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Honours ProjectsAssociate Professor Yonglin RenPosition: Assoc. Prof. in Plant Biosecurity
Email: Y.Ren@murdoch.edu.au
Phone:
9360 1397
Room: BioSc/3.013
BackgroundThe importance of plant biosecurity to Australia Australia is relatively free from many plant pests and diseases that have serious impacts on agriculture, horticulture, forestry and natural ecosystems in other countries. Through the absence of many pests and diseases found overseas, Australia’s plant industries have a valuable competitive advantage in terms of securing market access and maintaining lower production costs. Australia’s plant industries are worth over $ 18 billion at the farm gate, and the introduction of exotic pests and diseases into Australia could impact greatly on Australia’s exports, but would also have a negative impact on its reputation as a producer of safe, quality food products. The projects listed below all relate to food and plant biosecurity and will provide students wanting to undertake research in this area with ‘cutting edge’ opportunities and a valuable training ground in this important area of science which has direct and tangible benefits to the wider Australian community. Research OpportunitiesAll students will have a generous research maintenance budget and will receive $ 2,000-3,000 as a living allowance per year to support PhD and Honours Students. The projects will provide PhD and honours students with opportunities to study:
A number of project outlines are listed below. Please come and talk to me (Biological Sciences Room 3.013, telephone 9360 1397) or email: Y.Ren@murdoch.edu.au for more details and other project ideas. Potential PhD and Honours Student ProjectsUnless specified projects listed can be adapted to either PhD or Honours projects.Projects listed under the following areas:
1) Chemical ecology of insect pests, nematodes and pathogensProject 1: Study on chemical signals (volatiles) to identify target insects which are the proper receiversCo-supervisor: Dr Rob Emery, Principal Entomologist, DAFWA Project outcomes that student could expect to achieve:
Project 2: Evaluate volatiles as diagnostic indicators for pests, pathogens (bacteria, fungi, nematodes) of grains, fruit and vegetables Co-supervisor: Professor Mike Jones, Murdoch University Issues of concern with regards to post-harvest biosecurity – pest and disease control include: (a) consumer sensitivity to pesticide residues, and (b) trade disruption resulting from the incursion of new insects and pathogens. The diagnosis of insect pests, particularly exotic invasive pests, and chemical contaminants are a central function of plant biosecurity. This research project will be based around the principal of the volatiles that are released from commodities after harvest and during storage in response to infestation by pests and pathogens. The contents of volatiles are related with the history of the food (pre and post harvest conditions and treatment) product. Therefore, volatiles produced in storage can be monitored and used as diagnostic indictors of pests and pathogens involved in food, fruit and vegetable spoilage/contamination. Project outcomes that student could expect to achieve:
Project 3: Study on the evolutionary processes between host plant and invasive insect pests Co-supervisors: Professor Giles Hardy and Dr. T. Burgess, the Centre for Phytophthora Science and Management, Murdoch University Understanding evolutionary processes between host plant and invasive insect pests (insects and nematodes) through the communication between insects and the host plant, chemical ecology and molecular analysis. To determine the influence of chemical signals on insect behaviour such as finding food and social communication. Understanding the biological and chemical bases for these signals could lead to new technologies in the monitoring, diagnosis and bio-treatment of these invasive pests based on semiochemicals. Project outcomes that student could expect to achieve:
Project 4: Evaluation of the potential of major volatiles as indicators of soil health (nutrient fluxes - degradation of applied and naturally occurring chemicals), particularly, volatile and nutrient fluxes under climate change Co-supervisor: Professor Giles Hardy, State Centre of Excellence on Climate Change, Woodland and Forest Health There are mass (volatiles) and energy (temperature) exchanges between soil and vegetation, atmosphere and water bodies (lakes, rivers, oceans). The major exchanged masses are volatiles (gas phase substances), such as water vapor, green house gases, some ozone depleting substances, sulfur (contributes to rain and odour formation)/ carbon (contribute to form green house gases) / nitrogen / phosphorous (contribute to plant or soil nutrient cycles) containing volatiles. The volatiles in soil are mainly formed by bioactivity of plants and microorganisms, and fertilizer / pesticide / herbicide degradation, irrigation and chemical / biogeochemical inter-conversion. The masses are exchanged by flux (vaporization and emission), rain, irrigation and floods (H2O and water soluble volatiles). Climate change will lead to a change in the degradation of these chemicals in soils and vegetation. Therefore, any kind of soil treatment, such as the application of chemicals (eg., fumigants, fertilisers, pesticides and herbicides), irrigation and plantation establishment will result in volatile (including odour types and naturally occurring compounds) and nutrient fluxes and sinks and the interconversion of the major volatiles. The hazardous volatile fluxes and sinks will be directly affected by climate change. Project outcomes that student could expect to achieve:
2) Bio-information, risk and pest managementProject 1: Study on the relationship between bio-information, risk and pest managementCo-supervisor: Dr Shashi Sharma, director of Division of Plant Biosecurity, DAFWA In insects, chemosensory cues are used to identify individuals, signify social rank, mark territories, and indicate reproductive and health status. In addition, chemical cues are often used to guide migration and regulate reproductive behaviour. Therefore, chemical cues or semiochemicals for insect pests or host plants or the impact of climate change on interactions between soil/host tree/insect pest and forest health are sources of bio-information which potentially have the ability to indicate risk and the appropriate way to manage pests. For example, it is possible that semiochemicals could disrupt and destroy the organization on which social insects depend. Project outcomes that student could expect to achieve:
Co-supervisor: Dr Shashi Sharma, director of Division of Plant Biosecurity, DAFWA Biosecurity encompasses all policy, planning, science and underpins all operations involved in the safeguarding of natural resources from exotic biological threats. Almost all nations face the challenges of maximizing the benefits of globalization while minimizing the impact of potential biological (invasive pest, pathogen and weed species) risks to their economies due to detrimental impacts on their agricultural, forest and natural ecosystems. This requires a concerted effort for the development of biosecurity risk management arrangements from the farm to the national level. Project outcomes that student could expect to achieve:
3) Insect population dynamics, dispersion/distribution and migrationProject 1: Impact of climate change (volatiles chemicals) on interactions between insect pests (nematodes & pathogens) and host plants/ forest and soilCo-supervisor: Professor Giles Hardy, the Centre for Phytophthora Science and Management, Murdoch University Understand the impact of chemical (water, fumigants, fertilisers, pesticides and herbicides) treatments on plants and soils though : a) volatile fluxes and sinks, b) their role in chemical / biogeochemical (sulphur, nitrogen, carbon and phosphorous) budgets ,and cycles, and c) insects population dynamics and behaviors. Project outcomes that student could expect to achieve:
Project 2: Evaluate stable isotope marker (e.g., 13C or 44Ca) to study insect dispersion and migration Co-supervisor: Professor Mike Jones, Murdoch University and Dr Rob Emery, Principal Entomologist, DAFWA Release insects marked with stable isotopes (13C or 44Ca) and then recapturing these over time along the pathways of possible insect flow to identify dispersion and migration of these insects at different developmental stages (containing 13C or 44Ca). The results will provide knowledge and understanding for monitoring insect dispersal, insect communication, guiding good agricultural practice and the management of insect resistance. This technology can become a very useful tool for the study of exotic invasive pests (insects, weed seeds and other pests), and their dispersial and migration.
4) Understand phosphine and develop technologies for management of phosphine resistance, in particular, phosphine/aluminium phosphate application technologyProject 1: Sorption of phosphine on grain and its efficiency for control of stored product insect pestsSuccessful fumigation of a commodity requires the fumigant concentration to be maintained for long enough to eliminate the target organism. In practice, many fumigations fail as excessive levels of the fumigant are absorbed into the grain, particularly where oats, sorghum and barley and other high moisture content grains are fumigated. In a truly gas-tight system, the phenomena known as sorption is an important factor that affects the action of fumigants generally, and can determine whether a treatment is successful or not. Sorption can remove a significant proportion of active gas molecules from the free space, reducing the total number of molecules that are able to diffuse freely throughout the system, or to penetrate further into the interstices of bulk materials (e.g. grain stored in bulk silos). The rate of sorption is significantly affected by type of grain, moisture content and temperature. There has been some progress in modelling particular sorption processes. However, to date there is no adequate mathematical relationship that describes the influence and complex interaction of all the factors involved, and also incorporates desorption and the formation of breakdown-products and residues generally.
Project 2: Develop technologies for management of phosphine resistance, in particular, phosphine/aluminium phosphate application technology Co-supervisor: Dr Rob Emery, Principal Entomologist, DAFWA In Australia, almost all grain stored in farm bins is treated with phosphine generated from aluminium phosphide. However, because gas concentrations are not maintained in storage at sufficient levels long enough to penetrate and kill all life stages of stored-grain insects, fumigations often use dosages that are larger than necessary to accomplish satisfactory insect control. The concentration-time product (CTP) model of mortality depends on the rate of phosphine generation and the “half-life” of the phosphine gas maintained in the storage structure, which in turn relies on the gas tightness of the bin. A possible solution is the use of a combination of different rates of release of aluminium phosphide formulations (pellets in combination with tablets for initial fast release of phosphine with continued slow release to maintain phosphine at sufficient levels for long enough). Laboratory investigation will evaluate the rate of phosphine release from different mixtures of tablets and pellets and then their performance will be assessed with on-farm bin trials. Project outcomes that student could expect to achieve:
5) Develop eradication technologies for grain, vegetable, fruit, timber, soil and quarantine treatment to target insect pests, nematodes, pathogens and weeds.Project 1: Evaluate allyl isothiocyanate (AITC) as a fumigant for stored product insect pestsAllyl isothiocyanate (AITC), a member of the ITC family, exists in many plant species in the Cruciferae family, such as mustard, wasabi, Brassica nigra Koch and B. juncea (L.) Coss. Recently, the possibility of using AITC as a biological control agent has received a great deal of interest, with studies being focused on the insecticidal function of AITC. It could be a potential chemical for the protection of stored grain from insect infestation and contamination. Project outcomes that student could expect to achieve:
Co-supervisor: Dr Stewart Learmonth, Entomologist, DAFWA Issues of concern regarding pest control include consumer sensitivity to pesticide residues and trade disruption as a result of incursions from new insects and diseases. A central function in providing biosecurity is an ability to apply an effective biocide to the area infested with an exotic pest or disease in order to prevent its spread (for import incursions) or to achieve hygienic conditions – no insects or residues (for export and domestic insect control). Development of compounds that are effective and environmentally friendly, safe to users and consumers, to replace current pesticides such as organic phosphates (OPs) will be a significant benefit to the Australian horticultural industry and trade. This project will focus on the development of rapid technologies for disinfestation of fruit and vegetables to control exotic pests or pathogens. Project outcomes that student could expect to achieve:
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