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1.
Lettuce (Lactuca sativa) is the major leafy vegetable that is susceptible to powdery mildew disease under greenhouse and field conditions. Quantitative trait loci (QTLs) for resistance to powdery mildew under greenhouse conditions were mapped in an interspecific population derived from a cross between susceptible L. sativa cultivar Salinas and the highly susceptible L. serriola accession UC96US23. Four significant QTLs were detected on linkage groups LG 1 (pm‐1.1), LG 2 (pm‐2.1 and pm‐2.2) and LG 7 (pm‐7.1), each explaining between 35 to 42% of the phenotypic variation. The four QTLs are not located in the documented hotspots of lettuce resistance genes. Alleles for the disease resistance at the four QTLs originated from both parents (two from each), demonstrating that even highly susceptible accessions may provide alleles for resistance to powdery mildew. These QTLs appeared to operate during limited periods of time. Results of the field trials with F2:3 and F3:4 families derived from a Soraya (moderately resistant) × Salinas cross demonstrated effective transfer of resistance to powdery mildew in this material. An integrated rating approach was used to estimate relative levels of resistance in 80 cultivars and accessions tested in a total of 23 field and greenhouse experiments. Generally, very low resistance was observed in crisphead‐type lettuces, while the highest relative resistance was recorded in leaf and butterhead types. Comparison of two disease assessment methods (percentage rating and the area under the disease progress steps, AUDPS) for detection of QTLs shows that the two approaches complement each other. 相似文献
2.
This paper reviews the taxonomy, biology, importance, host–pathogen interactions and control of lettuce powdery mildew. The main causal agent of this disease, Golovinomyces cichoracearum s.s., is an important powdery mildew pathogen of many members of the family Asteraceae. The pathogen is distributed worldwide and occurs on Lactuca sativa as well as wild Lactuca spp. and related taxa (e.g. Cichorium spp.). Powdery mildew of lettuce can be a major problem in production areas with favourable environmental conditions for disease development (dry, hot weather). The fungus grows ectophytically and appears as white, powdery growth on both the upper and lower sides of leaves. There is rather limited information on the geographic distribution of powdery mildew on wild Lactuca spp. Most L. sativa cultivars have been found to be susceptible. Large variability in virulence was confirmed and existence of different races is supposed. Resistance in L. sativa and some related wild Lactuca spp. is characterized by race‐specificity, but the genetic background of resistance is poorly understood. Sources of resistance are known in L. saligna and L. virosa. Lettuce powdery mildew can be effectively controlled by common fungicides (e.g. sulphur, myclobutanil, quinoline, strobilurins, etc.) and protective compounds (e.g. extract of neem oil, Reynoutria sachaliensis extracts). However, fungicide resistance may arise. Non‐fungicidal activators of plant systemic acquired resistance (SAR) had no direct effect on the causal agent. Future issues regarding lettuce powdery mildew research are summarized. 相似文献
3.
Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh), is a worldwide disease problem on barley (Hordeum vulgare) with potentially severe impact on yield. Historically, resistance genes have been identified chiefly from cultivated lines and landraces; however, wild barley (H. vulgare subsp. spontaneum) accessions have proven to be extraordinarily rich sources of powdery mildew resistance. This study describes the characterization of a collection of 316 wild barley accessions, known as the Wild Barley Diversity Collection (WBDC), for resistance to powdery mildew and the genetic location of powdery mildew resistance loci. The WBDC was phenotyped for reaction to 40 different Bgh isolates at the seedling stage and genotyped with 10 508 molecular markers. Accessions resistant to all 40 isolates of Bgh were not found; however, three accessions (WBDC 053, 085 and 089) exhibited resistance to 38 of the isolates. Gene postulation analyses revealed that many accessions, while resistant, contained none of the 12 genes present in the Pallas near‐isogenic lines Mla1, Mla3, Mla6, Mla7, Mla9, Mla12, Mla13, Mlk1, MlLa, Mlg, Mlat and Ml(Ru2), suggesting that the accessions carry novel genes or gene combinations. A genome‐wide association study of powdery mildew resistance in the WBDC identified 21 significant marker‐trait associations that resolved into 15 quantitative trait loci. Seven of these loci have not been previously associated with powdery mildew resistance. Taken together, these results demonstrate that the WBDC is a rich source of powdery mildew resistance, and provide genetic tools for incorporating the resistance into barley breeding programmes. 相似文献
4.
为西北农林科技大学小麦新育成品种（系）在黄淮麦区的大面积推广,该研究对83份西农新育成的小麦品种（系）进行苗期抗条锈病和白粉病鉴定,成株期抗条锈病、白粉病、叶锈病和赤霉病鉴定,并在田间自然环境下对其抗性进行鉴定及对相关抗病基因进行分子检测。结果显示,在苗期人工接种鉴定中,有63、29和16份小麦品种（系）分别对条锈菌Puccinia striiformis f.sp.tritici生理小种CYR32、CYR33和CYR34表现出抗性,9份小麦品种（系）对3个条锈菌生理小种均表现出抗性;有10、3和0份小麦品种（系）分别对白粉菌Blumeria graminis f.sp.tritici生理小种E15、E09和A13表现出抗性。在成株期人工接种鉴定中,有23、15、28和62份小麦品种（系）分别对条锈病、白粉病、叶锈病和赤霉病表现出抗性。在83份小麦品种（系）中有6份在苗期和成株期均对小麦条锈病表现出抗性。在田间抗性鉴定中,有57、6、65和40份小麦品种（系）分别对条锈病、白粉病、赤霉病及叶锈病表现出抗性。在83份小麦品种（系）中,3份含有Yr5基因,22份含有Yr9基因,3份含有Yr17基因,2份含有Pm24基因,14份含有Lr1基因,所占比例分别为3.6%、26.5%、3.6%、2.4%和16.8%。 相似文献
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Zifu Yan Oene Dolstra Theo W. Prins Piet Stam Peter B. Visser 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(3):301-308
Powdery mildew (Podosphaera pannosa) is the most important fungal disease in greenhouse roses and is in practice controlled by fungicides. The creation of novel
cultivars with durable resistance to powdery mildew is highly desirable. To understand the inheritance of mildew resistance,
a tetraploid rose population with a size of 181 seedlings was obtained by crossing two tetraploid genotypes each having partial
resistance. The population and its parents were tested under greenhouse conditions with two well-defined monospore isolates
(2 and F1) using artificial inoculation with spore suspensions. Disease score at 11 days post-inoculation, latent period and
rate of symptom development were used to describe seedling resistance. The tests for both isolates exhibited a wide and significant
variation among genotypes for resistance. The distribution of the genotypic means of the disease scores was continuous and
showed a considerable transgression. Statistical analysis, scatter plot of disease scores for the isolates, and correlation
analyses indicated that the two isolates differed in pathogenicity. The outcome of the tests showed that the inoculation assay
with spore suspensions was a reliable and effective way to screen large numbers of genotypes under greenhouse conditions for
genetic and breeding studies. This is the first report on spore-suspension inoculation to be used successfully in rose. 相似文献
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Thirty barley landraces collected from Morocco in 1985 and 1989, and held in the Polish Gene Bank, IHAR, Radzików, Poland,
were screened for resistance to powdery mildew. Fifteen tested landraces (50%) showed powdery mildew resistance reactions
and 24 single plant lines were selected. Eighteen lines originating from 13 landraces were tested with 17 isolates of powdery
mildew and another six lines originating from six landraces were tested with 23; the isolates were chosen according to their
virulence spectra observed on the ‘Pallas’ isolines differential set. Three lines (E 1090-2-2, E 1110-3-2 and E 1077-1-1)
showed resistance to all powdery mildew virulence genes prevalent in Europe. In 21 lines, unknown genes alone or in combination
with specific ones were detected. Five different resistance alleles(Mlat, Mlal, Mla3, Mlg andMl(CP)) were postulated to be present in the tested lines, alone or in combination:Mlat was postulated to be present in nine (~38%) lines;Mlg andMl(CP) in two lines, andMla1 andMla3 in one tested line each. The use of newly identified sources of resistance in barley breeding as a means of controlling powdery
mildew is discussed. 相似文献
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Powdery mildew (Blumeria graminis f. sp. tritici) results in serious economic loss in wheat production. Exploration of plant resistance to wheat powdery mildew over several decades has led to the discovery of a wealth of resistance genes and quantitative trait loci (QTLs). We have provided a comprehensive summary of over 200 powdery mildew genes (permanently and temporarily designated genes) and QTLs reported in common bread wheat. This highlights the diverse and rich resistance sources that exist across all 21 chromosomes. To manage different data for breeders, here we also present a bridged mapping result from previously reported powdery mildew resistance genes and QTLs with the application of a published integrated wheat map. This will provide important insights to empower further breeding of powdery mildew resistant wheat via marker-assisted selection (MAS). 相似文献
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W. L. Fonseca J. E. Cardoso M. A. Ootani S. O. S. Brasil F. S. Assunção C. S. Lima F. M. P. Viana C. R. Muniz I. L. Andrade M. V. V. Martins 《Plant pathology》2019,68(6):1157-1164
Cashew powdery mildew is presently the most important disease of cashew trees in all Brazilian growing regions. Although it was described over a century ago, it had never threatened the Brazilian cashew industry until the first decade of the 21st century. Morphological and pathogenic evidence indicated the possibility of different pathogen species being involved in early and late types of cashew powdery mildew. This study was designed to elucidate this issue by comparing two different powdery mildew fungi occurring on cashew plants in Brazil according to the morphological characteristics, phylogenetic relationships with closely related powdery mildew fungi and pathogenic relationships. Based on morphology, molecular phylogenetics and pathogenicity on cashew, it was shown that two species of powdery mildew specimens are without question associated with cashew trees. One species, which infects young immature tissues such as shiny leaves, flowers and young fruits, is Erysiphe quercicola, while Erysiphe necator is associated exclusively with mature leaves. This is the first report of both E. quercicola and E. necator causing cashew powdery mildew, and the first detection of E. necator on cashew. 相似文献
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Anne-Sophie Miclot Sabine Wiedemann-Merdinoglu Eric Duchêne Didier Merdinoglu Pere Mestre 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(2):483-495
Powdery mildew caused by Erysiphe necator is one of the most important diseases affecting grapevine (Vitis vinifera, L.). Control of this pathogen is based on the use of fungicides, which cause environmental damage and increase production
costs. A cost-effective and environmentally friendly alternative to control the disease relies on using resistant varieties.
While most V. vinifera cultivars are susceptible to powdery mildew, several species belonging to the Vitaceae have been described as resistant. Several loci for resistance to grapevine powdery mildew have been identified through genetic
analysis of segregating populations derived from different resistance sources. Identifying quantitative trait loci (QTL) with
minor effects on the resistance may prove valuable in a strategy of pyramiding, which aims at increasing the durability of
the resistance. However, current methods for evaluation of resistance either do not take into account quantitative variations,
or, if they do, are not adapted to large sample sets. Here we develop a method for the analysis of quantitative resistance
to grapevine powdery mildew in large populations. We devised a semi-quantitative resistance scale and confirmed the usefulness
of a cell counter to quantify sporulation. We compared three inoculation methods and identified dry inoculation using a settling
tower as the one giving the best infection. Finally, we confirmed the value of the method by applying it to a set of plants
segregating for resistance to E. necator. Using the method described here for the quantitative analysis of the resistance to powdery mildew will prove valuable for
breeding for durable resistance. 相似文献
10.
小麦品种混种对白粉病的调控及其对部分产量性状及蛋白质含量的影响 总被引：2，自引：0，他引：2
对品种混合种植控制小麦白粉病的效果以及对小麦穗重、千粒重、蛋白质等指标的影响进行了研究,为混合种植控制白粉病提供理论依据和品种组合。在对37个小麦品种进行SSR多样性分析的基础上,选用8个生产品种（后备品种）,按品种数3、4、5、6、8进行组合,在田间以随机区组设计种植混播组合和单播小区,人工接种白粉菌,比较各小区中小麦白粉病的AUDPC值、穗重、千粒重和粗蛋白差异。结果表明,8个品种亲缘关系较远;4品种混种时AUDPC最小,穗重最重。26个品种混种组合中有防治效果的组合占到73.08%,相对防效为1.23%~56.65%;混种未对穗重和粗蛋白含量造成负面影响。品种多样性种植可以用做调控小麦白粉病的一项措施。 相似文献
11.
为明确海南省苦瓜白粉病的病原菌、生理小种及苦瓜对白粉病的抗性遗传规律,结合形态学鉴定和分子鉴定解析白粉病菌及生理小种种类,通过显微镜观察白粉病菌侵染过程,并应用主基因+多基因混合遗传模型分析法探讨苦瓜对白粉病的主要抗性遗传规律。结果表明:采集自海南省6个市(县)的苦瓜白粉病病原菌均为单囊壳白粉菌Sphaerotheca fuliginea,属生理小种2F,该菌在侵染苦瓜叶片时有4个关键时期:接种后4 h为分生孢子萌发高峰期,8 h为附着孢形成高峰期,16～24 h为次生菌丝形成高峰期,5 d为分生孢子梗形成高峰期。将其接种于苦瓜抗、感品系,对白粉病的抗性符合2对加性-显性-上位性主基因+加性-显性多基因模型,主基因和多基因共同控制苦瓜对白粉病的抗性,其中以主基因遗传为主,且会受到环境变异的影响。根据苦瓜抗性遗传规律,F2代主基因遗传率最高,受环境影响最小,在苦瓜的白粉病抗性育种中,以早期世代F2代作为有效选择世代。研究表明白粉病菌侵染叶片的前2 d是白粉病防治的最佳时期,所以在白粉病易发的物候期,可将防治时间提前1～2 d。 相似文献
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Sylwia Magdalena Okoń Maria Chrząstek Krzysztof Kowalczyk Aneta Koroluk 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(1):9-12
Powdery mildew caused by Blumeria graminis DC. f. sp. avenae Em. Marchal. is a deleterious foliar disease of common oat which occurs in many parts of the world. Resistance existing in oat cultivars is broken down by new races of this pathogen and because of this fact there is necessity to look for new and effective sources of resistance to powdery mildew in oat. To identify new potential resistance sources to powdery mildew, a total of 67 oat genotypes from five different species Avena sterilis, A. fatua, A. sativa, A. maroccana and A. murphyi and 20 powdery mildew isolates were investigated for disease reactions. Among tested oat accessions the highest level of resistance was associated with A. maroccana genotypes. Genotypes belonging to species of A. murphi and A. sterilis also showed a good level of resistance. Identified genotypes could be used in oat breeding programmes to improve levels of resistance to powdery mildew. 相似文献
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为明确小豆白粉病病原菌的种类以及小豆种质资源对白粉病的抗性,采用形态学和系统发育学方法对近年来在北京市发生的小豆白粉病病原菌种类进行鉴定,并采用室内苗期人工接种法评价小豆常见栽培品种（系）对白粉病的抗性。结果表明,从北京市采集的感白粉病小豆病样中培养获得病原菌BJ1,该菌能在小豆叶片和茎上产生明显的白色粉斑,分生孢子梗直立,不分枝,分生孢子单细胞,成链状着生于分生孢子梗上,呈椭圆形或卵圆形。通过rDNA-ITS序列系统发育分析,小豆白粉病菌BJ1被鉴定为白粉菌目白粉菌科的苍耳叉丝单囊壳Podosphaera xanthii。室内苗期人工接种条件下,19个供试小豆品种（系）接种小豆白粉病菌BJ1后均可发病,其中9个审定品种均表现为中度感病或高度感病,10个优良品系发病略轻。 相似文献
14.
Plant age and ambient temperature: significant drivers for powdery mildew (Erysiphe cruciferarum) epidemics on oilseed rape (Brassica napus) 
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下载免费PDF全文 Powdery mildew (Erysiphe cruciferarum) is an important disease in oilseed rape crops worldwide, but of sporadic importance in most southern Australian crops. Six Brassica napus cultivars were exposed to E. cruciferarum simultaneously in four plant age cohorts. First symptoms of powdery mildew appeared 9 days after inoculation (dai) on the oldest plants [42 days after seeding (das)], but 44 dai in the youngest plants that were exposed to inoculum from sowing, although final disease severity did not differ with the plant age at exposure. The maximum level of pod peduncle infestation was unaffected by plant age (P = 0.37) or cultivar (P = 0.28). The effect of temperature was also investigated. The development of disease on plants was slower and final severity reduced at a day/night temperature 14/10 °C compared with 22/17 °C. In vitro, maximum growth of germ tubes from conidia of E. cruciferarum was at 15–20 °C and survival of conidia reduced by temperatures >30 °C. The results explain the sporadic nature of powdery mildew outbreaks in winter‐grown oilseed rape in Australia, where slow rates of infection occur when seasonal colder prevailing winter conditions coincide with the presence of younger plants, together curtailing rapid disease development until temperatures increase in late winter/early spring. These results explain why epidemics are most severe in the two warmer cropping regions, viz. the northern agricultural region of Western Australia and New South Wales. This study suggests that with increases in winter temperatures under future climate scenarios, earlier and more severe powdery mildew outbreaks in Australia will be favoured. 相似文献
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Nikolett Réka Aranyi Ildikó Varga Péter Poczai István Cernák Gyula Vida Márta Molnár-Láng Borbála Hoffmann 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(1):19-25
This work is a detailed study of the infection of fungal biotrophic pathogens causing powdery mildew diseases on introgression lines originating from the intergeneric hybridisation between wheat and barley (Triticum aestivum L. × Hordeum vulgare L.). Powdery mildew fungi are among the most widespread biotrophic pathogens of plants also and infect dicot and monocot species. Most powdery mildew species are strictly host specific. They colonize only a narrow range of species or one particular host species. The intergeneric hybridisation between wheat and barley could result in expansions of host ranges of the barley powdery mildew. Our experiments covered natural infections in the field and artificial infections under greenhouse conditions. Formae speciales of powdery mildew were identified on the basis of the sequencing results of ribosomal internal transcribed spacer sequences (rDNA-ITS). We identified Blumeria graminis f.sp. tritici isolate 14 (HM484334) on the wheat parent and all wheat-barley introgression lines and B. g. f. sp. hordei isolate MUMH1723 (AB 273556) on the barley parent, respectively. The wheat-barley introgression lines were inoculated with barley powdery mildew under greenhouse conditions. According to our results the added barley chromosomes (or segments) do not cause host range expansion of barley powdery mildew. 相似文献
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Moshe Reuveni Reuven Reuveni 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(7):633-638
A spray inoculation of the first leaf of 2-leaf stage cucumber plants with a non-pathogenic isolate of Alternaria cucumarina or Cladosporium fulvum before a challenge inoculation with the pathogen Sphaerotheca fuliginea induced systemic resistance to powdery mildew on leaves 2–5. Systemic resistance was expressed by a significant (p < 0.05) reduction in the number of powdery mildew colonies produced on each leaf of the induced plants, as compared with water-sprayed plants. Systemic resistance was evident when a prior inoculation with each of the inducing fungi was administered 1, 3 or 6 days before the challenge inoculation with S. fuliginea. Increasing the inoculum concentration of A. cucumarina or C. fulvum enhanced the systemic protection and provided up to 71.6% or 80.0% reduction, respectively, in the number of colonies produced on upper leaves, relative to controls. Increasing the inoculum concentration of S. fuliginea used for challenge inoculation, increased the number of powdery mildew colonies produced on both induced and non-induced plants. Pre-treated plants, however, were still better protected than controls, indicating that the level of systemic protection was related to the S. fuliginea inoculum concentration. The induction of systemic resistance against powdery mildew by biotic agents, facilitates the development of a wide range of disease management tools. 相似文献