Fusarium head blight resistance exacerbates nutritional loss of wheat grain at elevated CO2

The nutritional integrity of wheat is jeopardized by rapidly rising atmospheric carbon dioxide (CO2) and the associated emergence and enhanced virulence of plant pathogens. To evaluate how disease resistance traits may impact wheat climate resilience, 15 wheat cultivars with varying levels of resistance to Fusarium Head Blight (FHB) were grown at ambient and elevated CO2. Although all wheat cultivars had increased yield when grown at elevated CO2, the nutritional contents of FHB moderately resistant (MR) cultivars were impacted more than susceptible cultivars. At elevated CO2, the MR cultivars had more significant differences in plant growth, grain protein, starch, fructan, and macro and micro-nutrient content compared with susceptible wheat. Furthermore, changes in protein, starch, phosphorus, and magnesium content were correlated with the cultivar FHB resistance rating, with more FHB resistant cultivars having greater changes in nutrient content. This is the first report of a correlation between the degree of plant pathogen resistance and grain nutritional content loss in response to elevated CO2. Our results demonstrate the importance of identifying wheat cultivars that can maintain nutritional integrity and FHB resistance in future atmospheric CO2 conditions.

Pydiflumetofen Co-Formulated with Prothioconazole: A Novel Fungicide for Fusarium Head Blight and Deoxynivalenol Control

Fusarium head blight (FHB) is an important disease of small grain cereals worldwide, resulting in reduced yield and quality as well as the contamination of harvested grains with mycotoxins. The key mycotoxin of concern is deoxynivalenol (DON), which has legislative and advisory limits in numerous countries. Cereal growers have a number of control options for FHB including rotation, cultivation, and varietal resistance; however, growers are still reliant on fungicides applied at flowering as part of an IPM program. Fungicides currently available to control FHB are largely restricted to triazole chemistry. This study conducted three field experiments to compare a new co-formulation of pydiflumetofen (a succinate dehydrogenase inhibitor (SDHI) with the tradename ADEPIDYN™) and prothioconazole (a triazole) against current standard fungicides at various timings (flag leaf fully emerged, mid-head emergence, early flowering, and late flowering) for the control of FHB and DON. Overall, the co-formulation showed greater efficacy compared to either pydiflumetofen alone or current fungicide chemistry. This greater activity was demonstrated over a wide range of spray timings (flag leaf fully emerged to late flowering). The availability of an SDHI with good activity against FHB and the resulting DON contamination of harvested grain will give growers an additional tool within an IPM program that will provide a greater flexibility of spray application windows and reduce fungicide resistance selection pressure.

tRNA-derived fragments from wheat are potentially involved in susceptibility to Fusarium head blight

Background Fusarium head blight (FHB) caused by Fusarium graminearum is a devastating fungal disease of wheat. The mechanism underlying F. graminearum-wheat interaction remains largely unknown. tRNA-derived fragments (tRFs) are RNase-dependent small RNAs derived from tRNAs, and they have not been reported in wheat yet, and whether tRFs are involved in wheat-F. graminearum interactions remains unknown. Results Herein, small RNAs from the spikelets inoculated with F. graminearum and mock from an FHB-susceptible variety Chinese Spring (CS) and an FHB-resistant variety Sumai3 (SM) were sequenced respectively. A total of 1249 putative tRFs were identified, in which 15 tRFs was CS-specific and 12 SM-specific. Compared with mock inoculation, 39 tRFs were significantly up-regulated across both wheat varieties after F. graminearum challenge and only nine tRFs were significantly down-regulated. tRFGlu, tRFLys and tRFThr were dramatically induced by F. graminearum infection, with significantly higher fold changes in CS than those in SM. The expression patterns of the three highly induced tRFs were further validated by stem-loop qRT-PCR. The accumulation of tRFs were closely related to ribonucleases T2 family members, which were induced by F. graminearum challenge. The tRFs’ targets in host were predicted and were validated by RNA sequencing. Conclusion Integrative analysis of the differentially expressed tRFs and their candidate targets indicated that tRFGlu, tRFLys and tRFThr might negatively regulate wheat resistance to FHB. Our results unvealed the potential roles of tRFs in wheat-F. graminearum interactions.

Identification and Chemotype Profiling of Fusarium Head Blight Disease in Triticale

This study aimed to assess the disease incidence and distribution of toxigenic in Korean triticale. The pathogen of triticale that cause Fusarium head blight were isolated from five different triticale cultivars that cultivated in Suwon Korea at 2021 year. The 72 candidate were classified as a Fusarium asiaticum by morphology analysis and by ITS1, TEF-1α gene sequence analysis. And the results of pathogenicity with 72 isolates on seedling triticale, 71 isolates were showed disease symptom. Also, seven out of 71 Fusarium isolates were inoculated on the wheat, to test the pathogenicity on the different host. The results showed more low pathogenicity on the wheat than triticale. The results of analysis of toxin type with 72 isolates, 64.6% isolates were produced nivalenol type toxin and other 4.6% and 30.8% isolates were produce 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol, respectively. To select fungicide for control, the 72 Fusarium isolates were cultivated on the media that containing four kinds fungicide. The captan, hexaconazole, and difenoconazole·propiconazole treated Fusarium isolates were not showed resistance response against each fungicide. However, six isolates out of 72 isolates, showed resistance response to fludioxonil. This study is first report that F. asiaticum causes Fusarium head blight disease of triticale in Korea.

Combination of yeast antagonists and Acibenzolar-S-Methyl reduced the severity of Fusarium head blight of wheat incited by Fusarium graminearum sensu stricto

The combination of yeast antagonists and Acibenzolar-S-Methyl (ASM) was tested against Fusarium graminearum on a spring wheat cultivar PAN3471. Two strains of Papiliotrema flavescens (Strains WL3 and WL6) and a strain of Pseudozyma sp. (MGO1) were combined with full strength ASM at anthesis, half strength ASM at anthesis and quarter strength ASM at late boot stages. The yeast and ASM treatments were applied prior to F. graminearum inoculation and disease progress was assessed over time. The combination of yeast and ASM treatments effectively reduced Fusarium Head Blight (FHB) severity and deoxynivalenol (DON) concentration compared to when the treatments were used alone. A positive correlation was observed between the Area Under Disease Progress Curve (AUDPC) and Percentage Seed Infection (PSI) (r = 0.44) whereas a negative correlation was observed between AUDPC and Hundred Seed Weight (HSW) (r = -0.77) and PSI and HSW (r = -0.44). The best combination treatment providing the highest reduction in final disease severity (41.83%), high HSW and moderate PSI was 0.075 g/l ASM at anthesis plus P. flavescens strain WL3. The highest DON reduction (19.35%) was by the treatment 0.075 g/l ASM at anthesis plus P. flavescens strain WL6. The best treatment was P. flavescens combined with 0.075 g/l ASM at anthesis. Although Pseudozyma sp. strain MGO1 did not provide the best FHB and DON reduction, its combination with ASM application improved disease control efficacy. To the best of our knowledge, this study presents the first report of the combination of P. flavescens and ASM in the management of FHB caused by F. graminearum in wheat plants.

AAC Awesome special purpose spring wheat

AAC Awesome is a high yielding spring wheat (Triticum aestivum L.) cultivar eligible for the Canada Western Special Purpose (CWSP) wheat class. Based on 29 site-years of testing over 3 years in the General Purpose Wheat Registration trial (2013–2015), AAC Awesome yielded 14% more grain than AC Andrew, and surpassed yields of Sadash, 5702PR, and Pasteur by 12%, 22%, and 9%, respectively. AAC Awesome had similar maturity, was slightly taller, had higher test weight and larger kernels as compared to AC Andrew. AAC Awesome had excellent levels of resistance to the prevalent races of leaf, stem and stripe rust. It expressed an intermediate level of resistance to Fusarium head blight (FHB), common bunt and loose smut. It also expressed tolerance to the orange wheat blossom midge. AAC Awesome is eligible for grades of Canada Western Special Purpose Wheat class.

GPTransformer: A Transformer-Based Deep Learning Method for Predicting Fusarium Related Traits in Barley

Fusarium head blight (FHB) incited by Fusarium graminearum Schwabe is a devastating disease of barley and other cereal crops worldwide. Fusarium head blight is associated with trichothecene mycotoxins such as deoxynivalenol (DON), which contaminates grains, making them unfit for malting or animal feed industries. While genetically resistant cultivars offer the best economic and environmentally responsible means to mitigate disease, parent lines with adequate resistance are limited in barley. Resistance breeding based upon quantitative genetic gains has been slow to date, due to intensive labor requirements of disease nurseries. The production of a high-throughput genome-wide molecular marker assembly for barley permits use in development of genomic prediction models for traits of economic importance to this crop. A diverse panel consisting of 400 two-row spring barley lines was assembled to focus on Canadian barley breeding programs. The panel was evaluated for FHB and DON content in three environments and over 2 years. Moreover, it was genotyped using an Illumina Infinium High-Throughput Screening (HTS) iSelect custom beadchip array of single nucleotide polymorphic molecular markers (50 K SNP), where over 23 K molecular markers were polymorphic. Genomic prediction has been demonstrated to successfully reduce FHB and DON content in cereals using various statistical models. Herein, we have studied an alternative method based on machine learning and compare it with a statistical approach. The bi-allelic SNPs represented pairs of alleles and were encoded in two ways: as categorical (–1, 0, 1) or using Hardy-Weinberg probability frequencies. This was followed by selecting essential genomic markers for phenotype prediction. Subsequently, a Transformer-based deep learning algorithm was applied to predict FHB and DON. Apart from the Transformer method, a Residual Fully Connected Neural Network (RFCNN) was also applied. Pearson correlation coefficients were calculated to compare true vs. predicted outputs. Models which included all markers generally showed marginal improvement in prediction. Hardy-Weinberg encoding generally improved correlation for FHB (6.9%) and DON (9.6%) for the Transformer network. This study suggests the potential of the Transformer based method as an alternative to the popular BLUP model for genomic prediction of complex traits such as FHB or DON, having performed equally or better than existing machine learning and statistical methods.