INVESTIGADORES
GUNDEL Pedro Emilio
artículos
Título:
Herbicide selection of Italian ryegrass under different levels of UVB radiation
Autor/es:
MARTÍNEZ-GHERSA, M.A.; VILA-AIUB, M.M.; GHERSA, C.M.; GUNDEL, P.E. & E.H. SATORRE.
Revista:
JOURNAL OF ENVIRONMENTAL QUALITY
Editorial:
HighWire Press(R)
Referencias:
Lugar: Stanford (USA); Año: 2004 vol. 33 p. 1376 - 1386
ISSN:
0047-2425
Resumen:
Ultraviolet-B
radiation is an environmental stress for plants and this situation could become
aggravated in the next decades. In this study we used Italian ryegrass (Lolium
multiflorum Lam.) as a model system to test whether an environmental stress
derived from global change, such as UVB, can influence the efficacy of control
procedures and evolution toward herbicide resistance. We grew three generations
of Italian ryegrass plants with and without UVB light and subjected them to a
series of diclofop-methyl {(±)-2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic
acid, methyl ester} doses. The effect of selection history was tested with
herbicide dose response. The effect of herbicide application on plant survival
and biomass varied significantly among herbicide doses and with absence or
presence of UVB light. In the absence of herbicide, the decrease in individual
fecundity with increasing plant density was similar under both no-UVB and UVB
light treatments. Only plants growing without UVB light increased production of
reproductive structures in response to the decrease in density caused by
herbicide application. Our study shows that UVB light was a weak stress factor
for the ryegrass plants. However, when herbicide selection pressure was high,
UVB light reduced the evolution toward herbicide tolerance. When selection
pressure on the parental plants was lower, the two stress factors had a
synergistic effect, causing changes in herbicide efficacy that in turn had
demographic and evolutionary consequences. In the field, these interactions
between stress factors might be of significance for annual weeds in which seed
output is a major determinant in fitness.