Completed projects and reports
Permanent URI for this communityhttp://elibrary2.sugarresearch.com.au/handle/11079/13840
Sugar Research Australia, Sugar Research Development Corporation and BSES reports from completed research projects and papers.
Browse
5 results
Search Results
Now showing 1 - 5 of 5
Item Seed dormancy and establishment: a critical gap in knowledge to support safe deployment of GM(2015) Bonnett, GThe development and adoption of new varieties is a major investment in the Australian sugar industry. There are several modern techniques now being introduced into sugarcane breeding, such as introgression of Erianthus and the use of molecular markers. As these techniques contribute to better performing varieties these benefits can be readily captured through normal paths to market that have been established for improved varieties. Genetic modification (GM) is providing another method to introduce traits into crop plants. There is an increasing number of countries deploying a large number of GM varieties. This however, requires a different path to market involving regulatory systems that determine if there are potential harms that could result and what the likelihood of this may be. In Australia, environmental harm is assessed by the Office of the Gene Technology Regulator (OGTR). Some of the key considerations in determining the path to harms, in general, are an understanding of the reproductive biology (both sexual and asexual) of the crop. For sugarcane, a crop grown from pieces of stalk to harvest more stalks, the asexual propagation in farmer’s fields is relatively well understood. Sexual reproduction, however, has only been the concern of breeders and is not part of the productive cycle in farmer’s fields. In a previous project we have documented that flowering of sugarcane is widespread, though the Australian industry with a greater concentration from the Burdekin to Mossman. Within this area, viable pollen and seed production was found to be most significant from the Herbert to Mossman regions. Additional experiments demonstrated the potential for pollination and hence gene flow between fields and the presence of populations of a compatible wild relative, S. spontaneum. It was apparent that seed production occurred at a time not optional for seed germination. Consequently the current project has conducted studies to determine the likely fate in the environment of the sugarcane seeds and relate this to potential paths to harm, so that all future GM sugarcanes can be evaluated against this baseline. In this project we have used a combination of field and laboratory based studies. A third part of the methodology has been the use of a consultative group to assess both results obtained and plans for the coming year. These annual meetings involved representatives of the end users of the research. Both regulators and sugar industry representatives were active participants in this and have ensured the most relevant studies were conducted and end user engagement throughout the project. We have conducted extensive field work (i) to collect sugarcane seeds from farmer fields (ii) to assess the longevity of sugarcane seeds under field conditions and (iii) assess the likely competition between sugarcane seeds and weeds in the soil seed bank in and around sugarcane field. These studies were complemented by laboratory experiments that determined the abiotic limits to germination, the level of dormancy and the composition of sugarcane seeds. We demonstrated that in farmer’s fields in the most northerly areas, when sugarcane flowers, it has a low fertility and, the seeds that are produced are short-lived and rare in the soil seed bank in and around sugarcane fields. We established that sugarcane seeds do not display dormancy and germination could occur at relatively low temperatures (Tb=11°C - 16°C) with a base water potential of germination ranging from -1.1 MPa to -1.5 MPa. This means that, at least in Australia the major impediment to seed germination during the flowering period is the water availability. Significantly we showed that the number of weed seeds compared to sugarcane seeds in the seedbank was orders of magnitude higher, hence competition from weeds greatly limits sugarcane seedling establishment. Interestingly sugarcane seeds contain relatively high levels of lipid material compared to many other grasses. A link between composition and seed longevity was not established. In conclusion, we demonstrated that, in the Australian environment, the likelihood of sugarcane seeds establishing in the Australian environment is very low. Additionally as a result of the studies we have now developed several techniques that can be used to compare any changes in the response of the processes that comprise sugarcane sexual reproduction as a result of GM changes. When appropriate (for example when deliberate changes to abiotic stress tolerance have been engineered) these can be used to determine any biologically meaningful alterations. The results and implications of the project have been published in International Journals, discussed at ASSCT, discussed directly with regulators and have and will contribute to reference publications (biology documents) used by regulators world-wide.Item Sugarcane compositional analysis to enable food safety assessment of modified varieties(2013) Rae, A; Bonnett, GAn important component of demonstrating that the products of GM sugarcane varieties are substantially equivalent to conventional varieties is whether the nutritional composition falls within the range of compositions that are currently found in production. For sugarcane, the food safety assessment will focus on the stalk, as the plant part that provides the food product, and the nutritional components that will be assessed are the proximates (comprising moisture content, crude fibre, protein, fat, ash and N-free extractives) and the soluble sugars. For feed purposes, information on the proportions of neutral detergent fibre (NDF) and acid detergent fibre (ADF) will also be required. Although some components such as sugars are routinely measured in sugarcane stalks, there was a lack of information on most of the nutritional components. The aim of this project was to determine the range of nutritional compositions found in Australian sugarcane varieties under normal agronomic practicesItem Understanding the reproductive biology and ecology of sugarcane to manage the safe release of genetically modified cultivars(2010) Bonnett, G; Olivares-Villegas; Berding, N; Morgan, T; Collins, PThis project set out to obtain basic and previously unavailable information on the ecology and sexual reproduction of sugarcane primarily so advances in sugarcane biotechnology can be utilised to the benefit of the Australian sugarcane industry and the broader Australian economy. The production and commercialisation of genetically modified (GM) sugarcane has attracted increased international interest in recent years, and this has been exemplified by significant, sustained investment in sugarcane biotechnology by large national and international companies. To commercialise GM sugarcane, the proposed cane has to undergo rigorous regulatory assessment including safety to humans and the environment. A significant part of this assessment relates to how a given sugarcane clone functions in the environment (s) where it will be grown, and the likelihood and impact of transfer of the modified trait to other commercial sugarcane or other sympatric sexually compatible species. While such assessments are performed for each proposed GM sugarcane cultivar under consideration, general information about the sexual reproduction and ecology of sugarcane is also important to help understand potential hazards. For sugarcane, this basic information is scant, largely because the stalk not the seed is the harvested product (i.e. sugarcane is vegetatively propagated) and so the sexual reproduction process have not previously been studied in commercially grown sugarcane. This project undertook a series of studies to help fill the ‘information void’ on sugarcane. The project involved several surveys and experiments using cane in farmers’ fields to understand the level of flowering and viable seed production under commercial production. Species that could be sexually compatible with sugarcane were determined through analysis of the breeding literature to see what crosses had been achieved with human intervention. This was followed by comparison with botanical records to determine which of the potential species were present in sugar growing regions.Item SmutBuster: accelerated breeding of smut-resistant sugarcane varieties : SRDC final report BSS325(BSES, 2011) Cox, MC; Croft, BJ; Bonnett, GSugarcane smut is caused by the fungus, Ustilago scitaminea Syd., and is one of the most serious diseases of sugarcane. At the end of 1983, only the sugar industries of Australia and Fiji remained free from smut. Sugarcane smut was reported for the first time in Australia in July 1998 in the Ord River Irrigation Area. Eight years later, smut was identified on the east coast of Australia at Childers. By December 2007 sugarcane smut was widespread and established in the Bundaberg?Isis, Central Queensland and Herbert River districts, and by 2010 the Mulgrave, Tully and Burdekin districts were also infested. The average yield loss reported in papers at the time of the east coast smut incursion was 6% yield loss for each 10% increase in per cent-infected plants. To minimise losses susceptible varieties will need to be completely replaced with equivalent/higher yielding smut-resistant varieties, as fast as possible. This would necessitate changing ~80% of the2006 sugarcane crop. Replacement of susceptible varieties will be achieved, not only by rapid scale-up of smut-resistant varieties, but also accelerated development of high yielding,smut-resistant varieties. The parental pool of high breeding value, smut-resistant germplasm was however severely limited, adversely impacting the core crossing program. Without a significant plant breeding response, the rate of genetic gain for productivity would decrease and fewer productive, smut-resistant varieties would be released from the BSES-CSIRO Sugarcane Variety Improvement Program. The SmutBuster project was a key component of the RD&E response to sugarcane smut with the specific objective of developing high yielding smut-resistant varieties through the utilisation of high breeding value parental germplasm with susceptible reaction to smut.Item TRAILblazers : 2012 report(Sugar Research and Development Corporation (SRDC), 2012) Bonnett, GThe TRAILblazers program offers a unique opportunity for seasoned leaders who may not have had the chance to undertake formal leadership training previously, or who need to refresh their leadership agenda and goals. The program also allows them extend their circle of influence beyond their immediate industry sector.