Baseline sensitivity of Fusarium graminearum from wheat fields in Henan, China, to metconazole and analysis of cross resistance with carbendazim and phenamacril

Abstract

The filamentous plant pathogenic fungus Fusarium graminearum is one of the most important pathogens causing Fusarium head blight (FHB) in wheat in the Henan Province of China. Metconazole is among the demethylation inhibitor (DMI) fungicides with a higher inhibitory activity on the mycelial growth of F. graminearum. In 2016 and 2017, 119 single spore isolates of F. graminearum, prior to being exposed to metconazole, were recovered from 52 wheat fields near 11 cities in Henan Province. The inhibitory activity of metconazole on the mycelia of the Henan F. graminearum population was determined, and EC50 values were calculated. The range of EC50 values of the Henan F. graminearum population to metconazole was 0.0103 to 0.0775 μg/ml with an average EC50 value of 0.0293 ± 0.0114 μg/ml. The sensitivity frequency distribution curve presented a single peak in a narrow range. No cross‐resistance was found between the DMI fungicide metconazole and the benzimidazole fungicide carbendazim or the cyanoacrylate fungicide phenamacril. Therefore, these sensitivity data could be used as the baseline of F. graminearum susceptibility to metconazole in the Henan Province and provide the basis for monitoring metconazole resistance in this area.

Antifungal Activity of Quinofumelin against Fusarium graminearum and Its Inhibitory Effect on DON Biosynthesis

“…The average EC 50 value for mycelial growth of 100 F. graminearum isolates was 0.019 ± 0.007 μg/mL. To our knowledge, the mean EC 50 value for quinofumelin-inhibiting mycelial growth of F. graminearum was lower than phenamacril, tebuconazole, carbendazim, metconazole, and epoxiconazole [ 12 , 17 , 18 , 31 , 32 ]. Previous studies reported that Quinone outside inhibitors (QoIs) and Succinate dehydrogenase inhibitors (SDHIs) had good effects in the control of FHB.…”

Tebuconazole resistance of Fusarium graminearum field populations from wheat in Henan Province

“…Among them, FHB is the most harmful to wheat. In recent years, with the transformation of modern agriculture and the impact of global warming, F. graminearum has caused serious economic losses to wheat production of the world (Liu, Fu, et al., 2020; Liu et al., 2019; Liu, Liu, et al., 2020; McKay et al., 2019; Xu & Nicholson, 2009). FHB can lead to the decline of wheat grain quality and produce mycotoxins (for instance, 3‐acetyl‐deoxynivalenol, 15‐acetyl‐deoxynivalenol, etc.)…”

“…FHB can lead to the decline of wheat grain quality and produce mycotoxins (for instance, 3‐acetyl‐deoxynivalenol, 15‐acetyl‐deoxynivalenol, etc.) in the susceptible grains, which may cause human and animals poisoning (Duan et al., 2018; Liu, Fu, et al., 2020; Liu et al., 2010, 2019; Liu, Liu, et al., 2020; McKay et al., 2019; Pasquali et al., 2020; Qu et al., 2008; Yan et al., 2020; Yin et al., 2009). In China, FHB is common in regions with mild climate and high humidity such as several major river basins (Hao et al., 2017; Liu, Fu, et al., 2020; Liu et al., 2019; Liu, Liu, et al., 2020).…”

“…in the susceptible grains, which may cause human and animals poisoning (Duan et al., 2018; Liu, Fu, et al., 2020; Liu et al., 2010, 2019; Liu, Liu, et al., 2020; McKay et al., 2019; Pasquali et al., 2020; Qu et al., 2008; Yan et al., 2020; Yin et al., 2009). In China, FHB is common in regions with mild climate and high humidity such as several major river basins (Hao et al., 2017; Liu, Fu, et al., 2020; Liu et al., 2019; Liu, Liu, et al., 2020). Henan Province, which straddles Yellow River Basin and Huai River Basin, is one of six major wheat‐producing areas in China, with wheat production accounting for more than a quarter of the whole national yield.…”

“…However, considering the shortage of high resistance varieties and the limitations of biological control, the chemical control has been the most popular strategy to avoid the occurrence of FHB for a long time. At present, growers usually spraying benzimidazole fungicides (carbendazim and thiophanate‐methyl), cyanoacrylate fungicide (phenamacril), succinate dehydrogenase inhibitor (SDHI) fungicide (pydiflumetofen) and sterol demethylation inhibitor (DMI) fungicides (tebuconazole and metconazole) against FHB in the flowering stage of wheat in China (Duan et al., 2018; Liu, Fu, et al., 2020; Liu, Liu, et al., 2020; Sun et al., 2020; Zhou & Wang, 2001). Since 1970, benzimidazole fungicides, particularly carbendazim, were used to control FHB, but F. graminearum strains resistant to carbendazim was found in the field in 1992 due to long‐term use (Liu et al., 2019; Zhou & Wang, 2001).…”