Tesis Agronomía
Permanent URI for this collectionhttp://repositorio.uta.edu.ec/handle/123456789/36414
Browse
2 results
Search Results
Item Aislamiento y caracterización del agente causal de pudriciones en el cultivo de Allium sativum L.(2023-09) Tituaña Cajahuishca, Mónica Tatiana; Guerrero Cando, David AníbalGarlic (Allium sativum L.) is one of the crops with the smallest planting area in Ecuador due to its phytosanitary problems and the lack of quality seed bulbs. One of the factors that affects the production of this crop is the presence of diseases, among the most common is bulb rot. For this reason, the present investigation was proposed with the objective of identifying the causal agents that occur in the rotting of the garlic crop in the Pilahuín parish belonging to the Tungurahua province. Three isolates were obtained from infected bulb tissue, which were selected for cultural and morphological characterization. The results indicated that the causative agents of the most common rots were Fusarium oxysporum f.sp. cepae, Penicillium allii and Sclerotium cepivorum Berk. It is hoped that the results of these studies serve as a basis for the establishment of an integrated disease management program that leads to an increase in the garlic (Allium sativum L.) planting area in order to reach a supply in Ecuador.Item Evaluación de la capacidad de fijación del nitrógeno atmosférico de las bacterias asociadas con la rizosfera de plantas de Solanum tuberosum L. Var. Superchola en la provincia de Tungurahua(2023-09) Altamirano Diaz, Vanessa Carolina; Leiva Mora, MichelThe present study was developed with the purpose of isolating, quantifying, characterizing, evaluating and conserving free-living bacteria associated with the potato rhizosphere with atmospheric nitrogen fixation capacity, from soil samples from four localities in the province of Tungurahua. First, soil samples were collected from the potato crop and placed in plastic containers of 6 L capacity, where tubers of the Superchola variety were planted. After 60 days, samples of rhizospheric soil (area near the roots) were extracted. For isolation, the pour plate method was used in Jensen culture medium free of nitrogen sources. To quantify viable bacteria per gram of soil from each locality, serial solutions were prepared where 100 µl were deposited in solid medium, incubated for 72 hours at 30 ºC in inverted position and the plate count was performed. The locality of Santa Rita in the canton of Pillaro had the highest number of CFU/g of soil. A total of 72 isolates were obtained from the potato rhizosphere, of which only 38 isolates produced a positive reaction with the color change of the medium modified with bromothymol blue from green to blue, these were subjected to morphological and cultural characterization. In relation to morphology, 84% were predominantly Gram (-) bacteria, bacilli (95%) and their grouping was mostly in the form of diplobacilli (37%). In the cultural characterization, the following shapes predominated: circular (42%), entire margin (84%), smooth texture (87%), flat surface (42%), smooth consistency (82%) and 95% showed brightness. The bacterial isolate with the greatest capacity to fix atmospheric nitrogen was (T1-FCAGP-BFN1) from the El Placer sector of the Quero canton, which had no statistically significant difference with respect to isolates T3-FCAGP-BFN14, T3-FCAGP-BFN16 and T4- FCAGP-BFN24. The purified isolates were deposited in eppendorf tubes with 15% glycerol and BHI liquid medium + 20% glycerol and stored at -20 ºC. The bacterial isolates with the highest nitrogen-fixing capacity obtained could be used to determine their plant growth-promoting activity in greenhouses prior to their possible use as biofertilizers under field conditions.