ORCID Profile
0000-0003-3885-7707
Current Organisation
University of Adelaide
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Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02201
Abstract: Malt extract represents the soluble material extracted from malt during the mashing process of barley. The measurement of malt extract is used by maltsters and brewers to assess the quality of the barley they are purchasing and is therefore one of the most important parameters used by breeders to assess the quality of new barley varieties before release. This paper identifies and investigates several regions (quantitative trait loci, QTLs) found to be associated with malt extract and discusses the uses of these regions for marker assisted selection (MAS).Eight regions of the barley genome were found to be associated with malt extract in 3 mapping populations. Five regions were found in the Sloop/Alexis and Sloop-sib/Alexis mapping populations on chromosomes 1H, 2H, 3H, 4H, and 5H. Two regions were found in the Chebec/Harrington population on chromosomes 1H and 5H and a single region was found on chromosome 2H in the Galleon/Haruna Nijo mapping population. Markers from 6 of these regions were investigated using several breeding populations with a high malt extract variety as a parent. The 'allele' from the high malt extract parent was found to be associated with a significant increase in malt extract in 4 regions, 2 regions on chromosome 2H and 2 regions on chromosome 5H.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02179
Abstract: A genetic linkage map consisting of 435 molecular markers has been constructed using a doubled-haploid mapping population derived from a cross between the Australian barley feed variety Galleon and Haruna Nijo, a Japanese barley cultivar of high malting quality. This map was used to locate the genes conferring CCN and SFNB resistance from Galleon and to locate malting and brewing quality genes from Haruna Nijo. Closely linked markers to the trait loci have been identified and are now being widely implemented in Australian breeding programs.
Publisher: Wiley
Date: 22-11-2022
DOI: 10.1111/JPY.13290
Abstract: Crustose coralline algae (CCA) are one of the most important benthic substrate consolidators on coral reefs through their ability to deposit calcium carbonate on an organic matrix in their cell walls. Discrete polysaccharides have been recognized for their role in biomineralization, yet little is known about the carbohydrate composition of organic matrices across CCA taxa and whether they have the capacity to modulate their organic matrix constituents amidst environmental change, particularly the threats of ocean acidification (OA) and warming. We simulated elevated p CO 2 and temperature (IPCC RCP 8.5) and subjected four mid‐shelf Great Barrier Reef species of CCA to 2 months of experimentation. To assess the variability in surficial monosaccharide composition and biomineralization across species and treatments, we determined the monosaccharide composition of the polysaccharides present in the cell walls of surficial algal tissue and quantified calcification. Our results revealed dissimilarity among species' monosaccharide constituents, which suggests that organic matrices are composed of different polysaccharides across CCA taxa. We also observed that species differentially modulate composition in response to ocean acidification and warming. Our findings suggest that both variability in composition and ability to modulate monosaccharide abundance may play a crucial role in surficial biomineralization dynamics under the stress of OA and global warming.
Publisher: Wiley
Date: 07-2010
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02215
Abstract: A doubled haploid population of 120 in iduals was produced from the parents Chebec, an Australian 2-row barley of feed quality with resistance to the cereal cyst nematode, and Harrington, a 2-rowed, Canadian variety of premium malting quality. This paper describes 18 field and laboratory experiments conducted with the population and summarises the traits mapped and analysed. The genomic location of 25 traits and genes is described and marker–trait associations for 5 traits (malt extract, diastatic power, resistance to cereal cyst nematode, early flowering, resistance to pre-harvest sprouting) important to Australian efforts to improve malting barley varieties have been used in practical breeding programs. Detailed maps for these populations are shown in this paper, while a consensus map incorporating these maps and further experiments on the populations are described elsewhere in this issue.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02218
Abstract: A map for the barley doubled haploid population Amagi Nijo × WI2585 was constructed to examine manganese efficiency derived from Amagi Nijo. Manganese efficiency conferred by the previously identified locus Mel1 was validated. No other loci contributing to manganese efficiency were identified, possibly because of poor maker coverage in some regions. The map was additionally used to look for loci contributing to some aspects of malting quality. A locus on 2HL was found to be associated with malt extract, and 2 loci on 4HL and 5H, respectively, were found to be associated with diastatic power.
Publisher: American Chemical Society (ACS)
Date: 27-11-2013
DOI: 10.1021/JF403558U
Abstract: The nutritional values associated with the cell walls of cereal endosperm flours are due to a combination of solubilized arabinoxylan and (1-3,1-4)-β-d-glucan as well as residual nonsolubilized cell wall material. In order to investigate structure-nutrition relationships, an appropriate method for the complete functional and structural characterization of cell wall polysaccharides in various cereal endosperm flours is described. This involves the separation of soluble polymers and the residual cell wall fraction without using organic solvents, and the fractionation of soluble polymers into arabinoxylan- and (1-3,1-4)-β-d-glucan-rich fractions for subsequent analysis. This methodology is applied to endosperm flours from wheat, hull-less barley and rye, and could be extended to include studies on the effects of food processing with respect to yield and characteristics of the three fractions in order to better understand the structural basis for nutritional functionality.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02193
Abstract: The usefulness of marker assisted selection (MAS) to improve diastatic power was demonstrated by selecting quantitative trait loci (QTLs) and structural gene alleles involved in enhanced diastatic power and activity of its component hydrolytic enzymes from Alexis, Amagi Nijo, Harrington, Haruna Nijo, and Sloop. Six unmapped breeders' populations involving these donor sources of malting quality were used for MAS. For each population, in idual lines were pooled into classes separated on the basis of either the presence or absence of malting quality parent marker alleles at each of 9 identified loci (QTLs or structural genes). Diastatic power, β-amylase, and α-amylase activities were determined for each line, and used to compare alternative marker allele class means. Lines carrying malting parent marker alleles at a chromosome 5H locus abg463 were associated with 21–44% higher α-amylase activity levels, depending on the cross. The malting parent alleles at the chromosome 4H Bmy1 locus were associated with increased diastatic power and β-amylase activity. A simple PCR marker detecting the Bmy1 locus was found to be effective in screening for improved diastatic power, β-amylase activity, and thermostability. Lines carrying malting parent alleles at the chromosome 2H Bmy2 locus produced differences in diastatic power and β-amylase activity that, after adjusting for the correlated effect of malt protein, became non-significant. The Alexis allele of the chromosome 1H EBmac501 locus was associated with significant differences in all traits for a population carrying this source. The implication of these results to the improvement of diastatic power through MAS is discussed.
Publisher: Elsevier BV
Date: 2016
Publisher: Wiley
Date: 04-07-2007
DOI: 10.1111/J.1365-3040.2007.01693.X
Abstract: Cultivar differences in root elongation under B toxic conditions were observed in barley (Hordeum vulgare L.). A significant increase in the length and width of the root meristematic zone (RMZ) was observed in Sahara 3771 (B tolerant) when it was grown under excessive B concentration, compared to when grown at adequate B supply. This coincided with an increase in cell width and cell numbers in the meristematic zone (MZ), whereas a significant decrease in the length and no significant effect on the width of the MZ was observed in Clipper (B intolerant) when it was grown under excessive B supply. This was accompanied by a decrease in cell numbers, but an increase in the length and width of in idual cells present along the MZ. Excessive B concentrations led to a significantly lower osmotic potential within the cell sap of the root tip in SloopVic (B tolerant) and Sahara 3771, while the opposite was observed in Clipper. Enhanced sugar levels in the root tips of SloopVic were observed between 48 and 96 h after excess B was applied. This coincided with an increase in the root elongation rate and with a 2.7-fold increase in sucrose level within mature leaf tissue. A significant decrease in reducing sugar levels was observed in the root tips of Clipper under excessive B concentrations. This coincided with significantly lower root elongation rates and lower sucrose levels in leaf tissues. Results indicate a B tolerance mechanism associated with a complex control of sucrose levels between leaf and root tip that assist in maintaining root growth under B toxicity.
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/AR06203
Abstract: Selection for malting quality traits is a major breeding objective for barley breeding programs. With molecular markers linked to loci affecting these traits, this selection can be undertaken at an earlier stage of the breeding program than is possible using conventional tests. Quantitative trait loci (QTLs) associated with malting quality traits were mapped in 2 populations derived from parents with elite malting quality. Progeny from an Arapiles/Franklin population grown in 4 environments and an Alexis/Sloop population grown in 5 environments were tested for grain protein percentage, α-amylase activity, diastatic power, hot water extract, wort viscosity, wort β-glucan, β-glucanase, and free α-amino acids. QTL analysis was performed using a one-stage approach, which allowed for modelling of spatial variation in the field, and in each phase of the malting quality analysis in the laboratory. QTLs for malting quality traits were detected on all chromosomes and for both populations. Few of these QTLs were significant in all of the environments, indicating that QTL × environment interactions were important. There were many coincident QTLs for traits that are expected to be related such as diastatic power and α-amylase activity, wort β-glucan and wort viscosity and for some traits that are not expected to be related such as hot water extract and malt viscosity.
Publisher: Oxford University Press (OUP)
Date: 19-09-2019
DOI: 10.1093/JXB/ERZ407
Abstract: Overexpression of the HvCslF6 gene in hull-less barley grain perturbs sucrose uptake and allocation, and impairs transfer tissue and endosperm development
Publisher: Wiley
Date: 27-04-2018
DOI: 10.1111/PCE.13196
Abstract: Chickpea (Cicer arietinum L.) is an important nutritionally rich legume crop that is consumed worldwide. Prior to cooking, desi chickpea seeds are most often dehulled and cleaved to release the split cotyledons, referred to as dhal. Compositional variation between desi genotypes has a significant impact on nutritional quality and downstream processing, and this has been investigated mainly in terms of starch and protein content. Studies in pulses such as bean and lupin have also implicated cell wall polysaccharides in cooking time variation, but the underlying relationship between desi chickpea cotyledon composition and cooking performance remains unclear. Here, we utilized a variety of chemical and immunohistological assays to examine details of polysaccharide composition, structure, abundance, and location within the desi chickpea cotyledon. Pectic polysaccharides were the most abundant cell wall components, and differences in monosaccharide and glycosidic linkage content suggest both environmental and genetic factors contribute to cotyledon composition. Genotype-specific differences were identified in arabinan structure, pectin methylesterification, and calcium-mediated pectin dimerization. These differences were replicated in distinct field sites and suggest a potentially important role for cell wall polysaccharides and their underlying regulatory machinery in the control of cooking time in chickpea.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR03002
Abstract: Barley kernel discoloration (KD) leads to substantial annual loss in value through downgrading and discounting of malting barley. KD is a difficult trait to introgress into elite varieties as it is controlled by multiple genes and strongly influenced by environment and maturity. As the first step towards marker assisted selection for KD tolerance, we mapped quantitative trait loci (QTLs) controlling KD measured by grain brightness [Minolta L (Min L)], redness (Min a), and yellowness (Min b) in 7 barley populations. One to 3 QTLs were detected for grain brightness in various populations, and one QTL could account for 5–31% of the phenotypic variation. The QTL located around the centromere region of chromosome 2H was consistently detected in 6 of the 7 populations, explaining up to 28% of the phenotypic variation. In addition, QTLs for grain brightness were most frequently identified on chromosomes 3H and 7H in various populations. Australian varieties Galleon, Chebec, and Sloop contribute an allele to increase grain brightness on chromosome 7H in 3 different populations. A major gene effect was detected for grain redness. One QTL on chromosome 4H explained 54% of the phenotypic variation in the Sloop/Halcyon population, and was associated with the blue aleurone trait. A second QTL was detected on the long arm of chromosome 2H in 3 populations, accounting for 23–47% of the phenotypic variation. The major QTLs for grain yellowness were mapped on chromosomes 2H and 5H. There were strong associations between the QTLs for heading date, grain brightness, and yellowness. The molecular markers linked with the major QTLs should be useful for marker assisted selection for KD.
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.NUT.2015.03.006
Abstract: The aim of this study was to investigate how a moderate increase in dietary meat content combined (or not) with soluble fibre would influence protein digestion as well as digesta characteristics and flow. Four groups of pigs were fed Western-style diets (high-protein/high-fat) containing two types of barbecued red meat, one with and one without a wheat arabinoxylan-rich fraction. After 4 wk, digesta s les were collected from small and large intestinal sites and analyzed for protein, amino acids, dry matter, and acid-insoluble ash. Tissue s les were also collected from each site. Arabinoxylan consumption led to somewhat lower apparent protein digestibility within the small and large intestines as well as shorter mean retention times. This suggests that the lowered protein digestibility is due, at least partly, to shorter access time to digestive proteases and absorptive surfaces. Additionally, digesta mass was higher in pigs fed arabinoxylan while dry matter (%) was lower, indicating an increased digesta water-holding capacity due to the presence of a soluble dietary fiber. Data showed that solubilized wheat arabinoxylan provides potential health benefits through decreased protein digestibility, increased digesta mass, and reduced mean retention time, even for diets with a moderately higher protein content. These factors are associated with efficiency of digestion and satiety, both of which have implications for prevention of obesity and other health disorders.
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.PLANTSCI.2015.08.009
Abstract: Water uptake by mature barley grains initiates germination and is the first stage in the malting process. Here we have investigated the effects of starchy endosperm cell wall thickness on water uptake, together with the effects of varying amounts of the wall polysaccharide, (1,3 ,4)-β-glucan. In the latter case, we examined mutant barley lines from a mutant library and transgenic barley lines in which the (1,3 ,4)-β-glucan synthase gene, HvCslF6, was down-regulated by RNA interference. Neither cell wall thickness nor the levels of grain (1,3 ,4)-β-glucan were significantly correlated with water uptake but are likely to influence modification during malting. However, when a barley mapping population was phenotyped for rate of water uptake into grain, quantitative trait locus (QTL) analysis identified specific regions of chromosomes 4H, 5H and 7H that accounted for approximately 17%, 18% and 11%, respectively, of the phenotypic variation. These data indicate that variation in water uptake rates by elite malting cultivars of barley is genetically controlled and a number of candidate genes that might control the trait were identified under the QTL. The genomics data raise the possibility that the genetic variation in water uptake rates might be exploited by breeders for the benefit of the malting and brewing industries.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02190
Abstract: Two populations between the German malting variety Alexis and the Australian malting variety Sloop were constructed, mapped, phenotyped, and subjected to quantitative trait loci analysis. One population consisted of 153 F4-derived recombinant inbred lines and the other of 111 doubled haploid lines. This paper describes 18 field and laboratory experiments conducted with the populations and summarises the traits mapped and analysed. The genetic basis of 5 traits (malt extract, resistance to leaf rust, resistance to powdery mildew, early flowering, plant stature) important to Australian efforts to improve malting barley varieties was elucidated. Detailed maps for these populations are shown in this paper, while a consensus map incorporating these maps and further experiments on the populations are described elsewhere in this issue.
Publisher: Elsevier BV
Date: 12-2014
No related grants have been discovered for Helen Collins.