Tests of transmission of cynodon white leaf phytoplasma to sugarcane and maize in northern Australia

2003 ◽  
Vol 54 (4) ◽  
pp. 423 ◽  
Author(s):  
K. R. Blanche ◽  
L. Tran-Nguyen ◽  
K. S. Gibb
Keyword(s):  
Cynodon Dactylon ◽  
Field Trials ◽  
Insect Species ◽  
Sufficient Information ◽  
Agricultural Crops ◽  
Northern Australia ◽  
Saccharum Spp ◽  
White Leaf ◽  
Starting Point ◽  
White Leaf Disease

Cynodon white leaf disease is associated with cynodon white leaf phytoplasma in Cynodon dactylon growing in Darwin, Northern Territory. In order to effectively assess and manage the risk to agricultural crops posed by this phytoplasma, it is necessary to establish whether there is an insect species capable of transmitting it from C.�dactylon to grasses like Saccharum spp. hybrids and Zea mays. We used field and cage trials to investigate transmission of cynodon white leaf phytoplasma in these grasses. No transmission of the phytoplasma occurred in any of the trials, even to C. dactylon, the known host, and the phytoplasma did not persist in the potential leafhopper vector, Chiasmus varicolor. These results suggest that C. varicolor is not a vector of cynodon white leaf phytoplasma and that some requirement for successful transmission was not met in our field trials. We do not have sufficient information to determine whether transmission to Saccharum spp. hybrids or Z. mays is possible. Our study demonstrates the techniques that can be applied to this problem and provides a starting point for further investigation using different transmission conditions and insect species.

Clavibacter XYLI subsp. cynodontis. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
Host Range ◽  
Geographical Distribution ◽  
Sugar Cane ◽  
Cynodon Dactylon ◽  
Bermuda Grass ◽  
Artificial Inoculation ◽  
Mechanical Transmission ◽  
Ecological Significance ◽  
Sudan Grass ◽  
White Leaf

Abstract A description is provided for Clavibacter XYLI subsp. cynodontis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Cynodon dactylon, where it is limited to the xylem. It also multiplies in the xylem of sugar cane and a Sudan grass-sorghum hybrid when artificially inoculated, but symptoms are not produced (61, 4328). Further host range not yet recorded. DISEASE: Bermuda grass stunting disease. Natural occurrences so far discovered have been in combination with mycoplasma-like organisms thought to cause white leaf and witches' broom symptoms. The presence of the bacterium causes considerably more severe symptoms. The full ecological significance of this bacterium has not yet been evaluated, but a further stress is usually required to produce noticeable symptoms. GEOGRAPHICAL DISTRIBUTION: Taiwan, USA (Florida). TRANSMISSION: So far only mechanical transmission, by artificial inoculation, is known. Cutting blades and possibly grazing animals are likely to spread the infection.

Evaluation of risks for two native mammal species from feral cat baiting in monsoonal tropical northern Australia

2018 ◽  
Vol 45 (6) ◽  
pp. 518 ◽  
Author(s):  
Jaime Heiniger ◽  
Skye F. Cameron ◽  
Graeme Gillespie
Keyword(s):  
Rhodamine B ◽  
Native Species ◽  
Field Trials ◽  
Camera Traps ◽  
Northern Australia ◽  
Target Species ◽  
Mammal Species ◽  
Feral Cat ◽  
Feral Cats ◽  
Dry Tropics

Context Feral cats are a significant threat to native wildlife and broad-scale control is required to reduce their impacts. Two toxic baits developed for feral cats, Curiosity® and Hisstory®, have been designed to reduce the risk of baiting to certain non-target species. These baits involve encapsulating the toxin within a hard-shelled delivery vehicle (HSDV) and placing it within a meat attractant. Native animals that chew their food more thoroughly are predicted to avoid poisoning by eating around the HSDV. This prediction has not been tested on wild native mammals in the monsoonal wet–dry tropics of the Northern Territory. Aim The aim of this research was to determine whether northern quolls (Dasyurus hallucatus) and northern brown bandicoots (Isoodon macrourus) would take feral cat baits and ingest the HSDV under natural conditions on Groote Eylandt. Methods We hand-deployed 120 non-toxic baits with a HSDV that contained a biomarker, Rhodamine B, which stains animal whiskers when ingested. The species responsible for bait removal was determined with camera traps, and HSDV ingestion was measured by evaluating Rhodamine B in whiskers removed from animals trapped after baiting. Key results During field trials, 95% of baits were removed within 5 days. Using camera-trap images, we identified the species responsible for taking baits on 65 occasions. All 65 confirmed takes were by native species, with northern quolls taking 42 baits and northern brown bandicoots taking 17. No quolls and only one bandicoot ingested the HSDV. Conclusion The use of the HSDV reduces the potential for quolls and bandicoots to ingest a toxin when they consume feral cat baits. However, high bait uptake by non-target species may reduce the efficacy of cat baiting in some areas. Implications The present study highlighted that in the monsoonal wet–dry tropics, encapsulated baits are likely to minimise poisoning risk to certain native species that would otherwise eat meat baits. However, further research may be required to evaluate risks to other non-target species. Given the threat to biodiversity from feral cats, we see it as critical to continue testing Hisstory® and Curiosity® in live-baiting trials in northern Australia.

How to begin a sequel?

2020 ◽  
Vol 6 (1) ◽  
pp. 46-58
Author(s):  
Péter Hajdu
Keyword(s):  
Sufficient Information ◽  
General Description ◽  
Literary Genres ◽  
Fictional Narratives ◽  
Starting Point ◽  
Fictional Worlds ◽  
In The Beginning ◽  
Formal Feature

AbstractBeginnings of fictional narratives apply various strategies to introduce their readers to the represented world, and even if they select a starting point in the flow of events as definitive, they tend to tell something about how the starting situation has been constituted by earlier events and circumstances. Some literary genres represent fictional worlds so different from the readers’ that a general description of the former is also needed in the beginning. A sequel may seem free of the burden of a descriptive introductory beginning, since readers (if they have read the previous work or works) have sufficient information to be able to cope with in medias res beginning. However, long series of many sequels have to be accessible for new readers as well, therefore they offer introductions for a double audience. The paper analyses several beginnings from Terry Pratchett’s Discworld novels. I show how the early novels use the description of the Discworld as a formal feature to begin the narrative; those descriptions fulfil the double purpose of introducing new readers and entertaining the trained ones by new ways of elaboration and adding some new traits.

scholarly journals Candidates for Symbiotic Control of Sugarcane White Leaf Disease

2012 ◽  
Vol 78 (19) ◽  
pp. 6804-6811 ◽  
Author(s):  
Jureemart Wangkeeree ◽  
Thomas A. Miller ◽  
Yupa Hanboonsong
Keyword(s):  
Developmental Stages ◽  
Cloning And Sequencing ◽  
Content Type ◽  
Leaf Disease ◽  
White Leaf ◽  
Symbiotic Control ◽  
Sugarcane White Leaf ◽  
White Leaf Disease ◽  
Bacterial Genes

ABSTRACTThe leafhopperMatsumuratettix hiroglyphicus(Matsumura) is the most important vector of a phytoplasma pathogen causing sugarcane white leaf (SCWL) disease. The purpose of this study was to evaluate candidate bacterial symbionts for possible use as vehicles in the control of the disease. 16S rRNA bacterial genes were amplified from whole bodies ofM. hiroglyphicusleafhoppers and analyzed by cloning and sequencing. Two dominant groups were found: one belonged to theBetaproteobacteriathat did not closely match any sequences in the database and was named bacterium associated withM. hiroglyphicus(BAMH). Another one found to be abundant in this leafhopper is “CandidatusSulcia muelleri” in the orderBacteroidetes, which was previously reported in the insect members of the Auchenorrhyncha. MostM. hiroglyphicusleafhoppers carry both BAMH and “Ca. Sulcia muelleri.” Fluorescentin situhybridization showed that BAMH and “Ca. Sulcia muelleri” colocalized in the same bacteriomes. BAMH was present in the midgut and ovaries of the leafhopper and was found in all developmental stages, including eggs, nymphs, and adults. Because BAMH appears to be specific for the SCWL vector, we evaluated it as a candidate for symbiotic control of sugarcane white leaf disease.

scholarly journals First report of a 'Candidatus Phytoplasma trifolii'-related strain (16SrVI-A) associated with white leaf disease in Spirea japonica

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Eray Şimşek ◽  
Hümeyra Ayvacı ◽  
Havva Akkurak ◽  
Murat Dikilitas ◽  
Mehmet Ertuğrul Güldür
Keyword(s):  
Related Strain ◽  
First Report ◽  
Leaf Disease ◽  
White Leaf ◽  
White Leaf Disease
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