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
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
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
Simple sequence repeats (SSR) have been widely used as molecular markers due to their abundance and high polymorphism, However, up to now, the SSR markers had not been developed in the obligate biotrophic phytopatho...Simple sequence repeats (SSR) have been widely used as molecular markers due to their abundance and high polymorphism, However, up to now, the SSR markers had not been developed in the obligate biotrophic phytopathogenic fungus, Blumeria graminis f.sp. tritici. From (AC)10 and (AG)10 enriched genomic libraries for Bgt, 25 primer pairs were designed using the FIASCO (fast isolation by AFLP of sequences containing repeats) protocol. Five primer pairs exhibited polymorphism with allelic diversity from two to seven alleles and produced 29 alleles in a survey of 90 isolates collected from six provinces (cities) in China, while the others displayed monomorphic. Levels of observed heterozygosity ranged from 0.000-0.044 (mean 0.025) and expected heterozygosity ranged from 0.297-0.816 (mean 0.538). These molecular markers provide a novel source to genetic diversity assays and to genetic and physical mapping ofBgt. SSR markers of Bgt need to be further explored.展开更多
Powdery mildew(PM),caused by Blumeria graminis f.sp.tritici(Bgt),is one of the destructive wheat diseases worldwide.Wild emmer wheat(Triticum turgidum ssp.dicoccoides,WEW),a tetraploid progenitor of common wheat,is a ...Powdery mildew(PM),caused by Blumeria graminis f.sp.tritici(Bgt),is one of the destructive wheat diseases worldwide.Wild emmer wheat(Triticum turgidum ssp.dicoccoides,WEW),a tetraploid progenitor of common wheat,is a valuable genetic resource for wheat disease resistance breeding programs.We developed three hexaploid pre-breeding lines with PM resistance genes derived from three WEW accessions.These resistant pre-breeding lines were crossed with susceptible common wheat accessions.Segregations in the F2populations were 3 resistant:1 susceptible,suggesting a single dominant allele in each resistant parent.Mapping of the resistance gene in each line indicated a single locus on the long arm of chromosome 7A,at the approximate location of previously cloned Pm60 from T.urartu.Sanger sequencing revealed three different Pm60 haplotypes(Hap 3,Hap 5,and Hap 6).Co-segregating diagnostic markers were developed for identification and selection of each haplotype.The resistance function of each haplotype was verified by the virus-induced gene silencing(VIGS).Common wheat lines carrying each of these Pm60 haplotypes were resistant to most Bgt isolates and differences in the response arrays suggested allelic variation in response.展开更多
从药用植物一年蓬茎组织中分离并筛选获得了1株内生生防细菌EA19。经形态学、生理生化和16 S rRNA编码基因序列分析等实验,EA19与解淀粉芽孢杆菌(Bacillus amyloliquefaciens)亲缘关系最近。采用菌丝生长速率法对EA19进行了10种植物病...从药用植物一年蓬茎组织中分离并筛选获得了1株内生生防细菌EA19。经形态学、生理生化和16 S rRNA编码基因序列分析等实验,EA19与解淀粉芽孢杆菌(Bacillus amyloliquefaciens)亲缘关系最近。采用菌丝生长速率法对EA19进行了10种植物病原真菌的抑菌活性测定。结果表明,EA19菌体对稻梨孢、镰孢菌、胶孢炭疽菌、稻平脐蠕孢、立枯丝核菌、核盘菌、链格孢和青霉菌等植物病原真菌具有拮抗活性,对稻梨孢和核盘菌的抑制率分别达到96.99%±1.10%和99.16%±0.65%。EA19菌体对小麦白粉病菌(Blumeria graminis f.sp.tritici)的分生孢子萌发和吸器形成具有极显著的抑制作用(P<0.01),并导致病菌附着胞发育畸形。展开更多
【目的】通过室内及田间试验,筛选对小麦白粉病防治效果较好的化学药剂及合理的使用方法。【方法】采取室内盆栽接菌试验及田间小区试验相结合的方式进行,在植株发病后喷雾防治,药后定期调查防治效果。【结果】药后10 d,250 g/L丙环唑乳...【目的】通过室内及田间试验,筛选对小麦白粉病防治效果较好的化学药剂及合理的使用方法。【方法】采取室内盆栽接菌试验及田间小区试验相结合的方式进行,在植株发病后喷雾防治,药后定期调查防治效果。【结果】药后10 d,250 g/L丙环唑乳油112.5 g a.i/hm2处理在室内及田间试验对白粉病的防效分别为82.02%和74.02%,防治效果优于其它药剂处理的防效;其次是25%三唑酮可湿性粉剂135 g a.i/hm2处理,室内及田间试验防效分别为81.84%和67.24%;400 g/L氟硅唑乳油48 g a.i/hm2处理的室内及田间试验防效分别为69.25%和67.99%,对白粉病的防效也较好。25%乙嘧酚水悬浮剂187.5 g a.i/hm2处理、250 g/L已唑醇悬浮剂18.75 g a.i/hm2处理、10%苯醚菌酯悬浮剂12 g a.i/hm2处理在室内试验中对白粉病防治效果较好,但田间小区试验中防效略低。【结论】250 g/L丙环唑乳油112.5 g a.i/hm2处理、25%三唑酮可湿性粉剂135 g a.i/hm2处理、400 g/L氟硅唑乳油48 g a.i/hm2处理可有效控制小麦白粉病的发生及危害,且对小麦生长安全,可在大田合理轮换使用。展开更多
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 (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.
基金supported by the National Basic Research Program of China(2006CB100203 and 2011CB100403)the Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD08A05)the Special Fund for Agro-Scientific Research in the Public Interest(3-15),China
文摘Simple sequence repeats (SSR) have been widely used as molecular markers due to their abundance and high polymorphism, However, up to now, the SSR markers had not been developed in the obligate biotrophic phytopathogenic fungus, Blumeria graminis f.sp. tritici. From (AC)10 and (AG)10 enriched genomic libraries for Bgt, 25 primer pairs were designed using the FIASCO (fast isolation by AFLP of sequences containing repeats) protocol. Five primer pairs exhibited polymorphism with allelic diversity from two to seven alleles and produced 29 alleles in a survey of 90 isolates collected from six provinces (cities) in China, while the others displayed monomorphic. Levels of observed heterozygosity ranged from 0.000-0.044 (mean 0.025) and expected heterozygosity ranged from 0.297-0.816 (mean 0.538). These molecular markers provide a novel source to genetic diversity assays and to genetic and physical mapping ofBgt. SSR markers of Bgt need to be further explored.
基金supported by grants from the National Key Research and Development Program of China(2023YFF1000404,2022YFF10001501)the National Natural Science Foundation of China(32171971)。
文摘Powdery mildew(PM),caused by Blumeria graminis f.sp.tritici(Bgt),is one of the destructive wheat diseases worldwide.Wild emmer wheat(Triticum turgidum ssp.dicoccoides,WEW),a tetraploid progenitor of common wheat,is a valuable genetic resource for wheat disease resistance breeding programs.We developed three hexaploid pre-breeding lines with PM resistance genes derived from three WEW accessions.These resistant pre-breeding lines were crossed with susceptible common wheat accessions.Segregations in the F2populations were 3 resistant:1 susceptible,suggesting a single dominant allele in each resistant parent.Mapping of the resistance gene in each line indicated a single locus on the long arm of chromosome 7A,at the approximate location of previously cloned Pm60 from T.urartu.Sanger sequencing revealed three different Pm60 haplotypes(Hap 3,Hap 5,and Hap 6).Co-segregating diagnostic markers were developed for identification and selection of each haplotype.The resistance function of each haplotype was verified by the virus-induced gene silencing(VIGS).Common wheat lines carrying each of these Pm60 haplotypes were resistant to most Bgt isolates and differences in the response arrays suggested allelic variation in response.
文摘【目的】通过室内及田间试验,筛选对小麦白粉病防治效果较好的化学药剂及合理的使用方法。【方法】采取室内盆栽接菌试验及田间小区试验相结合的方式进行,在植株发病后喷雾防治,药后定期调查防治效果。【结果】药后10 d,250 g/L丙环唑乳油112.5 g a.i/hm2处理在室内及田间试验对白粉病的防效分别为82.02%和74.02%,防治效果优于其它药剂处理的防效;其次是25%三唑酮可湿性粉剂135 g a.i/hm2处理,室内及田间试验防效分别为81.84%和67.24%;400 g/L氟硅唑乳油48 g a.i/hm2处理的室内及田间试验防效分别为69.25%和67.99%,对白粉病的防效也较好。25%乙嘧酚水悬浮剂187.5 g a.i/hm2处理、250 g/L已唑醇悬浮剂18.75 g a.i/hm2处理、10%苯醚菌酯悬浮剂12 g a.i/hm2处理在室内试验中对白粉病防治效果较好,但田间小区试验中防效略低。【结论】250 g/L丙环唑乳油112.5 g a.i/hm2处理、25%三唑酮可湿性粉剂135 g a.i/hm2处理、400 g/L氟硅唑乳油48 g a.i/hm2处理可有效控制小麦白粉病的发生及危害,且对小麦生长安全,可在大田合理轮换使用。