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.

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End date: 1999Has files: Yes

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Now showing 1 - 10 of 43
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    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.
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    Effect of far-red radiation on flowering of Saccharum spp. hybrids : SRDC Final report BS1S
    (1990) Berding, N; Moore, PH
    Many tropical sugarcane clones (Saccharum spp. hybrids) are unavailable for hybridization because of poor flowering. Methods are required to improve the flowering of such clones. This study was conducted to determine whether far-red radiation (> 700 nm) at end-of day would improve flowering. Three treatments in a photoperiod facility (PPF) were compared to an external control (EC) under natural photoperiod. A basic treatment known as modified Florida (MF) was used in all PPF treatments and served as the internal control. This was altered to provide a far-red (FR) treatment, by addition of either 5 or 10 min of far-red radiation at end-of-day, and a day interrupt (Dr) treatment, by imposition of 2 hr of darkness in mid afternoon. Percent flowering as harvested panicles was 21.0, 24.2, 24.6, and 9.5 for FR, Dr, MF, and EC, respectively. Total flowering was 23.4, 28.9, 27.0, and 10.7, respectively. The PPF treatments did not differ significantly for either measure. All were highly significantly greater than EC. The far-red treatments did not differ for harvested panicles. Treatments differed significantly for time of flowering. The flowering sequence was EC, MF, FR, and then DI. There were significant differences among clones in all treatments for emergence day, initiation day, elapsed days, and pollen test. Correlations among these measures were varied, with some being significant. Far red at end-of-day neither stimulated nor inhibited flowering in the PPF treatments. The FR and Dr treatments delayed emergence of flowering.
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    Map-based chromosome and trait tagging in sugarcane using cytological and RFLP markers
    (1999) McIntyre, L
    Sugarcane is a complex aneuploid, polyploid, interspecific hybrid. At the time that this project began, molecular mapping in sugarcane was in its infancy and was only being attempted in interspecific crosses or within the selfed progeny of a variety. Two objectives of this project were, therefore, to demonstrate that markers could be used in variety by variety crosses in sugarcane and that molecular marker maps could be constructed in such crosses. Using a variety of marker types, these objectives have been met as described below. The major aim of the project was to enable the Australian sugar industry to access overseas information on traits, markers and genome organisation in sugarcane and other grasses. This was to be achieved using two strategies. Firstly, other groups nationally and overseas have begun searching for markers linked to agronomic traits of interest and relevance to sugarcane. These markers, identified in sugarcane and related grasses such as sorghum and maize, might provide a more rapid means of identifying useful markers for the Australian sugarcane industry, as compared to searching for markers de novo, as had been done in all other sugarcane populations to date. The second strategy was to develop a framework map in an Australian sugarcane cross using these and other markers. This map could then be used as a means of both identifying new markers linked to traits of interest in sugarcane and of aligning Australian co-segregation groups with linkage groups, and the information contained within, identified in other maps of sugarcane and related grasses in other laboratories.
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    Assessment of bulk segregant analysis and marker- assisted selection for economically important traits in sugarcane : SRDC final report BS138
    (1998) Carroll, B; Berding, N; McIntyre, L
    The main aim of this project was to assess the feasibility of bulk segregant analysis (BSA) and marker-assisted selection for important traits in sugarcane. The target trait for this feasibility study was rust resistance. Initially, crosses were successfully made between susceptible and resistant parents to produce two mapping populations. Unfortunately and surprisingly, we were not able to identify fully susceptible clones in four separate rust trials on the two populations. Poor rust development occurred in the first bench trial in 1996 at Meringa (including clones known to be susceptible), and the second trial in January 1997 was a total failure due to lack of rust development. The third rust resistance trial was conducted in Meringa in July 1997, but all of the clones in the mapping populations were resistant. The fourth rust trial on these two populations was completed at the start of 1998, and the results confirmed that all of the clones in these two initial mapping populations were resistant to common rust. Lack of segregation for rust resistance within progeny of sugarcane crosses had not been observed previously by sugarcane breeders in Meringa. This unexpected problem delayed the project as BSA could only proceed after a mapping population segregating for rust resistance had been identified.
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    Building strategic research capacity for the sugar industry aimed at overcoming physiological, biochemical and environmental constraints to cane growth, breeding and sucrose yield
    (1999) Grof, C; Campbell, J
    Using the CSIRO Controlled Environment Facility, the discrete effects on the rate and extent of sucrose accumulation in sugarcane of four significant environmental parameters (daily light integral, radiation levels, temperature and humidity) have been investigated. These experiments have attempted to address some existing industry problems and have provided some basic understanding of sugarcane physiology, a platform from which to launch a more detailed investigation of the metabolic processes that control the rate and final level of sucrose accumUlation.
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    Molecular tagging of economically important genes and promoters in sugarcane
    (1992) Birch, RG
    Project Objectives : The overall aim of this project was to develop techniques for the isolation of useful gene control sequences (promoters) in sugarcane. Early in the project we also undertook preliminary studies to lay some groundwork for techniques to tag and isolate useful genes in sugarcane. Specific objectives were: I. Develop techniques for the isolation of specific sugarcane gene control sequences. This led us to evaluate the applicability of differential cDNA hybridisation to recover tissue specific genes from sugarcane, followed by genomic library screening to recover corresponding tissue-specific promoters. 2. Prepare genetic constructs for transfer into sugarcane to assist identification and isolation of useful genes and promoters in sugarcane. This led us to test the effectiveness of a range of well characterised foreign promoters and novel artificial promoters in sugarcane. 3. Probe the sugarcane genome for endogenous transposable elements homologous to those isolated from other Oramineae, to help evaluate the potential for transposon tagging of useful sugarcane genes. All project objectives were achieved.
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    Effect of far-red radiation on flowering of Saccharum spp. Hybrids : SRDC final report BS1S
    (1990) Berding, N; Moore, PH
    Many tropical sugarcane clones (Saccharum spp. hybr ids) are unavailable for hybridization because of poor flowering. Methods are required to improve the flowering of such clones. This study was conducted to determine whether far-red radiation (> 700 nm) at end-ofday would improve flowering. Three treatments in a photoperiod facility (PPF) were compared to an external control (EC) under natural photoperiod. A basic treatment known as modified Florida (MF) was used in all PPF treatments and served as the internal control. This was altered to provide a far-red (FR) treatment, by addition of either 5 or 10 min of far-red radiation at end-of-day, and a day interrupt (DI) treatment, by imposition of 2 hr of darkness in mid afternoon. Percent flowering as harvested panicles was 21.0, 24.2, 24.6, and 9.5 for FR, DI, MF, and EC, respectively. Total flowering was 23.4, 28.9, 27.0, and 10.7, respectively. The PPF treatments did not differ significantly for ei ther measure. All were highly significantly greater than EC. The far-red treatments did not differ for harvested panicles. Treatments differed significantly for time of flowering. The flowering sequence was EC, MF, FR, and then Dr. There were significant differences among clones in all treatments for emergence day, initiation day, elapsed days, and pollen test. Correlations among these measures were varied, with some being significant. Far red at end-of-day neither stimulated nor inhibited flowering in the PPF treatments. The FR and Dr treatments delayed emergence of flowering.
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    Fine mapping of major rust resistance gene in cultivar R570 with a view towards it closing through map-bases chromosome walking
    (1999) D'Hont, A
    A major gene for rust resistance has been identified in cultivar R570 (Daugrois et ai, 19%). Rust disease is caused by the fungus Puccinia malenocephala Syd P. Syd and is distributed worldwide. Inheritance of resistance to rust was investigated in the self progeny of cultivar R570, which was also used to build the RFLP genetic map of this cultivar (Grivet et ai, 1996). Resistance was evaluated through both field and controled greenhouse trials. The results demonstrated that the field scores are very well correlated between plant cane and first ratoon and in very good agreement with the greenhouse artificial inoculation tests. A cle;r-cut 3 (resistance) : 1 (susceptible) segregation indicative of a dominant resistance gene was observed. RFLP mapping indicated that this gene was linked at approximately 10 cM to a marker revealed by the cDNA clone CDSR 29. This marker was not linked to any of the cosegregation groups of the R570 map (Grivet et ai, 19%). This gene is the first major gene identified in sugarcane. ICSB was thus interested in using it to test the feasability of map-based cloning in the complex aneuploid polyploid that sugarcane is. For this purpose the BAC library developed by RWing and co-workers was constructed using cultivar R570 (Tomkins et ai, 1999). The first step for map-based cloning is to develop a fine map in the vicinity of the gene; this was the objective of the present project. For this purpose, we developed and characterized for rust resistance large selfed progenies of R570 and we followed two strategies to find markers closely surrounding the rust resistance gene ; one is based on the synteny and colinearity demonstrated between Graminae species and the second is based on Bulked Segregant Analysis (BSA) with AFLP markers. We also tested the pathogenicity variability of the fungus.
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    The production of genetic constructs for expression of sugarcane mosaic virus coat protein in sugarcane protoplasts : SRDC final report BS9S
    (1990) SRDC
    This project was one phase of research required for production of transgenic sugarcane. Through this project the sugar industry now has a synthetic resistance gene against SCMV that expresses in sugarcane plant cells. When sugarcane plants are regenerated from protoplasts or the biolistic gene is adopted for use in sugarcane, this gene may be used to produce transgenic cane plants combining their original agronomic characteristics with SCMV resistance.
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    The role of root growth and activity in determining sugarcane productivity : SRDC final report CLW002 (previously CSS02 & CSS2S)
    (1999) Magarey, R; Nable, R; Reghenzani, J; Smith, J; Berthelsen, S; Grace, D; Robertson, M
    Research conducted in this project aimed to better understand the relationship between root and shoot growth, in areas such as how the size of the root system affects shoot growth, do particular root parameters have a controlling influence on shoot growth, how do soil characteristics affect root penetration rates, and how the root system develops through the life of a sugarcane crop. This was achieved through the application of a wide range of experimental techniques in both the glasshouse and field situation. The study of root systems in sugarcane is difficult - due to the size of the crop and the length of the cropping period. As a result there have been few previous studies on sugarcane root systems in Australia, and indeed around the world. A number of techniques were either developed, or adapted, in this project research. A soilless aeroponic culture technique was installed and refined at Tully Sugar Experiment Station. This allowed sugarcane roots to be examined on a daily basis and root measurements made, or root pruning to occur. This overcame the difficulty of dealing with the bulky, opaque soil medium. A tall pot system was adapted for sugarcane where sugarcane could be grown for an extended period in controlled conditions. This enabled plant water relations to be studied in association with modification to root growing conditions. Root image analysis techniques were further refined for sugarcane, allowing measurement of both whole glasshouse-grown root systems, or the quantification of root lengths in material from soil cores obtained in the field. A technique for growing sugarcane with a split root system was also adapted enabling the direct and indirect effects of water stress and root pruning in a soil culture to be examined, and the likely presence of root signals as a mechanism for control of shoot growth. Studies using these techniques facilitated an examination of the relationship between roots and shoots under various experimental conditions - ranging from controlled conditions with no soil in the glasshouse, through other soil-based glasshouse trials, to the field situation. This gave depth to project results and a broader understanding of root-shoot relationships using a range of experimental observations.