Further studies on Carrot virus Y: hosts, symptomatology, search for resistance, and tests for seed transmissibility

2005 ◽  
Vol 56 (8) ◽  
pp. 859 ◽  
Author(s):  
R. A. C. Jones ◽  
L. J. Smith ◽  
B. E. Gajda ◽  
T. N. Smith ◽  
L. J. Latham
Keyword(s):  
Host Species ◽  
Field Survey ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Anethum Graveolens ◽  
Additional Species ◽  
Wild Carrot ◽  
Natural Hosts ◽  
New Locations ◽  
Seed Transmissibility

Carrot virus Y (CarVY) was studied to provide information on its host range and symptoms, identify any alternative natural hosts and sources of host resistance in carrot germplasm, and determine whether it is seed-borne. Twenty-two species belonging to the Apiaceae were inoculated with CarVY by viruliferous aphids in the glasshouse. Systemic infection with CarVY developed in carrot itself, 4 other Daucus species, 5 herbs, 1 naturalised weed, and 2 Australian native plants. When 7 of these host species were exposed to infection in the field, all became infected systemically. In both glasshouse and field, the types of symptoms that developed in infected plants and their severity varied widely from host to host. Following inoculation with infective sap, the virus was detected in inoculated leaves of 1 additional species in the Apiacaeae, and 2 species of Chenopodiaceae. A field survey did not reveal any alternative hosts likely to be important as CarVY infection reservoirs. When 34 accessions of wild carrot germplasm and 16 of other Daucus spp. were inoculated with infective aphids, symptom severity varied widely among accessions but no source of extreme resistance to CarVY was found. Tests on seedlings grown from seed collected from individual infected plants or field plantings (most with CarVY incidences of >92%) of cultivated carrot (34 135 seeds), wild carrot (20 978 seeds), Anethum graveolens (22 921 seeds), and 3 other host species (3304 seeds) did not detect any seed transmission of CarVY. The implications of these results for control of the virus in carrot crops, minimising the losses it causes, and avoiding its introduction to new locations are discussed.

scholarly journals Role of Soybean mosaic virus–Encoded Proteins in Seed and Aphid Transmission in Soybean

2013 ◽  
Vol 103 (9) ◽  
pp. 941-948 ◽  
Author(s):  
Sushma Jossey ◽  
Houston A. Hobbs ◽  
Leslie L. Domier
Keyword(s):  
Mosaic Virus ◽  
Seed Quality ◽  
Soybean Mosaic Virus ◽  
Seed Transmission ◽  
Aphid Transmission ◽  
Plant Introduction ◽  
Sequence Motif ◽  
Coding Region ◽  
Encoded Proteins ◽  
Seed Transmissibility

Soybean mosaic virus (SMV) is seed and aphid transmitted and can cause significant reductions in yield and seed quality in soybean (Glycine max). The roles in seed and aphid transmission of selected SMV-encoded proteins were investigated by constructing mutants in and chimeric recombinants between SMV 413 (efficiently aphid and seed transmitted) and an isolate of SMV G2 (not aphid or seed transmitted). As previously reported, the DAG amino acid sequence motif near the amino terminus of the coat protein (CP) was the major determinant in differences in aphid transmissibility of the two SMV isolates, and helper component proteinase (HC-Pro) played a secondary role. Seed transmission of SMV was influenced by P1, HC-Pro, and CP. Replacement of the P1 coding region of SMV 413 with that of SMV G2 significantly enhanced seed transmissibility of SMV 413. Substitution in SMV 413 of the two amino acids that varied in the CPs of the two isolates with those from SMV G2, G to D in the DAG motif and Q to P near the carboxyl terminus, significantly reduced seed transmission. The Q-to-P substitution in SMV 413 also abolished virus-induced seed-coat mottling in plant introduction 68671. This is the first report associating P1, CP, and the DAG motif with seed transmission of a potyvirus and suggests that HC-Pro interactions with CP are important for multiple functions in the virus infection cycle.

scholarly journals Importance of Different Pathways for Maize Kernel Infection by Fusarium moniliforme

1997 ◽  
Vol 87 (2) ◽  
pp. 209-217 ◽  
Author(s):  
G. P. Munkvold ◽  
D. C. McGee ◽  
W. M. Carlton
Keyword(s):  
Fusarium Moniliforme ◽  
Field Experiments ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Maize Hybrids ◽  
Systemic Movement ◽  
Kernel Infection ◽  
Important Pathway ◽  
Infection Pathways ◽  
Systemic Development

The relative importance of several infection pathways (silks, stalks, and seed) leading to kernel infection of maize hybrids by Fusarium moniliforme was investigated in field experiments in 1993 and 1994. Systemic movement of specific fungal strains within plants was detected by using vegetative compatibility as a marker. Transmission of F. moniliforme from inoculated seed to stalks and developing kernels was detected in two of three field experiments; the seed-inoculated strain was detected in kernels on approximately 10% of ears. The percentage of kernels infected with the seed-inoculated strain ranged from 0 to 70%, with a mean of 0 to 2.5% (0 to 8.3% of F. moniliforme-infected kernels). Other pathways to kernel infection were more effective than seed transmission and systemic infection. F. moniliforme strains inoculated into the crowns and stalks of plants were found throughout the stalks and in up to 95% of the kernels in individual plants. Infection through the silks was clearly the most effective pathway to kernel infection. This was the only inoculation method that significantly increased overall incidence of F. moniliforme infection in kernels; the silk-inoculated strain infected up to 100% of the kernels in individual ears, with a treatment mean as high as 83.7% of kernels. When plants were silk-inoculated, the percentage of kernels infected by other F. moniliforme strains from the seed or stalk was reduced, apparently due to competition among strains. This study provides evidence that systemic development of F. moniliforme from maize seed and stalk infections can contribute to kernel infection, but silk infection is a more important pathway for this fungus to reach the kernels.

Pseudomonas cichorii. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
New York ◽  
Geographical Distribution ◽  
Solanum Melongena ◽  
Seed Transmission ◽  
Chrysanthemum Morifolium ◽  
Apium Graveolens ◽  
Gerbera Jamesonii ◽  
Pseudomonas Cichorii ◽  
Water Splash ◽  
Natural Hosts

Abstract A description is provided for Pseudomonas cichorii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Naturally infects the following: Araceae: Scindapsus sp. (46, 3116); Compositae: Chrysanthemum morifolium, Chrysanthemum sp. (40: 473; 51, 3694j), Cichorium intybus, C. endivia (5: 275; 42: 236), Gerbera jamesonii (53, 580), Lactuca sativa (50, 1025); Cruciferae: Brassica oleracea (cabbage and cauliflower: 35: 859; 51, 2027); Papaveraceae: Papaver rhoeas, P. orientale (50, 3853); Rubiaceae: Coffea arabica (55, 4727); Solanaceae: Lycopersicon escutentum (53, 4375), Nicotiana tabacum (40: 75), Solanum melongena (57, 5808); Umbelliferae: Apium graveolens (44, 2940). In addition to these natural hosts a large number of plants from various families have been successfully infected by artificial inoculation. DISEASE: Leaf spot symptoms start as small watersoaked spots, which enlarge and rapidly become dark brown to blackish. The disease is frequently systemic and produces a rot of the centre leaves in chicory, and long dark brown streaks on the stems of tomatoes. Vascular darkening is also seen in tomato (53, 4375). GEOGRAPHICAL DISTRIBUTION: The known distribution is widespread but rather scattered. It is probably present in many more countries than those reported, which include the following: Tanzania (as P. papaveris, 35: 188); India (58, 2991); Japan (57, 5808); Taiwan (14: 738); New Zealand (53, 4375); Bulgaria (45, 929); France (51, 2027); Germany (14: 418); Italy (50, 1025); England; USA (Montana, Illinois, Florida, Georgia, New York); Barbados; Brazil (40: 75). TRANSMISSION: Mainly by water splash. It is rapid under warm, wet conditions. Seed transmission occurs in lettuce (45, 929).

Subterranean clover mottle virus infection of subterranean clover: widespread occurrence in pastures and effects on productivity

1992 ◽  
Vol 43 (7) ◽  
pp. 1597 ◽  
Author(s):  
JM Wroth ◽  
RAC Jones
Keyword(s):  
Systemic Infection ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Transmission ◽  
Dry Weight ◽  
Widespread Occurrence ◽  
Transmission Rates ◽  
Type Isolate ◽  
Growing Seasons ◽  
South West

In 1989 and 1990, infection with subterranean clover mottle sobemovirus (SCMV) was widespread in subterranean clover ( Trifolium subterraneum L.) pastures in the south-west of Western Australia. The virus was detected in 61% of the pastures sampled and incidences of infection ranged from 1 to 50%. The virus was more common in old pastures than in pastures resown with newer cultivars during the preceeding 5 year period. When 12 isolates of SCMV were inoculated to subterranean clover plants grown in the glasshouse, symptoms varied from mild to severe. SCMV isolates P23 and F4 decreased the herbage dry weight of cw. Daliak and Woogenellup grown in plots as spaced plants by 81-88% while the Type isolate caused losses of 92%. By contrast, losses were 37-49% with cv. Karridale, a cultivar in which systemic infection was either delayed or prevented during winter. Infection decreased seed yield by c. 90% in cvv. Karridale and Woogenellup with all three isolates; seed weight was decreased 21-55%. A small proportion of cv. Woogenellup transplants outgrew the infection in new shoots during late spring to produce abundant healthy foliage. SCMV seed transmission rates in seed collected from infected transplants of cv. Woogenellup were 0.06, 0.07 and 0.43% for the Type, P23 and F4 isolates respectively. It was concluded that SCMV was present in most pastures, but at low incidences, and that it persists in them from year to year. Extended growing seasons and hard grazing are likely to increase its incidence.

New Species of the Genus Periglischrus (Acari: Spinturnicidae) from Monophyllus Bats (Chiroptera: Phyllostomidae) in the West Indies, Including a Morphometric Analysis of Its Intraspecific Variation

2019 ◽  
Vol 57 (2) ◽  
pp. 418-436
Author(s):  
Juan B Morales-Malacara ◽  
Gabriela Castaño-Meneses ◽  
Hans Klompen ◽  
Carlos A Mancina
Keyword(s):  
New Species ◽  
Morphometric Analysis ◽  
Morphological Variation ◽  
Host Species ◽  
West Indies ◽  
Field Survey ◽  
Museum Collections ◽  
The West ◽  
Specific Variation ◽  
A New Species

Abstract The discovery of a new species, Periglischrus empheresotrichus, was determined through a review of museum collections, as well as a field survey of ectoparasites of island bats. This new species parasitizes on two bat species of the genus Monophyllus Leach, the Greater Antillean Long-tongued bat Monophyllus redmani Leach and the Lesser Antillean Long-tongued bat Monophyllus plethodon Miller. The female, male, deuthonymphs, and protonymph are described and illustrated. P. empheresotrichus n. sp. has an insular distribution, we evaluated the morphological variation of the adult populations, and concluded that intra-specific variation is correlated both with host species and locality (island) in the West Indies.

scholarly journals High and novel genetic diversity of Francisella tularensis in Germany and indication of environmental persistence

2016 ◽  
Vol 144 (14) ◽  
pp. 3025-3036 ◽  
Author(s):  
C. SCHULZE ◽  
K. HEUNER ◽  
K. MYRTENNÄS ◽  
E. KARLSSON ◽  
D. JACOB ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Phylogenetic Diversity ◽  
Systemic Infection ◽  
Environmental Water ◽  
Phylogenomic Analysis ◽  
Nyctereutes Procyonoides ◽  
Wild Animals ◽  
Eurasian Beaver ◽  
Natural Hosts ◽  
Serological Studies

SUMMARYIn Germany tularemia is a re-emerging zoonotic disease. Therefore, we investigated wild animals and environmental water samples for the presence and phylogenetic diversity of Francisella tularensis in the poorly studied Berlin/Brandenburg region. The phylogenomic analysis of three isolates from wild animals revealed three new subclades within the phylogenetic tree of F. tularensis [B.71 from a raccoon dog (Nyctereutes procyonoides); B.74 from a red fox (Vulpes vulpes), and B.75 from a Eurasian beaver (Castor fiber albicus)]. The results from histological, PCR, and genomic investigations on the dead beaver showed that the animal suffered from a systemic infection. Indications were found that the bacteria were released from the beaver carcass into the surrounding environment. We demonstrated unexpectedly high and novel phylogenetic diversity of F. tularensis in Germany and the fact that the bacteria persist in the environment for at least one climatic season. These findings support a broader host species diversity than previously known regarding Germany. Our data further support the assumption derived from previous serological studies of an underestimated frequency of occurrence of the pathogen in the environment and in wild animals. F. tularensis was isolated from animal species not previously reported as natural hosts in Germany.

scholarly journals EVALUATION OF LYCOPERSICON GERMPLASM COLLECTION FOR RESISTANCE TO TOMATO SPOTTED WILT VIRUS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1077b-1077
Author(s):  
S.J. Scott ◽  
M. Stevens ◽  
R.C. Gergerich
Keyword(s):  
Immunosorbent Assay ◽  
Tomato Spotted Wilt Virus ◽  
Germplasm Collection ◽  
Systemic Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Additional Species ◽  
Tomato Spotted Wilt ◽  
Lycopersicon Species ◽  
Wilt Virus

Seedlings of eight accessions of L. hirsutum and susceptible L. esculentum `VF Pink' controls were spray inoculated twice in the greenhouse with tomato spotted wilt virus (TSWV) Arkansas 85-9. Plants lacking symptoms were reinoculated, then evaluated for TSWV by enzyme-linked immunosorbent assay (ELISA). Controls were consistently infected; sixty noninfected L. hirsutum were propagated by cuttings and inoculated with TSWV isolates T2 (lettuce), G-87 (gloxinia), 87-34 (tomato) and a mixture of the four isolates. All selections became infected in at least one test, but systemic infection was often delayed. Additional wild Lycopersicon species and numbers of accessions evaluated for resistance to TSWV include L. cheesmanii (9), L. chmielewskii (17), L. hirsutum (24), L. hirsutum f. glabratum (17), L. parviflorum (4) and L. pennellii (44). No new sources of strong resistance have been identified yet. Evaluation of additional species and accessions is continuing.

scholarly journals Malaria Parasites in Macaques in Thailand: Stump-Tailed Macaques (Macaca Arctoides) are New Natural Hosts for Plasmodium Knowlesi, P. Inui, P. Coatneyi and P. Fieldi.

2020 ◽  
Author(s):  
Wirasak Fungfuang ◽  
Chanya Udom ◽  
Daraka Tongthainan ◽  
Khamisah Abdul Kadir ◽  
Balbir Singh
Keyword(s):  
Nested Pcr ◽  
Plasmodium Knowlesi ◽  
Sampling Site ◽  
Macaca Arctoides ◽  
Malaria Parasites ◽  
Zoonotic Malaria ◽  
Natural Hosts ◽  
New Locations ◽  
Pcr Assays ◽  
Nested Pcr Assays

Abstract Background:Certain species of macaques are natural hosts ofPlasmodium knowlesi and P. cynomolgi, which can both cause malaria in humans, and P. inui, which can be experimentally transmitted to humans. A significant number of zoonotic malaria cases have been reported in humans throughout Southeast Asia, including Thailand. There have been only two studies undertaken in Thailand to identify malaria parasites in non-human primates in 6 provinces. The objective of this study was to determine the prevalence of P. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldiin non-human primates from 4 new locations in Thailand. Methods:A total of 93 blood samples from Macaca fascicularis, M. leonina and M. arctoides were collected from four locations in Thailand: 32 were captive M. fascicularisfrom Chachoengsao Province (CHA), 4 were wild M. fascicularis from Ranong Province (RAN), 32 were wildM. arctoidesfromPrachuap Kiri Khan Province (PRA), and 25 were wild M. leoninafrom Nakornratchasima Province (NAK). DNA was extracted from these samples and analysed by nested PCR assays to detect Plasmodium, and subsequently to detectP. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldi.Results:Twenty-seven of the 93 (29%) samples were Plasmodium-positive by nested PCR assays. Among wild macaques, all 4 M. fascicularis at RAN were infected with malaria parasites followed by 50% of 32 M. arctoides at PRA and 20% of 25 M. leonina at NAK. Only 2 (6.3%) of the 32 captive M. fascicularisat CHA were malaria-positive. All 5 species of Plasmodium were detected and 16 (59.3%) of the 27 macaques had single infections, 9had double and 2 had triple infections.The composition of Plasmodium species in macaques at each sampling site was different. Macaca arctoides from PRA were infected with P. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldi. Conclusions:The prevalence and species of Plasmodiumvaried among the wild and captive macaques, and betweenmacaques at 4 sampling sites in Thailand. Macaca arctoidesis a new natural host for P. knowlesi, P. inui,P. coatneyi and P. fieldi.

scholarly journals Plasmodium knowlesi invasion following spread by infected mosquitoes, macaques and humans

Parasitology ◽  
2017 ◽  
Vol 145 (1) ◽  
pp. 101-110 ◽  
Author(s):  
LAITH YAKOB ◽  
ALUN L. LLOYD ◽  
ROWLAND R. KAO ◽  
HEATHER M. FERGUSON ◽  
PATRICK M. BROCK ◽  
...  
Keyword(s):  
Host Species ◽  
Plasmodium Knowlesi ◽  
Behavioural Plasticity ◽  
Biological Processes ◽  
Local Conditions ◽  
Transmission Potential ◽  
Imported Infection ◽  
Natural Hosts ◽  
Invasion Analysis ◽  
Local Vectors

SUMMARYPlasmodium knowlesi is increasingly recognized as a major cause of malaria in Southeast Asia. Anopheles leucosphyrous group mosquitoes transmit the parasite and natural hosts include long-tailed and pig-tailed macaques. Despite early laboratory experiments demonstrating successful passage of infection between humans, the true role that humans play in P. knowlesi epidemiology remains unclear. The threat posed by its introduction into immunologically naïve populations is unknown despite being a public health priority for this region. A two-host species mathematical model was constructed to analyse this threat. Global sensitivity analysis using Monte Carlo methods highlighted the biological processes of greatest influence to transmission. These included parameters known to be influential in classic mosquito-borne disease models (e.g. vector longevity); however, interesting ecological components that are specific to this system were also highlighted: while local vectors likely have intrinsic preferences for certain host species, how plastic these preferences are, and how this is shaped by local conditions, are key determinants of parasite transmission potential. Invasion analysis demonstrates that this behavioural plasticity can qualitatively impact the probability of an epidemic sparked by imported infection. Identifying key vector sub/species and studying their biting behaviours constitute important next steps before models can better assist in strategizing disease control.

Sign in / Sign up

Export Citation Format

Share Document