Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics ...Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen due mainly to the nature of obligate biotrophism and the lack of systems for studying its genetics and molecular manipulations. To overcome these limitations, a natural Pst population comprising 352 isolates representative of a diverse virulence spectrum was genotyped using 97 secreted protein-single nucleotide polymorphism (SP-SNP) markers to identify candidate avirulence genes using association analysis. Among avirulence genes corresponding to 19 resistance genes, significantly associated SP-SNP markers were detected for avirulence genes AvYr1, AvYr2, AvYr6, AvYr7, AvYr8, AvYr44, AvYrExp2, AvYrSP, and AvYrTye. These results indicate that association analysis can be used to identify markers for avirulence genes. This study has laid the foundation for developing more SP-SNPs for mapping avirulence genes using segregating populations that can be generated through sexual reproduction on alternate hosts of the pathogen.展开更多
In order to realize monitoring and early warning and comprehensive management of wheat stripe rust and to reduce its occurrence in Nanchong City,the occurrence and epidemic regularity of wheat stripe rust in Nanchong ...In order to realize monitoring and early warning and comprehensive management of wheat stripe rust and to reduce its occurrence in Nanchong City,the occurrence and epidemic regularity of wheat stripe rust in Nanchong was studied by system monitoring and general survey,resistance identification,physiological race monitoring and meteorological data analysis. The initial occurrence location and spreading pathway of Puccinia striiformis f. sp. tritici( Pst) were first verified;there were two infection peaks of wheat stripe rust in Nanchong and one to three epidemic peaks in fields,in which the occurrence area of the first epidemic peak played a pivotal role in disease prevalence in that year; the cumulative occurrence area in late January was positively correlated with annual occurrence area,with the correlation coefficient of 0. 769; the prediction model for infected field rate,diseased plant rate and annual occurrence area was established. The internal reason for heavy occurrence and prevalence of wheat stripe rust in Nanchong was the decline or loss of wheat resistance against stripe rust,as well as the appearance of physiological races of Pst,which later became dominant races. Large fluctuation of temperature in warm winter and spring and more fog and dew days were external reasons responsible for prevalence of stripe rust. From 2002 to 2014,the accuracy rate of short-term prediction of wheat stripe rust reached 100%,while that of medium-term and long-term prediction reached over 98% and 95%,respectively,5%- 15% higher than that of the years before 1998.展开更多
Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental fa...Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental factor affecting the occurrence and epidemiology of wheat stripe rust. Investigating UV-B radiation effects on the epidemiology of stripe rust may be conducive to monitoring and predicting this disease. In this study, wheat seedlings were exposed to UV-B radiation during different periods under laboratory conditions and radiation effects on epidemiological components of wheat stripe rust were investigated. Results showed that incubation period was shortened, and the infection efficiency, sporulation quantity and disease index increased when UV-B radiation was performed only pre-inoculation. When the UV-B radiation was performed only postinoculation or both pre-and post-inoculation, the incubation period was prolonged, and the infection efficiency, sporulation quantity and disease index were reduced. When healthy wheat seedlings were inoculated using urediospores collected from wheat leaves irradiated by UV-B only post-inoculation or both pre-and post-inoculation, infection efficiency, sporulation quantity and disease index were also reduced. However, in the latter, the disease incubation period did not differ under varying UV-B radiation intensities compared to that when wheat leaves were not treated with UV-B radiation. Overall, the effects of direct exposure of wheat plants to UV-B radiation with different intensities in different periods on epidemiological components of wheat stripe rust were systematically explored, and the results suggest that the effects of UV-B radiation increased gradually with the increase of UV-B radiation intensity. This information provides a basis for monitoring and predicting this disease as well as for conducting further studies on pathogen virulence variation.展开更多
Puccinia striiformis Westend.f.sp.tritici Erikss.(Pst)infects wheat and causes stripe rust.The rust is heteroecious with wheat as the primary uredinial and telial host and barberry(Berberis spp.)as the alternate pycni...Puccinia striiformis Westend.f.sp.tritici Erikss.(Pst)infects wheat and causes stripe rust.The rust is heteroecious with wheat as the primary uredinial and telial host and barberry(Berberis spp.)as the alternate pycnial and aecial host.More than 40 Berberis species have been identified as alternate hosts for Pst,and most of these are Chinese Berberis species.However,little is known about Berberis species or their geographic distributions in the Yunnan-Guizhou plateau in southwestern China.The Yunnan-Guizhou plateau is considered to be an important and relatively independent region for the evolution of the wheat stripe rust pathogen in China because the entire disease cycle can be completed within the region.In this study,we conducted a survey of barberry plants in the Yunnan-Guizhou plateau and identified the eight Pst-susceptible Berberis species under controlled conditions,including B.julianae,B.tsienii,B.veitchii,B.wilsonae,B.wilsonae var.guhtzunica,B.franchetiana,B.lepidifolia and B.pruinosa.These species are reported here for the first time to serve as alternate hosts for the wheat stripe rust pathogen under controlled conditions.展开更多
Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.( Pst),is one of the most destructive diseases of wheat( Triticum aestivum L.) worldwide. Sichuan province plays an important role in str...Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.( Pst),is one of the most destructive diseases of wheat( Triticum aestivum L.) worldwide. Sichuan province plays an important role in stripe rust epidemic in China. To identify and evaluate wheat stripe rust resistance in Sichuan Province,134 wheat cultivars( lines) were inoculated with seven Pst races at seedling stage and adult stage. The results indicated that the resistance frequencies of wheat cultivars( lines) against seven races CYR31,Su11-7,CYR29,Su11-4,CYR32,CYR33 and V26 were 92. 4%,92. 5%,89. 3%,89. 4%,87. 3%,85. 0% and 82. 8%,respectively. Among 134 materials,76( 56. 0%) performed resistance against all tested races both in seedling and adult stages. The virulence of new pathogenic type V26 of Pst on wheat cultivars( lines) was stronger than the dominant races CYR32 and CYR33. All wheat cultivars( lines) were classified into three types according to analysis of resistance spectrum; 66. 4% of cultivars( lines) showed all-stage resistance,17. 9% were adult-plant resistance,and 15. 7% were susceptible. This indicated that although the overall resistance level of wheat cultivars( lines) in Sichuan Province was very high,the resistance type was simple. Therefore,it is important to identify new resistance genes and enhance resistance gene diversity. Meanwhile,pyramiding breeding of all-stage resistance gene and adult-plant resistance gene could be gradually developed,to achieve durable resistance of wheat cultivars(lines) against stripe rust in Sichuan Province.展开更多
The aim of this study is to clarify the application effect of pesticide decrement synergist‘Jijian'on wheat stripe rust. Sampling investigation,randomized block design and statistic analysis were carried out to f...The aim of this study is to clarify the application effect of pesticide decrement synergist‘Jijian'on wheat stripe rust. Sampling investigation,randomized block design and statistic analysis were carried out to find out the field efficacy of adding‘Jijian'to triadimefon WP and propiconazole EC on controlling wheat stripe rust. The results showed that during the epidemic period of stripe rust,the control effects on the 7^(th) and the 19^(th)d reached more than 93% and 100%,respectively,by the application of 15% triadimefon WP of 1 200 g/hm^2 and 25% propiconazole EC of 600 mlhm^2,respectively for 2 times; when 15% triadimefon WP of 840 g/hm^2+ ‘Jijian'of 225 g/hm^2 or 25% propiconazole EC of 420 mlhm^2+‘Jijian'of 225 g/hm^2 were applied( adding‘Jijian'and reducing the dosage of the 2 pesticides by 30%),the control effect on the 7 thd was 89. 4% and 91. 7%,respectively,while the control effect on the 19^(th)d was 99. 8-100%; when15% triadimefon WP of 720-600 g/hm^2+ ‘Jijian'of 225 g/hm^2 or 25% propiconazole EC 360-300 mlhm^2+‘Jijian'of 225 g/hm^2 were applied( adding‘Jijian'and reducing the dosage of the 2 pesticides by 40%-50%),the control effect on the 7^(th)day reached more than 78. 0%,while the control effect on the 19 th day was 97. 7%-99. 8%. There was no significant difference on the control effect at the 7^(th)d between the treatments using the 2 pesticides alone and the treatments adding‘Jijian'and reducing the dosage of the 2 pesticides by 30%,but all had significant differences from the treatments adding‘Jijian'and reducing the dosage of the 2 pesticides by 40%-50%. There was no significant difference on the control effect of the 19 thd among different treatments. Therefore,if the disease is not serious,the application of‘Jijian'can reduce the application amounts of pesticides by 40%-50%,that is,15% triadimefon WP of 720-600 g/hm^2+ ‘Jijian'of 225 g/hm^2 or 25% propiconazole EC of 360-300 ml/hm^2+‘Jijian'of 225 g/hm^2,which is helpful to reduce the pesticide application amounts and pesticide residue pollution,and save the control costs.展开更多
Identifying sources of phytopathogen inoculum and determining their contributions to disease outbreaks are essential for predicting disease development and establishing control strategies.Puccinia striiformis f.sp.tri...Identifying sources of phytopathogen inoculum and determining their contributions to disease outbreaks are essential for predicting disease development and establishing control strategies.Puccinia striiformis f.sp.tritici(Pst),the causal agent of wheat stripe rust,is an airborne fungal pathogen with rapid virulence variation that threatens wheat production through its long-distance migration.Because of wide variation in geographic features,climatic conditions,and wheat production systems,Pst sources and related dispersal routes in China are largely unclear.In the present study,we performed genomic analyses of 154 Pst isolates from all major wheat-growing regions in China to determine Pst population structure and diversity.Through trajectory tracking,historical migration studies,genetic introgression analyses,and field surveys,we investigated Pst sources and their contributions to wheat stripe rust epidemics.We identified Longnan,the Himalayan region,and the Guizhou Plateau,which contain the highest population genetic diversities,as the Pst sources in China.Pst from Longnan disseminates mainly to eastern Liupan Mountain,the Sichuan Basin,and eastern Qinghai;that from the Himalayan region spreads mainly to the Sichuan Basin and eastern Qinghai;and that from the Guizhou Plateau migrates mainly to the Sichuan Basin and the Central Plain.These findings improve our current understanding of wheat stripe rust epidemics in China and emphasize the need for managing stripe rust on a national scale.展开更多
Wheat(Triticum aestivum)is one of the most essential human energy and protein sources.However,wheat production is threatened by devastating fungal diseases such as stripe rust,caused by Puccinia striiformis Westend.f....Wheat(Triticum aestivum)is one of the most essential human energy and protein sources.However,wheat production is threatened by devastating fungal diseases such as stripe rust,caused by Puccinia striiformis Westend.f.sp.tritici(Pst).Here,we reveal that the alternations in chloroplast lipid profiles and the accumulation of jasmonate(JA)in the necrosis region activate JA signaling and trigger the host defense.The collapse of chloroplasts in the necrosis region results in accumulations of polyunsaturated membrane lipids and the lipid-derived phytohormone JA in transgenic lines of Yr36 that encodes Wheat Kinase START 1(WKS1),a high-temperature-dependent adult plant resistance protein.WKS1.1,a protein encoded by a full-length splicing variant of WKS1,phosphorylates and enhances the activity of keto-acyl thiolase(KAT-2B),a critical enzyme catalyzing theβ-oxidation reaction in JA biosynthesis.The premature stop mutant,kat-2b,accumulates less JA and shows defects in the host defense against Pst.Conversely,overexpression of KAT-2B results in a higher level of JA and limits the growth of Pst.Moreover,JA inhibits the growth and reduces pustule densities of Pst.This study illustrates the WKS1.1-KAT-2B-JA pathway for enhancing wheat defense against fungal pathogens to attenuate yield loss.展开更多
Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathoge...Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.展开更多
To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image pro...To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image processing was developed using MATLAB GUIDE platform in combination with Local C Compiler(LCC).The system is independent of the MATLAB environment and can be run on a computer without the MATLAB software.Using this system,automatic counting of Pst urediospores in a microscopic image can be implemented via image processing technologies including image scaling,clustering segmentation,morphological modification,watershed transformation,connected region labeling,etc.Structure design of the automatic counting system,the key algorithms used in the system and realization of the main functions of the system were described in detail.Spore counting tests were conducted using microscopic digital images of Pst urediospores and the high accuracies more than 95%were obtained.The results indicated that it is feasible to count Pst urediospores automatically using the developed system based on image processing.展开更多
The wheat canopy reflectance spectrum is affected by many internal and external factors such as diseases and growth stage. Separating the effects of disease stress on the crop from the observed mixed signals is crucia...The wheat canopy reflectance spectrum is affected by many internal and external factors such as diseases and growth stage. Separating the effects of disease stress on the crop from the observed mixed signals is crucial for increasing the precision of remote sensing monitoring of wheat stripe rust. The canopy spectrum of winter wheat infected by stripe rust was processed with the difference-in-differences(DID) algorithm used in econometrics. The monitoring accuracies of wheat stripe rust before and after processing with the DID algorithm were compared in the presence of various external factors, disease severity, and several simulated satellite sensors. The correlation between the normalized difference vegetation index processed by the DID algorithm(NDVI-DID) and the disease severity level(SL) increased in comparison with the NDVI before processing. The increase in precision in the natural disease area in the field in the presence of large differences in growth stage, growth, planting, and management of the crop was greater than that in the controlled experiment. For low disease levels(SL < 20%), the R2 of the regression of NDVI-DIDon SL was 38.8% higher than that of the NDVI and the root mean square error(RMSE) was reduced by 11.1%. The increase in precision was greater than that for the severe level(SL > 40%).According to the measured hyperspectral data, the spectral reflectance of three satellite sensor levels was simulated. The wide-band NDVI was calculated. Compared with the wide-band NDVI and vegetation indexes(VI) before DID processing, there were increases in the correlation between SL and the various types of VIS-DID, as well as in the correlation between SL and NDVI-DID. It is feasible to apply the DID algorithm to multispectral satellite data and diverse types of VISfor monitoring wheat stripe rust. Our results improve the quantification of independent effects of stripe rust infection on canopy reflectance spectrum,increase the precision of remote sensing monitoring of wheat stripe rust, and provide a reference for remote sensing monitoring of other crop diseases.展开更多
Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most...Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most effective strategy to control diseases in crop plants. Chinese wheat lines Mengmai 58 and Huaiyang 1 are highly resistant to PST race CYR34(V26) at the adult plant stage. To genetically map the underlying resistance genes we developed segregating populations by crossing Mengmai 58 and Huaiyang 1 with the susceptible cultivar Nongda 399. The stripe rust resistances in Mengmai 58 and Huaiyang 1 were both controlled by single dominant genes, provisionally designated YrMM58 and YrHY1, respectively. Bulked segregant RNA-Seq(BSR-Seq) analysis showed that YrMM58 and YrHY1 were located in the same distal ~16 Mb region on chromosome 2 AS.Comparative genomics analysis with the physical map of Aegilops tauschii proved useful for developing additional markers to saturate the genetic linkage map. YrMM58 and YrHY1 were mapped to the distal end of chromosome arm 2 AS, with the closest marker WGGB148 being 7.7 cM and 3.8 cM from the resistance gene, which was considered to be Yr17. These markers can be used in marker-assisted selection.展开更多
Several new stripe rust pathogen races emerged in the wheat growing regions of China in recent years.These races were virulent to most of the designated wheat seedling resistance genes.Thus,it is necessary and worthwh...Several new stripe rust pathogen races emerged in the wheat growing regions of China in recent years.These races were virulent to most of the designated wheat seedling resistance genes.Thus,it is necessary and worthwhile to identify new valuable resistant materials for the sake of diversifying resistant sources,pyramiding different resistance genes and achieving durable resistance.Here,we identified the resistance gene,temporarily designated as YrH9017,in wheat-Psathyrostachys huashanica introgression line H9017-14-16-5-3.A total of 146 F2 plants and their derived F2:3 families in a cross of Mingxian 169 and H9017-14-16-5-3 were used to evaluate seedling stripe rust response and as a mapping population.Finally,we constructed a genetic map including eight simple sequence repeat(SSR) markers and expressed sequence tag(EST) markers.YrH9017 was located on the long arm of chromosome 2A and closely linked with two EST-sequence tagged site(EST-STS) markers BG604577 and BE471201 at 1.3 and 1.8 cM distance,respectively.The two closest markers could be used for marker-assisted selection of YrH9017 in breeding.展开更多
Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the major diseases of wheat in China.In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars(lines)from the Pacific Nort...Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the major diseases of wheat in China.In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars(lines)from the Pacific Northwest(PNW)of the United States,to provide resistance resources for genetic improvement of wheat stripe rust resistance in China,59 wheat cultivars(lines)from PNW of the United States were infected by 3 mixed races of predominant Chinese stripe rust races CRY31,CRY32,and CRY33 to evaluate their resistance at seedling and adult plant stages,and screened with molecular markers tightly linked to currently effective all-stage resistance genes Yr10,Yr15 and adult plant resistance genes Yr18,Yr39.Of 59 American cultivars(lines),five cultivars(lines),Expresso,02W50076,ACS52610,WA008012,and WA00801833,had all-stage resistance,showing resistance to mixed races of CRY31,CRY32,and CRY33 at both seedling and adult plant stages.33 cultivars(lines)had adult plant resistance,only showing resistance to stripe rust at adult stage.Based on the molecular screening,none of the 59 PNW cultivars(lines)had the polymorphic bands of linked markers to Yr10.There were 12,33 and 29 cultivars(lines)which had polymorphic bands of linked markers to Yr15,Yr18 and Yr39,accounting for 20,55 and 49% of the 59 PNW cultivars(lines),respectively.All these results suggested that Yr15,Yr18 and Yr39 were widespread among PNW cultivars(cultivars)and could be utilized in Chinese wheat stripe rust resistance breeding.展开更多
Thinopyrum intermedium(2 n = 6 x = 42, JJJ^sJ^sStSt) has been hybridized extensively with common wheat and has proven to be a valuable germplasm source for improving disease resistance, quality attributes, and yield p...Thinopyrum intermedium(2 n = 6 x = 42, JJJ^sJ^sStSt) has been hybridized extensively with common wheat and has proven to be a valuable germplasm source for improving disease resistance, quality attributes, and yield potential in wheat. We characterized new disease resistant wheat-Th. intermedium derivatives A1082 and A5-5 using sequential multi-color fluorescence in situ hybridization(mc-FISH), genomic in situ hybridization(GISH), PCRbased landmark unique gene(PLUG) and intron targeting(IT) markers. A1082 was identified as a wheat-Th. intermedium 3J disomic addition line, and A5-5 was a T4BS·5J^sL homozygous Robertsonian translocation line. Seventy-one and 106 pairs of primers amplified Th.intermedium-specific bands allowing chromosomes 3J and 5J^s to be tracked, respectively. A new oligonucleotide probe, Oligo-6 H-2-100, was developed for FISH labeling of the subterminal region of the long arm of chromosome 5J^s. Both lines were highly resistant to stripe rust pathogen races prevalent in Chinese field screening nurseries. A5-5 also displayed a significant increase in tiller number compared to its wheat parent. The new lines can be exploited as useful germplasms for wheat improvement.展开更多
Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and ...Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and the contents of iron(Fe),zinc(Zn),and seed gluten proteins.Forty-two of the accessions were classified as resistant to stripe rust,while the other four accessions were classified as susceptible to stripe rust in four environments.The average HD of Ae.umbellulata was significantly longer than that of three common wheat cultivars(180.9 d vs.137.0 d),with the exception of PI226500(138.9 d).The Ae.umbellulata accessions also showed high variability in Fe(69.74-348.09 mg kg^(-1))and Zn(49.83-101.65 mg kg^(-1))contents.Three accessions(viz.,PI542362,PI542363,and PI554399)showed relatively higher Fe(230.96-348.09 mg kg^(-1))and Zn(92.46-101.65 mg kg^(-1))contents than the others.The Fe content of Ae.umbellulata was similar to those of Ae.comosa and Ae.markgrafii but higher than those of Ae.tauschii and common wheat.Aegilops umbellulata showed a higher Zn content than Ae.tauschii,Ae.comosa,and common wheat,but a lower content than Ae.markgrafii.Furthermore,Ae.umbellulata had the highest proportion of γ-gliadin among all the species investigated(Ae.umbellulata vs.other species=mean 72.11%vs.49.37%;range:55.33-86.99%vs.29.60-67.91%).These results demonstrated that Ae.umbellulata exhibits great diversity in the investigated traits,so it can provide a potential gene pool for the genetic improvement of these traits in wheat.展开更多
Stem rust,caused by Puccinia graminis f.sp.tritici(Pgt),threatens global wheat production.Development of cultivars with increased resistance to stem rust by identification,mapping,and deployment of resistance genes is...Stem rust,caused by Puccinia graminis f.sp.tritici(Pgt),threatens global wheat production.Development of cultivars with increased resistance to stem rust by identification,mapping,and deployment of resistance genes is the best strategy for controlling the disease.In this study,we performed fine mapping and characterization of the all-stage stem rust resistance(Sr)gene Sr8155B1 from the durum wheat line 8155-B1.In seedling tests of biparental populations,Sr8155B1 was effective against six Chinese Pgt races tested.In a segregating population of 5060 gametes,Sr8155B1 was mapped to a 0.06-cM region flanked by markers Pku2772 and Pku43365,corresponding to 1.5-and 2.7-Mb regions in the Svevo and Chinese Spring reference genomes.Both regions include several typical nucleotide-binding leucine-rich repeat(NLR)and protein kinase genes that represent candidate genes.Among them,three NLR genes and three receptor-like protein kinases were highly polymorphic between the parental lines and their transcripts were upregulated in the homozygous resistant line TdR2 relative to its susceptible sister line TdS4.Four markers(Pku2772,Pku43365,Pku2950,and Pku3721)developed in this study,together with seedling resistance responses,correctly predicted Sr8155B1 absence or presence in 78 tetraploid wheat genotypes tested.The presence of Sr8155B1 in tetraploid wheat accessions CItr 14916,PI 197492,and PI 197493 was confirmed by mapping in three F_(2)populations.The genetic map and linked markers developed in this study may accelerate the deployment of Sr8155B1-mediated resistance in wheat breeding programs.展开更多
Wheat rust diseases are one of the major types of fungal diseases that cause substantial yield quality losses of 15%–20%every year.The wheat rust diseases are identified either through experienced evaluators or compu...Wheat rust diseases are one of the major types of fungal diseases that cause substantial yield quality losses of 15%–20%every year.The wheat rust diseases are identified either through experienced evaluators or computerassisted techniques.The experienced evaluators take time to identify the disease which is highly laborious and too costly.If wheat rust diseases are predicted at the development stages,then fungicides are sprayed earlier which helps to increase wheat yield quality.To solve the experienced evaluator issues,a combined region extraction and cross-entropy support vector machine(CE-SVM)model is proposed for wheat rust disease identification.In the proposed system,a total of 2300 secondary source images were augmented through flipping,cropping,and rotation techniques.The augmented images are preprocessed by histogram equalization.As a result,preprocessed images have been applied to region extraction convolutional neural networks(RCNN);Fast-RCNN,Faster-RCNN,and Mask-RCNN models for wheat plant patch extraction.Different layers of region extraction models construct a feature vector that is later passed to the CE-SVM model.As a result,the Gaussian kernel function in CE-SVM achieves high F1-score(88.43%)and accuracy(93.60%)for wheat stripe rust disease classification.展开更多
文摘Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen due mainly to the nature of obligate biotrophism and the lack of systems for studying its genetics and molecular manipulations. To overcome these limitations, a natural Pst population comprising 352 isolates representative of a diverse virulence spectrum was genotyped using 97 secreted protein-single nucleotide polymorphism (SP-SNP) markers to identify candidate avirulence genes using association analysis. Among avirulence genes corresponding to 19 resistance genes, significantly associated SP-SNP markers were detected for avirulence genes AvYr1, AvYr2, AvYr6, AvYr7, AvYr8, AvYr44, AvYrExp2, AvYrSP, and AvYrTye. These results indicate that association analysis can be used to identify markers for avirulence genes. This study has laid the foundation for developing more SP-SNPs for mapping avirulence genes using segregating populations that can be generated through sexual reproduction on alternate hosts of the pathogen.
基金Supported by Comprehensive Prevention and Treatment Monitoring Station of Inoculum Source of Wheat Stripe Rust in Nanchong City(NYBNJH[2003]104)Notice of the Ministry of Agriculture on Identification of the First Batch of National Modern Agricultural Demonstration Zone(NJF[2010]22)+2 种基金Occurrence and Epidemic Regularity of Wheat Stripe Rust and Its Integrated Control Technology in Nanchong City(N1998-ZC018)Fundamental Research Funds for the Central Universities(XDJK2015C060,SWU114046,2362015xk04)Open Project Program of State Key Laboratory of Crop Stress Biology for Arid Areas(CSBAA2015009)
文摘In order to realize monitoring and early warning and comprehensive management of wheat stripe rust and to reduce its occurrence in Nanchong City,the occurrence and epidemic regularity of wheat stripe rust in Nanchong was studied by system monitoring and general survey,resistance identification,physiological race monitoring and meteorological data analysis. The initial occurrence location and spreading pathway of Puccinia striiformis f. sp. tritici( Pst) were first verified;there were two infection peaks of wheat stripe rust in Nanchong and one to three epidemic peaks in fields,in which the occurrence area of the first epidemic peak played a pivotal role in disease prevalence in that year; the cumulative occurrence area in late January was positively correlated with annual occurrence area,with the correlation coefficient of 0. 769; the prediction model for infected field rate,diseased plant rate and annual occurrence area was established. The internal reason for heavy occurrence and prevalence of wheat stripe rust in Nanchong was the decline or loss of wheat resistance against stripe rust,as well as the appearance of physiological races of Pst,which later became dominant races. Large fluctuation of temperature in warm winter and spring and more fog and dew days were external reasons responsible for prevalence of stripe rust. From 2002 to 2014,the accuracy rate of short-term prediction of wheat stripe rust reached 100%,while that of medium-term and long-term prediction reached over 98% and 95%,respectively,5%- 15% higher than that of the years before 1998.
基金supported by the National Key Basic Research Program of China(2013CB127700)the National Natural Science Foundation of China(31101393)
文摘Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental factor affecting the occurrence and epidemiology of wheat stripe rust. Investigating UV-B radiation effects on the epidemiology of stripe rust may be conducive to monitoring and predicting this disease. In this study, wheat seedlings were exposed to UV-B radiation during different periods under laboratory conditions and radiation effects on epidemiological components of wheat stripe rust were investigated. Results showed that incubation period was shortened, and the infection efficiency, sporulation quantity and disease index increased when UV-B radiation was performed only pre-inoculation. When the UV-B radiation was performed only postinoculation or both pre-and post-inoculation, the incubation period was prolonged, and the infection efficiency, sporulation quantity and disease index were reduced. When healthy wheat seedlings were inoculated using urediospores collected from wheat leaves irradiated by UV-B only post-inoculation or both pre-and post-inoculation, infection efficiency, sporulation quantity and disease index were also reduced. However, in the latter, the disease incubation period did not differ under varying UV-B radiation intensities compared to that when wheat leaves were not treated with UV-B radiation. Overall, the effects of direct exposure of wheat plants to UV-B radiation with different intensities in different periods on epidemiological components of wheat stripe rust were systematically explored, and the results suggest that the effects of UV-B radiation increased gradually with the increase of UV-B radiation intensity. This information provides a basis for monitoring and predicting this disease as well as for conducting further studies on pathogen virulence variation.
基金the National Key R&D Program of China(2018YFD0200500)the National Natural Science Foundation of China(31960524,31071641 and 32072358)+1 种基金the Fundamental Research Funds for the Central Universities(2452019046)the Natural Science Basic Research Plan in Shaanxi Province of China(2020JZ-15,2017JM3006)。
文摘Puccinia striiformis Westend.f.sp.tritici Erikss.(Pst)infects wheat and causes stripe rust.The rust is heteroecious with wheat as the primary uredinial and telial host and barberry(Berberis spp.)as the alternate pycnial and aecial host.More than 40 Berberis species have been identified as alternate hosts for Pst,and most of these are Chinese Berberis species.However,little is known about Berberis species or their geographic distributions in the Yunnan-Guizhou plateau in southwestern China.The Yunnan-Guizhou plateau is considered to be an important and relatively independent region for the evolution of the wheat stripe rust pathogen in China because the entire disease cycle can be completed within the region.In this study,we conducted a survey of barberry plants in the Yunnan-Guizhou plateau and identified the eight Pst-susceptible Berberis species under controlled conditions,including B.julianae,B.tsienii,B.veitchii,B.wilsonae,B.wilsonae var.guhtzunica,B.franchetiana,B.lepidifolia and B.pruinosa.These species are reported here for the first time to serve as alternate hosts for the wheat stripe rust pathogen under controlled conditions.
基金Supported by China Agriculture Research System(CARS-03)International Joint Research Project of Sichuan Province(2014HH0052)+1 种基金Key Research Project of Wheat Breeding in Sichuan ProvinceInnovation Team Project of Wheat in Sichuan Province
文摘Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.( Pst),is one of the most destructive diseases of wheat( Triticum aestivum L.) worldwide. Sichuan province plays an important role in stripe rust epidemic in China. To identify and evaluate wheat stripe rust resistance in Sichuan Province,134 wheat cultivars( lines) were inoculated with seven Pst races at seedling stage and adult stage. The results indicated that the resistance frequencies of wheat cultivars( lines) against seven races CYR31,Su11-7,CYR29,Su11-4,CYR32,CYR33 and V26 were 92. 4%,92. 5%,89. 3%,89. 4%,87. 3%,85. 0% and 82. 8%,respectively. Among 134 materials,76( 56. 0%) performed resistance against all tested races both in seedling and adult stages. The virulence of new pathogenic type V26 of Pst on wheat cultivars( lines) was stronger than the dominant races CYR32 and CYR33. All wheat cultivars( lines) were classified into three types according to analysis of resistance spectrum; 66. 4% of cultivars( lines) showed all-stage resistance,17. 9% were adult-plant resistance,and 15. 7% were susceptible. This indicated that although the overall resistance level of wheat cultivars( lines) in Sichuan Province was very high,the resistance type was simple. Therefore,it is important to identify new resistance genes and enhance resistance gene diversity. Meanwhile,pyramiding breeding of all-stage resistance gene and adult-plant resistance gene could be gradually developed,to achieve durable resistance of wheat cultivars(lines) against stripe rust in Sichuan Province.
基金Supported by the Notice of the Ministry of Agriculture on Approving the First National Modern Agricultural Demonstration Zones in China(Nongjifa[2010]No.22)the Notice of the General Office of the Ministry of Science and Technology on the Construction of the Sixth National Agricultural Science and Technology Parks(National Science and Technology Office for Agriculture[2015]No.9)the Chongqing Research Program of Basic Research and Frontier Technology(cstc2016jcyjA 0316)
文摘The aim of this study is to clarify the application effect of pesticide decrement synergist‘Jijian'on wheat stripe rust. Sampling investigation,randomized block design and statistic analysis were carried out to find out the field efficacy of adding‘Jijian'to triadimefon WP and propiconazole EC on controlling wheat stripe rust. The results showed that during the epidemic period of stripe rust,the control effects on the 7^(th) and the 19^(th)d reached more than 93% and 100%,respectively,by the application of 15% triadimefon WP of 1 200 g/hm^2 and 25% propiconazole EC of 600 mlhm^2,respectively for 2 times; when 15% triadimefon WP of 840 g/hm^2+ ‘Jijian'of 225 g/hm^2 or 25% propiconazole EC of 420 mlhm^2+‘Jijian'of 225 g/hm^2 were applied( adding‘Jijian'and reducing the dosage of the 2 pesticides by 30%),the control effect on the 7 thd was 89. 4% and 91. 7%,respectively,while the control effect on the 19^(th)d was 99. 8-100%; when15% triadimefon WP of 720-600 g/hm^2+ ‘Jijian'of 225 g/hm^2 or 25% propiconazole EC 360-300 mlhm^2+‘Jijian'of 225 g/hm^2 were applied( adding‘Jijian'and reducing the dosage of the 2 pesticides by 40%-50%),the control effect on the 7^(th)day reached more than 78. 0%,while the control effect on the 19 th day was 97. 7%-99. 8%. There was no significant difference on the control effect at the 7^(th)d between the treatments using the 2 pesticides alone and the treatments adding‘Jijian'and reducing the dosage of the 2 pesticides by 30%,but all had significant differences from the treatments adding‘Jijian'and reducing the dosage of the 2 pesticides by 40%-50%. There was no significant difference on the control effect of the 19 thd among different treatments. Therefore,if the disease is not serious,the application of‘Jijian'can reduce the application amounts of pesticides by 40%-50%,that is,15% triadimefon WP of 720-600 g/hm^2+ ‘Jijian'of 225 g/hm^2 or 25% propiconazole EC of 360-300 ml/hm^2+‘Jijian'of 225 g/hm^2,which is helpful to reduce the pesticide application amounts and pesticide residue pollution,and save the control costs.
基金supported by the National Key Research and Development Program of China to X.H.and Y.L.(2021YFD1401000)the National Natural Science Foundation of China(31471731 and 31772102)to X.H.the Postdoctoral Science Foundation of China to Y.L.(2021M690130).
文摘Identifying sources of phytopathogen inoculum and determining their contributions to disease outbreaks are essential for predicting disease development and establishing control strategies.Puccinia striiformis f.sp.tritici(Pst),the causal agent of wheat stripe rust,is an airborne fungal pathogen with rapid virulence variation that threatens wheat production through its long-distance migration.Because of wide variation in geographic features,climatic conditions,and wheat production systems,Pst sources and related dispersal routes in China are largely unclear.In the present study,we performed genomic analyses of 154 Pst isolates from all major wheat-growing regions in China to determine Pst population structure and diversity.Through trajectory tracking,historical migration studies,genetic introgression analyses,and field surveys,we investigated Pst sources and their contributions to wheat stripe rust epidemics.We identified Longnan,the Himalayan region,and the Guizhou Plateau,which contain the highest population genetic diversities,as the Pst sources in China.Pst from Longnan disseminates mainly to eastern Liupan Mountain,the Sichuan Basin,and eastern Qinghai;that from the Himalayan region spreads mainly to the Sichuan Basin and eastern Qinghai;and that from the Guizhou Plateau migrates mainly to the Sichuan Basin and the Central Plain.These findings improve our current understanding of wheat stripe rust epidemics in China and emphasize the need for managing stripe rust on a national scale.
基金supported by the National Natural Science Foundation of China(32372557,31972350)the China Postdoctoral Science Foundation(2021M700850)an open project of the State Key Laboratory of Crop Stress Adaptation and Improvement at Henan University,and the Central Government guided Local Science and Technology Development Funds(2023ZY1016).
文摘Wheat(Triticum aestivum)is one of the most essential human energy and protein sources.However,wheat production is threatened by devastating fungal diseases such as stripe rust,caused by Puccinia striiformis Westend.f.sp.tritici(Pst).Here,we reveal that the alternations in chloroplast lipid profiles and the accumulation of jasmonate(JA)in the necrosis region activate JA signaling and trigger the host defense.The collapse of chloroplasts in the necrosis region results in accumulations of polyunsaturated membrane lipids and the lipid-derived phytohormone JA in transgenic lines of Yr36 that encodes Wheat Kinase START 1(WKS1),a high-temperature-dependent adult plant resistance protein.WKS1.1,a protein encoded by a full-length splicing variant of WKS1,phosphorylates and enhances the activity of keto-acyl thiolase(KAT-2B),a critical enzyme catalyzing theβ-oxidation reaction in JA biosynthesis.The premature stop mutant,kat-2b,accumulates less JA and shows defects in the host defense against Pst.Conversely,overexpression of KAT-2B results in a higher level of JA and limits the growth of Pst.Moreover,JA inhibits the growth and reduces pustule densities of Pst.This study illustrates the WKS1.1-KAT-2B-JA pathway for enhancing wheat defense against fungal pathogens to attenuate yield loss.
基金supported by the Major Program of National Agricultural Science and Technology of China (NK20220607)the National Natural Science Foundation of China (32272059 and31971883)the Science and Technology Department of Sichuan Province (2022ZDZX0014, 2021YFYZ0002, 2021YJ0297, and23NSFTD0045)。
文摘Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.
基金supported by International Research Exchange Scheme of the Marie Curie Program of the 7th Framework Program(Ref.PIRSES-GA-2013-612659)National Key Basic Research Program of China(2013CB127700)National Key Technologies Research and Development Program of China(2012BAD19BA04).
文摘To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image processing was developed using MATLAB GUIDE platform in combination with Local C Compiler(LCC).The system is independent of the MATLAB environment and can be run on a computer without the MATLAB software.Using this system,automatic counting of Pst urediospores in a microscopic image can be implemented via image processing technologies including image scaling,clustering segmentation,morphological modification,watershed transformation,connected region labeling,etc.Structure design of the automatic counting system,the key algorithms used in the system and realization of the main functions of the system were described in detail.Spore counting tests were conducted using microscopic digital images of Pst urediospores and the high accuracies more than 95%were obtained.The results indicated that it is feasible to count Pst urediospores automatically using the developed system based on image processing.
基金supported by the National Natural Science Foundation of China (42171394, 41601467)。
文摘The wheat canopy reflectance spectrum is affected by many internal and external factors such as diseases and growth stage. Separating the effects of disease stress on the crop from the observed mixed signals is crucial for increasing the precision of remote sensing monitoring of wheat stripe rust. The canopy spectrum of winter wheat infected by stripe rust was processed with the difference-in-differences(DID) algorithm used in econometrics. The monitoring accuracies of wheat stripe rust before and after processing with the DID algorithm were compared in the presence of various external factors, disease severity, and several simulated satellite sensors. The correlation between the normalized difference vegetation index processed by the DID algorithm(NDVI-DID) and the disease severity level(SL) increased in comparison with the NDVI before processing. The increase in precision in the natural disease area in the field in the presence of large differences in growth stage, growth, planting, and management of the crop was greater than that in the controlled experiment. For low disease levels(SL < 20%), the R2 of the regression of NDVI-DIDon SL was 38.8% higher than that of the NDVI and the root mean square error(RMSE) was reduced by 11.1%. The increase in precision was greater than that for the severe level(SL > 40%).According to the measured hyperspectral data, the spectral reflectance of three satellite sensor levels was simulated. The wide-band NDVI was calculated. Compared with the wide-band NDVI and vegetation indexes(VI) before DID processing, there were increases in the correlation between SL and the various types of VIS-DID, as well as in the correlation between SL and NDVI-DID. It is feasible to apply the DID algorithm to multispectral satellite data and diverse types of VISfor monitoring wheat stripe rust. Our results improve the quantification of independent effects of stripe rust infection on canopy reflectance spectrum,increase the precision of remote sensing monitoring of wheat stripe rust, and provide a reference for remote sensing monitoring of other crop diseases.
基金financially supported by the National Key Research and Development Program of China (2016YFD0101802)
文摘Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most effective strategy to control diseases in crop plants. Chinese wheat lines Mengmai 58 and Huaiyang 1 are highly resistant to PST race CYR34(V26) at the adult plant stage. To genetically map the underlying resistance genes we developed segregating populations by crossing Mengmai 58 and Huaiyang 1 with the susceptible cultivar Nongda 399. The stripe rust resistances in Mengmai 58 and Huaiyang 1 were both controlled by single dominant genes, provisionally designated YrMM58 and YrHY1, respectively. Bulked segregant RNA-Seq(BSR-Seq) analysis showed that YrMM58 and YrHY1 were located in the same distal ~16 Mb region on chromosome 2 AS.Comparative genomics analysis with the physical map of Aegilops tauschii proved useful for developing additional markers to saturate the genetic linkage map. YrMM58 and YrHY1 were mapped to the distal end of chromosome arm 2 AS, with the closest marker WGGB148 being 7.7 cM and 3.8 cM from the resistance gene, which was considered to be Yr17. These markers can be used in marker-assisted selection.
基金funded by the National Natural Science Foundation of China (31660513,31501620 and 31701911)the Provincial Natural Science Foundation of Qinghai,China (2017-ZJ-793)
文摘Several new stripe rust pathogen races emerged in the wheat growing regions of China in recent years.These races were virulent to most of the designated wheat seedling resistance genes.Thus,it is necessary and worthwhile to identify new valuable resistant materials for the sake of diversifying resistant sources,pyramiding different resistance genes and achieving durable resistance.Here,we identified the resistance gene,temporarily designated as YrH9017,in wheat-Psathyrostachys huashanica introgression line H9017-14-16-5-3.A total of 146 F2 plants and their derived F2:3 families in a cross of Mingxian 169 and H9017-14-16-5-3 were used to evaluate seedling stripe rust response and as a mapping population.Finally,we constructed a genetic map including eight simple sequence repeat(SSR) markers and expressed sequence tag(EST) markers.YrH9017 was located on the long arm of chromosome 2A and closely linked with two EST-sequence tagged site(EST-STS) markers BG604577 and BE471201 at 1.3 and 1.8 cM distance,respectively.The two closest markers could be used for marker-assisted selection of YrH9017 in breeding.
基金funded by the National Natural Science Foundation of China(30971778)Open Fund Project of State Key Laboratory for Biology of Plant Diseases and Insect Pests,China(2008.1-2008.12)China Postdoctoral Science Foundation(200902552)
文摘Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the major diseases of wheat in China.In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars(lines)from the Pacific Northwest(PNW)of the United States,to provide resistance resources for genetic improvement of wheat stripe rust resistance in China,59 wheat cultivars(lines)from PNW of the United States were infected by 3 mixed races of predominant Chinese stripe rust races CRY31,CRY32,and CRY33 to evaluate their resistance at seedling and adult plant stages,and screened with molecular markers tightly linked to currently effective all-stage resistance genes Yr10,Yr15 and adult plant resistance genes Yr18,Yr39.Of 59 American cultivars(lines),five cultivars(lines),Expresso,02W50076,ACS52610,WA008012,and WA00801833,had all-stage resistance,showing resistance to mixed races of CRY31,CRY32,and CRY33 at both seedling and adult plant stages.33 cultivars(lines)had adult plant resistance,only showing resistance to stripe rust at adult stage.Based on the molecular screening,none of the 59 PNW cultivars(lines)had the polymorphic bands of linked markers to Yr10.There were 12,33 and 29 cultivars(lines)which had polymorphic bands of linked markers to Yr15,Yr18 and Yr39,accounting for 20,55 and 49% of the 59 PNW cultivars(lines),respectively.All these results suggested that Yr15,Yr18 and Yr39 were widespread among PNW cultivars(cultivars)and could be utilized in Chinese wheat stripe rust resistance breeding.
基金funded by the National Key Research and Development Program of China (2016YFD0102000)Applied and Basic Project (2016JY0075) from Science and Technology Department of Sichuan Province, ChinaNational Natural Science Foundation of China (No. 31171542)
文摘Thinopyrum intermedium(2 n = 6 x = 42, JJJ^sJ^sStSt) has been hybridized extensively with common wheat and has proven to be a valuable germplasm source for improving disease resistance, quality attributes, and yield potential in wheat. We characterized new disease resistant wheat-Th. intermedium derivatives A1082 and A5-5 using sequential multi-color fluorescence in situ hybridization(mc-FISH), genomic in situ hybridization(GISH), PCRbased landmark unique gene(PLUG) and intron targeting(IT) markers. A1082 was identified as a wheat-Th. intermedium 3J disomic addition line, and A5-5 was a T4BS·5J^sL homozygous Robertsonian translocation line. Seventy-one and 106 pairs of primers amplified Th.intermedium-specific bands allowing chromosomes 3J and 5J^s to be tracked, respectively. A new oligonucleotide probe, Oligo-6 H-2-100, was developed for FISH labeling of the subterminal region of the long arm of chromosome 5J^s. Both lines were highly resistant to stripe rust pathogen races prevalent in Chinese field screening nurseries. A5-5 also displayed a significant increase in tiller number compared to its wheat parent. The new lines can be exploited as useful germplasms for wheat improvement.
基金supported by the National Natural Science Foundation of China(31771783)the Key Research and Development Program of Sichuan Province,China(2021YFYZ0002)the Sichuan Science and Technology Program,China(2018HH0130 and 2022YFH0105)。
文摘Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and the contents of iron(Fe),zinc(Zn),and seed gluten proteins.Forty-two of the accessions were classified as resistant to stripe rust,while the other four accessions were classified as susceptible to stripe rust in four environments.The average HD of Ae.umbellulata was significantly longer than that of three common wheat cultivars(180.9 d vs.137.0 d),with the exception of PI226500(138.9 d).The Ae.umbellulata accessions also showed high variability in Fe(69.74-348.09 mg kg^(-1))and Zn(49.83-101.65 mg kg^(-1))contents.Three accessions(viz.,PI542362,PI542363,and PI554399)showed relatively higher Fe(230.96-348.09 mg kg^(-1))and Zn(92.46-101.65 mg kg^(-1))contents than the others.The Fe content of Ae.umbellulata was similar to those of Ae.comosa and Ae.markgrafii but higher than those of Ae.tauschii and common wheat.Aegilops umbellulata showed a higher Zn content than Ae.tauschii,Ae.comosa,and common wheat,but a lower content than Ae.markgrafii.Furthermore,Ae.umbellulata had the highest proportion of γ-gliadin among all the species investigated(Ae.umbellulata vs.other species=mean 72.11%vs.49.37%;range:55.33-86.99%vs.29.60-67.91%).These results demonstrated that Ae.umbellulata exhibits great diversity in the investigated traits,so it can provide a potential gene pool for the genetic improvement of these traits in wheat.
基金the National Key Research and Development Program of China(2022YFD1201300)the Key R&D Program of Shandong Province(ZR202211070163)+1 种基金the Provincial Natural Science Foundation of Shandong(ZR2021ZD30,ZR2021MC056)the Young Taishan Scholars Program of Shandong Province.
文摘Stem rust,caused by Puccinia graminis f.sp.tritici(Pgt),threatens global wheat production.Development of cultivars with increased resistance to stem rust by identification,mapping,and deployment of resistance genes is the best strategy for controlling the disease.In this study,we performed fine mapping and characterization of the all-stage stem rust resistance(Sr)gene Sr8155B1 from the durum wheat line 8155-B1.In seedling tests of biparental populations,Sr8155B1 was effective against six Chinese Pgt races tested.In a segregating population of 5060 gametes,Sr8155B1 was mapped to a 0.06-cM region flanked by markers Pku2772 and Pku43365,corresponding to 1.5-and 2.7-Mb regions in the Svevo and Chinese Spring reference genomes.Both regions include several typical nucleotide-binding leucine-rich repeat(NLR)and protein kinase genes that represent candidate genes.Among them,three NLR genes and three receptor-like protein kinases were highly polymorphic between the parental lines and their transcripts were upregulated in the homozygous resistant line TdR2 relative to its susceptible sister line TdS4.Four markers(Pku2772,Pku43365,Pku2950,and Pku3721)developed in this study,together with seedling resistance responses,correctly predicted Sr8155B1 absence or presence in 78 tetraploid wheat genotypes tested.The presence of Sr8155B1 in tetraploid wheat accessions CItr 14916,PI 197492,and PI 197493 was confirmed by mapping in three F_(2)populations.The genetic map and linked markers developed in this study may accelerate the deployment of Sr8155B1-mediated resistance in wheat breeding programs.
文摘Wheat rust diseases are one of the major types of fungal diseases that cause substantial yield quality losses of 15%–20%every year.The wheat rust diseases are identified either through experienced evaluators or computerassisted techniques.The experienced evaluators take time to identify the disease which is highly laborious and too costly.If wheat rust diseases are predicted at the development stages,then fungicides are sprayed earlier which helps to increase wheat yield quality.To solve the experienced evaluator issues,a combined region extraction and cross-entropy support vector machine(CE-SVM)model is proposed for wheat rust disease identification.In the proposed system,a total of 2300 secondary source images were augmented through flipping,cropping,and rotation techniques.The augmented images are preprocessed by histogram equalization.As a result,preprocessed images have been applied to region extraction convolutional neural networks(RCNN);Fast-RCNN,Faster-RCNN,and Mask-RCNN models for wheat plant patch extraction.Different layers of region extraction models construct a feature vector that is later passed to the CE-SVM model.As a result,the Gaussian kernel function in CE-SVM achieves high F1-score(88.43%)and accuracy(93.60%)for wheat stripe rust disease classification.
