Artículos Científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14754

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In Vitro Culture of the Anxiolytic Plant, Souroubea Sympetala
(Universidad Nacional, Costa Rica, 2020) Rojas Vargas, Alejandra; Hine, Ana; Lui, Rui; Otárola Rojas, Marco Antonio; Sánchez Vindas, Pablo; Durst, Tony; Arnason, John
A protocol for the in vitro culture of the anxiolytic medicinal plant Souroubea sympetala (Marcgraviaceae) was developed, representing one of the first in vitro cultures for the family. This species was previously very difficult to cultivate from seed or cuttings. Methods included (1) the improvement of seed germination by axenic culture (2) development of regenerative cultures in vitro, then cultivation under greenhouse and finally field conditions and (3) creation of cell suspensions. Phytochemical analysis was undertaken by liquid chromatography coupled to mass spectrometry (HPLC-MS). The percentage of seed germination was improved from 2% to 59% in axenic culture and the full development of the seedling with its apical shoot and root took twenty-four days. The best seedling development was obtained in Gamborg B5 culture medium. Most friable callus formation, (66.7%) was obtained in the Murashige and Skoog medium supplemented with naphthalene acetic acid (1 mg · L–1) and kinetin (0.5 mg · L–1) from which viable cell cultures were developed. Analysis identified 4 main triterpenes with both in vitro plants and greenhouse grown plants derived from them. The triterpenes were betulinic acid, ursolic acid, alpha-amyrin and beta-amyrin. The betulinic acid found in greenhouse plants was comparable to wild plants. The cell suspension cultures had much lower levels of betulinic acid than plants and are not at present a viable source of this anxiolytic triterpene. In conclusion the method provides healthy plants for cultivation of this new medicinal plant and consequently harvesting of wild plants is not required.
Nutrient concentration age dynamics of teak (Tectona grandis L.f.) plantations in Central America
(Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 2013-02-04) Fernandez-Moya, J.; Murillo, R.; Portuguez, E.; Fallas, J. L.; Rios, V.; Kottman, F.; Verjans, J. M.; Mata, R.; Alvarado, A.
Aim of study: Appropriate knowledge regarding teak (Tectona grandis L.f.) nutrition is required for a better management of the plantations to attain high productivity and sustainability. This study aims to answer the following questions: How can it be determined if a teak tree suffers a nutrient deficiency before it shows symptoms? Are nutrient concentration decreases in older trees associated with age-related declines in forest productivity? Area of study: Costa Rica and Panama. Material and methods: Nutrient concentration in different tree tissues (bole, bark, branches and foliage) were measured at different ages using false-time-series in 28 teak plantations. Research highlights: Foliar N concentration decreases from 2.28 in year 1 to 1.76% in year 19. Foliar Mg concentration increases from 0.23 in year 1 to 0.34% in year 19. The foliar concentrations of the other nutrients are assumed to be constant with tree age: 1.33% Ca, 0.88% K, 0.16% P, 0.12% S, 130 mg kg–1 Fe, 43 mg kg–1 Mn, 11 mg kg–1 Cu, 32 mg kg–1 Zn and 20 mg kg–1 B. The nutrient concentration values showed can be taken as a reference to evaluate the nutritional status of similar teak plantations in the region. The concentrations of K, Mg and N could be associated with declines in teak plantation productivity as the plantation becomes older. Whether age-related changes in nutrient concentrations are a cause or a consequence of age-related declines in productivity is an issue for future research with the aim of achieving higher growth rates throughout the rotation period.

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