IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Impact of ALS target-site resistance mutations on Raphanus raphanistrum growth under herbicide selection
Autor/es:
LI, M; YU, Q; VILA AIUB, MM; HAN, H; POWLES, SB
Reunión:
Conferencia; Global Herbicide Resistance Challenge Conference; 2013
Institución organizadora:
Australian Herbicide Resistance Initiative
Resumen:
For herbicide
resistance to evolve in plants, two conditions must be met: a resistance trait
must endow a fitness advantage over the wild type under herbicide selection and
this advantage should exceed any fitness or ecological disadvantage associated
with the resistance trait in the absence of herbicide selection. The fitness
advantage endowed by a herbicide resistance trait is conditional on the
efficiency of the resistance mechanism in protecting the plants from herbicide
damage. In the present study we quantified the effect of various specific homozygous
target-site ALS resistance alleles (Ala-122-Tyr, Pro-197-Ser, Asp-376-Glu or
Trp-574-Leu) on survival, ALS activity and growth components of Raphanus
raphanistrum under chlorsulfuron (sulfonylurea) and
metosulam (triazolopyrimidine) treatment. The ability of plants to respond to
herbicide treatment was assessed by estimating growth traits (biomass, leaf
area, relative growth rate (RGR) and
components, net assimilation rate (NAR)
and leaf area ratio (LAR)) when subjected
to the effect of field herbicide rates. Whereas similar survival rates were
observed, significant differences in growth were recorded among plants with these
specific resistance alleles. Nearly no growth reduction was
observed for Tyr-122 plants, while a significant growth inhibition was recorded
for plants with the Glu-376. Considering all evaluated traits, it is possible
to rank the ALS resistance alleles for the level of protection (fitness
advantage) to both herbicides: Tyr-122 > Leu-574 > Ser-197 > Glu-376. The
implication of these results for the evolution of ALS resistance in R. raphanistrum is discussed.