ABSTRACT
Schinus fasciculata es un árbol de la ecorregión chaqueña argentina. Es una especie de bajo porte, usada como antiséptico, analgésico, antiinflamatorio y antifúngico. Estudios previos registraron baja germinación y deficiente sanidad. El objetivo fue evaluar la germinación y la respuesta de las plántulas in vitro en dos medios de cultivo. Se recolectaron frutos, se desinfectaron por 20 min con HClNa y se sembraron en agar-agua. Las plántulas se repicaron a medio MS en dos diluciones: un cuarto (MS ») y un medio (MS ½). Se hicieron ensayos de germinación y vigor (tiempo medio de germinación máxima en días). Se evaluó % de contaminación. A los 20 días del repique se evaluó % de explantos con hojas, número de hojas y altura de plántulas. Paralelamente se hizo un ensayo de germinación y vigor en arena. La contaminación fue de 16 %, la germinación de 84 %, el vigor de 4,9 días. El 94 y el 100 % de los explantos en MS » y MS ½ presentaron hojas. El número promedio de hojas fue de 7,5 y 7,4 y la altura promedio fue de 3,35 cm y 2,98 cm en MS » y MS ½, observándose diferencias significativas en altura. La germinación en arena fue de 46 % y el vigor de 4,6 días. La utilización de la técnica de cultivo in vitro en S. fasciculata facilita la multiplicación de esta especie de alto valor farmacológico, permitiendo aumentar el porcentaje de frutos germinados y obtener plántulas libres de patógenos todo el año.
Schinus fasciculata is a tree of Argentina Chaco eco-region. It is a low-growing species, used as an antiseptic, analgesic, anti-inflammatory and antifungal. Previous studies reported low germination and poor health. The object of this work was to evaluate the germination and in vitro response of seedlings in two culture media. Fruits were collected, disinfected for 20 min with HClNa and sowing in agar - water. The seedlings were seeded onto MS medium in two dilutions: fourth (» MS) and half (½ MS). Germination and vigor tests (mean time to maximum germination in days) were made. Contamination percentage was evaluated. At 20 days of transplanted were evaluated: % of explants with leaves, leaf number and height of seedlings. Parallel assay germination and vigor in sand was made. Contamination was 16%, germination was 84% and vigor 4.9 days. The 94 % and the 100% of the explants in MS » and ½ MS showed leaves. The average leaf number was 7.5 and 7.4 and the average height was 3.35 cm and 2.98 cm in MS » and MS ½, with a significant difference in height. Germination in sand was 46 % and vigor was of 4.6 days. The technique of in vitro culture in S. fasciculata facilitates the multiplication of this species of high pharmacological value, allowing to increase the percentage of germination and obtain pathogen-free all year seedlings.
ABSTRACT
Amazonia and the Gran Chaco are the largest phytogeographic units of the Neotropical Region. The Forest Wedge of the Santa Fe province of Argentina is the southernmost part of the Eastern Chaco, and there are three main types of forest, 1) the mixed dense forests, 2) the Schinopsis balansae "quebrachal" and 3) the Prosopis nigra var. ragonesei forests, distributed along an environmental gradient correlated with topographic elevation. In this paper litterfall and organic matter decomposition of four species were studied in two different microsites in a Schinopsis balansae forest during three years. Litter fall varied along the year following seasonal environmental variation but litterfall variations between years were not significant. Litterfall was not uniform over the whole surface, under close canopy monthly average litterfall amounts 32.67 g/m2, in open gaps 4.47 g/m2 and 15.07 g/m2 under medium density canopy. Organic matter decomposition, like in other forests, was a negative exponential function of time, and the decomposition rate is independent from the microsites where it falls, 0.15 and 0.12 in sunny and shadow microsites respectively for Maytenus vitis-idaea, 0.10 and 0.11 in sunny and shadow microsites respectively for Achatocarpus praecox, 0.04 and 0.03 for Acacia praecox, 0.04 and 0.06 for Schinopsis balansae in sunny and shadow microsites respectively. Shurbs litter was decomposed faster than the tree litter, and the shurbs litter nutrientes level was also higher. Therefore the rate of organic matter decomposition is more correlated with leaf characteristics than with environmental variables.