Varieties, plant breeding and release

Permanent URI for this collectionhttp://elibrary2.sugarresearch.com.au/handle/11079/13841

Research outcomes: Comprehensive and efficient variety breeding, selection and release programs responding to yield expectations, environmental constraints, resource scarcity and regional preferences. Faster varietal adoption using advanced methods for bulking, distribution and planting.

Browse

Filters

2000 - 20095

Advanced Search

Filter by

Settings

Author: search.filters.author.Cox, MCStart date: 2000

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Whole-farm planning for management of varieties to maximise productivity and reduce losses from diseases : SRDC final report BSS294
    (2009) Croft, BJ; Cox, MC; Millard, D; Burrows, A
    The appropriate selection of sugarcane varieties is critical for maximising profitability and sustainability for both growers and millers in the Australian sugarcane industry. Growers are faced with many complex decisions when selecting varieties such as yield potential, suitability to soil type, optimum mix of varieties to maximize sugar content throughout the season, resistance to diseases and pests, ratooning ability and tolerance to stresses such as drought, frost and flooding. This project has developed a web-based variety decision support tool and information resource for the Australian sugarcane industry named QCANESelect to help growers make the best variety choices.
  • Thumbnail Image
    Item
    Maximising whole-of-industry benefits from the Australian sugarcane improvement program through an optimal genetic evaluation system
    (2007) Wei, X; Stringer, J; Jackson, P; Cox, MC
    An optimal genetic evaluation system (GES) is the backbone of any breeding program because maximising genetic gains is primarily a matter of efficient selection. A GES provides information to breeders about which individuals should be selected as parents for crossing and which ones should be selected for commercial production.At the commencement of this project, selection of both parents and clones for commercial production was principally based on the index knows as net merit grade (NMG). NMG is based on the performance of a test clone (or a cross) relative to the average of a number of commercial varieties (or corsses) for the traits of commercial cane sugar (CCS), tonnes of cane per hectare (TCH), appearance grade and fibre content. NMG was used to generate a breeding code for selecting parental clones for crossing. Cross ratio, a measure of each cross's performance relative to the whole population at each selection stage, was used to determine priority of crosses. For selecting elite clones to be retained for further testing, NMG was used in all three selection stages to determine which clones would be advanced to next stage.
  • Thumbnail Image
    Item
    Manual of procedures for the control of BSES Limited varieties: variety audit, DNA fingerprinting and plant breeder's rights
    (2004) Cox, MC
    Plant Breeders' Rights (PBR) is designed to protect industry investment in Plant breeding. Currently it protects the equity of growers and millers continuing to support plant improvement through the 'Service Fee'. However, different funding arrangements in the future may increase the importance of PBR to BSES Limited. Thus, it is imperative that the procedures described in this manual are rigorously followed to ensure that PBR is not compromised and can, if necessary, be defended in court.
  • Thumbnail Image
    Item
    Breeding clones with high early sugar content : SRDC final report BSS93
    (2002) Cox, MC
    The project BSS25 ?Breeding of clones with high early sugar content? concluded that the potential for increasing CCS through breeding and selection was greatest early in the season. BSS25 commenced a recurrent selection program with short generation interval aimed mainly at population improvement. The aim of BSS93 was to continue a recurrent selection program for early CCS and to assess the realised genetic gain made in the previous project.At the start of BSS93, BSES had changed its selection program from family assessment in clonal 4-sett plots to family assessment as original seedlings. The recurrent selection program for high early CCS reflected this change. Twenty families with high early CCS parents were selected for planting in New South Wales, southern, central, Burdekin, Herbert and northern regions from 1993 to 1996. At each location, the best 600 out of 1 200 seedlings (based on visual appearance) were sampled in May and June in the following year for CCS. The best 10 clones, based on mean CCS, were selected as parents and sent to Meringa for further crossing. Two hundred clones in total were selected as parents. The 10 parent clones and up to 10 additional clones were selected for testing in Clonal Assessment Trials. A total of 377 clones were selected over the duration of this project. Of these 377 clones, 107 clones were derived from families with at least one recurrent parent from the previous project. Good performing clones from this stage were promoted to advanced selection stages. A number of clones from both the current and previous projects have performed well in advanced trials. To date, two varieties have been released, Q185A (central region) and Q205A (southern region).Replicated trials were planted in the southern, central and northern regions to assess the genetic gain realised in the selected clones from the previous project (BSS25). Parents and elite (selected) clones from the families tested were included along with a base population (a group of 29 randomly selected clones from the breeding population) and a core population (a group of 30 clones from core selection programs with known high early CCS). Trials were sampled for CCS in May and June in plant and first-ratoon crops. Mean CCS was calculated and the various populations were compared.At all locations, the parent population had significantly higher CCS than the base population, and the core and elite populations had significantly higher CCS than the parent population. At Bundaberg, the elite population had significantly higher CCS than the core population, but there were no differences in mean CCS between these two populations at Mackay or Meringa.In terms of realised genetic gain, at Bundaberg both southern parent and elite populations showed steady gains from 1987 to 1991, averaging about 0.26 unit of CCS per year. There were no indications of a decrease in variability in these populations and it was concluded that it was likely further genetic gains would be sustained in the future.At Mackay, the central parent populations showed a modest but somewhat inconsistent improvement over the period and this was repeated for these populations tested at Bundaberg and Meringa. The central elite populations showed good improvement for the first 3 years, but this was not sustained over the subsequent 2 years. Extremely difficult selection environments (flooding and extreme moisture stress) impacted on the clonesselected in the final two elite populations and may explain this decline. It was difficult to come to a firm conclusion on continued genetic gain for the central region.At Meringa, the northern parent populations showed a small, but significant improvement over the 4 years of about 0.13 units of CCS per year. However, the northern elite populations showed no improvement over this period. This was not expected, as the parent populations showed a fairly steady improvement. Interestingly, good improvement was shown by the northern elite populations (first 3 years only) when grown at Bundaberg (0.39 unit CCS per year) and Mackay (0.21 unit of CCS per year). It is difficult to explain these results, but it may indicate that the wet tropics pose some unique difficulties in breeding and selection for high early CCS.
  • Thumbnail Image
    Item
    Field performance of transgenic sugarcane plants carrying genes for resistance to SCMV : final report BSS154
    (2000) Smith, GR; Taylor, GO; Harding, RM; Stringer, JK; Cox, MC; Yoyce, PA
    The field resistance of transgenic sugarcane plants to sugarcane mosaic potyvirus was successfully demonstrated, and a number of transgenic lines are available for consideration for agronomic evaluation. Some of the transgenic lines yielded significantly more tonnes sugar per hectare in this trial, but a firm conclusion about the overall performance of the transgenic lines compared to the parental clone can not be concluded due to the limitations of this trial. These plants contain the coat protein gene of sugarcane mosaic virus and prove that pathogen-derived resistance can be engineered into a genetically complex monocot. The precise molecular basis of the resistance appears to be RNA mediated. More research is necessary to prove this as a number of the resistant lines do not exhibit the usual RNA profiles of transgenic plants from other species which are virus resistant. A second pathogen-derived resistance gene, based on the virus replicase gene, is also capable of conferring virus resistance in sugarcane.Analysis of sugar and syrup produced from transgenic cane has revealed that no genes, native or transgenic, survive the laboratory production process. There is every confidence that this result would also be found with mill produced sugar, when the opportunity to mill transgenic sugarcane eventuates. There is now good scientific evidence to contribute to the debate that sugar manufactured from transgenic sugarcane plants is indistinguishable or substantially equivalent to sugar produced from non-transgenic plants.