Browsing by Author "Salazar Orellana, Marjorie Jazmin"

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Endophytic fungi associated with roots of epiphytic orchids in two andean forests in southern Ecuador and their role in germination
(2020) Salazar Orellana, Marjorie Jazmin; Pomavilla Lema, Yesenia Marisol; Pollard, Anne Therese; Chica Martínez, Eduardo José; Peña Tapia, Denisse Fabiola
Orchids are known to establish complex relationships with endophytic fungi throughout their life cycle, and particularly during germination of their reserves-deprived seeds. Characterizing generalist or specialist interactions between orchids and associated fungi is key to supporting orchid conservation efforts. Here, endophytic fungi associated with roots of epiphytic orchids were studied in two montane Andean forests in Southern Ecuador. Orchid root samples were collected from ten ~500 m 2 plots distributed between two neighboring forests. Endophytic fungi associated with these roots were then isolated, cultured, and identified by sequencing of rDNA markers. In total, 52 pure isolates were recovered from the roots of 10 orchid species. These isolates were classified into nine taxonomic groups except for one isolate that remained unclassified. Most fungal isolates were found in roots of up to two different orchid species; however, Coprinellus radians was found in the roots of all sampled orchids. The potential of C. radians to promote germination of orchid seeds was tested in a separate assay using seeds from two orchid species different than those found in the experimental forest plots. Of the two C. radians isolates tested, one improved germination in the two orchids evaluated to a level about half of that observed in seeds germinated in nutrient-rich medium (Phytamax) and above the null germination observed in plates without the fungus. Together, these results revealed a generalist relationship between C. radians and all the studied epiphytic orchids and the potential role of this fungus as a promoter of orchid seed germination
Especificidad del hongo micorrizico (Rhizoctonia sp.) en Phalaenopsis sp., Cymbidium sp., Trichoceros antenifer, Oncidium excavatum, y Cyrtochilum sp.
(2016) Ordoñez Tenesaca, Silvia Liliana; Pillacela Zhunio, Dora Priscila; Salazar Orellana, Marjorie Jazmin; Peña Tapia, Denisse Fabiola
Orchids produce abundant small seeds, lacking endosperm, cotyledons and reserve substances to support germination. That is why the seeds strategically establish a symbiotic relationship with a mycorrhizal fungus favoring germination and development. The aim of this study was to determine whether the mycorrhizal fungus Rhizoctonia sp. establishes a specific association with five orchid genera that stimulates seed germination. Two culture media were used: 1) PhytamaxTM and 2) oatmeal- agar+Rhizoctonia sp. The germination was assessed at day 45 and 75 and showed no specificity between the fungus Rhizoctonia sp. and Trichoceros antenifer, the orchid species from which the fungus was isolated. Germination in three of the five genera tested was higher in the treatment oatmeal agar+Rhizoctonia sp., showing in this treatment increased sizes and the development of vigor plants; although these data were not evaluated. The results also suggest that the host plant of the inoculated fungus could have an advantage in terms of time required for germination, but other species are also favored with the inoculum even if isolated from a different species.
Estudio comparativo de la riqueza de hongos endófitos asociados a la diversidad de orquídeas epífitas en los bosques de Mazán y la zona de influencia del Parque Nacional El Cajas
(2017) Salazar Orellana, Marjorie Jazmin; Peña Tapia, Denisse Fabiola
The microorganisms play a preponderant role in the nutrition and development of plants. For the case of orchids, it is known that these plants require a forced symbiosis for their nutrition and germination. However, not much it is known about the diversity of fungi that colonize these species and remain endophytes meeting several functions, many of which are completely uncharacterized. The objective of the present study was to determine the species of endophytes fungi which are present in roots of epiphytic orchids and their possible association with diversity patterns of these orchids in the evergreen upper montane forests Mazán and Llaviuco. From the roots collected along the field, endophytes fungi were isolated, 52 strains were identified through the sequencing of the ITS of ribosomal DNA region. The diversity of epiphytic orchids was registered, and it was possible to identify 6 types and 10 species in total, differences between the orchid diversity and richness of cultivable endophytic fungi could not be found when comparing the forests evaluated. The data showed a positive correlation between the association and the richness of the endophytic fungi and the orchid diversity, making evident the role of endophytic fungi in the dynamic of orchids populations. The isolation and conservation of pure strains of fungi identified as possible formers of mycorrhizae will be the base for new research associated with the symbiotic germination, information expected to be very useful for conservation and reintroduction programs of orchids
Inducción de la brotación in vitro de microplántulas de Nogal (Juglans neotropica) tratadas con Thidiazuron (TDZ) y 6-Bencilaminnopurina (BAP)
(2014) Peña Tapia, Denisse Fabiola; Rocano Curillo, Melida Noemi; Salazar Orellana, Marjorie Jazmin; Torres Inga, Carlos Santiago
The walnut (Juglans neotropica) is a species of great potential for conservation projects and eco-agro- production in the Andean region. However, low germination capacity limits its spread for reforestation. The aim of this study was to determine the effect of treatment with Thidiazuron (TDZ) and 6-Benzylaminopurine (BAP) on in vitro shoot induction of J. neotropica. The micro plantlets treated with BAP produced more shoots than those treated with TDZ. The micro plantlets treated with BAP and TDZ in turn generated more shoots than the non-treated micro plantlets. In the test, the effect of concentration of BAP and TDZ in the medium was also evaluated; however not statistically significant differences between the tested concentrations were detected. In summary, findings indicate that the treatment with cytokines, BAP specifically, increases the number of shoots produced by micro plantlets J. neotropica. It is believed that this treatment can be applied on projects of mass propagation of this species within the frame of reforestation programs.