IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The role of plant size in pesticide selection intensity and resistance evolution
Autor/es:
VILA AIUB, MM; GUNDEL, P.E.; ROMERO, I; DEVOTO-GALLARDO, S; POWLES, SB
Reunión:
Conferencia; Global Herbicide Resistance Challenge Conference; 2013
Resumen:
Survival
and growth of herbicide resistant (R)
and susceptible (S) Sorghum halepense populations to
glyphosate selection at different plant sizes (i.e. germinating seeds,
seedlings, young and adult plants) was evaluated. Glyphosate resistance was evident at all plant stages. More
glyphosate was required to have the same impact on fitness components of R and S individuals under increments of plant size. However, glyphosate R individuals exhibited
higher survival rates and growth in response to glyphosate with increments in
plant size. Under coexistence of similar-sized R and S individuals,
selection intensity increased with higher herbicide doses and was higher at the
seedling and young stage of both R
and S plants. The same outcome was
observed when young R plants
coexisted with adult S plants. Only
when R seedlings coexisted with
larger S plants (young or adult) no
selective advantage for resistance was observed.
Knowledge
of the size class structure in perennial populations enables a better
prediction and understanding of selection intensity and evolutionary dynamics
of resistance traits. Decisions taken in the management of herbicide resistance
in terms of selection timing and doses of herbicides can provide contrasting results
depending on the plant size distribution and consequent attained fitness traits
of populations.