ABSTRACT
RESUMEN Neltuma alba Griseb es una especie emblemática de la Ecorregión Chaqueña, por el valor de su madera y frutos. Los resultados de la presente investigación, dan cuenta de que las semillas de algarrobo blanco pueden ser críoconservadas sin afectar el poder y la energía para germinar. Las semillas fueron conservadas por tres meses a Temperatura ambiente (24° y 30°C, Congelamiento (-18°C) y Nitrógeno líquido (-196°C). Posteriormente, fueron escarificadas mecánicamente y sembradas en tierra negra y aserrín (3:1). Los resultados fueron sometidos a pruebas no paramétricas de Kruskal-Wallis, analizándose poder, energía y vigor germinativo, y no se detectaron diferencias significativas entre tratamientos. Para la regeneración in vitro en medio de cultivo MS suplementados con 3 mg L-1 IBA y 0,05 mg L-1 CIN, se utilizaron segmentos nodales de 2 cm de longitud obtenidos de plántulas provenientes de semillas. Los porcentajes de enraizamiento obtenidos fueron elevados (87-90%). No existiendo diferencias significativas entre los tratamientos ensayados. El almacenamiento de semillas a 24°-30°C resulta ser el más apropiado para alcanzar altos porcentajes de germinación
ABSTRACT Neltuma alba Gris is an emblematic specie of Chaco Ecoregion for its wood and fruits value. This research show that algarrobo blanco's seeds can cryopreserve without affecting germination power and energy. The seeds were kept for three months at 24°-30°C, (-18°C) and (-196°C). Later, they were mechanically scarified and sown in black soil and sawdust (3: 1). The results were subjected to non-parametric Kruskal-Wallis tests, analyzing germination power, energy and vigor. The test did not detect significant differences between treatments. The nodal segments (2 cm long) obtained from plants of seeds were used for in vitro regeneration in MS culture medium supplemented with 3 mg L-1 IBA and 0.05 mg L-1 CIN, The rooting percentages obtained were high (87-90%). There are no significant differences between treatments tested. The storage of seeds at 24°-30°C is the most approppiate to rich high percentages of germination.
ABSTRACT
Seeds of Prosopis alba were scarified with abrasive paper and placed to germinate on MS (Murashige and Skoog 1962) nutrient medium. After 7 days of culture, the basal part of cotyledons was removed and pieces of 4 mm" from distal parts were cultured on Murashige and Skoog (1962) mineral salts and vitamins (MS) (3 sucrose) supplemented with growth regulators. Callus proliferation took place in the majority of the media tested. A low percentage of calluses with green buds that developed on MS basal medium containing 0.1 mg.L-1 2,4-D alone or supplemented with BAP at 0.1 mg.L-1 was observed. Neither cotyledonary segments in any medium assayed regenerated the whole plants. Bud elongation (near 70) was achieved when single-nodal-stem segments cut from 20 days old seedlings were cultured on MS salts supplemented with 3 mg.L-1 NAA or 3 mg.L-1 IBA combined with 0.05 mg.L-1 KIN after 60 days in culture. Multiple shoots per bud were also observed. Single-nodal-stem segments from five-year-old plants were also cultured on the same media used for seedling explants. Maximal frequency of explants with bud elongation (near 70) was found on MS with 0.1 mg.L-1 NAA plus 1 mg.L-1 BAP after 60 days of culture. Single-nodal-stem explants cut from adult trees (more than 20 years) were also employed, but the number of bud elongation was lesser. For rooting, the elongated shoots were transferred to a semisolid or liquid MS culture medium employing a paper bridge, supplemented with 0.5 mg.L-1 IBA or 0.1 mg.L-1 NAA.