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1.
Kazutaka Kido Tomofumi Mochizuki Kazutoshi Matsuo Chika Tanaka Kenji Kubota Takehiro Ohki Shinya Tsuda 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(2):189-194
The single recessive gene, nsv, which confers resistance against Melon necrotic spot virus (MNSV), has recently been used to develop virus-resistant melon cultivars in Japan. However, the Chiba isolate of MNSV, a
common isolate in Japan, infected resistant cultivars when inoculated melon plants were grown at 15°C. Viral RNAs accumulated
in protoplasts from resistant cultivars at both 15 and 20°C. Mechanical inoculation of the cotyledons caused MNSV to spread
throughout the leaves at 15°C, but not at 20°C. These results support our novel hypothesis that a temperature-sensitive inactivation
of disease resistance genes occurs at the nsv locus in melon cultivars with the resistance gene grown at temperatures below 20°C.
The first and second authors contributed equally to this research. 相似文献
2.
Jian-Qun Chen Begonia Martin Yvan Rahbé Alberto Fereres 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(6):521-536
The Vat resistance gene (in Cucumis melo L.) inhibits the transmission of non-persistent viruses by Aphis gossypii Glover, but does not affect transmission by Myzus persicae (Sulz.). To see whether this difference was behaviourally determined, we investigated the stylet penetration behaviour of these two aphid species by recording EPGs (Electrical Penetration Graphs) of 8 and 20 min on two sets of susceptible and resistant isogenic melon lines. During the 20 min EPG study, inoculation with CMV (Cucumber Mosaic Virus) was also investigated. For both sets of isogenic lines, the two aphid species were able to detect the presence of Vat. The mean duration of individual intracellular punctures on the resistant genotypes was significantly reduced for both M. persicae and A. gossypii (-10% and -8% respectively for duration of pattern ‘pd’ in the 20 min experiment); this reaction appeared faster for M. persicae, a species for which melon was not a suitable host-plant. Therefore, in contrast to Vat's anti-transmission effect, this behavioural effect was not aphid species-specific. Also, the frequency of intracellular punctures on the resistant genotypes was significantly reduced in A. gossypii (but not in M. persicae): on average, this frequency dropped from ≈0.65 pd.min-1 on the susceptible genotypes to ≈0.5 pd.min-1 on the resistant ones. It was concluded that (intracellular?) chemical cues were detected very early by aphids probing on the resistant genotypes carrying the Vat gene. However, a comprehensive analysis of the behavioural traits of both aphids on the two genotypes could not alone account for the complete inhibition of transmission which was found only to occur for A. gossypii on resistant genotypes. None of the differences detected (between aphid species or between plant genotypes) could account for the Vat phenotype, although they may explain quantitative differences in transmission efficiencies between aphid species. It was thus concluded that Vat effect was primarily chemically mediated. Finally, some intracellular punctures bearing typical subphases have been identified in both aphid species and were designated as ‘long potential drops’ (pd-L). For A. gossypii, these were observed early after plant contact and their mean duration was twice that of standard intracellular punctures (≈8.5 s vs ≈4.2 s). Although not necessary for CMV inoculation, the duration of such phases was positively correlated with a high transmission efficiency by A. gossypii on the susceptible genotype. The nature of this pattern and a putative mechanism of action of the Vat gene are discussed. 相似文献
3.
蚜虫能够传播上百种植物病毒,是最重要的农业介体昆虫之一。蚜虫在刺探和取食植物过程中,唾液组分会连同附着在口针中的病毒粒子一同被分泌进入植物内,在调节植物诱导抗性、病毒侵染扩散、介体昆虫行为等过程中均有重要作用。本文围绕蚜虫传播病毒和获取病毒2个关键过程,总结分析了蚜虫独特的刺吸取食行为与传毒效率和获毒效率之间的联系;针对取食活动中关键的唾液蛋白在调控植物免疫抗性、帮助病毒侵染过程中的功能,阐述了蚜虫高效传播非持久病毒的分子基础;针对蚜虫的获毒过程,综述了病毒侵染植物间接调控蚜虫趋向和行为的作用方式。这些研究的开展将为解释蚜虫和病毒协同侵染的分子机制以及有效开展基于蚜虫取食行为调控的病虫害防控新技术提供思路。 相似文献
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D. Andrivon J. Avendaño‐Córcoles S. F. Carnegie L. R. Cooke R. Corbière D. Detourné L. J. Dowley D. Evans K. Forisekova D. G. Griffin A. Hannukkala A. K. Lees R. Lebecka F. Niepold Z. Polgar D. S. Shaw J. Thompson B. Trognitz H. M. G. van Raaij E. Zimnoch‐Guzowska 《Plant pathology》2011,60(3):556-565
Determining virulence towards race‐specific resistance genes is a prerequisite to understanding the response of pathogen populations to resistant cultivars, and therefore to assess the durability of these resistance genes and the performance of resistance management strategies. In Phytophthora infestans, virulence testing began shortly after the introduction of R‐genes from Solanum demissum into S. tuberosum cultivars. However, the characteristics of R‐gene expression, the sensitivity of the phenotype to environmental and physiological parameters, and the diversity of experimental protocols make the comparison of data from different studies problematic. This prompted European teams working on P. infestans diversity to: (i) design a joint protocol, using detached leaflets from greenhouse‐grown plants of a shared set of differential cultivars inoculated with standardized suspensions of inoculum, and (ii) assess the performance of this protocol in a blind ring test involving 12 laboratories and 10 European isolates of the pathogen. A high level of consensus in the determination of virulence/avirulence to R1, R3, R4, R7, R8, R10 and R11 was achieved among the collaborators, showing that the protocol could be robustly applied across a range of laboratories. However, virulence to R2, R5 or R9 was detected more frequently in some laboratories, essentially from northern Europe; these genes are known to be highly sensitive to host and environmental conditions. The consensus determination was often markedly different from the original virulence phenotype of the isolates, suggesting virulence instability in stored P. infestans isolates. This indicates that creating reliable core collections of pathogen isolates with known virulences could be difficult. 相似文献
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Xiu‐Dao Yu Zong‐Cai Liu Si‐Liang Huang Zhi‐Qin Chen Yong‐Wei Sun Peng‐Fei Duan You‐Zhi Ma Lan‐Qin Xia 《Pest management science》2016,72(6):1090-1098
Aphids (Aphididae) are major agricultural pests that cause significant yield losses of crop plants each year by inflicting damage both through the direct effects of feeding and by vectoring harmful plant viruses. Expression of double‐stranded RNA (dsRNA) directed against suitable insect target genes in transgenic plants has been shown to give protection against pests through plant‐mediated RNA interference (RNAi). Thus, as a potential alternative and effective strategy for insect pest management in agricultural practice, plant‐mediated RNAi for aphid control has received close attention in recent years. In this review, the mechanism of RNAi in insects and the so far explored effective RNAi target genes in aphids, their potential applications in the development of transgenic plants for aphid control and the major challenges in this regard are reviewed, and the future prospects of using plant‐mediated RNAi for aphid control are discussed. This review is intended to be a helpful insight into the generation of aphid‐resistant plants through plant‐mediated RNAi strategy. © 2016 Society of Chemical Industry 相似文献
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Differences in the responses of melon accessions to fusarium root and stem rot and their colonization by Fusarium oxysporum f. sp. radicis‐cucumerinum 
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下载免费PDF全文 R. Cohen G. Orgil Y. Burger U. Saar M. Elkabetz Y. Tadmor M. Edelstein E. Belausov M. Maymon S. Freeman O. Yarden 《Plant pathology》2015,64(3):655-663
Fusarium root and stem rot caused by the fungus Fusarium oxysporum f. sp. radicis‐cucumerinum is a major disease in greenhouse cucumbers. Over the past decade, the disease has been documented in melon greenhouses in Greece, and recently it has been sporadically recorded in greenhouse melons in Israel. Variations in disease response were found among 41 melon accessions artificially inoculated with the pathogen: 10 accessions were highly susceptible (90–100% mortality), 23 exhibited an intermediate response (20–86%) and eight were resistant (0–4%). Two melon accessions – HEM (highly resistant) and TAD (partially resistant) – were crossed with the susceptible accession DUL. The responses of the three accessions and F1 crosses between the resistant and susceptible parents were evaluated. HEM contributed higher resistance to the F1 hybrid than TAD. Roots of susceptible and resistant accessions were 100 and 79% colonized, respectively, following artificial inoculation. However, only susceptible plants showed colonization of the upper plant tissues. Microscopic evaluation of cross sections taken from the crown region of the susceptible DUL revealed profuse fungal growth in the intercellular spaces of the parenchyma and in xylem vessels. In the resistant cultivar HEM, very little fungal growth was detected in the intercellular spaces of the parenchyma, and none in the xylem or any other vascular tissue. Finding resistant accessions may create an opportunity to study the genetics of resistance inheritance and to develop molecular markers that will facilitate breeding resistant melon cultivars. 相似文献
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Basky Z 《Pest management science》2003,59(10):1152-1158
Russian wheat aphid, Diuraphis noxia (Kurdjumov) is a severe pest of cereals in South Africa and in the USA. In order to reduce D noxia damage, intensive resistance breeding programs have been undertaken, resulting in D noxia-resistant cultivars that are now widely used in South Africa and in the USA. However, there appear to be differences in the ability of different populations of D noxia to damage these resistant cereal cultivars. To determine whether different biotypes of D noxia are present, damage to eight wheat cultivars was compared when they were exposed to either Hungarian or South African aphid strains. It appeared that the Hungarian CVS MV Magdaléna, MV Magvas, and MV 17 were susceptible to D noxia from both Hungary and South Africa. The susceptible South African CV Betta was also severely damaged regardless of the country of origin of the aphids. None of the cultivars resistant in South Africa (Caledon, SST 333, SST 972 and Halt) were, however, resistant to Hungarian populations of D noxia. These cultivars, which carry resistance genes originating from the breeding lines PI 262660, PI 137739 and PI 372129, were severely damaged by the Hungarian D noxia. Apart from the highly resistant CV Halt, the resistant cultivars used in this study were developed in South Africa, with the biotype present there. Damage to all cultivars tested was significantly more severe in response to Hungarian than to South African D noxia, indicating that a more damaging aphid biotype occurs in Hungary. However, D noxia has not yet become a pest of wheat in Hungary, possibly due to a difference in cultural practices. 相似文献
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Blackleg disease (phoma stem canker) caused by the fungus Leptosphaeria maculans is a major disease of canola (oilseed rape, Brassica napus) worldwide. Canola plants in pots were exposed to blackleg‐infested stubble of canola with different complements of resistance genes and then assessed for disease. Plant mortality was reduced when plants were exposed to stubble from a cultivar with a different complement of resistance genes compared to stubble of a cultivar with the same resistance gene. These findings were consistent with 7 years of field surveys, which showed that changes in selection pressure as a result of extensive sowing of cultivars with major‐gene resistance, termed ‘sylvestris resistance’, dramatically influenced the frequency of virulent isolates in the population towards particular resistance genes, and therefore disease severity. All these data were supported by PCR‐genotyping surveys of fungal populations whereby the frequency of virulence alleles of avirulence genes AvrLm1 and AvrLm4 changed significantly depending on the resistance gene present in the cultivar from which the isolates were cultured. This is the first example of a study showing that sowing of canola cultivars with different complements of resistance genes in subsequent years, i.e. rotation of resistance genes, minimizes disease pressure by manipulating fungal populations. This approach provides a valuable disease management strategy for canola growers and is likely to be applicable to other plant diseases. 相似文献
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为拓展和获取对荻草谷网蚜Sitobion miscanthi表现稳定的小麦抗源,以我国146个小麦品种（系）为材料,利用2020年麦田蚜虫发生严重的机会,采用有蚜株蚜害级别计算抗蚜指数,采用耐蚜值（调查株蚜害级别/千粒重损失率）计算耐蚜指数,以此评估小麦的抗蚜性水平和耐蚜性水平;2022年利用人工辅助接蚜的方法对2020年表现稳定的部分小麦品种（系）的评估结果进行验证。结果显示,在自然感蚜条件下2个试验点6次调查中仅山农116、泉麦31和濮麦116表现稳定的抗蚜性,在人工接蚜时仅郑麦132表现稳定的抗蚜性;中育1220、泰禾麦2号和瑞华1408在自然感蚜时蚜量较低,千粒重损失率低于5.00%,人工接蚜亦表现良好的耐蚜性,表明其兼具耐蚜性和一定的抗蚜性;泰麦601、瑞华592、轮选166和中农麦4007在自然感蚜的高蚜量情况下和人工辅助接蚜时均能保持较低的千粒重损失率（小于15.00%）,表明成株期小麦的抗蚜性减弱是一种普遍现象,耐蚜性是比抗蚜性更稳定的遗传特征。 相似文献
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ABSTRACT The Cucumis melo accession TGR-1551 was found to be resistant to Watermelon mosaic virus (WMV, genus Potyvirus, family Potyviridae). The resistance resulted in a drastic and significant reduction of virus titer and infected plants were asymptomatic or exhibited mild disease symptoms. The same gene or closely linked genes restricted virus accumulation and ameliorated symptom expression. No effect was observed on virus accumulation in inoculated leaves, which suggested that the initial phases of infection were not affected. The resistance was effective against a range of WMV isolates from Spanish melon production areas. Using aphid inoculations, resistant plants showed a lower propensity for infection by WMV and for serving as virus sources for secondary spread once infected. Resistance was determined to be under recessive genetic control. 相似文献
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ABSTRACT Plant pathogens often exhibit variation in virulence, the ability to cause disease on host plants with specific resistance, evident from the diversity of races observed within pathogen species. The evolution of races in asexual fungal pathogens has been hypothesized to occur in a stepwise fashion, in which mutations to virulence accumulate sequentially in clonal lineages, resulting in races capable of overcoming multiple host plant resistance genes or multiple resistant cultivars. In this study, we demonstrate a simple stepwise pattern of race evolution in Fusarium oxysporum f. sp. ciceris, the fungus that causes Fusarium wilt of chickpeas. The inferred intraspecific phylogeny of races in this fungus, based on DNA fingerprinting with repetitive sequences, shows that each of the eight races forms a monophyletic lineage. By mapping virulence to each differential cultivar (used for defining races) onto the inferred phylogeny, we show that virulence has been acquired in a simple stepwise pattern, with few parallel gains or losses. Such a clear pattern of stepwise evolution of races, to our knowledge, has not been demonstrated previously for other pathogens based on analyses of field populations. We speculate that in other systems the stepwise pattern is obscured by parallel gains or losses of virulence caused by higher mutation rates and selection by widespread deployment of resistant cultivars. Although chickpea cultivars resistant to Fusarium wilt are available, their deployment has not been extensive and the stepwise acquisition of virulence is still clearly evident. 相似文献
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Foster SP Denholm I Rison JL Portillo HE Margaritopoulis J Slater R 《Pest management science》2012,68(4):629-633
BACKGROUND: Parthenogenetic clones of the green peach aphid, Myzus persicae (Sulzer), and the cotton aphid, Aphis gossypii Glover, were tested with the anthranilic diamide insecticide cyantraniliprole (i.e. DuPont? Cyazypyr?) in systemic‐uptake bioassays to investigate potential for cross‐resistance conferred by mechanisms of insecticide resistance to organophosphates, carbamates and pyrethroids and, in the case of M. persicae, reduced sensitivity to neonicotinoids. These data were compared with the response of field samples of M. persicae and A. gossypii collected from around Europe. RESULTS: Cyantraniliprole was not cross‐resisted by any of the known insecticide resistance mechanisms present in M. persicae or A. gossypii. The compound was equally active against resistant and susceptible aphid strains. The responses of the M. persicae field samples were very consistent with a maximum response ratio of 2.9 compared with a standard laboratory clone. The responses of the A. gossypii field samples were more variable, although a majority of the responses were not statistically different. CONCLUSION: Cyantraniliprole is currently the only anthranilic diamide (IRAC MoA 28) insecticide targeting aphid species such as M. persicae and A. gossypii. There is no evidence to suggest that the performance of this compound is affected by commonly occurring mechanisms that confer resistance to other insecticide chemistries. Cyantraniliprole is therefore a valuable tool for managing insecticide resistance in these globally important pests. Copyright © 2011 Society of Chemical Industry 相似文献
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为明确甜菜中由抗性基因R编码的包含富亮氨酸重复序列（leucine-rich repeat,LRR）和核苷酸结合位点（nucleotide-binding site,NBS）的家族成员及其功能,基于甜菜基因组全长序列,利用HMMER、TBtools、Pfam、NCBI等软件和在线程序对甜菜NBS-LRR家族成员进行筛选和鉴定,采用生物信息学方法对鉴定到的成员进行亚家族分类、染色体定位、结构域分析、进化树构建、顺式元件分析和同源序列筛选。结果显示,从甜菜基因组中最终筛选鉴定到267条NBS-LRR家族基因序列,占甜菜基因组的0.614%,通过对267条基因序列进行结构域预测并进行分类,分属于N型、NL型、CNL型、TNL型和RNL型5个亚家族,分别包含110、25、128、3和1条序列。甜菜NBS-LRR家族基因大多位于2号、3号、4号和7号染色体上,根据基因簇划分原则发现有73.25%的基因以基因簇形式存在。经Clustal Omega和MEME在线程序对CNL型亚家族中具有完整卷曲螺旋（coiled-coil,CC）、NBS和LRR结构域的24条基因序列进行结构域保守性分析,共发现7个保守性较高的基序,基于CNL型亚家族128条基因序列构建的进化树显示CNL型亚家族的系统进化受CC、NBS和LRR结构域的影响较大。甜菜NBS-LRR家族基因含有大量植物激素相关顺式元件和多种胁迫响应元件,部分序列含有植物生理响应元件。甜菜NBS-LRR家族基因与菠菜和藜麦的抗病蛋白同源性较高。 相似文献
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Dewhirst SY Birkett MA Loza-Reyes E Martin JL Pye BJ Smart LE Hardie J Pickett JA 《Pest management science》2012,68(10):1419-1429
BACKGROUND: Two important pests of the sweet pepper, Capsicum annuum, are the peach potato aphid, Myzus persicae, and the glasshouse potato aphid, Aulacorthum solani. Current aphid control measures include the use of biological control agents, i.e. parasitic wasps, but with varying levels of success. One option to increase parasitoid efficiency is to activate plant defence. Therefore, sweet pepper plants were treated with the naturally occurring plant defence activator cis-jasmone, and its impact upon the behaviour and development of aphids and aphid parasitoids was investigated. RESULTS: Growth rate studies revealed that the intrinsic rate of population increase of A. solani and M. persicae on sweet pepper plants treated with cis-jasmone (cJSP) was not affected compared with untreated plants (UnSP), but the positive behavioural response of alate M. persicae towards the volatile organic compounds (VOCs) from UnSP was eliminated by cis-jasmone treatment 48 h previously (cJSP48). In addition, the aphid parasitoid Aphidius ervi preferred VOCs from cJSP48 compared with UnSP, and a significant increase in foraging time was also observed on cJSP. Analysis of VOCs collected from cJSP48 revealed differences compared with UnSP. CONCLUSION: There is evidence that treatment with cis-jasmone has the potential to improve protection of sweet pepper against insect pests. © Crown copyright 2012. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. 相似文献
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Cowpea (Vigna unguiculata) is one of the most important legumes cultivated in many parts of the world. The diseases caused by Cowpea severe mosaic virus (CPSMV) and Cowpea aphid‐borne mosaic virus (CABMV) are considered among the most important constraints on yield and quality, especially in Latin America and Africa. Here, the concept of using an RNA interference construct to silence the CPSMV proteinase cofactor gene and the CABMV coat protein gene is explored, in order to generate resistant transgenic cowpea plants. Ten cowpea transgenic lines were produced, presenting a normal phenotype and transferring the transgene to the next generation. Plants were tested for resistance to both CABMV and CPSMV by mechanical co‐inoculation. Seven lines presented milder symptoms when compared to the control and three lines presented enhanced resistance to both viruses. Northern analyses were carried out to detect the transgene‐derived small interfering RNA (siRNA) in leaves and revealed no correlation between siRNA levels and virus resistance. Additionally, in the symptomless resistant lines the resistance was homozygosis‐dependent. Only homozygous plants remained uninfected while hemizygous plants presented milder symptoms. 相似文献
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蚜虫是农业生产上的重大害虫,不仅通过取食韧皮部直接为害植物,还会传播很多植物病毒病,严重影响农作物产量和品质。目前防治蚜虫仍以化学农药为主,然而生物防治作为绿色环保、可持续的防治策略在这几十年中也得到了长足发展。该文对我国近60年关于主要农作物蚜虫生物防治的研究进展进行概述,包括主要农作物蚜虫的天敌资源（主要寄生性天敌196种,主要捕食性天敌16种,主要病原微生物6种）、蚜虫主要天敌生物学和生态学研究、人工扩繁及应用技术及植物抗蚜机制和抗蚜种质资源挖掘,并对目前蚜虫生物防治中存在的问题及未来的研究方向进行展望,以期为蚜虫生物防治技术的发展和推广应用提供参考。 相似文献
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H. Banani B. Roatti B. Ezzahi O. Giovannini G. Gessler I. Pertot M. Perazzolli 《Plant pathology》2014,63(2):334-343
Downy mildew, caused by Plasmopara viticola, is one of the most destructive diseases of grapevine and is controlled with intense application of chemical fungicides. Treatment with Trichoderma harzianum T39 (T39) or benzothiadiazole‐7‐carbothioic acid S‐methyl ester (BTH) has been previously shown to activate grapevine resistance to downy mildew and reduce disease symptoms in the Pinot noir cultivar. However, enhancement of plant resistance can be affected by several factors, including plant genotype. In order to further extend the use of resistance inducers against downy mildew, the physiological and molecular properties of T39‐ and BTH‐activated resistance in different cultivars of table and wine grapes were characterized under greenhouse conditions. T39 treatment reduced downy mildew symptoms, but the degree of efficacy differed significantly among grapevine cultivars. However, efficacy of BTH‐activated resistance was consistently high in the different cultivars. Expression profiles of defence‐related genes differed among cultivars in response to resistance inducers and to pathogen inoculation. T39 treatment enhanced the expression of defence‐related genes in the responsive cultivars, before and after P. viticola inoculation. A positive correlation between the efficacy of T39 and the expression level of defence‐related genes was found in Primitivo and Pinot noir plants, while different genes or more complex processes were probably activated in Sugraone and Negroamaro. The data reported here suggest that the use of a responsive cultivar is particularly important to maximize the efficacy of resistance inducers and new natural inducers should be explored for the less responsive cultivars. 相似文献