80. The receiving environment forms part of the context in which the risks associated with dealings involving the GMOs are assessed. This includes the geographic regions where the release would occur and any relevant biotic/abiotic properties of these locations; the intended agronomic practices, including those that may be altered in relation to normal practices; other relevant GMOs already released; and any particularly vulnerable or susceptible entities that may be specifically affected by the proposed release (OGTR 2007a).
81. The proposed dealings involve planting GM sugarcane in the field within five BSES Sugar Experiment Stations (BSES Woodford, Southern, Central and Burdekin and at the planned BSES station), and cultivating GM sugarcane for crossing at a sixth BSES station (BSES Meringa, Table 1). BSES Southern could also be used for crossing. All BSES stations are in agricultural areas of Queensland on the outskirts of rural towns. Sugarcane is grown in the immediate vicinity of each of the established BSES stations proposed to be used for the trial, on both commercial sugarcane farms and within the experiment stations, except at BSES Woodford which is not close to commercial sugarcane farms. All BSES stations can only be accessed via private roads.
6.1 Relevant abiotic factors
82. The abiotic factors relevant to the growth and distribution of commercial sugarcane in Australia are discussed in The Biology of the Saccharum spp. (sugarcane) (OGTR 2008b).
83. The location of one of the BSES stations proposed to be used for the trial is yet to be determined, and the applicant states that it would be located in the Burdekin, Mackay or Bundaberg LGAs. As other BSES stations in the application are located in each of these LGAs, the general features of the receiving environment at the planned station have been taken into consideration.
84. The release is proposed to take place in the Queensland LGAs of Burdekin, Moreton Bay, Cairns, Bundaberg and Mackay. The Cairns and Burdekin regions have a tropical climatic type and the Mackay, Bundaberg and Moreton Bay regions have a sub-tropical climatic type (as defined by the Koeppen Classification system used by the Australian Bureau of Meteorology). The rainfall and temperature statistics for the proposed release sites or nearest locations are given in Table 5. With the exception of BSES Woodford, the proposed field locations are on flat arable land at minimal risk of flooding (information supplied by the applicant) and located at least 50 m from the nearest waterway, with the exception of one part of the crossing facility at BSES Meringa. BSES Woodford is located on a hilly site at which the high parts of the site proposed to be used for the trial have no history of flooding, and the GM sugarcane trial would be located at least 50 m from the nearest waterway. To date no incidents of dispersal of sugarcane plant material as a result of cyclones or storms have been reported.
Table 5. Monthly temperature and rainfall statistics for proposed release sites*
|Site||Nearest weather station||Mean max temp (oC) Summer||Mean min temp (oC) Summer||Mean max temp (oC) Winter||Mean min temp (oC) Winter||Mean monthly rainfall (mm) Summer||Mean monthly rainfall (mm) Winter|
|BSES Southern||Bundaberg post office||30.1||21.0||22.5||10.6||170||51|
|BSES Central||Te Kowai||30.8||21.6||23.8||10.8||294||43|
|BSES Burdekin||Burdekin Shire Council||32.1||22.1||25.8||12.5||213||21|
|BSES Meringa||Cairns airport||31.3||23.6||26.0||17.4||342||35|
6.2 Relevant biotic factors
85. The biotic factors pertaining to the growth and distribution of commercial sugarcane are discussed in The Biology of the Saccharum spp. (sugarcane) (OGTR 2008b), and of relevance to this release are the following points:
- The proposed release sites are on research stations or farms surrounded by commercial sugarcane growing fields.
- GM sugarcane lines released under DIR 070/2006 and DIR 078/2007 are being grown at BSES Woodford, Southern, Central, and Meringa research facilities at which the current release is proposed to take place. Traits of these other GM sugarcane lines are altered sugar production, enhanced nitrogen use efficiency, enhanced water use efficiency and altered plant architecture.
- Invertebrates, vertebrates and microorganisms are expected to be exposed to the introduced genes or RNAi constructs, their encoded proteins and end products. Fauna including rats and feral pigs may have access to the sites. To date there is no record of dispersal of sugarcane plant material by these vertebrates.
6.3 Relevant agricultural practices
86. The size, locations and duration of the proposed limited and controlled release of the GM sugarcane lines are outlined in Section 3.2 of this Chapter.
87. In Queensland commercial sugarcane is planted from autumn to spring and harvested after 12 –18 months. In the proposed release the GM sugarcane is to be grown in the field in 12 month planting seasons.
88. The proposed release consists of three rounds of assessment trials in which GM sugarcane lines are to be grown in the field and assessed for agronomic performance (Figure 2) in addition to disease testing, crossing, and maintenance of GM sugarcane lines in holding plots. Each trial consists of assessing agronomic characteristics of a single planting of sugarcane from planting to harvest at 12 months and at successive harvests of one or more ratoon crops at 12 month intervals. With successive trials a decreasing number of clones are to be selected and grown on increasingly larger scales under conditions more closely resembling commercial plantings. The most promising lines are to undergo disease screening and are proposed to be used in crosses from which progeny would enter new rounds of assessment trials.
89. The applicant proposes to carry out planting and harvest by hand or using machinery. For the purpose of minimising the spread of diseases, planting and harvest machinery used on BSES stations is routinely cleaned between uses (information supplied by the applicant). The applicant has proposed measures to distinguish field plantings of GM sugarcane from non-GM sugarcane so as to reduce the possibility of inadvertent harvesting of GM material, including separation of GM from non-GM sugarcane with a guard row of non-GM sugarcane and a 6 m isolation zone, marking GM plantings with signs and star pickets and implementing staff management procedures to inform harvest staff of GM sugarcane locations.
90. The initial GM sugarcane lines would be evaluated in progeny assessment trials in the first two years of the release. The applicant intends to transport tissue-cultured GM sugarcane plantlets which would be produced in PC2 facilities in Brisbane to four BSES stations, BSES Southern, Central, Burdekin and the planned station. At each station the plants would first be planted in pots in an area of seedling benches for hardening off, following which they would be planted into the field. Stalk weight and CCS are to be measured at first harvest of the crop (the plant crop) at approximately 12 months. These measurements are to be taken in the field (at laboratories set up for juice extraction, located at each BSES station) or from material sent to PC2 laboratories for analysis. The subsequent ratoon crop would be harvested at approximately 24 months for vegetative planting material for the following clonal assessment trial. Sugarcane is normally propagated vegetatively from lateral buds on stem pieces (setts), which establish roots and shoots once planted in a field. Once the clonal assessment trial is established the material remaining from the progeny assessment trial would be destroyed with herbicide treatment and ploughing.
91. Approximately 10% of GMOs would be selected from progeny assessment trials for the clonal assessment trials, which are intended to run in the third and fourth years of the release. Rows of clones would be propagated from stem cuttings planted directly into the field and harvested twice at approximately 12 month intervals (a plant and a ratoon crop). Measurements of cane yield and CCS would be taken at harvest. Treatments of varying nitrogen and water inputs would be carried out to assess nitrogen use efficiency and drought tolerance of lines in which these traits are expected to be enhanced. Material from selected plants would be collected for propagation for crossing, disease screening and final assessment trials. Following harvest of the ratoon crop the remaining field material would be destroyed with herbicide treatment and ploughing.
92. Approximately 1% of GMOs are to be selected for final assessment trials, which are designed to mimic commercial sugarcane cultivation. In these trials each GM line is to be grown in four-row plots for assessment of the plant and ratoon crops in the fourth and fifth years of the release. Concurrent with final assessment trials, selected GMOs are to undergo disease screening at BSES Woodford or BSES Southern. This is a requirement of the sugarcane breeding program (information supplied by the applicant). A second ratoon crop would be grown in the event that further stem material for propagation is required, however yield assessment would not be carried out.
93. The applicant proposes to cross GM sugarcane lines from six of the categories encompassing selectable marker expression (one category), altered plant growth (two categories) and altered drought tolerance (three categories, Table 4) to each other and to non-GM sugarcane cultivars. Lines for crossing are to be selected from clonal and final assessment trials, and stem material from these trials would be sent to up to two crossing facilities, at BSES Southern and BSES Meringa, for propagation. Sugarcane plants would be established from setts in non-PC2 glasshouses or on open-air seedling benches at both stations. At BSES Southern, plants would be maintained in a glasshouse until they become ready for induction of flowering, at which time they would be moved into the on-site photoperiod facility. At BSES Meringa, plants would be maintained adjacent to the on-site photoperiod facility until they become ready for induction of flowering, at which time they would be moved into the photoperiod facility. Sugarcane flowers somewhat unpredictably, and use of photoperiod facilities allows breeders to grow the plants in day lengths and temperatures most likely to induce flowering. Only those lines which flower could be used for crossing, with a maximum of 20 crosses being undertaken at each of the two BSES stations with crossing facilities in each year of the release. Inflorescences would be cut shortly before spikelets begin to open and transferred to buckets of acid in which they would be maintained until seeds develop. At BSES Meringa this would be done in a crossing shed, and at BSES Southern in the photoperiod facility. Inflorescences from the plants to be crossed would be enclosed together in bags (lanterns) which the applicant states are impermeable to pollen. Inflorescence material containing seed and flower parts (the fuzz) would be collected to muslin bags for drying. Seed may then be stored or germinated for further trials.
94. Seed from crosses would be germinated in growth cabinets (also known as germination chambers) or in glasshouses at BSES Southern and BSES Meringa and seedlings transported to other experiment stations as required for field trials. At recipient stations seedlings would be hardened in pots on seedling benches prior to planting in the field. It is proposed that progeny from crosses would undergo a round of assessment trials similar to the original GM lines, with successive rounds of assessment trials of lines generated by crossing occurring throughout the remainder of the 15 years of the proposed release.
95. Other cultivation practices used for planting and managing the proposed trial would follow the standard practices used for commercial (non-GM) sugarcane. These are outlined in The Biology of the Saccharum spp. (sugarcane) and include compliance with Queensland Government legislation for sugarcane disease control (OGTR 2008b).
6.4 Presence of related plants in the receiving environment
96. With the exception of BSES Woodford, the other BSES stations are located in sugarcane growing districts, and commercial sugarcane crops are grown on properties adjoining the stations at a minimum distance of 20 m from the proposed field planting sites (information provided by the applicant). BSES stations are used for breeding of commercial cultivars, including field trials of non-GM material, and in addition some material from BSES stations is sent to commercial sugar mills for processing with commercial crops. The applicant states that the minimum distance between field plantings of material from the current application and other sugarcane within BSES properties would be 10 m.
97. Sugarcane is known to cross with other species within the Saccharum genus, however of these species only S. spontaneum and S. officinarum are reported in Australia (OGTR 2008b). Other members of the genus are maintained in various Australian germplasm collections, including a clone garden near the proposed trial site at BSES Meringa, which includes S. officinarum, S. robustum and S. spontaneum plants. Naturalised populations of S. spontaneum have been recorded at several locations in north Queensland, including in sugarcane growing areas along a significant part of the Mulgrave river within the Cairns LGA (Bonnett et al. 2008). Preliminary molecular analysis of this population suggested the plants have reproduced vegetatively (Bonnett et al. 2008).
98. Sugarcane has been reported to produce hybrids with a number of species within closely related genera in a group known as the Saccharum complex, usually under controlled experimental conditions. Genera for which hybridisation has been verified are Erianthus and Miscanthus, and these exotic species do not occur in Queensland (reviewed by Bonnett et al. 2008). Possible hybridisations to the genera Narenga, Imperata (blady grass), Schlerostachya and Miscanthidium have been reported, however these events have not been verified by molecular methods (reviewed by Bonnett et al. 2008).
99. Sugarcane has been reported to cross with a number of species not considered close relatives. Hybrids between commercial sugarcane and sorghum (Sorghum bicolor) have not been observed under natural conditions, however hybrids have been generated from experiments in which large amounts of sorghum pollen were used to pollinate S. officinarum flowers (reviewed by Bonnett et al. 2008). Similarly, maize (Z. mays) has been shown to pollinate S. officinarum (at very low frequency), resulting in a single confirmed hybrid plant (reviewed by Bonnett et al. 2008). According to the applicant maize and sorghum are not cultivated in close proximity to the BSES stations proposed to be used for the trial. Wild Sorghum species occur as widespread weeds of cultivation in Queensland. Although hybridisation between Saccharum and Bambusa (bamboo) has been reported (Rao et al. 1967), subsequent analysis has suggested the hybridisation was not genuine (Grassl 1980).
6.5 Presence of the introduced genes and RNAi constructs or similar genes and encoded proteins in the environment
100. All of the introduced genes and RNAi constructs are isolated from naturally occurring organisms, most of which are already widespread and prevalent in the environment.
101. Many of the introduced genes and gene fragments in the RNAi constructs are derived from common crop plants including bean (P. coccineus), barley (H. vulgare), rice (O. sativa), sugarcane and maize (Z. mays). Genes highly similar to the majority of these genes are also expected to occur in most other plants. Therefore, it is expected humans and other organisms routinely encounter these introduced genes and gene fragments in the RNAi constructs, and their gene products, or their homologs, through contact with plants and food.
102. Some of the introduced genes are derived from bacteria, including the common gut bacterium E. coli. The three marker genes nptII, bla and uidA are derived from E. coli, which is widespread in human and animal digestive systems as well as in the environment (Blattner et al. 1997), and as such it is expected to be routinely encountered by humans. Activity of the GUS enzyme encoded by uidA has been detected in numerous microbial, plant and animal species (Flavell et al. 1992; Gilissen et al. 1998). GUS is recognised as commonly present on fresh food. The bla gene confers resistance to ß-lactam antibiotics such as ampicillin. It was isolated from the bacterial Tn3 transposon. The bla gene would not be expressed in the GM sugarcane lines because the gene’s bacterial (prokaryotic) promoter does not allow the expression in eukaryotes such as plants. The identities of some of the bacterial species from which the introduced genes were derived have been declared CCI and are not discussed further in this section.