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

Advanced Search

Filter by

Settings

Subject: search.filters.subject.Variety selection

Search Results

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Assessment of new soft cane varieties : final report 2015/081
    (Sugar Research Australia Limited, 2016) Kent, G; Parfitt, R
    The project objectives were to: experimentally determine whether extraneous matter affects the fibre quality parameters measured by SRA; experimentally determine whether the commercial cane preparation process affects the fibre quality parameters measured by SRA; experimentally compare the handle-ability properties of SRA1 andQC04-1411 to the major variety in the central and southern regions - Q208. In 2016, three new cane varieties, SRA1, SRA4 and QC04-1411, were either released or were proposed for release into the Bundaberg and Mackay districts. According to the pre-release fibre quality measurements undertaken by Sugar Research Australia, all three varieties were classified as a soft cane. This report documents a series of experiments undertaken to better define soft canes and to measure the effect that these three varieties had on factory operation and performance.
  • Thumbnail Image
    Item
    Selecting clones for better ratooning under wet harvesting conditions : SRDC final report CSR10S
    (1997) Jackson, P; Braunack, M; Foreman, J; Peatey, T; Wood, A
    There were three broad aims of this project: (i) To develop and evaluate a method for screening genetic material under conditions where there is (a) stool damage from harvesting machinery under wet conditions, and (b) waterlogging shortly after harvest. (ii) To evaluate a range of genetic material for ratooning under these conditions, including material generated from previous introgression breeding programs by CSR. (iii) To determine if a breeding program aimed at improving ratooning under wet conditions would be worthwhile, and if so, what sort of methods should be used.
  • 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
    Optimisation of experimental design and analysis for variety trials to maximise genetic gain : SRDC final report UQ023
    (2001) Basford, K; Hogarth, M
    The analysis of field experimental data usually assumes independent observations. This method is often inappropriate if the data contain strong spatial trends. Methods of analysis (commonly used in cereal trials) which account for the spatial variability existing within a field were shown to improve the precision of the estimates of clonal effects in sugarcane variety trials. As inter-plot competition was a major contributing factor biasing clonal estimates, a model which accounted for the competitive interaction between neighbouring clones was developed. Both factors could be incorporated into a more general model that jointly assessed inter-plot interference and fertility gradients. Two different estimation procedures (marginal likelihood and profile likelihood) for the parameters in the underlying models were investigated in a simulation study. Based on the criteria of average bias and mean-squared error, there was a slight preference for the marginal likelihood estimators. An empirical investigation of the relative efficiency of the augmented randomised complete block design versus the spatial unreplicated design in early generation sugarcane breeding programs was also undertaken. This indicated that the spatial design was to be preferred with respect to the bias in the parameter estimates, but using other criteria for design evaluation there were very few advantages in choosing the more complicated spatial design.
  • 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
    Optimum selection strategies in original seedlings particularly for heavily lodged crops : SRDC final report BS46S
    (1999) Kimbeng, CA; McRae, TA
    The objectives for this project were: to evaluate the effectiveness of family selection in the plant crop of original seedlings of sugarcane grown to full crop potential in the Burdekin region. The crop will probably be heavily lodged; to evaluate the effectiveness of visual (mass) selection in the young first ratoon crop; to determine the level of family performance in seedling populations required for a family to be selected. Information derived from this study would enable the breeder to design the most cost effective and efficient selection scheme for this stage of the breeding program for the Burdekin region
  • Thumbnail Image
    Item
    The inheritance of ash in juice from sugar cane
    (1983) Hogarth, DM; Kingston, G
    Ash per cent juice data were obtained for varieties within 97 crosses in original seedlings in 1979 and for varieties within 86 crosses from three factorial polycrosses in 1981, on the Bundaberg Sugar Experiment Station. The data showed that many crosses had higher ash levels than the standard variety Q87. In experiment I, Q87 had slightly lower ash levels than Q109 and Q111, and all three were significantly lower than Q110. It was found for experiments I and II, that 65 and 54 per cent respectively of the phenotypic variation was associated with genetic characters. As 95 per cent of genetic variation was additive, the prospects for breeding lower ash canes from low ash parents are very good. However, selections based on ash assessment may reject many varieties with other desirable agronomic characters. Negative correlations existed between ash per cent juice and Brix. However, the correlations were too low to assume that selection for high Brix canes would result in selections with lower ash levels.