ORCID Profile
0000-0001-9897-0846
Current Organisation
James Cook University
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Publisher: Springer Science and Business Media LLC
Date: 19-04-2016
Publisher: Unpublished
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 12-03-2020
Publisher: Elsevier BV
Date: 11-2013
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/A98051
Abstract: The development of recommendations for drying-off management in sugarcane is difficult due to climatic variability and lack of knowledge of the sensitivity of changes in sucrose content and cane yield to severity of water deficit. Relative cane biomass targets were developed for drying-off irrigated sugarcane before harvest based on derived relationships between cane yield, cane dry weight, and sucrose concentration, using pooled data from previous field studies. These targets were then linked to a crop–soil model and long-term climate data to determine the economically optimum duration of drying-off, and its variability from season to season for 2 locations in Australia and one location in South Africa, for a range of harvest dates and soil types. The crop–soil model was validated on yields measured in 37 drying-off treatments conducted in South Africa and Australia. The simulation results show that the required drying-off duration can be highly variable, although the level of variability is not necessarily correlated with rainfall per se. There were interactions between soil type and harvest date, but not at every location. The systems approach outlined here can be useful in developing recommendations for drying-off where experience is limited, such as in expanding areas of sugar industries, for districts in which the practice of irrigation is increasing, or for harvest dates outside the current harvesting season.
Publisher: Elsevier BV
Date: 06-2005
Publisher: Informa UK Limited
Date: 1988
Publisher: Elsevier BV
Date: 06-2005
Publisher: Oxford University Press (OUP)
Date: 30-11-2016
DOI: 10.1093/JXB/ERV505
Publisher: Scientific Research Publishing, Inc.
Date: 2015
Publisher: Informa UK Limited
Date: 2010
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/AR07167
Abstract: High sucrose content (SC) in sugarcane stalks is a priority for all sugarcane industries world wide. Partitioning to sucrose in the cane stalk is related to the supply of photo-assimilate and the demand for assimilate by other organs. If photosynthesis could be maintained, but leaf and stalk growth constrained, by genetics or management during the stalk elongation phase, it may be possible to reduce stalk height and to increase both SC and sucrose yield. This paper reports an experiment designed to test this hypothesis and to develop a methodology to assess variation in response to source–sink manipulation in sugarcane clones. The research was conducted on a ‘low’ (Q138) and a ‘high’ (Q183) SC cultivar in two temperature controlled and airtight glasshouses (chambers) at CSIRO’s Davies Laboratory in Townsville, Australia. Potted plants of each cultivar were placed in two chambers of the Tall Plant Facility (TPF). In one chamber, plants were irrigated to minimise water stress while plants in the other chamber were irrigated to reduce plant extension rate (PER) considerably more than photosynthesis. Water stress reduced gain in total biomass by 19% and gain in top mass by 37%, and increased sucrose mass gain by 27%. During the experiment, SC of dry matter increased 37% in the dry treatment and only 8% in the wet treatment and this effect was greater in Q183 than in Q138. Water stress reduced whole plant photosynthesis by 18%, thus largely accounting for the 19% reduction in biomass accumulation and it reduced PER by 41%, corresponding to the 37% reduction in mass of tops. Reduced PER resulted in reduced demand for photo-assimilate by fibre and tops thus allowing excess assimilate to accumulate in the form of sucrose. The techniques developed here to control PER and measure the resulting changes in carbon partitioning now allow further examination of both the control of the balance between growth and sucrose storage and the extent of genotypic variation to the response of reduced PER.
Publisher: Springer Singapore
Date: 2020
Publisher: Wiley
Date: 18-08-2011
Publisher: Elsevier BV
Date: 04-2016
Publisher: Oxford University Press (OUP)
Date: 24-09-2012
DOI: 10.1093/JXB/ERS251
Abstract: Water limitation is a major production constraint for sugarcane worldwide. However, to date, there has been little investigation of patterns of genetic variation in the response to water stress in sugarcane. Field experiments were conducted over 3 years under fully irrigated and managed water stress conditions at two locations in Northern Queensland in Australia. Eighty-nine genetically erse clones were evaluated for their yield performance and sugar attributes. Water stress treatments reduced cane yield [tonnes of cane per hectare (TCH)] and total dry matter (TDM) by 17-52% and 20-56%, respectively, compared with irrigated treatments in the same experiments. Nevertheless, there was little genotype×environment interaction variation for TCH, TDM, or commercial cane sugar (CCS), and hence high genetic correlations between the irrigated and water stress treatments across environments. Both commercial and unselected clones performed poorly under severe stress environments, while the commercial clones outperformed the unselected clones under mild and moderate stress conditions. The results presented here highlight the contribution of intrinsic potential yields (yield under well-irrigated conditions) of some selected and unselected clones to maintain relatively high productivity in a range of moderate stress conditions imposed. The physiological basis for the high genetic correlations is at present unclear, but some explanations are hypothesized. The choice of stress levels in selection trials would not appear to be a critical issue for sugarcane breeding programmes, at least for the early phases of selection, where similar ranking clones across a range of moderate water stresses may be expected.
Publisher: Wiley
Date: 06-12-2013
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 08-2017
Publisher: American Geophysical Union (AGU)
Date: 10-2003
DOI: 10.1029/2003WR002054
Publisher: Elsevier BV
Date: 09-2004
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 08-1995
Publisher: Elsevier BV
Date: 1994
Publisher: Elsevier BV
Date: 06-2005
Publisher: Informa UK Limited
Date: 1991
Publisher: Elsevier BV
Date: 06-2005
Publisher: Elsevier BV
Date: 12-1999
Publisher: Elsevier BV
Date: 06-2005
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/CP11128
Abstract: Until now raw sugar has been the predominant commodity produced from sugarcane (Saccharum spp. hybrids) with the exception of Brazil where fermentable sugars are used to produce ethanol. Worldwide interest in renewable energy has focussed attention on total biomass production of ‘energy canes’ rather than sucrose yield alone. Clones selected for biomass tend to have high fibre contents derived from the wild type, S. spontaneum. It is possible that high fibre genotypes can produce higher biomass yields than high sucrose types due to feedback on photosynthesis either by sucrose or sucrose signalling compounds as proposed in several recent publications on feedback responses in sugarcane leaves. Up to 20 sugarcane clones with either high fibre or high sucrose content were grown in one field and three pot experiments to elucidate some of the processes from source to sink that could be responsible for high rates of biomass accumulation expected in high fibre clones. We were particularly interested in the possibility that clones with high sucrose content may have reduced photosynthesis as sucrose levels increased in upper internodes due to feedback mechanisms. Photosynthesis of whole plants and of single leaves decreased with crop development as much as 60% in some cases. Maintenance of photosynthesis was not associated with low content of sugars in leaves or in internodes. Sink strength for sucrose storage in the upper internodes was strong in both high fibre and high sucrose clones despite plants being grown for 12 months in conditions controlled to achieve high sucrose contents. Our data supported previous conclusions about localised feedback on photosynthesis by sugars accumulating in the leaf resulting in reduced photosynthesis of small segments of in idual young leaves. However, whole-plant photosynthesis did not decline through the day indicating that older leaves may compensate for reduced photosynthesis in younger leaves in the afternoon. While photosynthesis declined with crop age and sucrose content increased we found no evidence to suggest that photosynthesis declined because sucrose content increased. An increase in biomass yield through breeding and selection may not necessarily result in reduced sucrose content and increased fibre content.
Publisher: Elsevier BV
Date: 1986
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP08272
Abstract: Relatively little is known about the physiological basis for variation in sucrose content among sugarcane clones despite substantial research at the molecular and biochemical levels. We used irrigation and continuous monitoring of photosynthesis and plant extension rate to modify dry matter partitioning in four clones differing widely in sucrose content. Three pot experiments were conducted on two low sucrose content clones, KQ97-2599 and KQ97-2835, and two high sucrose content clones, Q117 and KQ97-5080, in a temperature-controlled glasshouse. As expected, sucrose content on a dry mass basis of whole stalks was greater in high (55% maximum) than in low sucrose clones (40% maximum), but sucrose content in the two clones selected for low sucrose reached 55% in some internodes. Differences between clones in whole-plant net photosynthesis and aerial biomass accumulation were small. However, biomass was distributed over fewer stalks in the high sucrose clones (4–7 stalks per pot) than in the low sucrose clones (9–11 stalks per pot). The high sucrose clones also allocated a considerably greater proportion of dry matter to the stalk (70% maximum) than the low sucrose clones (60% maximum). It is suggested that the relatively large amount of new leaf tissue produced by the high tillering, low sucrose clones placed an additional demand for structural photo-assimilate in these clones and delayed the accumulation of sucrose in the stalk. The results indicated that there is little direct genetic control on the maximum amount of sucrose that can accumulate in stalk tissue and that genetic contrasts in sucrose content reside more in the morphology of the plant and responses to ripening stimuli such as mild water stress, and how these traits influence supply and demand for photo-assimilate.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/CP09262
Abstract: While substantial effort has been expended on molecular techniques in an attempt to break through the apparent ceiling for sucrose content (SC) in sugarcane stalks, molecular processes and genetics limiting sucrose accumulation remain unclear. Our own studies indicate that limiting expansive growth with water stress will enhance sucrose accumulation in both low- and high-sucrose clones. Sucrose accumulation was largely explained (72%) by an equation with terms for photosynthesis, plant extension rate (PER), and plant number. New research was conducted to determine if this simple model stands when using temperature rather than water stress to perturb the source–sink balance. We also applied a thinning treatment to test the proposal implicit in this equation that SC will increase if competition between plants for photo-assimilate is reduced. Four clones from a segregating population representing extremes in SC were planted in pots and subjected to warm and cool temperature regimes in a glasshouse facility. A thinning treatment was imposed on half the pots by removing all but 6 shoots per pot. Temperature as a means of reducing sink strength seemed initially to be more successful than water regime because PER was 43% lower in the cool than in the hot regime while photosynthesis was only 14% less. PER was a good indicator of dry matter allocation to expansive growth, limited by water stress but not by temperature, because stalks tended to thicken in low temperature. Thinning had little effect on any of the attributes measured. Nevertheless the clonal variation in plant numbers and the response of PER to temperature helped to explain at least 69% of the variation in sucrose accumulation observed in this experiment. Thus the earlier model for sucrose accumulation appeared to be valid for the effect on sucrose accumulation of both temperature and water stress on the source–sink balance. The next step is to include internodes in models of assimilate partitioning to help understand the limiting steps in sucrose accumulation from the basics of source–sink dynamics.
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/CP10182
Abstract: Sucrose content has reached ceiling levels in several countries despite aggressive crossing and selection programmes aimed at improving this important trait for the sugarcane industry. Much of the recent research effort has been directed towards molecular means for improving sucrose content and while some breakthroughs have been made in the laboratory, no plants modified for this purpose have been grown successfully in the field. Sugarcane grown mainly for its sucrose in the past is now being considered for its fibre content as well because of increased interest in renewable energy. The paper offers an account of the variation in fibre, sucrose and hexoses in aboveground organs in relation to genotype, temperature and water regime with the aim of an improved understanding of biomass partitioning needed to effectively exploit sugarcane’s potential for multiple production streams. Previous studies often focused on single genotypes and on partitioning within stalks and ignored the effects of whole-plant structural partitioning on sugar accumulation. A mathematical model was constructed of biomass partitioning (at whole-plant and phytomer levels) of two high and two low sucrose clones of sugarcane from data collected in two controlled environment experiments, with water and temperature as treatments. The model tested the hypothesis that genetic differences in sucrose accumulation and responses to water and temperature can be explained by differences in plant development and partitioning to structural components such as leaf and stalk fibre. Whole-plant biomass partitioning between leaf, stalk structure and stored sugars was adequately simulated using clone-specific partitioning fractions modified by water status and temperature. Leaf partitioning fractions varied significantly between clones (low sucrose clones had high leaf fractions) but not between treatments. Stalk fibre partitioning fractions did not vary between clones but increased with improved water status and increased temperature. These aspects were mostly represented successfully in the model mainly because partitioning parameters were derived from the same data. Sugar accumulation was simulated, reasonably successfully, as the remainder of the biomass pool after partitioning to structural pools. Phyllochron intervals determined the rate at which phytomers ceased structural growth and commenced sugar accumulation. Low sucrose clones had longer intervals and so started sucrose accumulation later than high sucrose clones. There were also clonal differences in the ratio of hexose to sucrose (low sucrose clones had high ratios) and this could largely be explained by the structural mass fraction present in biomass. Although the data did not allow independent tests of all model assumptions, modelling these experiments did assist in gaining improved understanding of the underlying mechanisms of genetic and environmental control of biomass partitioning at whole-plant and phytomer levels. Results suggest that a way to enhance sucrose yields could be to breed genotypes with appropriate phenological and structural partitioning traits such as rapid phytomer development and low leaf partitioning fractions. This needs to be confirmed by further studies on more genotypes and environments.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 06-2002
Publisher: Elsevier BV
Date: 08-2003
Publisher: Elsevier BV
Date: 08-2012
Publisher: Oxford University Press (OUP)
Date: 06-05-2015
DOI: 10.1093/JXB/ERV194
Abstract: Stomatal conductance (g(s)) and canopy temperature have been used to estimate plant water status in many crops. The behaviour of g(s) in sugarcane indicates that the internal leaf water status is controlled by regular opening and closing of stomata. A large number of g(s) measurements obtained across varying moisture regimes, locations, and crop cycles with a erse sugarcane germplasm composed of introgression, and commercial clones indicated that there is a high genetic variation for g(s) that can be exploited in a breeding programme. Regardless of the environmental influences on the expression of this trait, moderate heritability was observed across 51 sets of in idual measurements made on replicated trials over 3 years. The clone×water status interaction (G×E) variation was smaller than the clone (G) variation on many occasions. A wide range of genetic correlations (r(g)= -0.29 to 0.94) between g(s) and yield were observed across test environments in all three different production regions used. Canopy conductance (g(c)) based on g(s) and leaf area index (LAI) showed a stronger genetic correlation than the g(s) with cane yield (tonnes of cane per hectare TCH) at 12 months (mature crop). The regression analysis of input weather data for the duration of measurements showed that the predicted values of r(g) correlated with the maximum temperature (r=0.47) during the measurements and less with other environmental variables. These results confirm that the g(c) could have potential as a criterion for early-stage selection of clones in sugarcane breeding programmes.
Location: Australia
No related grants have been discovered for Geoff Inman-Bamber.