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1.
The reaction of several cultivated potato varieties (Solarium tuberosum L.) to three strains of tobacco etch potyvirus (TEV-F, TEV-Mex21 and TEV-ATCC) and the reaction of several pepper lines (Capsicum annuum L. and C. chinense L.) to two strains of potato Y potyvirus (PVYO and PVYN) and one strain of potato A potyvirus (PVA-M) was tested. The potato varieties included in this study carried resistance genes against PVY, PVA and potato V potyvirus, but all were susceptible to TEV and developed mottle and mosaic symptoms. TEV was readily transmitted by mechanical inoculation from tobacco and potato to potato, whereas transmission from pepper to potato occurred infrequently. TEV was transmitted through potato tubers, and from pepper to potato plants by aphids. Lack of detectable systemic infection following graft-inoculation indicated extreme resistance to PVYO and PVA in several pepper lines. No pepper line was systemically infected with PVYN following mechanical inoculation (graft-inoculation was not carried out with PVYN). The development of necrotic lesions following mechanical and graft-inoculation indicated hypersensitive response to PVYO in several pepper lines which resembled the resistance responses to these potyvirus strains in potato. Results of this study together with previous work indicate that C. annuum cv. Avelar is resistant to four potyviruses [PVY, PVA, pepper mottle potyvirus (PepMoV) and some isolates of TEV]; C. annuum cv. Criollo de Morelos and C. chinense PI 152225 and PI 159236 are resistant to three potyviruses (PVY, PepMoV and PVA; and PVY, PepMoV and TEV, respectively); C. annuum 9093–1 and 92016–1 are resistant to PVY and PepMoV; and C. annuum cv. Jupiter and C. annuum cv. RNaky are resistant to PVYN and PVA.  相似文献   

2.
Resistance to potato leafroll virus (PLRV), potato virus Y (PVYo) and potato virus X (PVX) was studied in symmetric and asymmetric somatic hybrids produced by electrofusion between Solanum brevidens (2n=2×=24) and dihaploid S. tuberosum (2n=2×=24), and also in regenerants (B-hybrids) derived through protoplast culture from a single somatic hybrid (chromosome number 48). All of the somatic hybrids between 5. brevidens and the two dihaploid lines of potato cv. Pito were extremely resistant to PLRV and PVYoand moderately resistant to PVX, irrespective of their chromosome number and ploidy level (tetraploid or hexaploid). Most (56%) of the asymmetric hybrids of irradiated S. brevidens and the dihaploid line of potato cv. Pentland Crown (PDH40) had high titres of PVYosimilar to those of PDH40, whereas the rest of the hybrids had PVYotitres less than a tenth of those in PDH40. Three B-hybrids had a highly reduced chromosome number (27, 30 and 34), but were however as resistant to PLRV, PVYoand PVX as 5. brevidens. Two asymmetric hybrids and one B-hybrid were extremely resistant to PLRV but susceptible to both PVY and PVX. The results suggested that resistance to PLRV in 5. brevidens is controlled by a gene or genes different from those controlling resistance to PVY and PVX, and the gene(s) for resistance to PVY and PVX are linked in S. brevidens.  相似文献   

3.
The potato cv. Igor is susceptible to infection with Potato virus Y (PVY) and in Slovenia it has been so severely affected with NTN isolates of PVY causing potato tuber necrotic ringspot disease (PTNRD) that its cultivation has ceased. Plants of cv. Igor were transformed with two transgenes that contained coat protein gene sequence of PVYNTN. Both transgenes used PVY sequence in a sense (+) orientation, one in native translational context (N‐CP), and one with a frame‐shift mutation (FS‐CP). Although most transgenic lines were susceptible to infection with PVYNTN and PVYO, several lines showed resistance that could be classified into two types. Following manual or graft inoculation, plants of partially resistant lines developed some symptoms in foliage and tubers, and virus titre in the foliage, estimated by ELISA, was low or undetectable. In highly resistant (R) lines, symptoms did not develop in foliage and on tubers, and virus could not be detected in foliage by ELISA or infectivity assay. Four lines from 34 tested (two N‐CP and two FS‐CP) were R to PVYNTN and PVYO and one additional line was R to PVYO. When cv. Spey was transformed with the same constructs, they did not confer strong resistance to PVYO.  相似文献   

4.
Potato virus Y (PVY) is one of the most important viruses affecting potato (Solanum tuberosum) production. In this study, a novel hypersensitive response (HR) gene, Ny-2, conferring resistance to PVY was mapped on potato chromosome XI in cultivar Romula. In cultivars Albatros and Sekwana, the Ny-1 gene was mapped on chromosome IX. In cv. Romula, the local lesions appeared in leaves inoculated with the PVYN-Wi isolate at 20 and 28 °C; PVY systemic infections were only occasionally observed at the higher temperature. In cvs. Albatros and Sekwana, expression of the necrotic reaction to virus infection was temperature-dependent. PVYN-Wi was localized at 20 °C; at 28 °C, the systemic, symptomless infection was observed. We developed the B11.61600 marker co-segregating with Ny-2 and the S1d11 marker specific for the Ny-1 gene. Fifty potato cultivars were tested with markers B11.6 and S1d11 and marker SC895 linked to the Ny-1 gene in cv. Rywal. These results indicated the utility of these markers for marker-assisted selection of HR-like PVY resistance in potato breeding programs.  相似文献   

5.
Potato virus Y (PVY) strains are transmitted by different aphid species in a non‐persistent, non‐circulative manner. Green peach aphid (GPA), Myzus persicae Sulzer, is the most efficient vector in laboratory studies, but potato aphid (PA), Macrosiphum euphorbiae Thomas (both Hemiptera: Aphididae, Macrosiphini), and bird cherry‐oat aphid (BCOA), Rhopalosiphum padi L. (Hemiptera: Aphididae, Aphidini), also contribute to PVY transmission. Studies were conducted with GPA, PA, and BCOA to assess PVY transmission efficiency for various isolates of the same strain. Treatments included three PVY strains (PVYO, PVYN:O, PVYNTN) and two isolates of each strain (Oz and NY090031 for PVYO; Alt and NY090004 for PVYN:O; N4 and NY090029 for PVYNTN), using each of three aphid species as well as a sham inoculation. Virus‐free tissue‐cultured plantlets of potato cv. Russet Burbank were used as virus source and recipient plants. Five weeks post inoculation, recipient plants were tested with quantitative DAS‐ELISA to assess infection percentage and virus titer. ELISA‐positive recipient plants were assayed with RT‐PCR to confirm presence of the expected strains. Transmission efficiency (percentage infection of plants) was highest for GPA, intermediate for BCOA, and lowest for PA. For all aphid species, transmission efficiency did not differ significantly between isolates within each strain. No correlations were found among source plant titer, infection percentage, and recipient plant titer. For both GPA and BCOA, isolates of PVYNTN were transmitted with greatest efficiency followed by isolates of PVYO and PVYN:O, which might help explain the increasing prevalence of necrotic strains in potato‐growing regions. Bird cherry‐oat aphid transmitted PVY with higher efficiency than previously reported, suggesting that this species is more important to PVY epidemiology than has been considered.  相似文献   

6.
7.
Hypersensitive resistance (HR) is an efficient defense strategy in plants that restricts pathogen growth and can be activated during host as well as non-host interactions. HR involves programmed cell death and manifests itself in tissue collapse at the site of pathogen attack. A novel hypersensitivity gene, Ny-1, for resistance to Potato virus Y (PVY) was revealed in potato cultivar Rywal. This is the first gene that confers HR in potato plants both to common and necrotic strains of PVY. The locus Ny-1 mapped on the short arm of potato chromosome IX, where various resistance genes are clustered in Solanaceous genomes. Expression of HR was temperature-dependent in cv. Rywal. Strains PVYO and PVYN, including subgroups PVYNW and PVYNTN, were effectively localized when plants were grown at 20°C. At 28°C, plants were systemically infected but no symptoms were observed. In field trials, PVY was restricted to the inoculated leaves and PVY-free tubers were produced. Therefore, the gene Ny-1 can be useful for potato breeding as an alternative donor of PVY resistance, because it is efficacious in practice-like resistance conferred by Ry genes.  相似文献   

8.
Potato virus Y (PVY, Potyvirus) is the fifth most important plant virus worldwide in terms of economic and scientific impact. It infects members of the family Solanaceae and causes losses in potato, tomato, tobacco, pepper and petunia production. In potato and its wild relatives, two types of resistance genes against PVY have been identified. While Ry genes confer symptomless extreme resistance, Ny genes cause a hypersensitive response visible as local necrosis that may also be able to prevent the virus from spreading under certain environmental conditions. The potato cultivar Sárpo Mira originates from Hungary and is highly resistant to PVY, although the source of this resistance remains unknown. We show that cv. Sárpo Mira reacts with a hypersensitive response leading to necrosis after PVYNTN infection in detached leaf, whole plant and grafting assays. The hypersensitivity to PVYNTN segregated amongst 140 individuals of tetraploid progeny of cvs. Sárpo Mira × Maris Piper in a 1:1 ratio, indicating that it was conferred by a single, dominant gene in simplex. Moreover, we identified five DNA markers linked to this trait and located the underlying locus (Ny-Smira) to the long arm of potato chromosome IX. This position corresponds to the location of the Ry chc and Ny-1 genes for PVY resistance. A simple PCR marker, located 1 cM from the Ny-Smira gene, can be recommended for selection of PVY-resistant progeny of cv. Sárpo Mira.  相似文献   

9.
Novel potyvirus resistance specificities were found in eight tested wild potato species (clones): hypersensitive resistance (HR) to potato Y potyvirus (PVY) strain groups PVYO in Solanum megistacrolobum and S. polyadenium and PVYN in S. stoloniferum; HR to potato V potyvirus (PW) in S. maglia, S. polyadenium, S. stoloniferum, S. sparsipilum and S. sucrense, HR to potato A potyvirus (PVA) strain group 1 in S. sucrense, and extreme resistance (ER) to PVA in S. polyadenium. S. commersonii and S. stoloniferum expressed HR to tobacco etch potyvirus (TEV) which has not been reported previously in potato species. The studied clone of S. stoloniferum expressed HR to all potyviruses and potyvirus strains tested. The clone of S. stoloniferum (2n = 48; nuclear DNA content (2C) = 3.6 pg) and S. chacoense (2n = 24; 2C=1.9 pg) were crossed and one hybrid (2n = 36; 2C = 2.9 pg) was obtained. The hybrid expressed HR to all tested potyviruses except PVA, which indicated that HR to PVA was controlled by a gene which is different from the genes (or gene) controlling HR to PVYO, PVYN, PVV and TEV in S. stoloniferum. On the other hand, S. chacoense and the hybrid expressed ER to cucumber mosaic cucumovirus (CMV), whereas S. stoloniferum was susceptible to CMV. All tested wild species and the six tested potato cultivars (S. tuberosum subsp. tuberosum) expressed HR to PVV. Expression of HR following infection with PVYN induced systemic acquired resistance (SAR) in S. chacoense. HR to PVYN in S. sparsipilum and S. sucrense and to PVYO in potato cv. Pito was efficiently expressed at lower temperatures (16/18°C) indicated by the development of distinct necrotic lesions and/or vein necrosis in inoculated leaves, whereas the HR was rendered less effective at higher temperatures (19/24°C) which was indicated by the development of systemic infection with leaf-drop and mosaic symptoms.  相似文献   

10.
A diploid backcross population derived from a cross between Solanum tuberosum and Solanum berthaultii segregated for monogenic dominant hypersensitivity to Potato virus Y (PVY). We propose the symbol Ny tbr for this locus because plants carrying this gene develop necrosis after inoculation with PVY and the allele originated in S. tuberosum. The gene mapped to chromosome IV between TG316 and TG208 at LOD=2.72. This location does not correspond to any other mapped resistance genes in potato. Received: 13 April 2001 / Accepted: 20 July 2001  相似文献   

11.
Potato virus Y (PVY) is one of the most damaging viruses of tobacco. In particular, aggressive necrotic strains (PVYN) lead to considerable losses in yield. The main source of resistance against PVY is linked to the va locus. However, va‐overcoming PVY isolates inducing necrotic symptoms were observed in several countries. In this context, it is important to find va‐independent protection strategies. In a previous study, the phenotyping of 162 tobacco varieties revealed 10 accessions that do not carry the va allele and do not exhibit typical PVYN‐induced veinal necrosis. Despite the absence of necrotic symptoms, normal viral accumulation in these plants suggests a va‐independent mechanism of tolerance to PVYN‐induced systemic veinal necrosis. Fine mapping of the genetic determinant(s) was performed in a segregating F2 population. The tolerance trait is inherited as a single recessive gene, and allelism tests demonstrated that eight of the 10 tolerant varieties carry the same determinant. Anchoring the linkage map to the tobacco genome physical map allowed the identification of a RPP8‐like R gene, called NtTPN1 (for t abacum P VY‐induced 相似文献   

12.
Plants of several potato clones with major gene resistance to potato virus Y (PVY) developed necrotic local lesions and systemic necrosis after manual inoculation with common (PVYo) or veinal necrosis (PVYN) strains of the virus. The clones reacted similarly, although their resistance genes are thought to be derived from four different wild species of Solarium. Mesophyll protoplasts from each clone became infected when inoculated with RNA of PVYo by the polyethylene glycol method. The proportion of protoplasts infected, assessed by staining with fluorescent antibody to virus particles, was similar to that of protoplasts of susceptible potato cultivars. In contrast, plants of potato cultivars Corine and Pirola, which possess gene Ry from S. stoloniferum, developed few or no symptoms when manually inoculated or grafted with PVYo. Moreover, only very few protoplasts of these cultivars produced virus particle antigen after inoculation with PVYo RNA. The extreme resistance to PVY of cvs Corine and Pirola was therefore expressed by inoculated protoplasts whereas the resistance of the necrotic-reacting potato clones was not.  相似文献   

13.
14.
Potato virus Y (PVY, genus Potyvirus, family Potyviridae) causes high economic losses worldwide, especially in the production of seed potatoes (Solanum tuberosum). PVY control systems rely on measuring virus pressure and vector pressure in the field. Calculation of the vector pressure is based on the relative efficiency factors (REFs) of aphid species. These REFs express the transmission efficiency of aphid species in relation to the transmission efficiency of Myzus persicae, the most efficient vector of PVY. In this paper, we report on the determination of aphids' relative transmission efficiency factors (REFs) for isolates of the PVY strains PVYN, PVYNTN and PVYN-Wi. Biotype Mp2 of M. persicae was tested for its transmission efficiency for six PVY isolates (one PVYN, three PVYNTN and two PVYN-Wi isolates) and showed comparable average transmission efficiencies for all isolates. The transmission rate of this biotype for the six PVY isolates was set to 1 and Mp2 was used as an internal control in transmission experiments to determine the REFs of three other biotypes of M. persicae and 16 other aphid species (three biotypes per species when available) for the six PVY isolates. Comparing the calculated REFs for PVYN with the REFs reported in the previous century for PVYN, we observe overall comparable REFs, except for Aphis fabae, Aphis spp., Hyperomyzus lactucae, Macrosiphum euphorbiae and Rhopalosiphum padi, which have a lower REF in our experiments, and Aphis frangulae and Phorodon humuli, which have now a higher REF. Comparing the new REFs found for the PVYNTN strains with the new REFs for PVYN, we observe that they are overall comparable, except for A. frangulae (0.17 compared with 0.53) and Schizaphis graminum (0.05 compared with 0.00). Comparing the REFs calculated for PVYN-Wi with those calculated for PVYN, we can observe six aphid species with higher REFs (Acyrthosiphon pisum, A. fabae, Aphis nasturtii, Aphis spp., P. humuli and R. padi). Only the species A. frangulae shows a lower REF for PVYN-Wi compared with the transmission efficiency of PVYN. Three aphid species (Aulacorthum solani, Myzus ascalonicus and S. graminum) for which no REF was determined earlier were found to be capable to transmit PVY and their REFs were determined.  相似文献   

15.
Surveys were made for the presence of potato virus Y (PVY) in the planted seed and harvested tubers in ware potato crops of cv. Record grown at three sites in England in 1994 (survey 1) and seven sites in 1995 (survey 2). PVY was not found in samples of planted seed, but high levels of infection were found in many, but not all, harvested crops. However, plants of volunteer potatoes (VP) (i.e. plants arising from tubers or true seed derived from previous crops and surviving in the soil) were frequently found to be infected. Infection in tubers harvested from crops in the first survey ranged from 2–52%. In 1995, VP were collected from two of the three English sites where potato crops had been grown the previous season and also from a site in Scotland where PVY infection in an experimental crop of cv. Record had been monitored in 1994. The percentages of infected VP ranged from 2–54%. PVYN was the predominant strain found in sampled VP, with only two plants (out of 300 infected) containing PVYO. In the second survey, VP were assessed within the 1995 ware crops and were found at four sites, at which they comprised between 4–8% of emerged potato plants. Between 31–93% of VP were infected. Again, PVYN was the predominant strain with one plant containing PVYO and another PVYC (out of 189 infected). A sample of harvested tubers from each site was also tested for PVY. At those sites which had many infected VP, the harvested crop contained a large percentage of infected tubers, ranging from 60–97%. Two sites which had not previously been used for cropping potatoes had no VP and a very low incidence of PVY infection in the harvested tubers (1% and 2%). However, although no VP were found at one site, 31% of harvested tubers were infected, suggesting that alternative inoculum sources may be important.  相似文献   

16.
Tobacco plant lines transformed with the coat protein (CP) gene of the tobacco veinal necrosis strain of potato virus Y (PVYN), and previously shown to be protected against mechanical inoculation with the virus, have now been tested for specificity and protection against virus infection mediated by viruliferous aphids. To determine the specificity of virus protection, two transgenic tobacco lines, A30 and A80, were challenged with several isolates of distinct PVY strains (PVYN, PVYO and PVYC) by mechanical inoculation. Clear levels of protection against the PVYO-isolates tested were maintained in the transgenic plants, although these levels were slightly lower than the protection against the homologous PVYN strain from which the CP gene was derived. Interestingly, no protection against mechanical virus inoculation with the Gladblaadje isolate of PVYC could be observed. To assess the levels of protection against aphid-mediated virus infection, two transgenic plant lines, A30 and D25, showing respective levels of protection of 95 and 80% against mechanical virus inoculation, were challenged using PVYN viruliferousMyzus persicae. Virus inoculation using six aphids per plant, resulted in similar levels of protection in both transgenic lines as found previously for mechanical inoculation. Protection was maintained in both lines, even when as many as 60 viruliferous aphids were used per plant in the inoculation experiments.  相似文献   

17.
Production of monoclonal antibodies for the detection of potato virus Y   总被引:1,自引:0,他引:1  
Monoclonal antibodies (McAb) were obtained to potato virus Y (PVY) after immunisation of BALB/c mice with purified PVY, tobacco necrotic strain (PVYn). Spleen cells from a mouse showing a high serum titre were used for fusion with X63NS1 myeloma cells. Hybridomas were selected in medium containing HAT. Culture supernatants were screened for antibody production against PVY, ordinary strain (PVY0) and PVYn using indirect ELISA. Clones of interest were further cross-reacted with 12 isolates each of PVY0 and PVYn and two isolates of potato virus A (PVA) and healthy sap. For further trials, two clones which reacted specifically with PVYn isolates and one which detected all PVY isolates except two of potato virus C (PVC) were selected.  相似文献   

18.
When 12 potato cultivars were inoculated with isolates (one each) of potato virus Y (PVY) ordinary (Yo), C (Yc) and tobacco veinal necrosis (Yn) strain groups, potato virus A (PVA) and potato virus V (PVV), none of them responded hypersensitively to Yn. However, with Yo, Yc, PVA and PW specific hypersensitive reactions developed depending on isolate-cultivar combination which were all independent of each other. When field isolates of PVY thought to be Yoor Ycwere inoculated to the same 12 cultivars, two did not fit into either strain group giving hypersensitive reactions in only two cultivars instead of seven with Yoor eight with Yc. These two isolates may represent a previously unreported PVY strain group (Yz). When Yowas graft-inoculated to seedlings of the cross Desiree × Maris Piper (hypersensitive × non-hypersensitive for Yo), the segregation ratio obtained for non-hypersensitive:hypersensitive reactions was close to 1:1 suggesting that a single dominant gene (Nytbr) determining Yospecific hypersensitivity may be present in cv. Desiree (simplex condition). In tests using PVV and Desiree × Maris Piper (non-hypersensitive × hypersensitive for PVV) seedlings, the segregation ratio obtained was close to 1:5 indicating that a single dominant gene (Nv) determining PVV specific hypersensitivity may be present in cv. Maris Piper (duplex condition). Cultivars Corine, Pirola and clone G5457(4) which each carry one of the extreme resistance genes (Ry) from Solanum stoloniferum were graft-inoculated with Yn, Yo, Yc, PVV and PVA. G5457(4) gave a strong localised hypersensitive reaction in all instances, while cv. Pirola did so with all except PVA to which it was immune. In cv. Corine a severe localised hypersensitive reaction developed with PVA, generalised hypersensitivity with PVV but an immune response with the three PVY strain groups. Large-scale grafting of Ynto plants of cvs Corine and Pirola gave no evidence of selection of a strain which overcomes Ry genes.  相似文献   

19.
In this study we applied RNA silencing to engineer potato plants that are resistant to potato virus Y (PVY). We expressed double-stranded (ds) RNA derived from the 3 terminal part of the coat protein gene of PVY, which is highly conserved in sequence amongst different PVY isolates, in transgenic potatoes of the commercial variety Spunta. Transgenic plants were analyzed for generation of transgene-derived short interfering RNAs (siRNAs) prior to virus inoculation. Twelve of fifteen transgenic lines produced siRNAs and were highly resistant to three strains of PVY, each belonging to three different subtypes of the virus (PVYN, PVYO and PVYNTN). Infection of transgenic plants with Potato virus X (PVX) simultaneously or prior to the challenge with PVY did not interfere with PVY-resistance.Anastasia Missiou: M.A. and K.K. have contributed equally to this workKriton Kalantidis: M.A. and K.K. have contributed equally to this work  相似文献   

20.
A total of 59 Solanum tuberosum androgenetic plants have been obtained through anther culture, 47 of which derived from a tetraploid clone, seven from a diploid hybrid, and five from an anther-derived clone. About two thirds of the anther-derived plants were dihaploids, a few were monohaploids (5.08%) or aneuploids (6.78%), whereas the tetraploid genotype generated about a third of tetraploids. Seven hundred twenty seven R1 plants arisen from tubers of the androgenetic potatoes were mechanically inoculated with the necrotic strain of the potato Y potyvirus (PVYN) and grown in a glasshouse. Fifty days after inoculation, the presence of PVYN in R1 plants was detected by DAS-ELISA (Double Autibody Sandwich). Only three plants (0.4%) of genotype H2-258 exhibited local necrotic symptoms (hypersensitivity reaction) suggesting the presence of the N y gene, and this extreme resistance is epistatic to hypersensitive resistance. The immunity (R y-gene) to PVYN was retained through anther culturing and present at all levels of ploidy. The pattern of segregation for immunity was differentiated according to the ploidy level of the anther-derived plants. This changed segregation pattern may be due to a loss of resistance during the culturing, when an endoreduplication has taken place or to the possible regeneration from Second-division restituted unreduced microspores. Anyway, this segregation pattern must be taken into account when gametoclones are used in genetic studies. Published in Russian in Fiziologiya Rastenii, 2007, Vol. 54, No. 4, pp. 572–578. The text was submitted by the authors in English.  相似文献   

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