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dc.contributor.advisorVerle-Rodrigues, José C.
dc.contributor.authorMiranda-Vélez, Magdiel A.
dc.description.abstractPapaya ringspot virus (PRSV) and Zucchini yellow mosaic virus (ZYMV) frequently infect tropical pumpkin (Cucurbita moschata) in Puerto Rico. Breeding programs depend on the development of efficient and reliable methods of assessing resistance. The goal of this research was to determine the best method to differentiate the level of resistance among genotypes of tropical pumpkin for both PRSV and ZYMV, determine if there are differences in seedling development of C. moschata infected with PRSV, ZYMV, or both PRSV+ZYMV, and to evaluate whether ‘Menina’ can serve as a source of resistance. The cotyledons of seven genotypes were inoculated with PRSV, ZYMV or PRSV+ZYMV. Analysis of the viral serological titer in the first five leaves was performed using ELISA tests. An ELISA reading <0.400 (A405nm) was considered to be negative for presence of virus. Symptoms and fresh and dry weight were taken. Small leaves, intervenal chlorosis, leaf deformation, curled leaves, and mosaic were some of the symptoms observed in susceptible genotypes inoculated with PRSV and ZYMV. Smaller leaves and chlorosis were observed in ‘Menina’ inoculated with PRSV and ZYMV and no symptoms were observed in ‘Nigerian Local’. For PRSV, sampling of the fourth leaf was required to differentiate between resistant versus susceptible genotypes. For ZYMV, leaves 2, 3, and 4 can be used to differentiate resistant from susceptible genotypes. No differences were found in ELISA readings from plants with single versus double inoculation. No differences in fresh and dry weight were found between uninoculated versus inoculated plants. Negative ELISA readings were obtained in the inoculation of susceptible genotypes with sap of inoculated resistant genotypes. ‘Menina’ was observed to be a useful source of resistance to ZYMV and PRSV. The results of this study can be used when developing a breeding program for resistance to these two viruses.en_US
dc.description.abstractPapaya ringspot virus (PRSV) y Zucchini yellow mosaic virus (ZYMV) frecuentemente infecta la calabaza tropical (Cucurbita moschata) en Puerto Rico. Los programas de mejoramiento dependen del desarrollo de métodos eficientes y confiables para evaluar la resistencia. El objetivo de esta investigación fue determinar el mejor método para diferenciar el nivel de resistencia para PRSV y ZMYV entre los genotipos de calabaza tropical, determinar si existen diferencias en el desarrollo de plántulas de C. moschata infectadas con PRSV, ZYMV, o PRSV+ZYMV, y evaluar si 'Menina' puede ser utilizada como una fuente de resistencia. Los cotiledones de siete genotipos fueron inoculados con PRSV, ZYMV o PRSV+ZYMV. Análisis de título serologíco viral en las primeras cinco hojas se realizó mediante pruebas ELISA. Una lectura de ELISA <0.400 (A405nm) se consideró que era negativa para presencia de virus. Se recopiló datos de síntomas, peso fresco y peso seco. Hojas pequeñas, clorosis intervencionista, deformación de la hoja, hojas rizadas y mosaico fueron algunos de los síntomas observados en los genotipos susceptibles inoculados con PRSV y ZYMV. Se observaron hojas pequeñas y clorosis en 'Menina' inoculada con PRSV y ZYMV y no se observaron síntomas en 'Nigerian Local'. Para PRSV, se requirió el muestreo de la cuarta hoja para diferenciar entre genotipos resistentes con susceptibles. Para ZYMV, las hojas 2, 3 y 4 puede ser utilizada para diferenciar genotipos resistentes de los susceptibles. No se encontraron diferencias en las lecturas de ELISA de plantas con la inoculación simple y doble. No se encontraron diferencias en peso fresco y peso seco entre plantas inoculadas y no inoculadas. Se obtuvieron lecturas de ELISA negativas en la inoculación de genotipos susceptibles con savia de genotipos resistentes previamente inoculados. Se observó que 'Menina' fue una fuente útil de resistencia a PRSV y ZYMV. Los resultados de este estudio pueden ser utilizados en el desarrollar en un programa de mejoramiento para la resistencia a estos dos virus.en_US
dc.description.sponsorshipUSDA-NIFA Award No. 2015-51181-24285 (Subaward No. RC105573UPRM (CucCAP, Z295); USDA-NIFA Hatch Accession No. 1000526 (H443)en_US
dc.subjectCucurbita moschata - Effect of Papaya ringspot virus on - Puerto Ricoen_US
dc.subjectCucurbita moschata - Effect of Zucchini yellow mosaic virus on - Puerto Ricoen_US
dc.subjectMenina from Portugal - Gene resistance - Virusen_US
dc.subject.lcshCucurbita--Seedlings--Diseases and pests--Puerto Ricoen_US
dc.subject.lcshPapaya ringspot virusen_US
dc.subject.lcshMosaic virusesen_US
dc.titleDisease assessment, inferences on virus movement, and seedling development in tropical pumpkin (Cucurbita moschata) infected with papaya ringspot virus and zucchini yellow mosaic virusen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2018 Magdiel A. Miranda Vélezen_US
dc.contributor.committeeWessel-Beaver, Linda
dc.contributor.committeeFerwerda, Feiko H.
dc.contributor.committeeVargas, Roberto
dc.contributor.representativeRíos López, Isabel Protectionen_US
dc.contributor.collegeCollege of Arts and Sciences - Sciencesen_US
dc.contributor.departmentDepartment of Crops and Agro-Environmental Sciencesen_US

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