¿Cuánto le cuesta al nabón (Raphanus sativus L.) ser resistencia a herbicidas AHAS?: Implicancias para el manejo.

VERCELLINO, ROMAN B.; PANDOLFO, CLAUDIO E.; BRECCIA, GABRIELA; HERNANDEZ, FERNANDO; CANTAMUTTO, MIGUEL; PRESOTTO, ALEJANDRO

Malezas

ASACIM - Asociación Argentina de Ciencia de Malezas

Lugar: Buenos Aires; Año: 2021 vol. 5 p. 4 - 17

2683-9180

Feral radish (Raphanus sativus L.) is a problematic weed widely distributed in temperate zones of the Americas that has become resistant to acetohydroxyacid synthase (AHAS) inhibitor herbicides due to the Trp574Leu mutation. AHAS gene mutations endowing herbicide resistance may have negative pleiotropic effects on fitness, also called cost of resistance. This study reports the effects of the Trp574Leu mutation on AHAS activity, reproductive traits of feral radish under no interspecific interference and total dry-biomass and reproductive traits of feral radish under two wheat densities interference. AHAS activity was 3.2-fold higher in the susceptible biotype than in the resistant one. Under no interspecific interference, the resistant biotype showed 22?38% lower seeds per plant and 21?47% lower plant yield than the susceptible. Under wheat interference, the resistant biotype had 36?46% less total above-ground biomass, 26?47% less seeds per plant, and 36?53% less plant yield than the susceptible one, and these differences were more evident at higher plant density. The fitness costs could reduce the frequency of the resistant allele in areas untreated with AHAS inhibiting herbicides. Our results suggest that incorporating non-AHAS herbicidal approaches into integrated weed-management programs and maintaining fence lines, roadsides and fields margin as refuges of susceptible plants provides an opportunity to minimize or reverse herbicide resistance evolution. Finally, feral radish interference could result in wheat yield losses greater than 65 %.