scholarly journals Physiological Studies on Thrips in Relation to Transmission of Tomato Spotted Wilt Virus

1954 ◽  
Vol 7 (3) ◽  
pp. 274 ◽  
Author(s):  
MF Day ◽  
H Irzykiewicz
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Reduction Potential ◽  
Thrips Tabaci ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Tomato Spotted Wilt ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Wilt Virus

The hydrogen ion concentration of the midguts of larval and adult Thrips tabaci and T. imaginis is between pH 5�0 and 5�6. The oxidation-reduction potential at these values is between + 0�184 and + 0�262 V. There is thus no difference between thrips that are vectors and those that are not vectors of the virus causing tomato spotted wilt. Furthermore, the pH and Eh conditions in the midgut of larval T. tabaci are unsuitable for long survival of the virus.

The Physiology of Hatching of Eggs of Ascaridia galli

1961 ◽  
Vol 35 (S1) ◽  
pp. 151-156 ◽  
Author(s):  
W. P. Rogers
Keyword(s):  
Reduction Potential ◽  
Carbonic Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Ascaridia Galli ◽  
Hydrogen Ion Concentration ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Gaseous Carbon Dioxide

The stimulus for the hatching of infective eggs of Ascaridia galli in vitro depended upon the concentration of undissociated carbonic acid plus dissolved gaseous carbon dioxide, the oxidation-reduction potential, and the hydrogen ion concentration. There was considerable overlap in the conditions which favoured the hatching of eggs of Ascaridia galli and Ascaris lumbricoides; both would be expected to hatch in the small intestine of a suitable species of host.

scholarly journals Further micro-injection studies on the oxidation-reduction potential of the cell-interior

1926 ◽  
Vol 99 (698) ◽  
pp. 383-397 ◽  
Keyword(s):  
Reduction Potential ◽  
Chemical Properties ◽  
Ion Concentration ◽  
Egg Cell ◽  
Cell Interior ◽  
Hydrogen Ion Concentration ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Physico Chemical ◽  
Before And After

In previous communications on this subject (20, 21, 22) we described the results obtained when coloured indicators of known physico-chemical properties were injected into individual living cells. Using a modification of the micromanipulator of Chambers (4), we have worked with various unicellular protozoa and egg-cells, and have been able to draw definite conclusions as to the average hydrogen-ion concentration and the average oxidation-reduction potential of the cell interior. Our first communication dealt with the amœba, and we showed that its internal p H was probably in the neighbourhood of 7.6, while its internal r H (oxidation-reduction potential, 5) was between 17 and 19. Both values are near neutrality, so that this cell could be said to be slightly alkaline and slightly on the electronegative or reducing side of oxidation-reduction neutrality. We next extended our investigation to several types of marine egg-cells before and after fertilisation, and during the early cleavage stages. The changes which the internal p H and r H undergo during these ontogenetic events are very small indeed, and the phylogenetic differences, for example, as between the ovum of the polychsete worm and that of the starfish are correspondingly slight. The egg-cell, then, appeared to have a of about 6.6 and an r H of the order of 21 or 22. It was therefore a little on the acid side of acidbase neutrality and a little on the electropositive side of oxidation-reduction neutrality, differing on both these counts from the amœba. The amœba, therefore, has a higher intensity of reduction than the egg-cell.

Some properties and thrip transmission of tomato spotted wilt virus in Canada

1974 ◽  
Vol 52 (6) ◽  
pp. 1177-1182 ◽  
Author(s):  
Y. C. Paliwal
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
High Titer ◽  
Tomato Leaf ◽  
Thrips Tabaci ◽  
Eastern Canada ◽  
Mesophyll Cells ◽  
Virus Particles ◽  
Tomato Spotted Wilt ◽  
Frankliniella Fusca ◽  
Wilt Virus

A virus isolated from white clover (Trifolium repens L.), dahlia, and tomato from Ontario, dahlia from Manitoba, and tomato and dahlia from British Columbia was identified as tomato spotted wilt virus (TSWV). Seven isolates of the virus examined had similar host reactions; four of them, investigated in detail, were similar in their localization in tomato leaf cells and physical properties also. The virus particles, 78–97 nm in diameter, were abundant in tomato leaf mesophyll cells and occurred in clusters or arrays surrounded by a membrane.The virus was purified by a method modified from a previously reported one and a specific antiserum was prepared. TSWV appears to be weakly immunogenic, as a high titer antiserum could not be obtained.At least three species of thrips, i.e. Thrips tabaci Lind., Frankliniella fusca Hinds, and F. occidentalis Perg., known as vectors of TSWV elsewhere, occur in Canada. F. fusca, which occurs in eastern Canada, efficiently transmitted all isolates of the virus. T. tabaci, a vector in several countries and widespread in Canada, failed to transmit the virus.

scholarly journals First Report of Vidalia Onion (Allium cepa) Naturally Infected with Tomato spotted wilt virus and Iris yellow spot virus (Family Bunyaviridae, Genus Tospovirus) in Georgia

Plant Disease ◽  
2004 ◽  
Vol 88 (11) ◽  
pp. 1285-1285 ◽  
Author(s):  
S. W. Mullis ◽  
D. B. Langston ◽  
R. D. Gitaitis ◽  
J. L. Sherwood ◽  
A. C. Csinos ◽  
...  
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Thrips Tabaci ◽  
Iris Yellow Spot Virus ◽  
Yellow Spot ◽  
Unknown Etiology ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Spot Virus ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Vidalia onion is an important crop in Georgia's agriculture with worldwide recognition as a specialty vegetable. Vidalia onions are shortday, Granex-type sweet onions grown within a specific area of southeastern Georgia. Tomato spotted wilt virus (TSWV) has been endemic to Georgia crops for the past decade, but has gone undetected in Vidalia onions. Tobacco thrips (Frankliniella fusca) and Western flower thrips (Frankliniella occidentalis) are the primary vectors for TSWV in this region, and a number of plant species serve as reproductive reservoirs for the vector or virus. Iris yellow spot virus (IYSV), an emerging tospovirus that is potentially a devastating pathogen of onion, has been reported in many locations in the western United States (2,4). Thrips tabaci is the known vector for IYSV, but it is unknown if noncrop plants play a role in its epidemiology in Georgia. During October 2003, a small (n = 12) sampling of onions with chlorosis and dieback of unknown etiology from the Vidalia region was screened for a variety of viruses, and TSWV and IYSV infections were serologically detected. Since that time, leaf and bulb tissues from 4,424 onion samples were screened for TSWV and IYSV using double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) with commercial kits (Agdia Inc., Elkhart, IN). Samples were collected from 53 locations in the Vidalia region during the growing season between November 2003 and March 2004. Plants exhibiting stress, such as tip dieback, necrotic lesions, chlorosis or environmental damage were selected. Of these, 306 were positive for TSWV and 396 were positive for IYSV using positive threshold absorbance of three times the average plus two standard deviations of healthy negative onion controls. Positive serological findings of the onion tissues were verified by immunocapture-reverse transcription-polymerase chain reaction (IC-RT-PCR) for TSWV (3) and RT-PCR for IYSV (1). In both instances, a region of the viral nucleocapsid (N) gene was amplified. The PCR products were analyzed with gel electrophoresis with an ethidium bromide stain in 0.8% agarose. Eighty-six percent (n = 263) of the TSWV ELISA-positive samples exhibited the expected 774-bp product and 55 percent (n = 217) of the IYSV ELISA-positive samples exhibited the expected 962-bp product. The reduced success of the IYSV verification could be attributed to the age and deteriorated condition of the samples at the time of amplification. Thrips tabaci were obtained from onion seedbeds and cull piles within the early sampling (n = 84) and screened for TSWV by the use of an indirect-ELISA to the nonstructural (NSs) protein of TSWV. Of the thrips sampled, 25 were positive in ELISA. While the incidence of IYSV and TSWV in the Vidalia onion crop has been documented, more research is needed to illuminate their potential danger to Vidalia onions. References: (1) I. Cortês et al. Phytopathology 88:1276, 1998. (2) L. J. du Toit et al. Plant Dis. 88:222, 2004. (3) R. K. Jain et al. Plant Dis. 82:900, 1998. (4) J. W. Moyer et al. (Abstr.) Phytopathology 93(suppl.):S115, 2003.

scholarly journals The hydrogen-ion concentration and the oxidation-reduction potential of the cell-interior: a micro-injection study

1925 ◽  
Vol 98 (689) ◽  
pp. 259-286 ◽  
Keyword(s):  
Methylene Blue ◽  
Gentian Violet ◽  
Reducing Power ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Living Organisms ◽  
Actual Formation ◽  
Qualitative Estimation

It has been recognised since the middle of the eighteenth century that one of the most fundamental characteristics of living organisms is their capacity to oxidise substances incapable of oxidation at ordinary temperatures; but no qualitative estimation of this power of oxidation was carried out until the time of Ehrlich, whose classical experiments on the injection of methylene blue into the intact animal revealed the fact that certain organs seemed to have a higher reducing power than others. Later, much histo-chemical work was done. Numerous observers studied the effect of staining tissues and cells in reagents which indicated by their colour whether they were reduced or oxidised. Several such indicators were used by the earlier workers, especially alphanaphthol and pyronin and alpha-naphthol and gentian violet; but the two chief methods were the intracellular formation of an indophenol, introduced by Röhmann and Spitzer in 1895 (20), and the oxidation of the leucobase of methylene blue, introduced by Unna in 1911 (23). In the latter case the cell was placed in a solution of the completely reduced dye, and the conclusion was that wherever the blue colour appeared, there the cell had been able to oxidise it. The indophenol method depended on the actual formation and precipitation of a dye in the cell by an oxidative condensation. The original reactants used were dimethylparaphenylenediamine and alpha-naphthol, but various later workers modified this by using other phenols and other aromatic amines, so that indophenols of different colours were produced.

scholarly journals The Efficiency by Which Thrips tabaci Populations Transmit Tomato spotted wilt virus Depends on Their Host Preference and Reproductive Strategy

2002 ◽  
Vol 92 (6) ◽  
pp. 603-609 ◽  
Author(s):  
Elisavet K. Chatzivassiliou ◽  
Dick Peters ◽  
Nikolaos I. Katis
Keyword(s):  
Reproductive Strategy ◽  
Tomato Spotted Wilt Virus ◽  
Host Preference ◽  
Datura Stramonium ◽  
Thrips Tabaci ◽  
Transmission Parameters ◽  
Tomato Spotted Wilt ◽  
Access Period ◽  
Increasing Temperature ◽  
Wilt Virus

Arrhenotokous and thelytokous populations of Thrips tabaci from tobacco or leek plants were evaluated for their ability to transmit Tomato spotted wilt virus (TSWV) and for their host preference. Transmission efficiencies were comparatively studied using leaf disks of Petunia hybrida, Datura stramonium, and Nicotiana tabacum cv. Basmas. Adults of arrhenotokous populations collected on infected tobacco plants in the field were efficient transmitters (up to 48.5% transmission) and remained so when maintained on tobacco for several generations. Arrhenotokous T. tabacipopulations from leek plants were poor transmitters (up to 3.1% transmission), whereas no transmission was obtained with thelytokous populations from leek. All populations could infest leek, however none of the arrhenotokous and thelytokous populations from leek plants was able to infest tobacco. TSWV could be acquired by both first and second larval instars of a T. tabacipopulation from tobacco. However, the transmission by adults decreased with the age at which the virus was acquired by larvae. The highest efficiencies (61% of males and 51% of females transmitted) were obtained when newborn (0- to 24-h old) larvae acquired the virus. The majority of thrips started to transmit after becoming adult and rates were positively correlated with the temperature at which the thrips were kept. The median latent period values found for adults decreased with increasing temperature. The median acquisition access period (AAP50) of the population was 41 min, whereas the AAP50 was 65 min for males and 35 min for females. The median inoculation access period of males was 246 and 365 min on tobacco and petunia, respectively, and 96 and 345 min for females. The results show that T. tabaci forms a complex in terms of host preference, reproductive strategy, and ability to transmit TSWV. The transmission parameters show that the thrips of arrhenotokous populations infesting tobacco are highly efficient vectors.

scholarly journals The hydrogen-ion concentration and oxidation-reduction potential of the cell-interior before and after fertilisation and cleavage: A micro-injection study on marine eggs

1926 ◽  
Vol 99 (695) ◽  
pp. 173-199 ◽  
Keyword(s):  
Single Cells ◽  
Biological Data ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Before And After ◽  
Egg Membrane ◽  
The Moment

In our previous communications on this subject we have described experiments dealing with the micro-injection of indicators into single cells. In the conclusion to our paper (10 a ) on the p H. and r H of the Amœba, we said, “It is hoped that other biological data will soon be available . . . such problems as the . . . oxidation-reduction potentials of egg-cells before and after fertilisation at once present themselves.” The present paper is devoted to these problems. Warburg (17) and Meyerhof (8), and afterwards other workers, observed an enormous increase in the oxygen-consumption of the egg to take place on fertilisation. Shearer (12) found that this occurred at the moment of contact of the spermatozoon with the egg membrane. In view of the fact that the increase was about 2000 per cent., it was clearly a matter of great interest to determine whether the r H changed at the same time. We have attempted to follow the changes in r H by micro-injection experiments and by staining. The two methods failed to give concordant results for reasons which are discussed in the text.

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