Basal Rachis Internode Injection (BRII): A novel inoculation method to evaluate wheat resistance to Fusarium head blight

2021 ◽  
Author(s):  
Yuhui Zhang ◽  
Aiai Li ◽  
Suqin Zhu ◽  
Lei Li ◽  
Xinyao He ◽  
...  

Fusarium head blight (FHB) is one of the most destructive fungal diseases of wheat. Difficulties in reliably phenotyping of this disease, however, greatly hindered the understanding of the mechanism of wheat-pathogen interaction and genetic improvement of FHB resistance. Here we report a novel inoculation method called “Basal Rachis Internode Injection” (BRII), which is implemented by injecting inoculum into the basal internode of a rachis instead of a floret as done in single floret inoculation (SFI). One of the prominent advantages of BRII over SFI and other traditional methods lies in its independence of moisture-maintaining system that is required for all existing methods, thus being insensitive to environmental humidity and cost-effective. Another unique feature for BRII is that this method produces nearly clear-cut reaction types, by which FHB resistance could be treated as a qualitative trait because generally no FHB symptom appeared on the spikelets of resistant genotypes. In addition, BRII outperformed SFI by higher infection rate and better goodness-of-fit with known FHB resistance and QTL components in a panel of 15 genotypes, as well as two populations of recombinant inbred lines (RILs) segregating in Fhb1. To be noteworthy, BRII and SFI methods are not mutually replaceable but rather complimentary to each other since each method has its own advantage in differentiating FHB resistance among genotypes. Combining these two methods would significantly improve the reliability and consistency of FHB phenotyping in wheat.

2009 ◽  
Vol 44 (No. 4) ◽  
pp. 147-159 ◽  
Author(s):  
Srinivasachary ◽  
N. Gosman ◽  
A. Steed ◽  
S. Faure ◽  
R. Bayles ◽  
...  

Fusarium head blight (FHB) is a destructive disease of wheat worldwide. We aimed to map QTL for FHB resistance in RL4137, a FHB resistant line derived from Frontana using 90 recombinant inbred lines (RIL) from a cross between RL4137 and the moderately FHB resistant variety Timgalen. A total of seven putative FHB resistance QTL (1B, 2B, 3A, 6A, 6B, 7A and 7D) were identified and in all but one instance, the alleles from RL4137 had a positive effect on FHB resistance. The QTL, Qfhs.jic-2band Qfhs.jic-6b contributed by the alleles from RL4137 and Timgalen, respectively were detected in multiple trials. Our study also identified three QTL for plant height (2B, 4A and 5B), two QTL for weight of infected spikelets from infected ears (2B and 6A) and one QTL for “awns” (2B). The QTL mapped on 2B for PH, WIS and awns co-localized with Qfhs.jic-2b. The FHB QTL on 1B and 6B were not associated with PH QTL and that the minor PH QTL on 4A and 5B, did not co-localise with any other FHB resistance QTL.


2020 ◽  
Vol 11 ◽  
Author(s):  
Yuefeng Ruan ◽  
Wentao Zhang ◽  
Ron E. Knox ◽  
Samia Berraies ◽  
Heather L. Campbell ◽  
...  

Durum wheat is an economically important crop for Canadian farmers. Fusarium head blight (FHB) is one of the most destructive diseases that threatens durum production in Canada. FHB reduces yield and end-use quality and most commonly contaminates the grain with the fungal mycotoxin deoxynivalenol, also known as DON. Serious outbreaks of FHB can occur in durum wheat in Canada, and combining genetic resistance with fungicide application is a cost effective approach to control this disease. However, there is limited variation for genetic resistance to FHB in elite Canadian durum cultivars. To explore and identify useful genetic FHB resistance variation for the improvement of Canadian durum wheat, we assembled an association mapping (AM) panel of diverse durum germplasms and performed genome wide association analysis (GWAS). Thirty-one quantitative trait loci (QTL) across all 14 chromosomes were significantly associated with FHB resistance. On 3BS, a stable QTL with a larger effect for resistance was located close to the centromere of 3BS. Three haplotypes of Fhb1 QTL were identified, with an emmer wheat haplotype contributing to disease susceptibility. The large number of QTL identified here can provide a rich resource to improve FHB resistance in commercially grown durum wheat. Among the 31 QTL most were associated with plant height and/or flower time. QTL 1A.1, 1A.2, 3B.2, 5A.1, 6A.1, 7A.3 were associated with FHB resistance and not associated or only weakly associated with flowering time nor plant height. These QTL have features that would make them good targets for FHB resistance breeding.


2007 ◽  
Vol 97 (5) ◽  
pp. 592-597 ◽  
Author(s):  
S. Kumar ◽  
R. W. Stack ◽  
T. L. Friesen ◽  
J. D. Faris

Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most destructive diseases of durum (Triticum turgidum sp. durum) and common wheat (T. aestivum). Promising sources of FHB resistance have been identified among common (hexaploid) wheats, but the same is not true for durum (tetraploid) wheats. A previous study indicated that chromosome 7A from T. turgidum sp. dicoccoides accession PI478742 contributed significant levels of resistance to FHB. The objectives of this research were to develop a genetic linkage map of chromosome 7A in a population of 118 recombinant inbred lines derived from a cross between the durum cv. Langdon (LDN) and a disomic LDN-T. turgidum sp. dicoccoides PI478742 chromosome 7A substitution line [LDN-DIC 7A(742)], and identify a putative FHB resistance quantitative trait locus (QTL) on chromosome 7A derived from LDN-DIC 7A(742). The population was evaluated for type II FHB resistance in three greenhouse environments. Interval regression analysis indicated that a single QTL designated Qfhs.fcu-7AL explained 19% of the phenotypic variation and spanned an interval of 39.6 cM. Comparisons between the genetic map and a previously constructed physical map of chromosome 7A indicated that Qfhs.fcu-7AL is located in the proximal region of the long arm. This is only the second FHB QTL to be identified in a tetraploid source, and it may be useful to combine it with the QTL Qfhs.ndsu-3AS in order to develop durum wheat germ plasm and cultivars with higher levels of FHB resistance.


Author(s):  
Hussein M. Khaeim ◽  
Anthony Clark ◽  
Tom Pearson ◽  
Dr. David Van Sanford

Head scab is historically a devastating disease affecting not just all classes of wheat but also barley and other small grains around the world. Fusarium head blight (FHB), or head scab, is caused most often by Fusarium graminearum (Schwabe), (sexual stage – Gibberella zeae) although several Fusarium spp. can cause the disease. This study was conducted to determine the effect of mass selection for FHB resistance using an image-based optical sorter. lines were derived from the C0 and C2 of two populations to compare genetic variation within populations with and without sorter selection. Our overall hypothesis is that sorting grain results in improved Fusarium head blight resistance. Both of the used wheat derived line populations have genetic variation, and population 1 has more than population 17. They are significantly different from each other for fusarium damged kernel (FDK), deoxynivalenol (DON), and other FHB traits. Although both populations are suitable to be grown for bulks, population 1 seems better since it has more genetic variation as well as lower FDK and DON, and earlier heading date. Lines within each population were significantly different and some lines in each population had significantly lower FDK and DON after selection using an optical sorter. Some lines had significant reduction in both FDK and DON, and some others had either FDK or DON reduction. Lines of population 1 that had significant reduction, were more numerous than in population 17, and FDK and DON reduction were greater.


Plant Disease ◽  
2021 ◽  
Author(s):  
Bhavit Chhabra ◽  
Lovepreet Singh ◽  
Sydney Wallace ◽  
Adam Schoen ◽  
Yanhong Dong ◽  
...  

Fusarium head blight (FHB) primarily caused by Fusarium graminearum is a key disease of small grains. Diseased spikes show symptoms of premature bleaching shortly after infection and have aborted or shriveled seeds, resulting in reduced yields. The fungus also deteriorates quality and safety of the grain due to production of mycotoxins, especially deoxynivalenol (DON), which can result in grain being docked or rejected at the point of sale. Genetic host resistance to FHB is quantitative and no complete genetic resistance against this devastating disease is available. Alternative approaches to develop new sources of FHB resistance are needed. In this study, we performed extensive forward genetic screening of the M4 generation of an EMS induced mutagenized population of cultivar Jagger to isolate variants with FHB resistance. In field testing, 74 mutant lines were found to have resistance against FHB spread and 30 lines out of these also had low DON content. Subsequent testing over two years in controlled greenhouse conditions revealed ten M6 lines showing significantly lower FHB spread. Seven and six lines out of those 10 lines also had reduced DON content and lower FDKs, respectively. Future endeavors will include identification of the mutations that led to resistance in these variants.


2021 ◽  
Author(s):  
Xianrui Guo ◽  
Qinghua Shi ◽  
Jing Yuan ◽  
Mian Wang ◽  
Jing Wang ◽  
...  

AbstractFusarium head blight (FHB), caused by Fusarium species, seriously threaten global wheat production. Three wheat-Th.elongatum FHB resistant translocation lines have been developed and used for breeding. Transcriptomic analysis identified a derivative glutathione S-transferase transcript T26102, which was homologous to Fhb7 and induced dramatically by Fusarium graminearum. Homologs of Fhb7 were detected in several genera in Triticeae, including Thinopyrum, Elymus, Leymus, Pseudoroegeria and Roegeria. Several wheat-Thinopyrum translocation lines carrying Fhb7 remain susceptible to FHB, and transgenic plants overexpressing the T26102 on different backgrounds did not improve the FHB resistance. Taken as a whole, we show the application of the chromatin derived from diploid Thinopyrum elongatum successfully conferring wheat with high level FHB resistance independent of the Fhb7.One Sentence SummaryThinopyrum elongatum chromatin from 7EL was successfully applied to wheat FHB resistance breeding, but the resistant gene other than the reported Fhb7 remained unknown.


2021 ◽  
Author(s):  
Yunzhe Zhao ◽  
Xinying Zhao ◽  
Mengqi Ji ◽  
Wenqi Fang ◽  
Hong Guo ◽  
...  

Abstract Background: Fusarium head blight (FHB) is a disease affecting wheat spikes caused by Fusarium species, which leads to cases of severe yield reduction and seed contamination. Therefore, identifying resistance genes from various sources is always of importance to wheat breeders. In this study, a genome-wide association study (GWAS) focusing on FHB using a high-density genetic map constructed with 90K single nucleotide polymorphism (SNP) arrays in a panel of 205 elite winter wheat accessions, was conducted in 3 environments. Results: Sixty-six significant marker–trait associations (MTAs) were identified (P<0.001) on fifteen chromosomes explaining 5.4–11.2% of the phenotypic variation therein. Some important new genomic regions involving FHB resistance were found on chromosomes 2A, 3B, 5B, 6A, and 7B. On chromosome 7B, 6 MTAs at 92 genetic positions were found in 2 environments. Moreover, there were 11 MTAs consistently associated with diseased spikelet rate and diseased rachis rate as pleiotropic effect loci. Eight new candidate genes of FHB resistance were predicated in wheat. Of which, three genes: TraesCS5D01G006700, TraesCS6A02G013600, and TraesCS7B02G370700 on chromosome 5DS, 6AS, and 7BL, respectively, were important in defending against FHB by regulating chitinase activity, calcium ion binding, intramolecular transferase activity, and UDP-glycosyltransferase activity in wheat. In addition, a total of six excellent alleles associated with wheat scab resistance were discovered. Conclusion: These results provide important genes/loci for enhancing FHB resistance in wheat breeding populations by marker-assisted selection.


2020 ◽  
Vol 8 (7) ◽  
pp. 1036 ◽  
Author(s):  
Akos Mesterhazy ◽  
Andrea Gyorgy ◽  
Monika Varga ◽  
Beata Toth

In resistance tests to Fusarium head blight (FHB), the mixing of inocula before inoculation is normal, but no information about the background of mixing was given. Therefore, four experiments (2013–2015) were made with four independent isolates, their all-possible (11) mixtures and a control. Four cultivars with differing FHB resistance were used. Disease index (DI), Fusarium damaged kernels (FDK) and deoxynivalenol (DON) were evaluated. The isolates used were not stable in aggressiveness. Their mixtures did not also give a stable aggressiveness; it depended on the composition of mix. The three traits diverged in their responses. After the mixing, the aggressiveness was always less than that of the most pathogenic component was. However, in most cases it was significantly higher than the arithmetical mean of the participating isolates. A mixture was not better than a single isolate was. The prediction of the aggressiveness level is problematic even if the aggressiveness of the components was tested. Resistance expression is different in the mixing variants and in the three traits tested. Of them, DON is the most sensitive. More reliable resistance and toxin data can be received when instead of one more independent isolates are used. This is important when highly correct data are needed (genetic research or cultivar registration).


Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 58 ◽  
Author(s):  
Moustafa Eldakak ◽  
Aayudh Das ◽  
Yongbin Zhuang ◽  
Jai Rohila ◽  
Karl Glover ◽  
...  

Fusarium head blight (FHB) is a highly detrimental disease of wheat. A quantitative trait locus for FHB resistance, Qfhb1, is the most utilized source of resistance in wheat-breeding programs, but very little is known about its resistance mechanism. In this study, we elucidated a prospective FHB resistance mechanism by investigating the proteomic signatures of Qfhb1 in a pair of contrasting wheat near-isogenic lines (NIL) after 24 h of inoculation of wheat florets by Fusarium graminearum. Statistical comparisons of the abundances of protein spots on the 2D-DIGE gels of contrasting NILs (fhb1+ NIL = Qfhb1 present; fhb1- NIL = Qfhb1 absent) enabled us to select 80 high-ranking differentially accumulated protein (DAP) spots. An additional evaluation confirmed that the DAP spots were specific to the spikelet from fhb1- NIL (50 spots), and fhb1+ NIL (seven spots). The proteomic data also suggest that the absence of Qfhb1 makes the fhb1- NIL vulnerable to Fusarium attack by constitutively impairing several mechanisms including sucrose homeostasis by enhancing starch synthesis from sucrose. In the absence of Qfhb1, Fusarium inoculations severely damaged photosynthetic machinery; altered the metabolism of carbohydrates, nitrogen and phenylpropanoids; disrupted the balance of proton gradients across relevant membranes; disturbed the homeostasis of many important signaling molecules induced the mobility of cellular repair; and reduced translational activities. These changes in the fhb1- NIL led to strong defense responses centered on the hypersensitive response (HSR), resulting in infected cells suicide and the consequent initiation of FHB development. Therefore, the results of this study suggest that Qfhb1 largely functions to either alleviate HSR or to manipulate the host cells to not respond to Fusarium infection.


Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 167-174 ◽  
Author(s):  
B. D. McCallum ◽  
A. Tekauz ◽  
J. Gilbert

Fusarium head blight (FHB) is currently the primary disease of concern in barley in Canada and sources of FHB resistance need to be identified. A diverse collection of 77 two-rowed and 81 six-rowed barley lines was screened for resistance to FHB in inoculated, irrigated nurseries from 1995 to 1998. Barley spikes were spray inoculated with conidia of Fusarium graminearum and visual symptoms of FHB were scored to determine an FHB index. Deoxynivalenol (DON) content was determined from harvested seed samples during 1997 and 1998. Although there was variation in the average FHB index and DON content among the different years of testing, the rankings of the lines generally were correlated among the years of testing and the two measures of FHB. Based on the FHB index from 1995 and 1996, a subset of 18 lines with low FHB and 12 lines with high FHB were compared with 20 FHB resistance sources and 7 Canadian lines or cultivars during 1997 and 1998 in both inoculated and noninoculated nurseries. Lines Nepolegajuscij, Krasnojarskij, Nordic, Murakaki-mochi, Golozernyj 1, Maris Mink, Symko, Ussurijskij 8, Suvenir, and Canadian cultivars AC Sterling and Morrison were similar to the best resistance sources (Zhedar1, Seijo II, and Chevron) and had consistently low DON content.


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