Fitness Costs of Evolved Herbicide Resistance

VILA-AIUB MM, NEVE P & POWLES SB

Encyclopedia of Pest Management

Año: 2005; p. 1 - 3

Herbicides have been intensively employed for the last 50 years to manage weed infestations in agricultural fields.[1] As a result of frequent use and the high selection pressure that herbicides impose herbicide resistant weed populations have evolved worldwide. Alleles conferring herbicide resistance arise in weed populations by random spontaneous mutation and are present at very low frequencies before herbicide selection. However, given the extraordinary advantage they confer, these alleles are rapidly selected in weed populations under herbicide selection.[1]             It has been often been assumed that genes conferring an advantage in a novel environment will usually exhibit a fitness cost in the previous environment.[2] For herbicides, this hypothesis is indirectly supported by the fact that resistance genes in unselected herbicide populations are rare. This theory predicts that herbicide resistance comes at an ecological and/or physiological cost.