Aislamiento, identificaci?n y evaluaci?n de los hongos m?s agresivos aislados de pitahaya amarilla (Selenicereus megalanthus) en el periodo poscosecha.
- Authors
- Vilaplana Ventura, Mar?a Rosa
- Format
- Article
- Status
- publishedVersion
- Description
Background: The production and export of yellow pitahaya (Selenicereus megalanthus) in Ecuador has increased during the last decade. However, the presence of pathogens that cause decay in this fruit is a risk factor for the export and marketing of this product. Objectives: To isolate and identify fungal strains in fruits of yellow pitaya, and to assess the severity caused by pathogenic fungi in whole pitahayas during the postharvest period. Methods: The isolation was performed in fruits which exhibited signs and symptoms of fungal diseases (40 fruits were used, with one repetition). The identification of each strain was performed by macro and microscopic analysis of the pathogen grown in PDA (Potato Dextrose Agar) at 25 ? C, then were compared with mycological keys. The assessment of severity in the fruits was performed with selected fungi. The fruits were artificially inoculated with two different spore concentrations (103 and 105 conidia mL-1) by a wound in the equatorial zone of the sterile fruit. The disease severity was evaluated by determining the rot diameter (cm) for 21 days at 12 ?C and 90% relative humidity (RH). 20 fruits, for each studied strain and for each inoculum concentration were used. An analysis of variance (ANOVA) was performed, the differences between averages and least significant difference (LSD) test at 95% confidence level were determined. Results: Strains of the genera: Alternaria, Aspergillus, Fusarium, Mucor, Penicillium and Rhizopus were identified as pathogens agents in postharvest of yellow pitahaya. Alternaria fungal genus was the most aggressive in the fruits of pitahaya, reaching a value of 4.44 cm at a concentration of 105 conidia mL-1 at 21 days of refrigerated storage. Conclusions: Of the six pathogens identified in the yellow pitahaya postharvest, Alternaria sp. was determined as the most aggressive pathogen.
Antecedentes: La producci?n y exportaci?n de pitahaya amarilla (Selenicereus megalanthus) en el Ecuador se ha incrementado durante la ?ltima d?cada. Sin embargo la presencia de pat?genos causantes del deterioro en los frutos es un factor de riesgo durante la exportaci?n y comercializaci?n de este producto. Objetivos: Aislar e identificar cepas f?ngicas en frutos de pitahaya amarilla, y evaluar la severidad causada por los hongos pat?genos en frutos enteros de pitahaya durante el periodo de poscosecha. M?todos: Se realiz? el aislamiento en frutos que presentaron signos y s?ntomas de enfermedades f?ngicas (se utilizaron 40 frutos, con una repetici?n). La identificaci?n de cada cepa se realiz? mediante el an?lisis macro y microsc?pico del pat?geno cultivado en PDA (Potato Dextrose Agar) a 25?C, luego se compararon con claves micol?gicas. La evaluaci?n de la severidad en los frutos se realiz? con hongos seleccionados. Los frutos fueron inoculados artificialmente con dos concentraciones diferentes de esporas (103 y 105 conidias mL-1) mediante una herida en la zona ecuatorial del fruto desinfectado. La severidad de la enfermedad fue evaluada mediante la determinaci?n del di?metro de podredumbre (cm), durante 21 d?as a 12?C y 90% de humedad relativa (HR). Se utilizaron 20 frutos para cada cepa estudiada y para cada concentraci?n de in?culo. Se realiz? un an?lisis de varianza (ANOVA), se determinaron las diferencias entre las medias con la prueba de m?nima diferencia significativa (LSD) a un 95% de nivel de confianza. Resultados: Se identificaron seis cepas de los g?neros: Alternaria, Aspergillus, Fusarium, Mucor, Penicillium y Rhizopus, como agentes pat?genos en la poscosecha de pitahaya amarilla. El hongo de g?nero Alternaria fue el de mayor agresividad en los frutos de pitahaya amarilla, alcanzando un valor de 4.44 cm a una concentraci?n de 105 conidias mL-1 a los 21 d?as de almacenamiento refrigerado. Conclusi?n: De los seis agentes pat?genos identificados en la poscosecha de pitahaya amarilla, se determin? que el pat?geno m?s agresivo fue Alternaria sp.
Escuela Polit?cnica Nacional
http://aprendeenlinea.udea.edu.co/revistas/index.php/vitae/article/view/26177/20779430
- Publication Year
- 2016
- Language
- spa
- Topic
- PITAHAYA AMARILLA
HONGOS PAT?GENOS
POSCOSECHA
SEVERIDAD
- Repository
- Repositorio SENESCYT
- Rights
- openAccess
- License
- restrictedAccess