Biodiversity Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Dr Jann Williams, RMIT University, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06749 3
Distribution and abundance of genetically modified organisms [BD Indicator 4.1]
A GMO is any organism with genetic material that has been altered by genetic engineering. GMO research programs have much in common with traditional plant and animal breeding programs whose intention is to produce individuals with new genetic composition, better adapted to the needs of agriculture, medicine or some other productive use. GMOs are novel because the tools of molecular biology allow genes to be introduced into species that would be difficult or impossible using traditional breeding techniques. There are potential ecological benefits from genetically modified (GM) plants and animals, including the prospect of plant varieties to rehabilitate salt-affected areas or soils contaminated by heavy metals. Some potential benefits are indirect and difficult to predict, such as reductions in the use of pesticides (Barnes 2000).
Like other introduced organisms, there is also the potential for ecological costs. With the proliferation of GM products and the almost exponential growth of land use for GM crops (AAS 1999), there is growing interest in the estimation of the risks to the environment of exposure to such products. The major potential hazards for biodiversity posed by GM species may be summarised under four headings (Levin 1992):
- transgenic leakage into related wild populations may occur by hybridisation, where genes from the GM species move by cross-pollination into wild relatives of the same or different but closely related species
- GM populations may become invasive of natural habitats, competing most intensely with wild relatives
- GM species may be a direct hazard to non-target species, where the specific properties of GMOs (e.g. insect resistance in crop plants) may make them allergenic or toxic to a range of species that are part of the ecosystem shared by the GM species
- GM species may have indirect effects through changes in agricultural practice, including establishment of crops and livestock in areas considered marginal for agriculture, made possible by the novel properties of GMOs.
The introduction and spread of GMOs in Australia is regulated by the Interim Office of the Gene Technology Regulator and its Genetic Manipulation Advisory Committee (GMAC). Institutional Biosafety Committees (IBCs) operate in institutions where GMO research is undertaken. They oversee the development of new proposals and the conduct of research, acting as a first filter before new ideas are forwarded to GMAC for their consideration. General releases of GMOs are controlled by the Commonwealth Minister for Health and Aged Care under interim arrangements announced by the Commonwealth in August 1999. A national system of statutory regulation will be in place by July 2001.
Because of the prospect of the spread of genes from GM crops to adjacent non-GM crops, or between related species by hybridisation, buffers between field trials and adjacent wild and non-transgenic crop populations are used. The extent and utility of these buffers has been the focus of some research, with quantification of some aspects of genetic systems, dispersal and gene introgression (di Giovanni & Beckett 1990; Adler et al. 1993; Timmons et al. 1996; Giddings et al. 1997; Hokanson et al. 1997; Moyes & Dale 1999). However, there has been little work on comprehensive, quantitative modelling of ecological risks of GMOs (Timmons et al. 1996; Hails 2000) in Australia or elsewhere.
Small-scale proposals include laboratory, glasshouse or clinical applications of recombinant DNA under contained conditions. They do not involve the release or cultivation of individuals under field conditions. A total of 4811 small-scale proposals were assessed by GMAC between 1981 and June 1999 (Figure 42). In June 1999, there were 1681 active, small-scale, contained projects.
Figure 42: Total of small-scale proposals (for laboratory, glasshouse or clinical applications of recombinant DNA under contained conditions) assessed by the Genetic Manipulation Advisory Committee (GMAC) between 1981 and 30 June 1999.
Source: GMAC Annual Report 1997-98 (GMAC 1997) and 1998-99 (GMAC 1999)
Deliberate releases of GMOs involve trials under field conditions and range from areas smaller than 1 ha up to many thousands of hectares, and numbers of individuals ranging from fewer than 50 to many millions. In June 1999, there were 13 large-scale projects and 109 deliberate releases underway, the latter an increase from June 1998 of 69 projects (Table 41). Most deliberate releases are for commercial crops. Cotton (Gossypium spp.) and Canola (Brassica spp.) have been the subjects of most attention and make up the bulk of field trials, although more than 30 different kinds of GM species had been trialed up to June 1999 (Table 42). GMOs have been trialed in all Australian states (Table 43). A general release implies that the product is commercially available. There were two general releases in Australia before March 2001, for cotton and carnations.
|Year||Small-scale contained work||Large-scale contained work||Deliberate
|Projects with the potential for unintended release||IBCs|
Source: GMAC Annual Report (1997-98) and 1998-99 (see http://www.health.gov.au/ogtr/index.htm).
|Target species||Number of projects||Objective of project|
|Agrobacterium radiobacter||1||Control of crown gall disease|
|Baker's Yeast||1||Commercial evaluation of melibiose|
|Barley||4||Barley yellow dwarf virus resistance; expression of marker genes|
|Canola||32||Protoplast fusion breeding lines; new hybridisation systems; seed increase; glufosinate ammonium tolerance; glyphosate herbicide tolerance; fungal disease resistance; photoperiod insensitivity; reduced glucosinolate content; dwarfed cultivars; reduced pod-shatter|
|Carnation||8||Modified colour, enhanced vase life; fungal resistance|
|Cattle||5||Bovine rhinotracheitis vaccine; salmonella vaccine in lactating dairy cows; release of bovine herpes virus for vaccination|
|Chrysanthemum||1||Glasshouse trial of transgenics|
|Cotton||90||Insect resistance (Bt); seed increase; glycophosate tolerance; 2,4-D resistance; bromoxynil resistance; yield and fibre tests; climate response assessment; integrated pest management & ecological assessment; progeny selection; Verticillium wilt tolerance; waterlogging tolerance|
|Field Pea||11||Enhanced grain sulfur levels; pea weevil (Bruchus pisorum) resistance; resistance to Ascochyta blight; resistance to Liberty|
|Grapevine||1||Evaluation of transgenes|
|Helicoverpa armigera||4||Transgenics for monitoring frequency of Bt resistance in field; dispersal, stability and transmission of a genetically marked Helicoverpa armigera singly-enveloped nucleopolyhedrovirus in cotton|
|Lentils||1||Resistance to Basta|
|Lupins||10||Herbicide resistance (Lupinus angustifolius); virus resistance; sunflower seed albumin|
|Oilseed Poppy||3||Field trial and release|
|Papaya||2||Virus resistance; superior post-harvest fruit quality|
|Pineapple||1||Control of flowering and ripening|
|Potatoes||9||Resistance to potato leafroll virus and potato virus Y; seed tuber production; viral resistance; low browning properties|
|Poultry||2||Salmonella vaccine; evaluation of fowlpox virus vaccine|
|Pseudomonas spp.||4||Test of microbial tracking system; non-chemical control of bacterial wilt (Pseudomonas solanacearum); colonisation ability of modified Pseudomonas biological control bacteria on wheat roots in soil|
|Rhizobium spp.||2||Field release of strain containing a plasmid marked with a transposon|
|Rose||3||Colour modification; kanamycin or chlorsulfuron resistance|
|Rumen bacteria||2||Detoxification of fluoroacetate in domestic animals|
|Sheep||2||Salmonella vaccine to prevent death during live sheep export|
|Subterranean Clover||9||Bromoxynil-tolerance; sunflower seed albumin|
|Sugar Cane||5||Resistance to leaf scald disease; resistance to sugarcane mosaic virus; modified sucrose metabolism and juice colour|
|Tomato||4||Insect resistance (Bt); seed increase|
|Wheat||5||Evaluation of gene flow using a herbicide-resistant marker gene; altered starch composition; modified grain qualities; Basta tolerance; production of a glutenin protein|
|White Clover||3||Resistance to alfalfa mosaic virus|
|Unknown||1||Fruit ripening and flavour development|
Source: GMAC Annual Report 1997-98 and 1998-99 (see http://www.health.gov.au/ogtr/publications/index.htm).
|ACT||New South Wales||Queensland||Victoria|
|Clover||Canola||Bovine Herpes Virus 1||Carnation|
|Rhizobium||Fowlpox Virus||Pineapple||Indian Mustard|
|Wheat||Helicoverpa armigera singly-enveloped nucleopolyhedrovirus
|Northern Territory||South Australia||Tasmania||Western Australia|
Source: GMAC, Canberra.
GMAC assessed almost all proposals as acceptable, after modification and with different levels of protection being required. Two proposals were rejected, both relating to a project focused on the development of bacteria in the guts of ruminant animals that would allow them to tolerate fluoroacetate poisons that naturally occur in native plant species. One of the concerns was the potential for the bacterium to find its way into the guts of non-target species, perhaps resulting in increased effects on natural vegetation from feral animals. In addition, it is possible that the effect of 1080 bait used in the Western Shield Project in Western Australia (see Managing introduced species) could be reduced if feral animals developed tolerance to these poisons.
There are several crop genera where Australian native species are found in the same genus (Table 44). Of the species listed, GM varieties of potatoes, tomatoes and cotton have been trialed in the field. Many other crop species have the potential to hybridise with native species outside their genus. For example, there are many Australian species in the family Brassicaceae that could hybridise with crops of Canola and Indian Mustard (genus Brassica). The native species are important in their own right, and represent important reservoirs for genetic resources for crop improvement. These species may be at risk from unwanted hybridisation, both from genetically modified variants and from stock developed by more traditional means. The risk of hybridisation depends on many factors including pollen size and mode of dispersal, seed dispersal mechanisms, timing of flowering, wind direction, water flows, outcrossing rates and the spatial proximity of populations.
|Field crops||Vegetables||Oils, fruits, nuts, spices|
|Latin name||Common name||Latin name||Common name||Latin name||Common name|
|Amaranthus||Pigweed, Chinese Spinach||Abelmoschus||Okra||B rassica|
|Vigna||Cow pea, Black-eyed Pea||Piper||Pepper (white, black etc.)|
|Prunus||Almond, Peach, Cherry|
Source: after Brown and Brubaker (2000).