Browsing by Author "Pillacela Zhunio, Dora Priscila"

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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.
Evaluación de la regeneración natural su relación con variables ambientales y de cobertura arbórea en ecosistemas naturales alto andinos de la Provincia del Azuay
(2017-10-11) Pillacela Zhunio, Dora Priscila; Jadán Maza, Ángel Oswaldo
Andean ecosystems are an important reserve of biodiversity. In addition to their biological wealth, these ecosystems, provide also numerous ecosystem services. In this study, natural regeneration was described and its relation with environmental variables and tree cover in High-Andean natural ecosystems (paramo and secondary forests) in the Azuay province was characterize d. Woody (≤ 5.0 cm de D.B.H.) and herbaceous species were described in permanent sampling plots to determine richness, diversity, abundance and dominance. These parameters were evaluated at the level of forest communities (FC) and paramo using non-parametric Kruskal-Wallis tests (P<0.05). Also, correlations between soil chemical parameters, environmental variables and tree cover were tested using non-parametric Spearman correlations (P<0.05). Forest communities one and two (FC1 and FC2, respectively) had the highest values of richness, Simpson and Shannon diversity indices for both herbaceous and woody species. Herbaceous and woody species richness was positively correlated with leaf area index and tree cover; density index was positively correlated with the altitude, but negatively correlated with leaf area index, tree cover and available phosphorous (P). The dominance of individuals was negatively correlated with the available phosphorous (P). Shannon's alpha diversity index presented a small positive correlation with the available phosphorous (P) and negatively correlated to altitude. In conclusion the natural regeneration can be an effective strategy for the conservation of plant biodiversity in the High-Andeans ecosystems.