A Seed Bioassay to Identify Acetyl-CoA Carboxylase Inhibitor Resistant Wild Oat (Avena fatua) Populations

Abstract

A seed bioassay was developed and tested for the rapid identification of aryloxyphenoxypropionate (APP) and cyclohexanedione (CHD) resistance in wild oat. Two susceptible (S) genotypes, UM5 and Dumont, were treated with fenoxaprop-P and sethoxydim over a range of dosages on filter paper and agar. The former is a wild oat line and the latter a tame oat cultivar. Within 5 d, shoot and root development of both genotypes were completely inhibited by 10 μM fenoxaprop-P and 5 μM sethoxydim. These dosages were then tested to determine if they were suitable for distinguishing between resistant (R) and susceptible (S) plants. Agar medium was preferred over filter paper because of the ease of preparation and maintenance. Four known R wild oat populations were included in the tests. Those with high levels of resistance produced significantly longer coleoptiles and roots than S genotypes, but those with moderate or low levels of resistance could not be separated statistically from S biotypes based on quantitative measurements. However, after exposing the germinating, treated seeds to light for 24 to 48 h, all the R populations produced green coleoptiles and initiated a first leaf, unlike the S genotypes which did not turn green or produce any new growth. This procedure proved useful in discriminating between R and S genotypes and in ranking populations in terms of relative levels of resistance.

Cross-resistance patterns of winter wild oat (Avena ludoviciana) populations to ACCase inhibitor herbicides

“…The herbicide effect on coleoptiles length was detectable 7 days following incubation with large differences between populations (Table 3). Shoot length is more sensitive than root length to APP and CHD herbicides (Murray et al 1996). The resistance ratio ranged from 0.68 (ES) to >26.21 (M2) ( Table 3).…”

“…As a consequence, they rapidly selected, and are still selecting, resistant plants within grass weed species (Délye 2005) and rank third in terms of the frequency of resistance cases in the world (Heap 2015). The first case of ACCase inhibitor resistance in wild oat was reported in Western Australia in 1985 (Heap 2015) followed by many other reports thereafter (e.g., Devine 1994, Seefeldt et al 1994;Murray et al 1996;Beckie et al 2002). Cross-or multiple-resistance patterns were also characterized in wild oat populations in some studies (Kern et al 1996;Friesen et al 2000;Uludag et al 2008).…”

“…Seed bioassays, which are quick and inexpensive, have been found to be a useful and accurate tool for screening-resistant populations. Such assays have been used to discriminate between resistant and susceptible biotypes in green foxtail (Setaria viridis) (Beckie et al 1990), Johnsongrass (Sorghum halepense) (Smeda et al 1995), wild oat (Avena fatua) (Murray et al 1996), and blackgrass (Alopecurus myosuroides) and ryegrass (Lolium spp.) (Letouze´, A., and Gasquez, J.…”

Diagnóstico da resistência aos herbicidas em plantas daninhas

“…Pelo mesmo método foi detectada, em apenas cinco dias, a resistência em biótipos de Avena fatua aos herbicidas inibidores de ACCase, como fenoxaprop-ethyl e sethoxydim (Murray et al, 1996). Kim et al (2000) utilizaram o método da germinação de sementes para diagnosticar a resistência de Echinochloa colonum aos herbicidas fenoxaprop-ethyl e propanil.…”

Inheritance of multiple herbicide resistance in wild oat (Avena fatua L.)

“…The susceptible biotype (wild type) used in this study was UM5. It was collected from Portage la Prairie, Manitoba and has been used and characterized in numerous studies (Devine et al 1993;Heap et al 1993;Murray et al 1995;Murray et al 1996).…”