Our Crop Biotechnology Programme is currently seeking PhD students to work on two exciting GRDC-supported research projects in winter cereals. The successful applicants, who must be Australian Residents, will be awarded an Australian Postgraduate Award Scholarship to support their candidature.
If you are interested in applying, please contact Prof Mark Sutherland immediately. We are keen to start these projects as soon as possible.
Project 1: Genetic analysis of crosses between hexaploid bread wheats and tetraploid durum wheats and effects on product quality
Supervisor: Dr Anke Martin
Australia is an important producer of tetraploid durum wheats used to produce pasta products and currently grows 300,000-500,000 tonnes annually. Current durum wheats are very susceptible to crown rot disease and to date durum lines with high resistance to this disease have not been identified. The development of varieties with improved resistance to crown rot is pivotal to any future expansion of the Australian durum industry.
Hexaploid bread wheats and wild tetraploid wheats carrying a level of resistance or tolerance to crown rot disease have been identified and USQ is currently involved in a national project which aims to transfer improved reaction to crown rot from these sources into high yielding commercial durum varieties, thus increasing returns to rural producers. USQ has previously investigated the cytogenetics of wheat x durum crosses to determine the inheritance of parental A, B and D genome material in subsequent generations derived from these crosses. Significant variation was observed among individual crosses in the proportions of A, B and D chromosomal segments inherited from the hexaploid parent. In particular, while several early generation populations retained a significant proportion of D genome material from the hexaploid parent, other equivalent populations from different crosses contained only tetraploid lines entirely lacking D genome segments.
The aim of this PhD study is to determine the rate at which loci from the hexaploid parents disappear in different randomly segregating hexaploid/durum backcross populations and how this relates to the product quality aspects of the progeny. This will also provide information on the genome segments which are vital to preserve the quality characteristics of durum wheats, allowing breeders to select for durum lines with partial crown rot resistance derived from a hexaploid wheat, whilst maintaining grain quality.
The successful applicant for this position will gain experience in the design and conduct of field trials as well as developing skills in genetic analysis of cereal genomes in the laboratory. They will join a team of researchers at USQ who are collaborating with four other research institutions across Australia as part of a national five year long initiative on improvement in durum disease resistance towards crown rot.
Project 2: A comparison of the growth patterns of three crown rot pathogens in wheat
Supervisor: Prof Mark Sutherland
Crown rot of winter cereals, caused by the fungus Fusarium pseudograminearum (Fpg), is recognised as a major disease constraint in many cereal growing regions in Australia. Annual yield losses in wheat due to crown rot disease have been estimated to be around $79 million with potential losses of up to $434 million in a single season. Crown rot is a significant disease in many other regions of the world such as Turkey, where other fungal species such as F. culmorum (Fc) and F. graminearum (Fg) also contribute to the disease. Recently we have developed quantitative PCR (polymerase chain reaction) primers that are specific for Fpg, Fc and Fg, enabling us to measure the amount of DNA from each fungus present in a segment of host tissue. Preliminary experiments suggest that there are differences in growth pattern and location in the plant between the three pathogen species. The following project is proposed, in which the successful candidate will:
1) Examine the comparative growth patterns of these pathogens in seedling and adult plants and the severity and location of the symptoms they produce over a range of host genotypes;
2) Investigate competition between all three pathogens in the field. Samples will be collected in Turkey, where all three pathogens can be readily found in a single field. Sample analysis using qPCR will be conducted in Australia.
3) Estimate the level of competition between the three Fusarium species and Bipolaris sorokiniana, the cause of the disease common root rot, whose effects can be similar to those of crown rot.
4) Where host materials have the relevant pedigree, apply well-established markers for resistance loci to assess the comparative effectiveness of these genes under Turkish and Australian conditions.
The successful applicant for this position will work in the field and laboratory in collaboration with an international team of researchers from CIMMYT in Turkey. While this project will be based in Australia at USQ, the student will be funded by GRDC to undertake a field trip to Turkey each year for field trial evaluation and sample collection. In addition GRDC will provide $10,000 per annum for project costs unrelated to travel. A further stipend of $17,000 in addition to the value of the APA scholarship may also be available.
Crop biotechnology includes a wide range of approaches employed to understand and manipulate the genetic constitution of crop plants, to maximise efficient production and to improve the products we manufacture from harvested produce. The tools of biotechnology can be used to breed resistance to biotic (e.g. insect pests, diseases) and abiotic (e.g. drought, salt) stresses, to increase environmental adaptation and yields and to enhance the nutritional content and quality of food products. In addition, these tools can be used for the diagnosis and control of plant diseases and for the evaluation and conservation of crop genetic resources.
Our crop biotechnology research program is focussed in three major subprograms based around two crops: cereal grains and wine grapes. These sub-programs are:
Marker-assisted selection, genetic engineering, population genetics, genome mapping, bioinformatics and gene expression approaches are being applied to develop genetic tools to assist plant breeders to improve the commercial wheat and barley varieties grown by Australian primary producers.
In order to defeat disease in grain crops, the epidemiology and the growth of the pathogen in the host plant need to be clearly understood. In this subprogram, collaboration with field-based plant pathologists is combined with physiological studies, microscopy, bioinformatics and molecular genetics to examine the growth of fungal pathogens in the tissues of their hosts and to identify genetic loci that confer disease resistance.
Researchers in this subprogram maintain a wide range of research ranging from growing the grapes (viticulture) through to the processes of wine making. In particular, biotechnology-based research focuses on fermentation processes and the environmental adaptation of fermentation yeasts.
Further information please contact Prof Grant Daggard or Dr Robert Learmonth and refer to the USQ ePrints database to search for staff publications.