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.