scholarly journals Behavior of Spanish durum wheat genotypes against Zymoseptoria tritici: resistance and susceptibility

2021 ◽  
Vol 19 (3) ◽  
pp. e1002-e1002
Author(s):  
Rafael Porras ◽  

Aim of study: Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is one of the most important wheat diseases worldwide, affecting both bread and durum wheat. The lack of knowledge about the interaction of durum wheat with Z. tritici, together with limited resources of resistant durum wheat material, have both led to a rising threat for durum wheat cultivation, particularly in the Mediterranean Basin. In Spain, STB has increased its incidence in the last few years, leading to higher costs of fungicide applications to control the disease. Therefore, identification of new sources of resistance through wheat breeding stands out as an efficient method of facing STB. Area of study: The experimental study was conducted in growth chambers at the IFAPA facilities in Córdoba (Spain). Material and methods: The percentage of necrotic leaf area, the disease severity, and the pycnidium development through image analysis were evaluated from 48 durum wheat Spanish accessions (breeding lines and commercial cultivars) in growth chambers against an isolate of Z. tritici from Córdoba. Main results: Two breeding lines and six commercial cultivars showed resistant responses by limiting STB development through the leaf or its reproduction ability, while the other 40 accessions presented a susceptible response. Research highlights: Provided these resources of resistance in Spanish durum wheat genotypes, future breeding programs could be developed, incorporating both agronomic traits and resistance to STB.

2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa M. Sri ◽  
...  

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.


Author(s):  
VALERIA Scala ◽  
Chiara Pietricola ◽  
valentina farina ◽  
marzia beccaccioli ◽  
slaven zjalic ◽  
...  

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce global yearly yield of wheat by up to 50%. In the last decade in Italy, SLBC incidence has increased; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health, and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g. mycotoxins). Specifically, we identified Tramesan: a 23 KDa -heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spraying of Tramesan (3.3 µM) in SLBC-susceptible varieties of durum significantly diminished symptoms of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB) by 75% and 65%, respectively. Tests were conducted under controlled conditions as well as in field. We show that Tramesan elicits wheat defence against SNB and STB augmenting the synthesis of defence-related hormones, notably JA and SA, that in turn switch on the expression of markers of defence (PR1, PR4 inter alia). In field experiments, yield of durum wheat plants treated with Tramesan was similar to that of untreated ones. The results suggest the use of Tramesan for protecting durum wheat against SLBC.


Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Adnan Riaz ◽  
Petra KockAppelgren ◽  
James Gerard Hehir ◽  
Jie Kang ◽  
Fergus Meade ◽  
...  

Zymoseptoria tritici is the causative fungal pathogen of septoria tritici blotch (STB) disease of wheat (Triticum aestivum L.) that continuously threatens wheat crops in Ireland and throughout Europe. Under favorable conditions, STB can cause up to 50% yield losses if left untreated. STB is commonly controlled with fungicides; however, a combination of Z. tritici populations developing fungicide resistance and increased restrictions on fungicide use in the EU has led to farmers relying on fewer active substances. Consequently, this serves to drive the emergence of Z. tritici resistance against the remaining chemistries. In response, the use of resistant wheat varieties provides a more sustainable disease management strategy. However, the number of varieties offering an adequate level of resistance against STB is limited. Therefore, new sources of resistance or improved stacking of existing resistance loci are needed to develop varieties with superior agronomic performance. Here, we identified quantitative trait loci (QTL) for STB resistance in the eight-founder “NIAB Elite MAGIC” winter wheat population. The population was screened for STB response in the field under natural infection for three seasons from 2016 to 2018. Twenty-five QTL associated with STB resistance were identified in total. QTL either co-located with previously reported QTL or represent new loci underpinning STB resistance. The genomic regions identified and the linked genetic markers serve as useful resources for STB resistance breeding, supporting rapid selection of favorable alleles for the breeding of new wheat cultivars with improved STB resistance.


Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 608 ◽  
Author(s):  
Valeria Scala ◽  
Chiara Pietricola ◽  
Valentina Farina ◽  
Marzia Beccaccioli ◽  
Slaven Zjalic ◽  
...  

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce wheat global yearly yield by up to 50%. In the last decade, SLBC incidence has increased in Italy; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g., mycotoxins). Specifically, we identified Tramesan: a 23 kDa α-heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spray of Tramesan (3.3 μM) on SLBC-susceptible durum wheat cultivars, before inoculation of causal agents of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB), significantly decreased disease incidence both in controlled conditions (SNB: −99%, STB: −75%) and field assays (SNB: −25%, STB: −30%). We conducted these tests were conducted under controlled conditions as well as in field. We showed that Tramesan increased the levels of jasmonic acid (JA), a plant defense-related hormone. Tramesan also increased the early expression (24 hours after inoculation—hai) of plant defense genes such as PR4 for SNB infected plants, and RBOH, PR1, and PR9 for STB infected plants. These results suggest that Tramesan protects wheat by eliciting plant defenses, since it has no direct fungicidal activity. In field experiments, the yield of durum wheat plants treated with Tramesan was similar to that of healthy untreated plots. These results encourage the use of Tramesan to protect durum wheat against SLBC.


2020 ◽  
Vol 71 (7) ◽  
pp. 645
Author(s):  
Mojgan Mahboubi ◽  
Reza Talebi ◽  
Mostafa Aghaee Sarbarzeh ◽  
Amir Mohammad Naji ◽  
Rahim Mehrabi

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, is an important disease of wheat worldwide. This study was performed to investigate the efficacy of Stb genes against 10 isolates of Z. tritici and to elucidate the resistance response pattern of 185 wheat genotypes to STB. The 10 isolates showed different virulence patterns on the Stb differentials. Effectiveness determination showed that most Stb genes (particularly Stb1–Stb9) were ineffective against the 10 isolates, whereas Kavkaz-K4500 (possessing Stb10, Stb12), Arina and Riband (possessing Stb15), and M3 (possessing Stb16 and Stb17) were resistant to all isolates tested. Of the 185 wheat genotypes, 72% were susceptible to all isolates, indicating that these genotypes lacked any effective resistance genes at the seedling stage against the isolates used. The remaining 51 genotypes showed specific resistance to one or more isolates, suggesting that they contain at least one effective resistance gene. Six genotypes were resistant to all isolates, indicating that they may possess broad-spectrum resistance gene(s) or a combination of diverse uncharacterised Stb genes that could be effectively used in breeding programs.


2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa . Sripa ◽  
...  

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.


2017 ◽  
Author(s):  
Graeme J. Kettles ◽  
Carlos Bayon ◽  
Caroline A. Sparks ◽  
Gail Canning ◽  
Kostya Kanyuka ◽  
...  

Abstract-The fungus Zymoseptoria tritici is the causal agent of Septoria Tritici Blotch (STB) disease of wheat leaves. Z. tritici secretes many functionally uncharacterised effector proteins during infection. Here we characterised a secreted ribonuclease (Zt6) with an unusual biphasic expression pattern.-Transient expression systems were used to characterise Zt6, and mutants thereof, in both host and non-host plants. Cell-free protein expression systems monitored impact of Zt6 protein on functional ribosomes, and in vitro assays of cells treated with recombinant Zt6 determined toxicity against bacteria, yeasts and filamentous fungi.-We demonstrated that Zt6 is a functional ribonuclease and that phytotoxicity is dependent on both the presence of a 22-amino acid N-terminal “loop” region and its catalytic activity. Zt6 selectively cleaves both plant and animal rRNA species, and is toxic to wheat, tobacco, bacterial and yeast cells but not to Z. tritici itself.-Zt6 is the first Z. tritici effector demonstrated to have a likely dual functionality. The expression pattern of Zt6 and potent toxicity towards microorganisms suggests that whilst it may contribute to the execution of wheat cell death, it is also likely to have an important secondary function in antimicrobial competition and niche protection.


2019 ◽  
Vol 58 (1) ◽  
pp. 27-33
Author(s):  
S. Kildea ◽  
D.E. Bucar ◽  
F. Hutton ◽  
S. de la Rosa ◽  
T.E. Welch ◽  
...  

Abstract The emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain.


Author(s):  
Tony Twamley ◽  
Mark Gaffney ◽  
Angela Feechan

AbstractFusarium graminearum and Zymoseptoria tritici cause economically important diseases of wheat. F. graminearum is one of the primary causal agents of Fusarium head blight (FHB) and Z. tritici is the causal agent of Septoria tritici blotch (STB). Alternative control methods are required in the face of fungicide resistance and EU legislation which seek to cut pesticide use by 2030. Both fungal pathogens have been described as either hemibiotrophs or necrotrophs. A microbial fermentation-based product (MFP) was previously demonstrated to control the biotrophic pathogen powdery mildew, on wheat. Here we investigated if MFP would be effective against the non-biotrophic fungal pathogens of wheat, F. graminearum and Z. tritici. We assessed the impact of MFP on fungal growth, disease control and also evaluated the individual constituent parts of MFP. Antifungal activity towards both pathogens was found in vitro but MFP only significantly decreased disease symptoms of FHB in planta. In addition, MFP was found to improve the grain number and weight, of uninfected and F. graminearum infected wheat heads.


2013 ◽  
Vol 55 (1) ◽  
pp. 233-246
Author(s):  
Ewa Mirzwa-Mróz ◽  
Czesław Zamorski

The response of Polish winter wheat genotypes to <i>M.graminicola</i> (preliminary experiments and cultivar collections) was observed in different regions of Poland. Observations were carried out in 1995-1999. The winter wheat genotypes showed a broad spectrum of reaction to this pathogen. Between 1997 and 1999 the highest degree of infection on winter wheat breeding lines was noted in Kończewice. During this time no genotypes free from infection were observed (preliminary breeding experiments). Cultivars with no symptoms of <i>Septoria tritici</i> blotch (Leszczyńska Wczesna and Żelazna) were found among old genotypes in Słupia Wielka only in earlier experiments (1995-1996). In the years 1997-1999 the winter wheat cultivars were classified into groups on the basis of their response to the pathogen. The degree of infection for the majority cultivars was quite high.


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