3: MB + BAP 1,5 ppm + ANA 0,1 ppm. In the laminar flow cabin and the twin-scale technique, the explants were obtained which were harvested and incubated during 45 days, 16/8 hours of photoperiod, temperature (25ºC±1) and humidity (70%±1). By means of a qualitative evaluation, it was observed that the T3 presented better response in length and size of leaves, as well as in number and diameter of bulbillos. Through the Principal Component Design Method, was determined that T3 (BAP 1,5 ppm + ANA 0,1 ppm) constitutes the optimal procedure for in vitro cultivation, for both species. It was recommended at the moment of cutting the explants and planting them, to have sufficient measures of asepsis, in order to prevent the contamination of fungus and/ or bacterium and obtain axenic cultivation.