Leafhopper Psammotettix Alienus Research Articles

Comparison of two different experimental environments for resistance screenings for the leafhopper-transmitted wheat dwarf virus in wheat

Wheat dwarf virus (WDV) causes high yield losses in wheat and other cereals and is therefore an important pathogen transmitted by the leafhopper Psammotettix alienus. Climate change will increase infections by insect-transmitted viruses due to the increasing spread of vectors. In the context of integrated pest management, the cultivation of WDV-resistant/tolerant varieties is an effective way of controlling WDV. Evaluation of tolerant/resistant genotypes is based on inoculation with viruliferous leafhoppers and subsequent phenotyping in gauze houses under semi-field conditions. For successful screening, it is important to ensure the uniform and reproducible inoculation of plants. Abiotic conditions, particularly temperature, have a critical influence on inoculation success, and thus, variations in infection rates were observed within and between previous replicates in the field. Furthermore, the leafhopper population reared in the greenhouse has to be reestablished after each infection, which delays the screening process. We addressed these issues by developing an improved inoculation assay in which plants are inoculated in small infection hoods in the greenhouse before being planted out in gauze houses. This procedure allows optimal environmental conditions for WDV infection of test plants and allows the plants with WDV infection to develop under natural environmental conditions for symptom scoring. In addition, the viruliferous leafhoppers were recollected from the test plants after infection, allowing a sustainable use of the insects. The method thus enables more reliable phenotyping by increasing infection success and testing a greater number of genotypes in a shorter time.

Impact of susceptible wheat cultivars on epidemiological parameters involved in the introduction and spread of wheat dwarf disease

AbstractDefence mechanisms in plants have been naturally or artificially selected to cope with virus infection and/or insect colonization. This creates a range of host susceptibility to viruses and/or insects that can impact the epidemiology of insect‐borne viral diseases. Wheat dwarf disease (WDD), one of the most important viral diseases on small‐grain cereals, is caused by wheat dwarf virus (WDV), which is transmitted by the leafhopper Psammotettix alienus. In the current context of the unavailability of either WDV‐resistant/tolerant wheat cultivars or effective methods to control WDD in French cereal fields, the accurate characterization of WDV‐susceptible genotypes must be considered to improve management strategies against this viral disease. In this study, the impact of 12 wheat cultivars on epidemiological parameters related to the introduction (host selection and virus infection) and spread (insect performance and virus transmission) of WDD was evaluated. Results showed no differences between the tested cultivars for host selection made by P. alienus, whereas four tested cultivars (Complice, Filon, Hyking and Nemo) reduced survival and/or fecundity of the leafhopper. Characterization of virus–host interactions highlights the lower host and source quality of cv. Filon for WDV. Finally, multivariate analyses allowed the identification of cvs Filon, Boregar, Solindo CS, Complice and Hyking as less suitable hosts for WDV and/or P. alienus, suggesting that these cultivars could present interesting genetic resource(s) that should be considered for future breeding programmes against WDD.

Genomic and biological characteristics of a novel leafhopper-transmitted marafivirus infecting Triticum aestivum.

Here, we report a novel wheat-infecting marafivirus, tentatively named "Triticum aestivum marafivirus" (TaMRV). The full-length genome sequence of TaMRV comprises 6,437 nucleotides, excluding the poly(A) tail. Pairwise sequence comparisons and phylogenetic analysis revealed that TaMRV may represent a novel species within the genus Marafivirus in the family Tymoviridae. We also observed a mass of isometric particles with a diameter of about 30 nm in ultrathin sections of infected wheat leaf tissue. In addition, the leafhopper Psammotettix alienus was identified as a vector for this virus. This is the first report of the occurrence of a wheat-infecting marafivirus.

The Past, Present, and Future of Wheat Dwarf Virus Management-A Review.

Wheat dwarf disease (WDD) is an important disease of monocotyledonous species, including economically important cereals. The causative pathogen, wheat dwarf virus (WDV), is persistently transmitted mainly by the leafhopper Psammotettix alienus and can lead to high yield losses. Due to climate change, the periods of vector activity increased, and the vectors have spread to new habitats, leading to an increased importance of WDV in large parts of Europe. In the light of integrated pest management, cultivation practices and the use of resistant/tolerant host plants are currently the only effective methods to control WDV. However, knowledge of the pathosystem and epidemiology of WDD is limited, and the few known sources of genetic tolerance indicate that further research is needed. Considering the economic importance of WDD and its likely increasing relevance in the coming decades, this study provides a comprehensive compilation of knowledge on the most important aspects with information on the causal virus, its vector, symptoms, host range, and control strategies. In addition, the current status of genetic and breeding efforts to control and manage this disease in wheat will be discussed, as this is crucial to effectively manage the disease under changing environmental conditions and minimize impending yield losses.

Identification and Validation of Quantitative Trait Loci for Wheat Dwarf Virus Resistance in Wheat (Triticum spp.).

Wheat dwarf virus (WDV) is transmitted by the leafhopper Psammotettix alienus. As a major pathogen in wheat and other cereals, WDV causes high yield losses in many European countries. Due to climate change, insect-transmitted viruses will become more important and the restrictions in the use of insecticides efficient against P. alienus renders growing of WDV resistant/tolerant varieties the only effective strategy to control WDV. So far, there is little information about the possible sources of resistance and no known information about the genome regions responsible for the resistance. In a screening for WDV resistance using artificial inoculation in gauze houses, a panel of 500 wheat accessions including cultivars, gene bank accessions, and wild relatives of wheat was phenotyped for virus titer, infection rate, as well as plant height and yield parameters relative to healthy controls of the same genotype. Additionally, 85 T. aestivum-Ae. tauschii intogression lines were tested for WDV resistance in the greenhouse. A subset of 250 hexaploid wheat accessions was genotyped with the 15k iSelect SNP Chip. By genome-wide association study (GWAS), the quantitative trait loci (QTL) for partial WDV resistance were identified. Within these studies, one cultivar was identified showing an average infection rate of only 5.7%. By analyzing single seed descent (SSD) and doubled haploid (DH) populations comprising 153 and 314 individuals for WDV resistance and by genotyping these with the 25k iSelect SNP Chip, QTL for yield per plant, thousand-grain weight, and relative virus titer were validated on chromosomes 1B, 2B, 3B, 4B, 4A, 5A, 6A, and 7A. These results will be the basis for marker-assisted selection for WDV resistance to replacing the laborious, time-consuming, and technically challenging phenotyping with WDV bearing leafhoppers.

Discovery and characterization of a novel insect-specific reovirus isolated from Psammotettix alienus.

A novel double-stranded RNA (dsRNA) virus designated Psammotettix alienus reovirus (PARV) was found in the leafhopper Psammotettix alienus in China. Spherical particles approximately 70 nm in diameter arranged in a crystalline array were observed in the salivary gland tissues of infected leafhoppers by transmission electron microscopy. Some viral particles were also encased in tubules, similar to those of previously described reoviruses. Whole-genome sequencing revealed that the dsRNA genome of PARV consists of 29 569 nucleotides (nt) divided into 10 segments ranging from 4403 to 1476 nt, with low G+C content (29.5-36.5 %). All segments contained conserved terminal sequences (5'AAC…GUCA3') and specific panhandle structures formed by inverted terminal repeats in the noncoding regions. Phylogenetic analysis based on the deduced RNA-dependent RNA polymerase (RdRp) revealed that PARV was in the fijivirus clade, but in a monophyletic lineage with an unassigned insect reovirus (Hubei insect virus 2, HBIV-2), although PARV and HBIV-2 are distinct enough to represent a new group within the genus Fijivirus. Biological assays showed that PARV infects P. alienus but not wheat plants, implying that it is a new insect-specific reovirus in the leafhopper. Given these features, PARV should be considered as a new species in the genus Fijivirus, family Reoviridae.

Leafhopper Psammotettix alienus hosts chuviruses with different genomic structures

The leafhopper Psammotettix alienus causes serious economic losses by directly sucking the plant sap and by transmitting plant viruses. Here, we obtained the full-genomic sequence of a novel chuvirus, Hancheng leafhopper mivirus (HCLeV), using RNA sequencing (RNA-seq) and rapid amplification of cDNA ends (RACE). The full genome of HCLeV comprises 9,852 nucleotides (nt) and includes two open reading frames (ORFs), which encode nucleocapsid and large polymerase protein, respectively. Its genomic features are similar to that of Tacheng tick virus 5, a member of chuviruses. However, HCLeV had only 36.6-44.4% identities in amino acid sequence for polymerase and 27.1-44.2% identities for nucleocapsid protein with chuviruses and other viruses in the order Mononegavirales and Jingchuvirales. Interestingly, we found this leafhopper can host two chuvirus species with different genomic structures. The discovery of this new virus potentially adds a new species to the family Chuviridae, and its new genomic structural form indicates broader genomic diversity among the chuviruses.

Comparative\u2002transcriptome\u2002analysis in Triticum aestivum infecting wheat dwarf virus reveals the effects of viral infection on phytohormone and photosynthesis metabolism pathways

Wheat dwarf virus (WDV), a mastrevirus transmitted by the leafhopper Psammotettix alienus, causes a severe disease in cereal crops. Typical symptoms of wheat plants infected by WDV are yellowing and severe dwarfing. In this present study, RNA-Seq was used to perform gene expression analysis in wheat plants in response to WDV infection. Comparative transcriptome analysis indicated that a total of 1042 differentially expressed genes (DEGs) were identified in the comparison between mock and WDV-inoculated wheat plants. Genomes ontology (GO) annotation revealed a number of DEGs associated with different biological processes, such as phytohormone metabolism, photosynthesis, DNA metabolic process, response to biotic stimulus and defense response. Among these, DEGs involved in phytohormone and photosynthesis metabolism and response pathways were further enriched and analyzed, which indicated that hormone biosynthesis, signaling and chloroplast photosynthesis-related genes might play an important role in symptom development after WDV infection. These results illustrate the dynamic nature of the wheat-WDV interaction at the transcriptome level and confirm that symptom development is a complex process, providing a solid foundation to elucidate the pathogenesis of WDV.

Functional Transcomplementation between Wheat Dwarf Virus Strains in Wheat and Barley.

Wheat dwarf virus, transmitted by the leafhopper Psammotettix alienus in a persistent, non-propagative manner, infects numerous species from the Poaceae family. Data associated with wheat dwarf virus (WDV) suggest that some isolates preferentially infect wheat while other preferentially infect barley. This allowed to define the wheat strain and the barley strain. There are contradictory results in the literature regarding the ability of each of these two strains to infect its non-preferred host. To improve knowledge on the interactions between WDV strains and barley and wheat, transmission experiments were carried out using barcoded P. alienus and an experimental design based on single/sequential acquisitions of WDV strains and on transmissions to wheat and barley. Results showed that (I) WDV strains are transmitted with similar efficiencies by P. alienus males, females and larvae, (II) WDV wheat and barley strains do not infect barley and wheat plants, respectively, and (III) a functional transcomplementation between the wheat and barley strains allows a mixed infection of barley and wheat. The described ability of each WDV strain to infect a non-host plant in the presence of the other viral strain must be considered to analyze data available on WDV host range.

Identification of the wild and cultivated hosts of wheat dwarf virus and oat dwarf virus in Iran.

In the last decade two mastreviruses, Wheat dwarf virus (WDV) and Oat dwarf virus (ODV) have been reported from cereal farms in Iran. In a survey, wild and cultivated hosts of these mastreviruses were studied during 2015 to 2017. Symptomatic small grain cereal samples and weed species were collected and assayed for WDV and/or ODV infection by PCR. While WDV which was detected in 139/284 (49%) of total symptomatic samples, low incidence (2%) was recorded for ODV which was detected only in slender wild oat (Avena barbata Pott ex Link) and red brome (Bromus rubens L.). In agroinfection studies, the clone of ODV infected common oat (A. sativa) and slender wild oat (A. barbata) with the low efficiency and did not infect wheat or barley. ODV was transmitted by the leafhopper Psammotettix alienus, from agroinfected common oat to healthy seedlings. The results show that, in contrast to WDV, ODV has a low incidence and a narrow host range in gramineous plants.

Consuming alternative prey does not influence the DNA detectability half-life of pest prey in spider gut contents.

BackgroundKey natural enemy-pest interactions can be mapped in agricultural food webs by analysing predator gut content for the presence of a focal pest species. For this, PCR-based approaches are the most widely used methods providing the incidence of consumption of a focal pest in field sampled predators. To interpret such data the rate of prey DNA decay in the predators’ gut, described by DNA detectability half-life (t1/2), is needed. DNA decay may depend on the presence of alternative prey in the gut of generalist predators, but this effect has not been investigated in one of the major predatory arthropod groups, spiders.MethodsIn a laboratory feeding experiment, we determined t1/2 of the key cereal pest virus vector leafhopper Psammotettix alienus in the digestive tracts of its natural enemy, the spider Tibellus oblongus. We followed the fate of prey DNA in spiders which received only the focal prey as food, or as an alternative prey treatment they also received a meal of fruit flies after leafhopper consumption. After these feeding treatments, spiders were starved for variable time intervals prior to testing for leafhopper DNA in order to establish t1/2.ResultsWe created a PCR protocol that detects P. alienus DNA in its spider predator. The protocol was further calibrated to the digestion speed of the spider by establishing DNA decay rate. Detectability limit was reached at 14 days, where c. 10% of the animals tested positive. The calculated t1/2 = 5 days value of P. alienus DNA did not differ statistically between the treatment groups which received only the leafhopper prey or which also received fruit fly. The PCR protocol was validated in a field with known P. alienus infestation. In this applicability trial, we showed that 12.5% of field collected spiders were positive for the leafhopper DNA. We conclude that in our model system the presence of alternative prey did not influence the t1/2 estimate of a pest species, which makes laboratory protocols more straightforward for the calibration of future field data.

Full genome sequence of a novel iflavirus from the leafhopper Psammotettix alienus.

A novel iflavirus was discovered in Psammotettix alienus by RNA sequencing. The virus genome has 10,826 nucleotides (nt) excluding the poly A tail, encodes a 3187-amino-acid polyprotein, and is tentatively named "Psammotettix alienus iflavirus 1" (PaIV1). PaIV1 has a similar genomic structure, conserved motifs, and a close phylogenetic relationship to members of the genus Iflavirus, but it shows only 41.9-55.2% sequence identity in the full genome and 16.2-49% in the deduced polyprotein. Thus, we suggest that it is a new member of the genus Iflavirus, family Iflaviridae.

Temperature affected transmission, symptom development and accumulation of Wheat dwarf virus

One of the biotic agents of yellowing and stunting in wheat and barley cultivations is Wheat dwarf virus (WDV) which is naturally transmitted by the leafhopper Psammotettix alienus (Dahlbom). WDV-Wheat and WDV-Barley isolates of WDV were transmitted to wheat and barley, respectively, using the leafhoppers under four temperature regimes of constant 20, 25, 30, and 35°C. Infection rate, symptom development and virus content of the virus-inoculated plants were determined and the data was statistically analysed. The results showed that the temperature of 25°C was associated with the highest infection rate caused by the viruses. Moreover, P. alienus nymphs were found to be more efficient vectors of WDV than adults, highlighting the importance of nymphs in the epidemiology of wheat dwarf disease. WDV-infected plants incubated at 35°C showed less symptoms than those kept at 20, 25, and 30°C. ELISA results showed that these plants had comparatively low virus content. However, there was no significant difference between the infection rate, symptom development and virus content in plants infected by WDV-Wheat or WDV-Barley.

Identification and Characterization of Wheat Yellow Striate Virus, a Novel Leafhopper-Transmitted Nucleorhabdovirus Infecting Wheat.

A new wheat viral disease was found in China. Bullet-shaped viral particles within the nucleus of the infected wheat leave cells, which possessed 180–210 nm length and 35–40 nm width, were observed under transmission electron microscopy. A putative wheat-infecting rhabdovirus vectored by the leafhopper Psammotettix alienus was identified and tentatively named wheat yellow striate virus (WYSV). The full-length nucleotide sequence of WYSV was determined using transcriptome sequencing and RACE analysis of both wheat samples and leafhoppers P. alienus. The negative-sense RNA genome of WYSV contains 14,486 nucleotides (nt) and seven open reading frames (ORFs) encode deduced proteins in the order N-P-P3-M-P6-G-L on the antisense strand. In addition, WYSV genome has a 76-nt 3′ leader RNA and a 258-nt 5′ trailer, and the ORFs are separated by conserved intergenic sequences. The entire genome sequence shares 58.1 and 57.7% nucleotide sequence identity with two strains of rice yellow stunt virus (RYSV-A and RYSV-B) genomes, respectively. The highest amino acid sequence identity was 63.8% between the L proteins of the WYSV and RYSV-B, but the lowest was 29.5% between the P6 proteins of these viruses. Phylogenetic analysis firmly established WYSV as a new member of the genus Nucleorhabdovirus. Collectively, this study provided evidence that WYSV is likely the first nucleorhabdovirus described infecting wheat via leafhopper P. alienus transmission.

Previous infestation withPsammotettix alienuson spring wheat seedlings decreased the fitness ofSitobion avenaein a subsequent infestation

Previous feeding by herbivores may influence the performance of other herbivores by altering the morphological and physiological properties of the shared host. The present study aimed to examine the fitness of the apterous aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae) when fed spring wheat that was previously attacked by the leafhopper Psammotettix alienus Dahlbom (Hemiptera: Cicadellidae), with an evaluation of the differences in aphid weight (WD), development time (D), mean relative growth rate (MRGR), daily production of nymphs (MDNP) and intrinsic rate of population increase (rm) under controlled greenhouse conditions. For the S. avenae reared on the two spring wheat cultivars that were previously infested with P. alienus, the WD and the MRGR decreased significantly. The S. avenae reared on the previously infested cv. Leguan had significantly prolonged D values and a lowered rm, whereas these parameters did not differ significantly when S. avenae was reared on the cv. Bobwhite. Overall, the fitness of the aphid S. avenae was adversely affected when reared on the two spring wheat cultivars that were previously infested with P. alienus.

Cool Headed Individuals Are Better Survivors: Non-Consumptive and Consumptive Effects of a Generalist Predator on a Sap Feeding Insect.

Non-consumptive effects (NCEs) of predators are part of the complex interactions among insect natural enemies and prey. NCEs have been shown to significantly affect prey foraging and feeding. Leafhopper's (Auchenorrhyncha) lengthy phloem feeding bouts may play a role in pathogen transmission in vector species and also exposes them to predation risk. However, NCEs on leafhoppers have been scarcely studied, and we lack basic information about how anti-predator behaviour influences foraging and feeding in these species. Here we report a study on non-consumptive and consumptive predator-prey interactions in a naturally co-occurring spider–leafhopper system. In mesocosm arenas we studied movement patterns during foraging and feeding of the leafhopper Psammotettix alienus in the presence of the spider predator Tibellus oblongus. Leafhoppers delayed feeding and fed much less often when the spider was present. Foraging movement pattern changed under predation risk: movements became more frequent and brief. There was considerable individual variation in foraging movement activity. Those individuals that increased movement activity in the presence of predators exposed themselves to higher predation risk. However, surviving individuals exhibited a ‘cool headed’ reaction to spider presence by moving less than leafhoppers in control trials. No leafhoppers were preyed upon while feeding. We consider delayed feeding as a “paradoxical” antipredator tactic, since it is not necessarily an optimal strategy against a sit-and-wait generalist predator.

Feeding behaviour of a virus‐vector leafhopper on host and non‐host plants characterised by electrical penetration graphs

AbstractMany sap‐feeders are vectors of plant diseases, acquiring and inoculating pathogens at various stages of the feeding process. In oligophagous species, certain aspects of probing behaviour on hosts and non‐hosts may have implications for the range of both pathogens and plants that can be inoculated. We addressed the question of which probing phases (including ingestion) occur on non‐host plants in the case of the common leafhopper Psammotettix alienus (Dahlbom) (Hemiptera: Cicadellidae). This species is a pest on cereals, a vector of the Wheat dwarf virus, and possible carrier of other pathogens. It is regarded as oligophagous on grasses, but has been reported also on other plant families. In a combined electrical penetration graph (EPG) video observation study, we aimed to give a description of the waveforms during the probing process. EPG recordings were made on a suitable host, barley, Hordeum vulgare L. (Poaceae), and on two non‐host plants, the sedge Carex tomentosa L. (Cyperaceae) and the ragweed Ambrosia artemisiifolia L. (Asteraceae). We demonstrated that P. alienus probes on plants other than Poaceae, including dicotyledons. Univariate and multivariate analyses of general probing variables revealed that total and maximal probe durations were shorter and probing progress less advanced on non‐host plants. Waveforms of the pathway phase were stereotypical and statistically not different between the host and non‐host plants. On sedge, the waveform signifying insertion through the plant epidermis was shortened but much more frequent, indicating penetration difficulties and retrials. Most importantly, waveforms indicating phloem ingestion were not present on either of the non‐host plants. Non‐host probing events terminating during the pathway phase suggested that rejection occurred when the stylets were in the mesophyllum. Overall, the EPG signals reflected the unsuitability of A. artemisiifolia and C. tomentosa compared to barley, but the occurrence of probing and the demonstrated level of probing progress imply that pathogen transmission cannot be excluded in the case of many non‐host plants and non‐specific pathogens.

A potential spider natural enemy against virus vector leafhoppers in agricultural mosaic landscapes – Corroborating ecological and behavioral evidence

We intended to establish the potential for interaction between the wheat dwarf virus (WDV) vector leafhopper Psammotettix alienus – a dominant sap feeding pest in cereal fields, and the spider Tibellus oblongus – a dominant predator of grassy field margins. The relationship is important, because with the senescing and harvest of cereals P. alienus migrates to alternative host species, grasses. We analyzed the potential of T. oblongus to be an effective natural enemy of P. alienus by studying the probability of their co-occurrence seasonally and at the habitat and microhabitat scale. By gathering data from long term research (1994–2011) in six agricultural regions of Hungary, we assembled 96 one-year-long datasets obtained by suction sampling from the four key habitats of the agricultural landscape mosaic. The analysis showed that both in space and time the spider has the potential to prey on P. alienus. T. oblongus populations can reach considerable densities and represent high dominance among other spiders in the habitats of the leafhopper. Given this co-occurrence pattern, we devised laboratory experiments to study whether P. alienus is included among the preferred prey types of T. oblongus and to ascertain whether prolonged feeding has no adverse effects and provides the nutrients for growth. P. alienus proved to be both a preferred prey type and one that can be utilized for growth by the spider. This study collected the circumstantial ecological and direct laboratory feeding trial proofs that T. oblongus can be an important biological control agent against the leafhopper pest P. alienus.

Partial resistance to Wheat dwarf virus in winter wheat cultivars

Four Hungarian winter wheat cultivars were investigated for their susceptibility to the geminivirus Wheat dwarf virus (WDV). Previously, two cultivars (Mv Regiment and Mv Emese) were assessed by breeders to exhibit virus symptoms in the field, whereas Mv Dalma and Mv Vekni showed few symptoms. Two inoculation techniques for WDV, vector transmission with the leafhopper Psammotettix alienus and agroinoculation, were used. Leafhopper transmission was more efficient than agroinoculation. However, irrespective of the technique used, no Mv Dalma or Mv Vekni plants showed clear WDV symptoms. In contrast, 3/30 Mv Emese and 4/36 Mv Regiment plants showed dwarfing and chlorosis after agroinoculation and 13/17 and 14/15 plants, respectively, had clear WDV symptoms after vector transmission. WDV‐specific PCR showed that Mv Vekni and Mv Dalma plants could be infected, especially following vector transmission (approximately 50% infection), but at significantly lower frequency than Mv Emese or Mv Regiment plants (100% infection). Furthermore, real‐time PCR showed that WDV DNA accumulated to much lower levels in infected Mv Vekni and Mv Dalma plants than in infected Mv Regiment and Mv Emese plants. The data strongly suggest that Mv Vekni and Mv Dalma are partially resistant to WDV infection. As WDV resistance has not previously been identified in wheat, and because WDV can cause significant yield losses, the resistance of Mv Vekni or Mv Dalma will provide a valuable breeding resource.

Development and validation of a method for the detection of altered resistance in transgenic plants against herbivore-pathogen-complexes

AbstractEnhanced or reduced uptake of viruses by vectors and changes in resistance level can be sensitive indicators for metabolic changes in transgenic plants caused by the new trait and not observed by conventional methods. In addition, the plant transformation process itself can lead to such changes. To be able to investigate this hypothesis in cereals we decided to use two highly important insect-transmitted viruses infecting them - Barley yellow dwarf virus (BYDV) and Wheat dwarf virus (WDV). Corresponding molecular tools for their quantification in plants as well as virus vectors had to be developed. Both viruses cause similar symptoms: dwarfing, stunting, leaf discoloration leading to yield losses or death of plant. BYDV (Luteoviridae) is one of the most important cereal-infecting viruses worldwide causing substantial yield losses. In Germany, the strain PAV is widespread. It is transmitted by the aphids Rhopalosiphum padi and Sitobion avenae in a persistent manner. WDV (Geminiviridae) is found in Germany since the early 1990s and has gained importance over the last years. It is transmitted by the leafhopper Psammotettix alienus in a persistent manner. Real-time PCR is the state of the art method for specific detection of viruses even in minor quantities. It allows exact quantification of the virus content of plants and vectors and is hence suited to monitor changes of it. We developed qPCR assays for WDV and RT-qPCR assays for BYDV-PAV based on TaqMan probe technology as well as the DNA-binding dye SybrGreen. The qPCR assays proved to be more sensitive than DAS-ELISA. For example, WDV is detected even at dilutions of 1:10^8^, whereas the corresponding threshold for ELISA is about 1:10^4^. As nucleic acid extraction procedures proved to be time consuming and expensive, detection methods are adopted now for immunocapture procedures. These methods will be applied to the analysis of several transgenic wheat lines.