共查询到20条相似文献,搜索用时 31 毫秒
1.
Malene Søltoft Lise N. Jørgensen Bo Svensmark Inge S. Fomsgaard 《Biochemical Systematics and Ecology》2008
Fusarium Head Blight (FHB) is a destructive disease that affects the grain yield and quality of cereals. The relationship between the natural defense chemicals benzoxazinoids and the FHB resistance of field grown winter wheat varieties was investigated. FHB resistance was assessed by the inoculation of wheat ears with mixtures of Fusarium avenaceum, Fusarium culmorum, Fusarium graminearum, and Microdochium nivale. 相似文献
2.
Schmolke M Zimmermann G Buerstmayr H Schweizer G Miedaner T Korzun V Ebmeyer E Hartl L 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(4):747-756
Fusarium head blight (FHB), mainly caused by Fusarium graminearum and F. culmorum, can significantly reduce the grain quality of wheat (Triticum aestivum L.) due to mycotoxin contamination. The objective of this study was to identify quantitative trait loci (QTLs) for FHB resistance in a winter wheat population developed by crossing the resistant German cultivar Dream with the susceptible British cultivar Lynx. A total of 145 recombinant inbred lines (RILs) were evaluated following spray inoculation with a F. culmorum suspension in field trials in 2002 in four environments across Germany. Based on amplified fragment length polymorphism and simple sequence repeat marker data, a 1,734 cM linkage map was established assuming that the majority of the polymorphic parts of the genome were covered. The area under disease progress curve (AUDPC) was calculated based on the visually scored FHB symptoms. The population segregated quantitatively for FHB severity. Composite interval mapping analysis for means across the environments identified four FHB resistance QTLs on chromosomes 6AL, 1B, 2BL and 7BS. Individually the QTLs explained 19%, 12%, 11% and 21% of the phenotypic variance, respectively, and together accounted for 41%. The QTL alleles conferring resistance on 6AL, 2BL and 7BS originated from cv. Dream. The resistance QTL on chromosome 6AL partly overlapped with a QTL for plant height. The FHB resistance QTL on 7BS coincided with a QTL for heading date, but the additive effect on heading date was of minor importance. The resistance QTL on chromosome 1B was associated with the T1BL.1RS wheat-rye translocation of Lynx. 相似文献
3.
Sonja Kollers Bernd Rodemann Jie Ling Viktor Korzun Erhard Ebmeyer Odile Argillier Maike Hinze J?rg Plieske Dagmar Kulosa Martin W. Ganal Marion S. R?der 《PloS one》2013,8(2)
A total of 358 recent European winter wheat varieties plus 14 spring wheat varieties were evaluated for resistance to Fusarium head blight (FHB) caused by Fusarium graminearum and Fusarium culmorum in four separate environments. The FHB scores based on FHB incidence (Type I resistance)×FHB severity (Type II resistance) indicated a wide phenotypic variation of the varieties with BLUE (best linear unbiased estimation) values ranging from 0.07 to 33.67. Genotyping with 732 microsatellite markers resulted in 782 loci of which 620 were placed on the ITMI map. The resulting average marker distance of 6.8 cM allowed genome wide association mapping employing a mixed model. Though no clear population structure was discovered, a kinship matrix was used for stratification. A total of 794 significant (−log10(p)-value≥3.0) associations between SSR-loci and environment-specific FHB scores or BLUE values were detected, which included 323 SSR alleles. For FHB incidence and FHB severity a total of 861 and 877 individual marker-trait associations (MTA) were detected, respectively. Associations for both traits co-located with FHB score in most cases. Consistent associations detected in three or more environments were found on all chromosomes except chromosome 6B, and with the highest number of MTA on chromosome 5B. The dependence of the number of favourable and unfavourable alleles within a variety to the respective FHB scores indicated an additive effect of favourable and unfavourable alleles, i.e. genotypes with more favourable or less unfavourable alleles tended to show greater resistance to FHB. Assessment of a marker specific for the dwarfing gene Rht-D1 resulted in strong effects. The results provide a prerequisite for designing genome wide breeding strategies for FHB resistance. 相似文献
4.
Resistance against Fusarium Head Blight in Transgenic Wheat Plants Expressing the ScNPR1 gene 总被引:1,自引:0,他引:1 下载免费PDF全文
Guihong Yu Xu Zhang Jingbao Yao MiaoPing Zhou Hongxiang Ma 《Journal of Phytopathology》2017,165(4):223-231
Fusarium head blight (FHB) is a severe global wheat disease that may cause severe yield losses, especially during epidemic years. Transforming the regulatory genes in the metabolic pathways of disease resistance into wheat via transgenic methods is one way to improve resistance to FHB. ScNPR1 (Secale cereale‐NPR1), a regulatory gene for systemic acquired resistance (SAR), was isolated from S. cereale cv Jingzhouheimai and transformed into the moderately FHB‐susceptible wheat variety Ningmai 13. RT‐PCR analysis indicated that the ScNPR1 gene was stably expressed in transgenic plants. An evaluation of the resistance to FHB revealed that six ScNPR1 transgenic lines (NP1, NP2, NP3, NP4, NP5 and NP6) exhibited significantly higher FHB resistance than the wild‐type wheat Ningmai 13 and the null‐segregated plants. The expression of pathogenesis‐related (PR) genes after Fusarium graminearum inoculation was earlier or higher than those in the wild‐type variety Ningmai 13. The high expression in the early stages of PR genes should account for the enhanced FHB resistance in the transgenic lines. Our results suggest that overexpression of ScNPR1 could be used to improve FHB resistance in wheat. 相似文献
5.
Zongkuan Wang Bo Yang Wenyue Zheng Lei Wang Xingxing Cai Jie Yang Rongrong Song Sen Yang Yuyin Wang Jin Xiao Huiquan Liu Yan Wang Xiue Wang Yuanchao Wang 《Plant biotechnology journal》2023,21(4):769-781
Fusarium head blight (FHB), caused by Fusarium graminearum, is a devastating disease in wheat (Triticum aestivum) that results in substantial yield losses and mycotoxin contamination. Reliable genetic resources for FHB resistance in wheat are lacking. In this study, we characterized glycoside hydrolase 12 (GH12) family proteins secreted by F. graminearum. We established that two GH12 proteins, Fg05851 and Fg11037, have functionally redundant roles in F. graminearum colonization of wheat. Furthermore, we determined that the GH12 proteins Fg05851 and Fg11037 are recognized by the leucine-rich-repeat receptor-like protein RXEG1 in the dicot Nicotiana benthamiana. Heterologous expression of RXEG1 conferred wheat responsiveness to Fg05851 and Fg11037, enhanced wheat resistance to F. graminearum and reduced levels of the mycotoxin deoxynivalenol in wheat grains in an Fg05851/Fg11037-dependent manner. In the RXEG1 transgenic lines, genes related to pattern-triggered plant immunity, salicylic acid, jasmonic acid, and anti-oxidative homeostasis signalling pathways were upregulated during F. graminearum infection. However, the expression of these genes was not significantly changed during infection by the deletion mutant ΔFg05851/Fg11037, suggesting that the recognition of Fg05851/Fg11037 by RXEG1 triggered plant resistance against FHB. Moreover, introducing RXEG1 into three other different wheat cultivars via crossing also conferred resistance to F. graminearum. Expression of RXEG1 did not have obvious deleterious effects on plant growth and development in wheat. Our study reveals that N. benthamiana RXEG1 remains effective when transferred into wheat, a monocot, which in turn suggests that engineering wheat with interfamily plant immune receptor transgenes is a viable strategy for increasing resistance to FHB. 相似文献
6.
F. A. van Eeuwijk A. Mesterhazy Ch. I. Kling P. Ruckenbauer L. Saur H. Bürstmayr M. Lemmens L. C. P. Keizer N. Maurin C. H. A. Snijders 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(2):221-228
To determine whether resistance to Fusarium head blight in winter wheat is horizontal and non-species specific, 25 genotypes from five European countries were tested at six locations across Europe in the years 1990, 1991, and 1992. The five genotypes from each country had to cover the range from resistant to susceptible. The locations involved were Wageningen, Vienna, Rennes, Hohenheim, Oberer Lindenhof, and Szeged. In total, 17 local strains of Fusarium culmorum, F. graminearum, and F. nivale were used for experimental inoculation. One strain, F. culmorum IPO 39-01, was used at all locations. Best linear unbiased predictions (BLUPs) for the head blight ratings of the genotypes were formed within each particular location for each combination of year and strain. The BLUPs over all locations were collected in a genotype-by environment table in which the genotypic dimension consisted of the 25 genotypes, while the environmental dimension was made up of 59 year-by-strain-by-location combinations. A multiplicative model was fitted to the genotype by-environment interaction in this table. The inverses of the variances of the genotype-by-environment BLUPs were used as weights. Interactions between genotypes and environments were written as sums of products between genotypic scores and environmental scores. After correction for year-by-location influence very little variation in environmental scores could be ascribed to differences between strains. This provided the basis for the conclusion that the resistance to Fusarium head blight in winter wheat was of the horizontal and non-species specific type. There was no indication for any geographical pattern in virulence genes. Any reasonable aggressive strain, a F. culmorum strain for the cool climates and a F. graminearum strain for the warmer humid areas, should be satisfactory for screening purposes. 相似文献
7.
J. A. Anderson R. W. Stack S. Liu B. L. Waldron A. D. Fjeld C. Coyne B. Moreno-Sevilla J. Mitchell Fetch Q. J. Song P. B. Cregan R. C. Frohberg 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(8):1164-1168
Genetic resistance to Fusarium head blight (FHB), caused by Fusarium graminearum, is necessary to reduce the wheat grain yield and quality losses caused by this disease. Development of resistant cultivars
has been slowed by poorly adapted and incomplete resistance sources and confounding environmental effects that make screening
of germplasm difficult. DNA markers for FHB resistance QTLs have been identified and may be used to speed the introgression
of resistance genes into adapted germplasm. This study was conducted to identify and map additional DNA markers linked to
genes controlling FHB resistance in two spring wheat recombinant inbred populations, both segregating for genes from the widely
used resistance source ’Sumai 3’. The first population was from the cross of Sumai 3/Stoa in which we previously identified
five resistance QTLs. The second population was from the cross of ND2603 (Sumai 3/Wheaton) (resistant)/ Butte 86 (moderately
susceptible). Both populations were evaluated for reaction to inoculation with F. graminearum in two greenhouse experiments. A combination of 521 RFLP, AFLP, and SSR markers were mapped in the Sumai 3/Stoa population
and all DNA markers associated with resistance were screened on the ND2603/Butte 86 population. Two new QTL on chromosomes
3AL and 6AS wer found in the ND2603/Butte 86 population, and AFLP and SSR markers were identified that explained a greater
portion of the phenotypic variation compared to the previous RFLP markers. Both of the Sumai 3-derived QTL regions (on chromosomes
3BS, and 6BS) from the Sumai 3/Stoa population were associated with FHB resistance in the ND2603/Butte 86 population. Markers
in the 3BS QTL region (Qfhs.ndsu-3BS) alone explain 41.6 and 24.8% of the resistance to FHB in the Sumai 3/Stoa and ND2603/Butte 86 populations, respectively.
This region contains a major QTL for resistance to FHB and should be useful in marker-assisted selection.
Received: 17 August 2000 / Accepted: 16 October 2000 相似文献
8.
Sung-Hwan Cho Jungkwan Lee Ki-Hong Jung Yin-Won Lee Jong-Chul Park Nam-Chon Paek 《Journal of Plant Biology》2012,55(1):64-72
Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most serious diseases in wheat (Triticum aestivum) and barley (Hordeum vulgare). Dahongmil is an elite Korean wheat cultivar with relatively high resistance to FHB. To identify differentially expressed genes in the resistant cultivar Dahongmil and the susceptible cultivar Urimil after inoculation of F. graminearum, we used the Affymetrix GeneChip® Wheat Genome Array to identify 328 ESTs that were differentially expressed in inoculated seedling tissues of the two cultivars. From these, we selected 16 induced genes and found that they have defense functions, such as genes encoding pathogen resistance proteins, oxidative stress-related proteins, metabolism, and proteins involved in defense mechanisms. To verify the DNA microarray results, we tested seven of these genes by semiquantitative RT-PCR and confirmed that these defense- and stress-related genes were expressed at much higher levels in the resistant Dahongmil cultivar. We next developed a hypothetical functional gene network and identified 89 interaction pairs mediated by four of the differentially expressed genes in the hypothetical network. We further refined the network by identifying nine genes showing significant up- or down-regulation after FHB challenge in the resistant cultivar and two genes having multiple interactions with queried proteins. We hope that the set of induced genes identified in this study can be used for development of new wheat and barley cultivars with improved resistance to FHB. 相似文献
9.
Sujon Sarowar Syeda T. Alam Ragiba Makandar Hyeonju Lee Harold N. Trick Yanhong Dong Jyoti Shah 《Molecular Plant Pathology》2019,20(5):626-640
Fusarium head blight (FHB) is a disease of the floral tissues of wheat and barley for which highly resistant varieties are not available. Thus, there is a need to identify genes/mechanisms that can be targeted for the control of this devastating disease. Fusarium graminearum is the primary causal agent of FHB in North America. In addition, it also causes Fusarium seedling blight. Fusarium graminearum can also cause disease in the model plant Arabidopsis thaliana. The Arabidopsis–F. graminearum pathosystem has facilitated the identification of targets for the control of disease caused by this fungus. Here, we show that resistance against F. graminearum can be enhanced by flg22, a bacterial microbe-associated molecular pattern (MAMP). flg22-induced resistance in Arabidopsis requires its cognate pattern recognition receptor (PRR) FLS2, and is accompanied by the up-regulation of WRKY29. The expression of WRKY29, which is associated with pattern-triggered immunity (PTI), is also induced in response to F. graminearum infection. Furthermore, WRKY29 is required for basal resistance as well as flg22-induced resistance to F. graminearum. Moreover, constitutive expression of WRKY29 in Arabidopsis enhances disease resistance. The PTI pathway is also activated in response to F. graminearum infection of wheat. Furthermore, flg22 application and ectopic expression of WRKY29 enhance FHB resistance in wheat. Thus, we conclude that the PTI pathway provides a target for the control of FHB in wheat. We further show that the ectopic expression of WRKY29 in wheat results in shorter stature and early heading time, traits that are important to wheat breeding. 相似文献
10.
11.
《Journal of microbiological methods》2007,68(3):534-542
Fusarium graminearum (teleomorph, Gibberella zeae) is the predominant causal agent of Fusarium head blight (FHB) of wheat resulting in yearly losses through reduction in grain yield and quality and accumulation of fungal generated toxins in grain. Numerous fungal genes potentially involved in virulence have been identified and studies with deletion mutants to ascertain their role are in progress. Although wheat field trials with wild-type and mutant strains are critical to understand the role these genes may play in the disease process, the interpretation of field trial data is complicated by FHB generated by indigenous species of F. graminearum. This report describes the development of a SYBR green-based real time PCR assay that quantifies the total F. graminearum genomic DNA in a plant sample as well as the total F. graminearum genomic DNA contributed from a strain containing a common fungal selectable marker used to create deletion mutants. We found our method more sensitive, reproducible and accurate than other similar recently described assays and comparable to the more expensive probe-based assays. This assay will allow investigators to correlate the amount of disease observed in wheat field trials to the F. graminearum mutant strains being examined. 相似文献
12.
Fusarium head blight (FHB) caused by Fusarium graminearum and F. culmorum is a devastating disease with high effects on grain yield and quality. We developed spring wheat lines incorporating the highly effective FHB resistance quantitative trait loci (QTL) Fhb1 and Qfhs.ifa‐5A. Whether these QTL lead to competition within Fusarium populations in the field resulting in isolates with higher aggressiveness has not been analysed. The aims of this study were to determine (i) the aggressiveness potential of F. graminearum and F. culmorum isolates, (ii) competition effects of these isolates in binary mixtures and (iii) the stability of resistant hosts. Six F. graminearum, two F. culmorum isolates and seven binary mixtures containing these isolates were tested for their aggressiveness and mycotoxin production at two locations in South Germany in 2007 and 2008. Host lines were four spring wheat lines containing the resistance QTL Fhb1 and/or Qfhs.ifa‐5A or none of them and one standard variety. Re‐isolates were sampled from plots inoculated with the binary mixtures to identify the percentage of each isolate in the mixture by simple sequence repeat markers. Resistant host lines reacted as expected and had a high stability to all isolates and mixtures. Only less important host × mixture interactions were detected. Aggressiveness among isolates and mixtures was significantly different. Type and amount of mycotoxin and high single isolate aggressiveness were not necessarily advantageous in the mixture. However, both F. culmorum isolates outcompeted F. graminearum isolates. Significant deviations from the inoculated 1 : 1 proportions occurred in 34 of 49 cases, illustrating that competition effects appeared in the mixtures. These differences depended mainly on the year and not on the level of host resistance. We conclude that resistance should not be affected by the Fusarium isolates and mixtures. 相似文献
13.
Dawid Perlikowski Halina Wi?niewska Tomasz Góral Micha? Kwiatek Maciej Majka Arkadiusz Kosmala 《PloS one》2014,9(10)
Numerous potential components involved in the resistance to Fusarium head blight (FHB) in cereals have been indicated, however, our knowledge regarding this process is still limited and further work is required. Two winter wheat (Triticum aestivum L.) lines differing in their levels of resistance to FHB were analyzed to identify the most crucial proteins associated with resistance in this species. The presented work involved analysis of protein abundance in the kernel bulks of more resistant and more susceptible wheat lines using two-dimensional gel electrophoresis and mass spectrometry identification of proteins, which were differentially accumulated between the analyzed lines, after inoculation with F. culmorum under field conditions. All the obtained two-dimensional patterns were demonstrated to be well-resolved protein maps of kernel proteomes. Although, 11 proteins were shown to have significantly different abundance between these two groups of plants, only two are likely to be crucial and have a potential role in resistance to FHB. Monomeric alpha-amylase and dimeric alpha-amylase inhibitors, both highly accumulated in the more resistant line, after inoculation and in the control conditions. Fusarium pathogens can use hydrolytic enzymes, including amylases to colonize kernels and acquire nitrogen and carbon from the endosperm and we suggest that the inhibition of pathogen amylase activity could be one of the most crucial mechanisms to prevent infection progress in the analyzed wheat line with a higher resistance. Alpha-amylase activity assays confirmed this suggestion as it revealed the highest level of enzyme activity, after F. culmorum infection, in the line more susceptible to FHB. 相似文献
14.
Jennifer Häberle Josef Holzapfel Günther Schweizer Lorenz Hartl 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(2):325-332
We report on the verification of a resistance quantitative trait locus (QTL) on chromosome 1BL (now designated Qfhs.lfl-1BL) which had been previously identified in the winter wheat cultivar Cansas. For a more precise estimation of the QTL effect
and its influence on plant height and heading date lines with a more homogeneous genetic background were created and evaluated
in four environments after spray inoculation with Fusarium culmorum. Qfhs.lfl-1BL reduced FHB severity by 42% relative to lines without the resistance allele. This QTL did not influence plant height, but
significantly delayed heading date by one day. All of the most resistant genotypes of the verification population carried
this major QTL displaying its importance for disease resistance. This resistance QTL has not only been found in the cultivar
Cansas, but also in the three European winter wheat cultivars Biscay, History and Pirat. A subsequent meta-analysis confirmed
the presence of a single QTL on the long arm of chromosome 1B originating from the four mentioned cultivars. Altogether, the
results of the present study indicate that Qfhs.lfl-1BL is an important component of FHB resistance in European winter wheat and support the view that this QTL would be effective
and valuable in backcross breeding programmes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
Background
Fusarium head blight (FHB) is a disease of cereal crops, which has a severe impact on wheat and barley production worldwide. Apart from reducing the yield and impairing grain quality, FHB leads to contamination of grain with toxic secondary metabolites (mycotoxins), which pose a health risk to humans and livestock. The Fusarium species primarily involved in FHB are F. graminearum and F. culmorum. A key prerequisite for a reduction in the incidence of FHB is an understanding of its epidemiology. 相似文献16.
17.
Overexpression of defense response genes in transgenic wheat enhances resistance to Fusarium head blight 总被引:2,自引:0,他引:2
Mackintosh CA Lewis J Radmer LE Shin S Heinen SJ Smith LA Wyckoff MN Dill-Macky R Evans CK Kravchenko S Baldridge GD Zeyen RJ Muehlbauer GJ 《Plant cell reports》2007,26(4):479-488
Fusarium head blight (FHB) of wheat, caused by Fusarium graminearum and other Fusarium species, is a major disease problem for wheat production worldwide. To combat this problem, large-scale
breeding efforts have been established. Although progress has been made through standard breeding approaches, the level of
resistance attained is insufficient to withstand epidemic conditions. Genetic engineering provides an alternative approach
to enhance the level of resistance. Many defense response genes are induced in wheat during F. graminearum infection and may play a role in reducing FHB. The objectives of this study were (1) to develop transgenic wheat overexpressing
the defense response genes α-1-purothionin, thaumatin-like protein 1 (tlp-1), and β-1,3-glucanase; and (2) to test the resultant
transgenic wheat lines against F. graminearum infection under greenhouse and field conditions. Using the wheat cultivar Bobwhite, we developed one, two, and four lines
carrying the α-1-purothionin, tlp-1, and β-1,3-glucanase transgenes, respectively, that had statistically significant reductions
in FHB severity in greenhouse evaluations. We tested these seven transgenic lines under field conditions for percent FHB disease
severity, deoxynivalenol (DON) mycotoxin accumulation, and percent visually scabby kernels (VSK). Six of the seven lines differed
from the nontransgenic parental Bobwhite line for at least one of the disease traits. A β-1,3-glucanase transgenic line had
enhanced resistance, showing lower FHB severity, DON concentration, and percent VSK compared to Bobwhite. Taken together,
the results showed that overexpression of defense response genes in wheat could enhance the FHB resistance in both greenhouse
and field conditions. 相似文献
18.
《Fungal biology》2020,124(9):753-765
The cereal infecting fungus Fusarium graminearum is predicted to possess a single homologue of plant RALF (rapid alkalinisation factor) peptides. Fusarium mutant strains lacking FgRALF were generated and found to exhibit wildtype virulence on wheat and Arabidopsis floral tissue. Arabidopsis lines constitutively overexpressing FgRALF exhibited no obvious change in susceptibility to F. graminearum leaf infection. In contrast transient virus-mediated over-expression (VOX) of FgRALF in wheat prior to F. graminearum infection, slightly increased the rate of fungal colonisation of floral tissue. Ten putative Feronia (FER) receptors of RALF peptide were identified bioinformatically in hexaploid wheat (Triticum aestivum). Transient silencing of two wheat FER homoeologous genes prior to F. graminearum inoculation did not alter the subsequent interaction outcome. Collectively, our VOX results show that the fungal RALF peptide may be a minor contributor in F. graminearum virulence but results from fungal gene deletion experiments indicate potential functional redundancy within the F. graminearum genome. We demonstrate that virus-mediated over-expression is a useful tool to provide novel information about gene/protein function when results from gene deletion/disruption experimentation were uninformative. 相似文献
19.
QTL associated with Fusarium head blight resistance in the soft red winter wheat Ernie 总被引:2,自引:0,他引:2
Liu S Abate ZA Lu H Musket T Davis GL McKendry AL 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(3):417-427
Fusarium head blight (FHB), mainly caused by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schw. (Petch)], is an increasingly important disease of wheat (Triticum aestivum L.). Host-plant resistance provides the best hope for reducing economic losses associated with FHB, but new sources of resistance
are limited. The moderately resistant winter wheat cultivar, Ernie, may provide a source of resistance that differs from Sumai
3 but these genes have not been mapped. Also hindering resistance breeding may be associations of resistance with agronomic
traits such as late maturity that may be undesirable in some production environments. This research was conducted to identify
QTL associated with type II FHB resistance (FHB severity, FHBS), and to determine if they are associated with days to anthesis
(DTA), number of spikelets (NOS), and the presence/absence of awns. Two hundred and forty-three F8 recombinant inbred lines from a cross between the resistant cultivar, Ernie and susceptible parent, MO 94-317 were phenotyped
for type II FHB resistance using point inoculation in the greenhouse during 2002 and 2003. Genetic linkage maps were constructed
using 94 simple sequence repeat (SSR) and 146 amplified fragment length polymorphic (AFLP) markers. Over years four QTL regions
on chromosomes 2B, 3B, 4BL and 5A were consistently associated with FHB resistance. These QTL explained 43.3% of the phenotypic
variation in FHBS. Major QTL conditioning DTA and NOS were identified on chromosome 2D. Neither the QTL associated with DTA
and NOS nor the presence/absence of awns were associated with FHB resistance in Ernie. Our results suggest that the FHB resistance
in Ernie appears to differ from that in Sumai 3, thus pyramiding the QTL in Ernie with those from Sumai 3 could result in
enhanced levels of FHB resistance in wheat. 相似文献
20.
The interactions between barley yellow dwarf virus (BYDV) and Fusarium head blight (FHB), caused by Fusarium graminearum, were studied in the two winter wheat cultivars (cvs.), Agent (susceptible to FHB) and Petrus (moderately resistant to FHB), using ultrastructural and immunocytochemical methods. Infections of wheat plants of both cvs. by BYDV increased susceptibility to FHB. BYDV infection caused numerous cytological changes in lemma tissue of both cvs. such as formation of vesicles in the cytoplasm, degradation of fine structures of chloroplasts of both cvs. and accumulation of large starch grains in the chloroplasts. Electron microscopical studies showed that the development of F. graminearum on spike surfaces was not affected in BYDV‐infected plants. After penetration and intercellular growth in lemma tissue, defence responses to Fusarium infections were markedly reduced in BYDV‐diseased plants compared to the tissue of virus‐free plants. At sites of contact of fungal cells with host tissue, depositions of cell wall material were distinctly less pronounced than in tissues of virus‐free plants of cv. Petrus. Detection of β‐1,3‐glucanases and chitinases in lemma tissue of cv. Agent revealed no appreciably increased accumulation of both defence enzymes in F. graminearum‐infected virus‐free and BYDV‐infected tissues compared to the non‐infected control tissue. On the other hand, in cv. Petrus, infection with F. graminearum induced a markedly enhanced activity of both enzymes 3 days after inoculation. The increase of both enzyme activities was less pronounced in BYDV‐infected plants than in tissue exclusively infected with F. graminearum. Cytological studies suggest that in contrast to the susceptible cv. Agent postinfectional defence responses may play still an important role in the resistance of the moderately resistant cv. Petrus to FHB. 相似文献