Spike culture derived wheat (Triticum aestivum L.) variants exhibit improved resistance to multiple chemotypes of Fusarium graminearum

Abstract

Fusarium head blight (FHB) in wheat (Triticum aestivum L.), predominantly caused by Fusarium graminearum, has been categorized into three chemotypes depending on the major mycotoxin produced. The three mycotoxins, namely, 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON) and nivalenol (NIV) also determine their aggressiveness and response to fungicides. Furthermore, prevalence of these chemotypes changes over time and dynamic changes in chemotypes population in the field have been observed. The objective of this study was to identify spike culture derived variants (SCDV) exhibiting resistance to multiple chemotypes of F. graminearum. First, the optimal volume of inoculum for point inoculation of the spikelets was determined using the susceptible AC Nanda wheat genotype. Fifteen μL of 105 macroconidia/mL was deemed optimal based on FHB disease severity assessment with four chemotypes. Following optimal inoculum volume determination, five chemotypes (Carman-NIV, Carman-705-2-3-ADON, M9-07-1-3-ADON, M1-07-2-15-ADON and China-Fg809-15-ADON) were used to point inoculate AC Nanda spikelets to confirm the mycotoxin produced and FHB severity during infection. Upon confirmation of the mycotoxins produced by the chemotypes, 55 SCDV were utilized to evaluate FHB severity and mycotoxin concentrations. Of the 55 SCDV, five (213.4, 244.1, 245.6, 250.2 and 252.3) resistant lines were identified with resistance to multiple chemotypes and are currently being utilized in a breeding program to develop wheat varieties with improved FHB resistance.

Antifungal activity of epecific plant essential oils against fusarium graminearum

“…These agents prevent the natural compounds from binding their natural targets and inhibit biochemical processes. These important processes are composed of nucleic acid metabolism, cytoskeleton, respiration, signal transduction and sterol biosynthesis [9][10][11][12][13]. Currently, the high use of these fungicides, the increased use of aromatic hydrocarbons, and use in common of various fungicides worldwide, led to an increase in the levels of fungicide resistance in fungus [14][15][16].…”

In Vitro Wheat Immature Spike Culture Screening Identified Fusarium Head Blight Resistance in Wheat Spike Cultured Derived Variants and in the Progeny of Their Crosses with an Elite Cultivar

“…Briefly, M 3 seeds from each of the selected 53 SCDV lines were grown in the greenhouse (University of Saskatchewan, Saskatoon, SK, Canada) during May to July 2015. At the onset of heading at least 20 immature spikes were collected for each of the SCDV lines, grown on spike culture media, and point-inoculated with a moderately virulent 3-ADON chemotype (M7-07-1) of F. graminearum (Huang et al, 2019). The remaining non-inoculated spikes were allowed to grow to maturity to obtain the M 4 seeds.…”

“…Three spikes were cut at heading stage from each of 191 wheat plants. After four days of culture in spike culture media (Ganeshan et al, 2010(Ganeshan et al, , 2012, the wheat spikes were inoculated with Fusarium graminearum 3-ADON strain M7-07-1 as described (Huang et al, 2019). Briefly, after inoculation, the plants were covered with clear plastic bags and placed in a Sanyo MIR-351H incubator (Sanyo Canada, Inc., Concord, ON, Canada) at 16-h day and 8-h night cycle, temperatures 24°C (night) and 26°C (day).…”

“…After 2.5 days of incubation, the bags were removed, and at 8 DAI, disease severity assessed. In our previous studies (Huang et al, 2019(Huang et al, , 2020 we determined that disease severity at 9 DAI was more informative and was therefore used for disease severity recording.…”

“…Fusarium infection of wheat also leads to accumulation of the trichothecene group of mycotoxins such as deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), and nivalenol (Huang et al, 2019;Kurata and Ueno, 1984;Marasas et al, 1984). Based on the different types of major mycotoxins produced, Fusarium graminearum strains have been recognized as chemotypes (reviewed in Desjardins, 2006).…”