This paper reviewed the research advances of Ug99 and its resistance breeding from the aspects of its discovery, race variation, pathogenicity, distribution, spread, exploration of relative resistant genes, linked mol...This paper reviewed the research advances of Ug99 and its resistance breeding from the aspects of its discovery, race variation, pathogenicity, distribution, spread, exploration of relative resistant genes, linked molecular marker selection and resistance breeding strategies, to provide basis for comprehensive understanding of the new Puccinia graminis f. sp. tritici race Ug99 and its potential threat to wheat production. Ug99 is a new Puccinia grarninis f. sp. tritici race with high variability, strong pathogenicity and rapid spread speed, which is likely to cause global damages to world wheat production. We should strengthen the exploration and utilization of new resistance genes in wheat and relative species and breeding of new wheat varieties with durable resistance, to control and prevent damages caused by Ug99 and its variants.展开更多
[Objective] The research aimed to study the relationship between the hypersensitive response of wheat to Blumeria graminis f.sp.tritici and hydrogen peroxide,3 enzyme activities changes and lay the foundation for disc...[Objective] The research aimed to study the relationship between the hypersensitive response of wheat to Blumeria graminis f.sp.tritici and hydrogen peroxide,3 enzyme activities changes and lay the foundation for discussing the resistant physiological mechanism of wheat to B.graminis.[Method] Taking B.graminis Bgt 17 and Bgt 6 and wheat cultivar Yang 158 as test materials,the number of hypersensitive cells and activities of POD,PPO and SOD in wheat leaves treated by H2O2 were determined.[Result] The mastoid...展开更多
With validamycin A.（0.2 billion spores/ml） Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for＇ rich sheath blight were in...With validamycin A.（0.2 billion spores/ml） Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for＇ rich sheath blight were investigated. The results of two- year test showed that when the application amount was in the range of 45-90 g.a.i/ hm^2, the field efficacy of validamycin A-（0.2 billion spores/ml） P. polymyxa DN-1 3% AS in the initial infection stage of rich sheath blight （Le., the diseased plant rate was below 5%） reached 80.38%-89.06%, and that in the peak infection stage （i.e., the diseased plant rate was higher than 10%） reached only 41.12%-53.26%. The field efficacy of validamycin A.（0.2 billion spores/ml） P. polymyxa DN-1 3% AS at the early onset of rich sheath blight was significantly better than that at the onset, so that the application time of validamycin A .（0.2 billion spores/ml） P. polymyxa DN-1 3% AS should be appropriately brought forward in the prevention and control of rice sheath blight.展开更多
Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is an important disease in China. To characterize the virulence and diversity of the pathogen, 1 082 isolates were obtained from 8 major wheat-growing ...Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is an important disease in China. To characterize the virulence and diversity of the pathogen, 1 082 isolates were obtained from 8 major wheat-growing regions during the spring growing season in 2011. The virulence test was performed by inoculation on detached leaves of 22 differential lines with known Pm genes. Frequencies of virulence on these genotypes ranged from 0 to 97.4%. None of the 1 082 isolates was compatible to Pm21 and less than 20.0%were virulent to the genotype carrying Pm13. In contrast, the virulence frequencies of each population was more than 50.0%to differentials carrying Pm1a, Pm3b, Pm3c, Pm3f, Pm5a, Pm6 and Pm8. In total, 1 028 pathotypes were detected, of which 984 were unique. Phenotypic diversity indices revealed a high level of diversity within populations. Genetic distance between different populations correlated signiifcantly with geographical distance （R2=0.494, P 0.001）. In addition, isolates from Xinjiang appear to form a separate group. Signiifcant positive or negative associations between alleles at pairs of virulence loci were detected in 57 allele pairs to Pm genes. Virulence and diversity of the 8 populations suggested that varieties with effective resistance gene combinations should be developed at a regional level.展开更多
Barley powdery mildew caused by Blumeria graminis f. sp. hordei （Bgh） is one of the most destructive foliar diseases of barley in the winter barley region of China. The evaluation and assessment of the virulence and...Barley powdery mildew caused by Blumeria graminis f. sp. hordei （Bgh） is one of the most destructive foliar diseases of barley in the winter barley region of China. The evaluation and assessment of the virulence and diversity of Bgh populations help to determine effective sources of resistance to the pathogen. 515 isolates were collected from seven populations of Bgh on cultivated barley in seven geographically distant locations in 2006. Their virulence was determined by inoculation onto 26 differential host lines. All of the isolates belonged to 58 pathotypes and 13 of which included 81% of these isolates. The most abundant pathotype was pathotype 0047 （18.3%）, the second most abundant was pathotype 0045 （11.8%） and the third most abundant was pathotype 0057 （7.8%）. Most of virulent genes investigated in this study showed similar frequencies in the seven different areas. These indicate that the seven locations may be in a uniform epidemiological region and barley cultivars in these areas may have similar genetic background. Diversities within these populations and distances between these populations measured by KOIND package were different. Correlations were not found between the genetic distance and the geographical distances between different locations. This suggested that long distance spread and local epidemics existed in the major winter barley growing regions in China.展开更多
To gain more precise information about molecular genetic variation for wild populations of Blumeria graminis f. sp. tritici from Qinghai Province, China, 38 single-colony isolates were purified from samples collected ...To gain more precise information about molecular genetic variation for wild populations of Blumeria graminis f. sp. tritici from Qinghai Province, China, 38 single-colony isolates were purified from samples collected from Haidong District, Xining City and Hainan Tibetan Autonomous Prefecture in 2010. The virulence of 21 isolates among them was tested at seedling stage on 34 wheat cultivars（lines） carrying known powdery mildew（Pm） resistant genes. The results showed that V1 a, V3 a, V3 c, V3 e, V5 a, V6, V7, V8 and V19 had high virulence frequencies（〉75%）, indicating a wide distribution; and V1 c, V5 b, V12, V13, V16, V21, VXBD, V2＋6, V2＋Mld and V4＋8, with less distribution, appeared to be lower in frequencies（0-20%）. The Nei＇s gene diversity（H）, Shannon＇s information index（I） and the percentage of polymorphic loci（P） were 0.23, 0.35 and 67.65%, respectively, which revealed a virulent diversity. The results from single nucleotide polymorphisms（SNPs） of 38 isolates showed that three housekeeping genes were found to contain a total of 9 SNP sites. 10 haplotypes（H1-H10） were inferred from the concatenated sequences, with 1 haplotype（H1） comprising of over 55% of Qinghai population. Phylogenic analysis did not show obvious geographical subdivision between the isolates. A multilocus haplotype network presented a radial structure, with H1 in the central as an inferred ancestor. Using analysis of molecular variance（AMOVA）, we found 1.63% of the total variation was among populations and 98.37% within populations, with a low fixations index（FST=0.01634, P〈0.05）. This revealed a relatively high genetic diversity but a low genetic divergence in Qinghai population. Moreover, the molecular data on gene flow（Nm=6.32） confirmed the migration of pathogen populations among areas in Qinghai Province.展开更多
A high degree of virulence diversity has been maintained in the population of Puccinia graminis f. sp. tritici （Pgt） in northwestern United States. Although Berberis vulgaris is present in the region and Pgt has bee...A high degree of virulence diversity has been maintained in the population of Puccinia graminis f. sp. tritici （Pgt） in northwestern United States. Although Berberis vulgaris is present in the region and Pgt has been isolated from aecial infections on B. vulgaris, the population is too diverse to be explained by the limited presence of B. vulgaris alone. Since 2008, we have isolated P. graminis from aecial infections on fruits of Mahonia repens and Mahonia aquifolium from northwestern United States. These two native woody shrub species, widely distributed in western North America, were once classified as resistant to P. graminis based on artificial inoculations. By isolating P. graminis from aecia, we established that M. repens and M. aquifolium along with B. vulgaris （albeit infrequent） serve as the alternate hosts ofP. graminis in the region. The isolates of P. graminis from Mahonia of North America had diverse virulence patterns and most of the isolates could be differentiated on Morocco, Line E, Chinese Spring, Little Club, LMPG-6, Rusty, and other genotypes that are considered to be universally susceptible to most Pgt isolates. This discovery explained the persistence of virulence diversity of Pgt observed in isolates derived from uredinia on cereal crops in the region. In addition to cereal crops, uredinial stage of the P. graminis population is sustained by wild grasses, especially Elymus glaucus, a native grass sharing the same habitat with the rusted Mahonia spp. Although virulence to some important stem rust resistance genes was observed in some isolates derived from Mahonia of North America when tested against single stem rust resistance gene stocks, the overall virulence is very limited in these isolates. This is likely a result of limited selection pressure on the rust population. In contrast to northwestern United Sates, the Pgt population in east of the Rocky Mountains of North America has declined steadily with a single race, QFCSC, being predominant in the last decade. This decline is likely due to a combination of factors, of which a lack of sexual recombination in the region is perhaps the most important one.展开更多
Wheat stem rust, caused by Puccinia graminis f. sp. tritici(Pgt), is a potentially devastating fungal disease of wheat worldwide. The present study was to evaluate the resistance of 42 wheat monogenic lines with known...Wheat stem rust, caused by Puccinia graminis f. sp. tritici(Pgt), is a potentially devastating fungal disease of wheat worldwide. The present study was to evaluate the resistance of 42 wheat monogenic lines with known stem rust resistance(Sr) genes and 69 wheat cultivars to three new Pgt races(34C0MRGQM, 34C3MKGQM, and 34C6MTGSM)identified from aeciospores at the seedling and adult-plant stages. The phenotyping results revealed that monogenic lines harboring resistance genes Sr9e, Sr17, Sr21, Sr22, Sr26, Sr30, Sr31, Sr33, Sr35, Sr36, Sr37, Sr38, Sr47, SrTmp,and SrTt3 were effectively resistant to all three Pgt races at the seedling and adult-plant stages. In contrast, monogenic lines containing Sr5, Sr6, Sr7b, Sr9a, Sr9d, Sr9f, Sr9g, Sr9b, Sr16, Sr24, Sr28, and Sr39 were highly susceptible to these races at both seedling and adult-plant stages. The other lines with Sr8a, Sr10, Sr11, Sr13, Sr14, Sr15, Sr18, Sr20,Sr19, Sr23, Sr25, Sr27, Sr29, Sr32, and Sr34, displayed variable levels of resistance to one or two of the tested races.Seedling infection types(ITs) and adult-plant infection responses(IRs) indicated that 41(59.4%) of the wheat cultivars showed high resistance to all the three races. Molecular marker analysis showed that four wheat culitvars likely carried Sr2, 20 wheat culitvars likely carried Sr31, 9 wheat culitvars likely carried Sr38, and none of the cultivars carried Sr24,Sr25, and Sr26. Our results provide a scientific basis for rational utilization of the tested Sr genes and wheat cultivars against these novel Pgt races.展开更多
基金Supported by Starting Fund for Introduction of Qualified Personnel from Henan Agricultural University (30300190)~~
文摘This paper reviewed the research advances of Ug99 and its resistance breeding from the aspects of its discovery, race variation, pathogenicity, distribution, spread, exploration of relative resistant genes, linked molecular marker selection and resistance breeding strategies, to provide basis for comprehensive understanding of the new Puccinia graminis f. sp. tritici race Ug99 and its potential threat to wheat production. Ug99 is a new Puccinia grarninis f. sp. tritici race with high variability, strong pathogenicity and rapid spread speed, which is likely to cause global damages to world wheat production. We should strengthen the exploration and utilization of new resistance genes in wheat and relative species and breeding of new wheat varieties with durable resistance, to control and prevent damages caused by Ug99 and its variants.
文摘[Objective] The research aimed to study the relationship between the hypersensitive response of wheat to Blumeria graminis f.sp.tritici and hydrogen peroxide,3 enzyme activities changes and lay the foundation for discussing the resistant physiological mechanism of wheat to B.graminis.[Method] Taking B.graminis Bgt 17 and Bgt 6 and wheat cultivar Yang 158 as test materials,the number of hypersensitive cells and activities of POD,PPO and SOD in wheat leaves treated by H2O2 were determined.[Result] The mastoid...
基金Supported by National Agricultural Science and Technology Achievement Transformation Fund of China(2010GB2C300196)Modern Agricultural Production Development Fund(Rice Industry)Project of Anhui Academy of Agricultural SciencesIntegration and Demonstration of Chemical Fertilizer and Agrochemical Reduction and Efficiency Increasing Technology for Rice in Rice-wheat(rape)Rotation Areas in Anhui(2016YFD0200806)~~
文摘With validamycin A.（0.2 billion spores/ml） Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for＇ rich sheath blight were investigated. The results of two- year test showed that when the application amount was in the range of 45-90 g.a.i/ hm^2, the field efficacy of validamycin A-（0.2 billion spores/ml） P. polymyxa DN-1 3% AS in the initial infection stage of rich sheath blight （Le., the diseased plant rate was below 5%） reached 80.38%-89.06%, and that in the peak infection stage （i.e., the diseased plant rate was higher than 10%） reached only 41.12%-53.26%. The field efficacy of validamycin A.（0.2 billion spores/ml） P. polymyxa DN-1 3% AS at the early onset of rich sheath blight was significantly better than that at the onset, so that the application time of validamycin A .（0.2 billion spores/ml） P. polymyxa DN-1 3% AS should be appropriately brought forward in the prevention and control of rice sheath blight.
基金supported by the National Basic Research Program of China (2013CB127700)the Special Fund for Agro-Scientific Research in the Public Interest, China (201303016)
文摘Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is an important disease in China. To characterize the virulence and diversity of the pathogen, 1 082 isolates were obtained from 8 major wheat-growing regions during the spring growing season in 2011. The virulence test was performed by inoculation on detached leaves of 22 differential lines with known Pm genes. Frequencies of virulence on these genotypes ranged from 0 to 97.4%. None of the 1 082 isolates was compatible to Pm21 and less than 20.0%were virulent to the genotype carrying Pm13. In contrast, the virulence frequencies of each population was more than 50.0%to differentials carrying Pm1a, Pm3b, Pm3c, Pm3f, Pm5a, Pm6 and Pm8. In total, 1 028 pathotypes were detected, of which 984 were unique. Phenotypic diversity indices revealed a high level of diversity within populations. Genetic distance between different populations correlated signiifcantly with geographical distance （R2=0.494, P 0.001）. In addition, isolates from Xinjiang appear to form a separate group. Signiifcant positive or negative associations between alleles at pairs of virulence loci were detected in 57 allele pairs to Pm genes. Virulence and diversity of the 8 populations suggested that varieties with effective resistance gene combinations should be developed at a regional level.
基金support from the National Natural Science Foundation of China (30671289)the National Key Tech-nologies R&D Program (2006B BAD0 2B 04)+1 种基金the Nationnal Special Fund for Agro-Scientific Research inthe Public Interest (nyhyzx017-001-barley)the Ear-marked Fund for Modern Agro-Industry Technology Research System,China
文摘Barley powdery mildew caused by Blumeria graminis f. sp. hordei （Bgh） is one of the most destructive foliar diseases of barley in the winter barley region of China. The evaluation and assessment of the virulence and diversity of Bgh populations help to determine effective sources of resistance to the pathogen. 515 isolates were collected from seven populations of Bgh on cultivated barley in seven geographically distant locations in 2006. Their virulence was determined by inoculation onto 26 differential host lines. All of the isolates belonged to 58 pathotypes and 13 of which included 81% of these isolates. The most abundant pathotype was pathotype 0047 （18.3%）, the second most abundant was pathotype 0045 （11.8%） and the third most abundant was pathotype 0057 （7.8%）. Most of virulent genes investigated in this study showed similar frequencies in the seven different areas. These indicate that the seven locations may be in a uniform epidemiological region and barley cultivars in these areas may have similar genetic background. Diversities within these populations and distances between these populations measured by KOIND package were different. Correlations were not found between the genetic distance and the geographical distances between different locations. This suggested that long distance spread and local epidemics existed in the major winter barley growing regions in China.
基金supported by the National Basic Research Program of China(2011CB100403 and 2013CB127704)the Special Fund for Agro-Scientific Research in the Public Interest,China(201303016)
文摘To gain more precise information about molecular genetic variation for wild populations of Blumeria graminis f. sp. tritici from Qinghai Province, China, 38 single-colony isolates were purified from samples collected from Haidong District, Xining City and Hainan Tibetan Autonomous Prefecture in 2010. The virulence of 21 isolates among them was tested at seedling stage on 34 wheat cultivars（lines） carrying known powdery mildew（Pm） resistant genes. The results showed that V1 a, V3 a, V3 c, V3 e, V5 a, V6, V7, V8 and V19 had high virulence frequencies（〉75%）, indicating a wide distribution; and V1 c, V5 b, V12, V13, V16, V21, VXBD, V2＋6, V2＋Mld and V4＋8, with less distribution, appeared to be lower in frequencies（0-20%）. The Nei＇s gene diversity（H）, Shannon＇s information index（I） and the percentage of polymorphic loci（P） were 0.23, 0.35 and 67.65%, respectively, which revealed a virulent diversity. The results from single nucleotide polymorphisms（SNPs） of 38 isolates showed that three housekeeping genes were found to contain a total of 9 SNP sites. 10 haplotypes（H1-H10） were inferred from the concatenated sequences, with 1 haplotype（H1） comprising of over 55% of Qinghai population. Phylogenic analysis did not show obvious geographical subdivision between the isolates. A multilocus haplotype network presented a radial structure, with H1 in the central as an inferred ancestor. Using analysis of molecular variance（AMOVA）, we found 1.63% of the total variation was among populations and 98.37% within populations, with a low fixations index（FST=0.01634, P〈0.05）. This revealed a relatively high genetic diversity but a low genetic divergence in Qinghai population. Moreover, the molecular data on gene flow（Nm=6.32） confirmed the migration of pathogen populations among areas in Qinghai Province.
文摘A high degree of virulence diversity has been maintained in the population of Puccinia graminis f. sp. tritici （Pgt） in northwestern United States. Although Berberis vulgaris is present in the region and Pgt has been isolated from aecial infections on B. vulgaris, the population is too diverse to be explained by the limited presence of B. vulgaris alone. Since 2008, we have isolated P. graminis from aecial infections on fruits of Mahonia repens and Mahonia aquifolium from northwestern United States. These two native woody shrub species, widely distributed in western North America, were once classified as resistant to P. graminis based on artificial inoculations. By isolating P. graminis from aecia, we established that M. repens and M. aquifolium along with B. vulgaris （albeit infrequent） serve as the alternate hosts ofP. graminis in the region. The isolates of P. graminis from Mahonia of North America had diverse virulence patterns and most of the isolates could be differentiated on Morocco, Line E, Chinese Spring, Little Club, LMPG-6, Rusty, and other genotypes that are considered to be universally susceptible to most Pgt isolates. This discovery explained the persistence of virulence diversity of Pgt observed in isolates derived from uredinia on cereal crops in the region. In addition to cereal crops, uredinial stage of the P. graminis population is sustained by wild grasses, especially Elymus glaucus, a native grass sharing the same habitat with the rusted Mahonia spp. Although virulence to some important stem rust resistance genes was observed in some isolates derived from Mahonia of North America when tested against single stem rust resistance gene stocks, the overall virulence is very limited in these isolates. This is likely a result of limited selection pressure on the rust population. In contrast to northwestern United Sates, the Pgt population in east of the Rocky Mountains of North America has declined steadily with a single race, QFCSC, being predominant in the last decade. This decline is likely due to a combination of factors, of which a lack of sexual recombination in the region is perhaps the most important one.
文摘Wheat stem rust, caused by Puccinia graminis f. sp. tritici(Pgt), is a potentially devastating fungal disease of wheat worldwide. The present study was to evaluate the resistance of 42 wheat monogenic lines with known stem rust resistance(Sr) genes and 69 wheat cultivars to three new Pgt races(34C0MRGQM, 34C3MKGQM, and 34C6MTGSM)identified from aeciospores at the seedling and adult-plant stages. The phenotyping results revealed that monogenic lines harboring resistance genes Sr9e, Sr17, Sr21, Sr22, Sr26, Sr30, Sr31, Sr33, Sr35, Sr36, Sr37, Sr38, Sr47, SrTmp,and SrTt3 were effectively resistant to all three Pgt races at the seedling and adult-plant stages. In contrast, monogenic lines containing Sr5, Sr6, Sr7b, Sr9a, Sr9d, Sr9f, Sr9g, Sr9b, Sr16, Sr24, Sr28, and Sr39 were highly susceptible to these races at both seedling and adult-plant stages. The other lines with Sr8a, Sr10, Sr11, Sr13, Sr14, Sr15, Sr18, Sr20,Sr19, Sr23, Sr25, Sr27, Sr29, Sr32, and Sr34, displayed variable levels of resistance to one or two of the tested races.Seedling infection types(ITs) and adult-plant infection responses(IRs) indicated that 41(59.4%) of the wheat cultivars showed high resistance to all the three races. Molecular marker analysis showed that four wheat culitvars likely carried Sr2, 20 wheat culitvars likely carried Sr31, 9 wheat culitvars likely carried Sr38, and none of the cultivars carried Sr24,Sr25, and Sr26. Our results provide a scientific basis for rational utilization of the tested Sr genes and wheat cultivars against these novel Pgt races.
