Pathotype Identification and Virulence Variation in Cochliobolus sativus in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Lin Chen ◽  
Quanjie Yao ◽  
Fengtao Wang ◽  
Yunxing Pang ◽  
Xiaowei Lang ◽  
...  
Keyword(s):  
Regional Climate ◽  
Cochliobolus Sativus ◽  
Wheat Varieties ◽  
Geographic Origins ◽  
High Virulence ◽  
Wheat Leaves ◽  
Barley Genotypes ◽  
Important Disease ◽  
Wheat Tissues ◽  
Virulence Variation

Spot blotch caused by Cochliobolus sativus has become an important disease in the wheat-growing regions in China due to changes of regional climate, agricultural cultivation pattern and widely growing susceptible wheat varieties. Little information is available about virulence variability and pathogenic specialization of the C. sativus isolates from major wheat-growing regions in China. Here, 12 representative wheat varieties and foundation breeding stocks were selected to characterize the pathotypes of C. sativus isolates from infected wheat plants. Based on the infection phenotypes in the 12 differential genotypes at the seedling stage, 70 Chinese pathotypes were identified from 110 isolates and clustered into three virulence groups. The high virulence isolates were collected from wheat leaves, crowns, and roots, with most (10 of 14) from the Henan province in the Huang-Huai plain. No relationship was evident between virulence variability of C. sativus isolates and their geographic origins or types of diseased wheat tissues. Cochliobolus sativus showed a significant pathogenic specialization in hosts of wheat and barley. Most of the wheat isolates (50 of 65) were avirulent to all the differential barley genotypes, and a few were virulent only to highly susceptible barley genotypes. These results indicated that C. sativus isolates from the wheat-growing regions in China varied considerably for their virulence in wheat varieties, and showed significant pathogenic specialization to the wheat and barley hosts.

scholarly journals Pathotypes of Cochliobolus sativus on Barley in North Dakota

Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1275-1278 ◽  
Author(s):  
M. Valjavec-Gratian ◽  
B. J. Steffenson
Keyword(s):  
North Dakota ◽  
Spot Blotch ◽  
The State ◽  
Cochliobolus Sativus ◽  
East Central ◽  
Barley Cultivars ◽  
High Virulence ◽  
Virulence Pattern ◽  
Important Disease ◽  
Japan And China

Spot blotch, caused by Cochliobolus sativus, has become an important disease on two-rowed barley cultivars in North Dakota. Information on the variability of virulence in C. sativus is essential for the development of spot blotch-resistant barley germ plasm. To establish the number and distribution of C. sativus virulence types in North Dakota, 22 isolates from the state were evaluated for their virulence on three differential barley genotypes: ND 5883, Bowman, and ND B112. Eleven additional isolates from Minnesota, South Dakota, Nebraska, Colorado, Japan, and China were included for comparison. Three pathotypes were identified from the thirty-three isolates tested based on the infection responses of the three host genotypes. These pathotypes were designated 0, 1, and 2 according to the coded triplet system of nomenclature. In North Dakota, pathotype 0 (exhibits low virulence on all three differentials) comprised 65%, pathotype 2 (exhibits high virulence on Bowman and low virulence on ND 5883 and ND B112) comprised 25%, and pathotype 1 (exhibits high virulence on ND 5883 and low virulence on Bowman and ND B112) comprised 10% of the total number of barley isolates examined. Within North Dakota, pathotype 1 was found in the east-central and northeastern region only, whereas pathotypes 2 and 0 were distributed throughout the state where samples were taken. Isolates with the pathotype 1 virulence pattern were identified in Colorado, Nebraska, Japan, and China. The remaining isolates collected outside North Dakota were pathotype 0. The information obtained from this study will facilitate the deployment of effective resistance to C. sativus in barley.

Effect of rhizobacteria strains on the induction of resistance in barley genotypes against Cochliobolus sativus

2020 ◽  
Vol 13 (2) ◽  
pp. 83-92 ◽  
Author(s):  
A. Adam
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Dry Weight ◽  
Cochliobolus Sativus ◽  
Resistance Level ◽  
Wet Weight ◽  
Number Of Leaves ◽  
Barley Genotypes

SummaryEnhancement of the resistance level in plants by rhizobacteria has been proven in several pathosystems. This study investigated the ability of four rhizobacteria strains (Pseudomonas putida BTP1 and Bacillus subtilis Bs2500, Bs2504 and Bs2508) to promote the growth in three barley genotypes and protect them against Cochliobolus sativus. Our results demonstrated that all tested rhizobacteria strains had a protective effect on barley genotypes Arabi Abiad, Banteng and WI2291. However, P. putida BTP1 and B. subtilis Bs2508 strains were the most effective as they reduced disease incidence by 53 and 38% (mean effect), respectively. On the other hand, there were significant differences among the rhizobacteria-treated genotypes on plant growth parameters, such as wet weight, dry weight, plant height and number of leaves. Pseudomonas putida BTP1 strain was the most effective as it significantly increased plant growth by 15-32%. In addition, the susceptible genotypes Arabi Abiad and WI2291 were the most responsive to rhizobacteria. This means that these genotypes have a high potential for increase of their resistance against the pathogen and enhancement of plant growth after the application of rhizobacteria. Consequently, barley seed treatment with the tested rhizobacteria could be considered as an effective biocontrol method against C. sativus.

scholarly journals Effect of leaf temperature on the estimation of photosynthetic and other traits of wheat leaves from hyperspectral reflectance

2020 ◽  
Author(s):  
Hammad A Khan ◽  
Yukiko Nakamura ◽  
Robert T Furbank ◽  
John R Evans
Keyword(s):  
Leaf Traits ◽  
Leaf Temperature ◽  
Physiological Traits ◽  
Leaf Mass Per Area ◽  
Hyperspectral Reflectance ◽  
Wheat Varieties ◽  
Unit Leaf ◽  
Temperature Signal ◽  
Wheat Leaves ◽  
Nitrogen Contents

Abstract A growing number of leaf traits can be estimated from hyperspectral reflectance data. These include structural and compositional traits, such as leaf mass per area (LMA) and nitrogen and chlorophyll content, but also physiological traits such a Rubisco carboxylation activity, electron transport rate, and respiration rate. Since physiological traits vary with leaf temperature, how does this impact on predictions made from reflectance measurements? We investigated this with two wheat varieties, by repeatedly measuring each leaf through a sequence of temperatures imposed by varying the air temperature in a growth room. Leaf temperatures ranging from 20 °C to 35 °C did not alter the estimated Rubisco capacity normalized to 25 °C (Vcmax25), or chlorophyll or nitrogen contents per unit leaf area. Models estimating LMA and Vcmax25/N were both slightly influenced by leaf temperature: estimated LMA increased by 0.27% °C–1 and Vcmax25/N increased by 0.46% °C–1. A model estimating Rubisco activity closely followed variation associated with leaf temperature. Reflectance spectra change with leaf temperature and therefore contain a temperature signal.

scholarly journals Virulence of Oat Crown Rust in Brazil and Uruguay

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 802-808 ◽  
Author(s):  
K. J. Leonard ◽  
J. A. Martinelli
Keyword(s):  
Avena Sativa ◽  
Western Siberia ◽  
Specific Resistance ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
South American ◽  
Oat Crown Rust ◽  
High Virulence ◽  
Important Disease

Race-specific resistance to crown rust, the most important disease of oat (Avena sativa) in Bra-zil, often fails within a few years of use in Brazilian cultivars. Virulence of 144 isolates of Puccinia coronata from cultivated oat in Brazil in 1997 to 1999 and 36 isolates from Uruguay in 1994-95 and 1998 was tested on a set of 27 oat crown rust differentials lines, each with a different Pc gene for race-specific resistance. Frequencies of virulence and mean virulence complexity were compared among these five collections from Brazil and Uruguay as well as with mean virulence complexity for a collection of 17 isolates from cultivated oat in western Siberia in Russia. Virulence-avirulence for each of the 27 Pc genes was polymorphic in both Brazil and Uruguay. Virulence frequencies were similar for collections from Brazil in 1998 and 1999 and for the collection from Uruguay from 1998, but there were large differences between the 1997 collection and the 1998 and 1999 collections from Brazil. Mean virulence complexity in both Brazil and Uruguay was greater than reported in the United States and much greater than in the Russian collection of P. coronata. A large number of races of P. coronata were found, with no more than five isolates of any race found in a single year in Brazil or Uruguay. The high virulence complexity and great diversity of virulence polymorphisms in Brazil and Uruguay make it unlikely that race-specific resistance can be effective there even though the South American populations of P. coronata are apparently entirely asexual.

scholarly journals Association of Pestalotiopsis Guepinii (DESM.) Stay. with Bipolaris Leaf Blight (BpLB) Infected Wheat Leaves-A new Record

2016 ◽  
Vol 40 (1) ◽  
pp. 87-90
Author(s):  
Shamim Shamsi ◽  
Mst Selina Momtaz
Keyword(s):  
New Record ◽  
Leaf Blight ◽  
Wheat Varieties ◽  
Anamorphic Fungus ◽  
Wheat Leaf ◽  
Wheat Leaves ◽  
Academy Of Sciences

Pestalotiopsis guepinii (Desm.) Stay an anamorphic fungus belonging to the class Celomycetes was isolated from Bipolaris leaf blight (BpLB) infected wheat leaf of two wheat varieties namely, Balaka and Saurab during the period of February to March, 2011. Association of Pestalotiopsis guepinii with wheat is a new record.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 1, 87-90, 2016

THE YELLOW COLORING MATTER OF KHAPLI WHEAT, TRITICUM DICOCCUM: II. THE CONSTITUTION OF TRICETIN

1932 ◽  
Vol 7 (3) ◽  
pp. 285-292 ◽  
Author(s):  
J. Ansel Anderson
Keyword(s):  
Melting Point ◽  
Related Compound ◽  
Mixed Melting Point ◽  
Water Soluble ◽  
Wheat Varieties ◽  
Wheat Leaves ◽  
Coloring Matter ◽  
Color Reactions ◽  
Hydrolysis Of ◽  
Derivatives Of

Khapli wheat leaves contain a very small quantity of a trihydroxydimethoxyflavone, tricin. Marquis yields a trace of the same compound. These two varieties also contain water-soluble coloring matters which are apparently glucosides of tricin or of a closely related compound. Dyeing tests carried out with six other wheat varieties indicate that all contain essentially the same coloring matters.Methylation of tricin and hydrolysis of the resulting O-trimethyltricin yielded 3,4,5-trimethoxybenzoic acid and 2-hydroxy-4,6-dimethoxyacetophenone. It was therefore assumed that tricetin, the pentahydroxyflavone derived from tricin, was 5,7,3′,4′,5′-pentahydroxyflavone. This was synthesized from 3,4,5-trimethoxybenzoic acid and phloracetophenone by the Allan-Robinson method. Mixed melting-point determinations showed that its O-pentamethyl and O-penta-acetyl derivatives are identical with the corresponding derivatives of tricetin. The dyeing properties and color reactions of synthetic and natural tricetin are identical and are in fair agreement with those described by Badhwar, Kang and Ventkataraman (3, p. 1111) who recently reported the synthesis of the same compound.

scholarly journals Comparative transcriptome and histological analyses of wheat in response to phytotoxic aphid Schizaphis graminum and non-phytotoxic aphid Sitobion avenae feeding

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yong Zhang ◽  
Yu Fu ◽  
Jia Fan ◽  
Qian Li ◽  
Frédéric Francis ◽  
...  
Keyword(s):  
Plant Defence ◽  
Sitobion Avenae ◽  
Schizaphis Graminum ◽  
Wheat Varieties ◽  
Leaf Chlorosis ◽  
Defence Genes ◽  
Genes Encoding ◽  
Defence Responses ◽  
Wheat Leaves ◽  
Ethylene Signalling

Abstract Background Infestation of the phytotoxic aphid Schizaphis graminum can rapidly induce leaf chlorosis in susceptible plants, but this effect is not observed with the nonphytotoxic aphid Sitobion avenae. However, few studies have attempted to identify the different defence responses induced in wheat by S. graminum and S. avenae feeding and the mechanisms underlying the activation of chlorosis by S. graminum feeding. Results S. graminum feeding significantly reduced the chlorophyll content of wheat leaves, and these effects were not observed with S. avenae. A transcriptomic analysis showed that the expression levels of genes involved in the salicylic acid, jasmonic acid and ethylene signalling defence pathways were significantly upregulated by both S. avenae and S. graminum feeding; however, more plant defence genes were activated by S. graminum feeding than S. avenae feeding. The transcript levels of genes encoding cell wall-modifying proteins were significantly increased after S. graminum feeding, but only a few of these genes were induced by S. avenae. Furthermore, various reactive oxygen species-scavenging genes, such as 66 peroxidase (POD) and 8 ascorbate peroxidase (APx) genes, were significantly upregulated after S. graminum feeding, whereas only 15 POD and one APx genes were induced by S. avenae feeding. The activity of four antioxidant enzymes was also significantly upregulated by S. graminum feeding. Cytological examination showed that S. graminum feeding induced substantial hydrogen peroxide (H2O2) accumulation in wheat leaves. The chlorosis symptoms and the loss of chlorophyll observed in wheat leaves after S. graminum feeding were reduced and inhibited by the scavenging of H2O2 by dimethylthiourea, which indicated that H2O2 plays important role in the induction of chlorosis by S. graminum feeding. Conclusions S. graminum and S. avenae feeding induces the JA, SA and ET signalling pathways, but S. graminum activated stronger plant defence responses than S. avenae. S. graminum feeding triggers strong ROS-scavenging activity and massive H2O2 production in wheat leaves, and the accumulation of H2O2 induced by S. graminum feeding is involved in the activation of chlorosis in wheat leaves. These results enhance our understanding of mechanisms underlying aphid-wheat interactions and provide clues for the development of aphid-resistant wheat varieties.

scholarly journals Presence of ice-nucleating Pseudomonas on wheat leaves promotes Septoria tritici blotch disease (Zymoseptoria tritici) via a mutually beneficial interaction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Helen N. Fones
Keyword(s):  
Frost Damage ◽  
Ice Nucleation ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Bacterial Populations ◽  
Wheat Leaf ◽  
Ina Bacteria ◽  
Wheat Leaves ◽  
Important Disease

Abstract Zymoseptoria tritici causes Septoria tritici blotch (STB) of wheat, an economically important disease causing yield losses of up to 10% despite the use of fungicides and resistant cultivars. Z. tritici infection is symptomless for around 10 days, during which time the fungus grows randomly across the leaf surface prior to entry through stomata. Wounded leaves show faster, more extensive STB, suggesting that wounds facilitate fungal entry. Wheat leaves also host epiphytic bacteria; these include ice-nucleating (INA+) bacteria, which induce frost damage at warmer temperatures than it otherwise occurs. Here, STB is shown to be more rapid and severe when wheat is exposed to both INA+ bacteria and sub-zero temperatures. This suggests that ice-nucleation-induced wounding of the wheat leaf provides additional openings for fungal entry. INA+ bacterial populations are shown to benefit from the presence of Z. tritici, indicating that this microbial interaction is mutualistic. Finally, control of INA+ bacteria is shown to reduce STB.

Formate metabolism and betaine formation in healthy and rust-infected wheat

1970 ◽  
Vol 48 (4) ◽  
pp. 803-811 ◽  
Author(s):  
Margaret S. Bowman ◽  
R. Rohringer
Keyword(s):  
Amino Acids ◽  
Nucleic Acid ◽  
Stem Rust ◽  
Betaine Lipids ◽  
Dark Metabolism ◽  
Synthesis Activity ◽  
C Metabolism ◽  
Wheat Leaves ◽  
Wheat Tissues ◽  
Formate Metabolism

Formate-14C was fed to detached primary leaves of wheat and the distribution of activity among various fractions was examined after 2 to 26 h of metabolism in the light or 4 h of metabolism in the dark.All samples contained activity in free neutral, acidic, and basic compounds. The radioactive metabolites in the basic fraction were examined in detail. Initially, in the light, glutamate, aspartate, serine, and an unknown, chromatographically similar to, but not identical with histidine, contained most of the activity. Activity in betaine increased with time until, at 26 h, it contained nearly half of the activity in this fraction. Following dark metabolism, most of the activity resided in glutamate and serine. Glycine was not radioactive, and most of the activity in serine resided in carbon 3, indicating that formate served as a precursor of C1-units that were used for serine synthesis. Activity was also detected in a number of other amino acids and choline, both in the light and dark.A comparison of formate-14C metabolism in the dark in stem rust resistant and susceptible wheat leaves revealed that betaine, lipids, nucleic acid bound adenine and guanine, and a protein-containing residue from rust-infected susceptible leaves contained much more activity than the corresponding components from healthy susceptible or from healthy or rust-infected resistant leaves.Activity from glycine-2-3H, methionine-14CH3, serine-3-14C, ethanolamine-1,2-14C, and choline-14CH3 was incorporated into betaine in the dark, but was not detected in sarcosine or dimethylglycine. These results support the view that betaine was synthesized from glycine via serine, ethanolamine, and choline with methionine as the methyl donor, and not by direct N-methylation of glycine.Betaine-14CH3 was translocated but not metabolized in healthy or rust-infected primary leaves of wheat, or in aerial portions of adult wheat plants. In these wheat tissues, betaine would thus appear to be a metabolic end product.

scholarly journals Brachypodium distachyon–Cochliobolus sativus Pathosystem is a New Model for Studying Plant–Fungal Interactions in Cereal Crops

2015 ◽  
Vol 105 (4) ◽  
pp. 482-489 ◽  
Author(s):  
Shaobin Zhong ◽  
Shaukat Ali ◽  
Yueqiang Leng ◽  
Rui Wang ◽  
David F. Garvin
Keyword(s):  
Molecular Mechanisms ◽  
Brachypodium Distachyon ◽  
Bipolaris Sorokiniana ◽  
Transgressive Segregation ◽  
Cochliobolus Sativus ◽  
Cereal Crops ◽  
New Model ◽  
Model Grass ◽  
Fungal Interactions ◽  
Important Disease

Cochliobolus sativus (anamorph: Bipolaris sorokiniana) causes spot blotch, common root rot, and kernel blight or black point in barley and wheat. However, little is known about the molecular mechanisms underlying the pathogenicity of C. sativus or the molecular basis of resistance and susceptibility in the hosts. This study aims to establish the model grass Brachypodium distachyon as a new model for studying plant–fungus interactions in cereal crops. Six B. distachyon lines were inoculated with five C. sativus isolates. The results indicated that all six B. distachyon lines were infected by the C. sativus isolates, with their levels of resistance varying depending on the fungal isolates used. Responses ranging from hypersensitive response-mediated resistance to complete susceptibility were observed in a large collection of B. distachyon (2n = 2x = 10) and B. hybridum (2n = 4x = 30) accessions inoculated with four of the C. sativus isolates. Evaluation of an F2 population derived from the cross between two of the B. distachyon lines, Bd1-1 and Bd3-1, with isolate Cs07-47-1 showed quantitative and transgressive segregation for resistance to C. sativus, suggesting that the resistance may be governed by quantitative trait loci from both parents. The availability of whole-genome sequences of both the host (B. distachyon) and the pathogen (C. sativus) makes this pathosystem an attractive model for studying this important disease of cereal crops.

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