IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Neotyphodium infection and vertical transmission in exotic grasses occurring in grassland communities of the Flooding Pampa (Argentina)
Autor/es:
GUNDEL, P.E.; GARIBALDI, L; TOGNETTI, P.M.; ARAGON, R; GHERSA, C.M.; OMACINI, M.
Revista:
MICROBIAL ECOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2009 vol. 57 p. 740 - 748
ISSN:
0095-3628
Resumen:
Abstract Cool-seasongrassesestablishsymbioseswith verticallytransmitted Neotyphodium endophyteswide- spreadinnature.Thefrequencyofendophyte-infected plantsinclosedpopulations (i.e.,withoutmigrations) dependsonboththedifferentialfitnessbetweeninfected andnon-infectedplants,andtheendophyte-transmission efficiency.Moststudieshavebeenfocusedonthefirst mechanismignoringthesecond.Infectionfrequencyand endophytetransmissionfromvegetativetissuestoseeds weresurveyedintwograssesgrowinginvegetationunits thatdifferinfloodandgrazingregimes,andsoilsalinity. Transmissionefficiencyandinfectionfrequencyfortall fescuedidnotvarysignificantlyandwere0.98and1.00, respectively.ForItalianryegrass,transmissionefficiency andinfectionfrequencywere0.88and0.57inhumid prairies,and0.96and0.96intheothervegetationunits. Onlyinhumidmesophyticmeadows,theobservedpattern wasirrespectiveofthepresenceorabsenceofgrazers. Ourresultssuggestthatselectionforcesforendophyte infectionaredifferentforbothspecies.Imperfecttrans- missionwasonlycompensatedintallfescuethroughan increasedfitnessofinfectedplants.Interpretingvariations ofinfectionfrequencyonlyintermsofdifferentialfitness canbemisleading,consideringthatendophytetransmis- sioncanbeimperfectandvariableinnature.Therefore, thisstudyhighlightstheimportanceofmeasuringtrans- missionefficiency.