In vitro callogenesis induction of Guarianthe skinneri (Bateman) Dressler and W.E. Higgins (Orchidaceae)

Guarianthe skinneri (Bateman) Dressler and W.E. Higgins, is a native orchid from Mexico, considered as threatened species in the NOM-ECOL-059-SEMARNAT-2010, mainly due to the disappearance of its natural habitat and illegal collection during the flowering season. The aim of this research was to induce in vitro callogenesis using different types of explants and phytoregulators, in order to establish a mass production technique as a contribution to the conservation of this species. We evaluated leaf and pseudobulb pith explants growing in semi-solid medium MS, adding BAP, 2, 4-D, Kin, the combination of BAP/2 and 4-D/Kin/Sad and a control without any type of plant growth regulators. Statistical analysis showed that pseudobulb pith explants are more suitable for in vitro callus induction in comparison to leaf explants, because of a lower percentage of contamination (18.8% in pith and 73.2% in leaves). Likewise, the pseudobulb pith explants showed increased callus formation (10.8%) in comparison to leaf explants (7.6%). Regarding the phytoregulators employed, BAP promoted increased callus formation (17%) compared to other phytoregulators (7-10%). This is the first report of the use of pseudobulb pith as an explant for callus induction in G. skinneri.Guarianthe skinneri (Bateman) Dressler and W.E. Higgins., is a native orchid from Mexico, considered as threatened species by NOM-ECOL-059-SEMARNAT-2010, mainly due to the disappearance of its natural habitat and the illegal collection during its flowering season. The aim of this research was to induce in vitro callogenesis from different type of explants, using phytoregulators, in order to look for a massive production technique to contribute to its conservation. We evaluated the leaf and pseudobulb marrow explants growing in semi-solid medium MS adding BAP, 2, 4-D, Kin, the interaction of BAP/2, 4-D/Kin/Sad and a control without any type of plant growth regulators. Statistical analysis showed the pseudobulb marrow explants are more suitable for in vitro introduction in comparison to leaf explants, since they perform a lower percentage of contamination (18.8% in marrow and 73.2% in leaves). Likewise, the pseudobulb marrow explants increased callus formation (10.8%) in comparison to leaf explants (7.6%). Regarding the phytoregulators employed, BAP have allowed to increased callus formation (17%) compared to other phytoregulators (7-10%). This is the first report, which proposes the use of pseudobulb marrow as explant for callus induction in G. skinneri

In vitro callogenesis induction of Guarianthe skinneri (Bateman) Dressler & W.E. Higgins (Orchidaceae)

Guarianthe skinneri (Bateman) Dressler & W.E. Higgins, is a native orchid from Mexico, considered as threatened species in the NOM-ECOL-059-SEMARNAT-2010, mainly due to the disappearance of its natural habitat and illegal collection during the flowering season. The aim of this research was to induce in vitro callogenesis using different types of explants and phytoregulators, in order to establish a mass production technique as a contribution to the conservation of this species. We evaluated leaf and pseudobulb pith explants growing in semi-solid medium MS, adding BAP, 2, 4-D, Kin, the combination of BAP/2 and 4-D/Kin/Sad and a control without any type of plant growth regulators. Statistical analysis showed that pseudobulb pith explants are more suitable for in vitro callus induction in comparison to leaf explants, because of a lower percentage of contamination (18.8% in pith and 73.2% in leaves). Likewise, the pseudobulb pith explants showed increased callus formation (10.8%) in comparison to leaf explants (7.6%). Regarding the phytoregulators employed, BAP promoted increased callus formation (17%) compared to other phytoregulators (7-10%). This is the first report of the use of pseudobulb pith as an explant for callus induction in G. skinneri

El uso ornamental de Guarianthe skinneri (Orchidaceae), en Chiapas y Guatemala, determina parcialmente su diversidad y estructura genética

Background and Aims: Guarianthe skinneri is a native orchid from Chiapas, Mexico, with a Central American distribution, which is threatened by extraction and illegal trade. For this reason, it is classified as threatened in the Mexican rule NOM-059-SEMARNAT-2010. In the region of Soconusco (Chiapas, Mexico) and Guatemala, it is commonly called “Candelaria”, because its flowering time coincides with the dates of the virgin of the same name. In Tapachula city (Chiapas, Mexico), it is common to find plants of this species in the courtyards of pri-vate gardens. The objective of this work was to estimate the diversity and genetic structure of G. skinneri from samples obtained from an urban population of Tapachula and from its comparison with five wild populations of Guatemala, in order to determine the potential of the urban population as a source of propagules and understand if genetic distance between populations could be related with the geographic distance that separates them. Methods: Nucleotidic variation in sequences of two regions of ribosomal nuclear DNA (ITS 1-2 and ITS 3-4) was used as genetic marker. The sequences were concatenated obtaining the conventional parameters of diversity and genetic structure. Key results: We observed populations with low and high genetic diversity. A total of 38 haplotypes were observed, whose number per population was between 1 and 15. Haplotidic diversity (Hd) was between 0 and 1, the average number of polymorphic sites was between 0 and 165. The nucleotidic diversity (p) and the average number of nucleotidic differences shows that Tapachula had the greatest diversity, followed by populations of Guatemala. The genetic structure was moderate (Fst=0.083) and the genetic distance was not associated with the geographic distance of the populations. Conclusions: The diversity patterns and genetic structure between populations were attributed to anthro-pogenic factors derived from its ornamental use, especially in the city of Tapachula.Antecedentes y Objetivos: Guarianthe skinneri es una orquídea nativa de Chiapas, México, con distribución centroamericana, objeto de extracción y comercio ilícito; por esta razón, está catalogada como amenazada en la Norma Mexicana NOM-059-SEMARNAT-2010. En la región del Soconusco (Chiapas, México) y Guatemala, se le denomina “Candelaria”, debido a que su época de floración coincide con las fechas de la homónima virgen. En la ciudad de Tapachula (Chiapas, México), es común encontrar individuos de esta especie en los patios de domicilios particulares. El objetivo de este trabajo fue estimar la diversidad y estructura genética de G. skinneri a partir de muestras obtenidas de una población urbana de Tapachula y de su comparación con cinco poblacio-nes silvestres de Guatemala, para determinar el potencial de la población urbana como fuente de propágulos y averiguar si la distancia genética entre poblaciones se relaciona con la distancia geográfica que las separa. Métodos: Como marcador genético se utilizó la variación nucleotídica en secuencias de dos regiones de ADN nuclear ribosomal (ITS 1-2 y ITS 3-4). Se concatenaron las secuencias y se obtuvieron los paráme-tros convencionales de diversidad y estructura genética. Resultados clave: Se observaron poblaciones desde bajos hasta altos niveles de diversidad genética. Se registró un total de 38 haplotipos cuyo número entre poblaciones osciló entre 1 y 15. La diversidad ha-plotípica (Hd) estuvo entre 0 y 1, el número promedio de sitios polimórficos entre 0 y 165. La diversidad nucleotídica (p) y el número promedio de diferencias nucleotídicas muestran que Tapachula tuvo la mayor diversidad, seguida por poblaciones de Guatemala. La estructura genética fue moderada (Fst=0.083) y la distancia genética no se asoció con la distancia geográfica de las poblaciones. Conclusiones: Los patrones de diversidad y estructura genética entre poblaciones se atribuyen a factores antropogénicos derivados de su uso ornamental, especialmente en la ciudad de Tapachula