Baron Hay Ct

South Perth, Australia

Baron Hay Ct

South Perth, Australia
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Hood-Nowotny R.,AIT Austrian Institute of Technology | Hood-Nowotny R.,University of Vienna | Harari A.,Israel Agricultural Research Organization | Seth R.K.,University of Delhi | And 8 more authors.
Florida Entomologist | Year: 2016

In this study we identified a number of moth (Lepidoptera) species that are potential targets for the sterile insect technique (SIT), and we assessed the feasibility of using stable isotope signatures as markers to distinguish mass-reared from wild moth species. Large natural differences in the isotopic signatures of commercially available sugars render them novel markers for mass-reared insects. Sugar beet (Beta vulgaris L.; Caryophyllales: Amaranthaceae), a C3 plant, has a stable isotopic signature (a measure of the ratio of the stable isotopes 13C:12C) of around -27‰ relative to Vienna Pee Dee Belemnite (VPDB; the international C isotope standard for the stable isotopes, 13C and 12C), and sugarcane (Saccharum spp.; Poales: Poaceae), a C4 plant, has an isotopic signature of around -11‰. Thus by means of such a distinct isotope ratio in the sugar in the diet, mass-reared insects can be easily distinguished from wild insects with a high degree of certainty. It was shown that the method could be extended using a multiple isotope approach, with 15N or a full suite of C, N, S and O isotopes. Intrinsic isotope marking of mass-reared moths proved to be an accurate means of distinguishing wild from mass-reared populations, based on isotopic differences between the wild host plant species and the diets used in mass-rearing, which where possible, had been manipulated to contain the isotopically divergent sugar type. This intrinsic labeling using stable isotopes could be useful in the assessment of the quality of mass-reared moths, because a stable isotope is a marker that does not affect the insect in any detrimental manner. © International Atomic Energy Agency 2016. Published by the Florida Entomological Society. All rights reserved.

Francki M.G.,Baron Hay Ct | Francki M.G.,Murdoch University | Shankar M.,Baron Hay Ct | Walker E.,Baron Hay Ct | And 4 more authors.
Phytopathology | Year: 2011

Stagonospora nodorum blotch (SNB) is a significant disease in some wheat-growing regions of the world. Resistance in wheat to Stagonospora nodorum is complex, whereby genes for seedling, flag leaf, and glume resistance are independent. The aims of this study were to identify alternative genes for flag leaf resistance, to compare and contrast with known quantitative trait loci (QTL) for SNB resistance, and to determine the potential role of host-specific toxins for SNB QTL. Novel QTL for flag leaf resistance were identified on chromosome 2AS inherited from winter wheat parent 'P92201D5' and chromosome 1BS from spring wheat parent 'EGA Blanco'. The chromosomal map position of markers associated with QTL on 1BS and 2AS indicated that they were unlikely to be associated with known host-toxin insensitivity loci. A QTL on chromosome 5BL inherited from EGA Blanco had highly significant association with markers fcp001 and fcp620 based on disease evaluation in 2007 and, therefore, is likely to be associated with Tsn 1-ToxA insensitivity for flag leaf resistance. However, fcp001 and fcp620 were not associated with a QTL detected based on disease evaluation in 2008, indicating two linked QTL for flag leaf resistance with multiple genes residing on 5BL. This study identified novel QTL and their effects in controlling flag leaf SNB resistance. © 2011 The American Phytopathological Society.

Broughton S.,Baron Hay Ct | Zhou G.,Baron Hay Ct | Teakle N.L.,Edith Cowan University | Teakle N.L.,University of Western Australia | And 6 more authors.
Molecular Breeding | Year: 2015

Tolerance to waterlogging is an important breeding objective for barley (Hordeum vulgare L.); however, it is a complex quantitative trait. It is difficult to screen large numbers of lines in the field due to environmental variability, and it is also challenging to screen large numbers in controlled conditions if yield data are to be collected. The direct measurement of traits that contribute to waterlogging tolerance, such as aerenchyma development in roots, may offer advantages especially if molecular markers can be developed to screen breeding populations. A doubled haploid population from a cross between Franklin and YuYaoXiangTian Erleng was screened for adventitious root porosity (gas-filled volume per unit root volume) as an indicator of aerenchyma formation. A single QTL for root porosity was identified on chromosome 4H which explained 35.7 and 39.0 % of phenotypic variation in aerated and oxygen-deficient conditions, respectively. The nearest marker was EBmac0701. This QTL is located in the same chromosomal region that contributed to tolerance when the same population was screened in an earlier independent soil waterlogging experiment. Comparative mapping revealed that this QTL is syntenic with the Qaer1.02-3 QTL in maize and the Sub1A-1 gene in rice, which are associated with aerenchyma formation (maize) and submergence tolerance (rice), respectively. This is the first report of a QTL for root porosity in barley which elucidates a major mechanism of waterlogging tolerance. © 2015, Springer Science+Business Media Dordrecht.

Crawford A.C.,Baron Hay Ct | Crawford A.C.,Murdoch University | Francki M.G.,Baron Hay Ct | Francki M.G.,Murdoch University
Molecular Genetics and Genomics | Year: 2013

Knowledge of molecular and genetic mechanisms controlling wheat grain quality characteristics is significant for improving flour for end-product functionality. Flour bcolour is an important quality trait for breeding wheat varieties to produce grain for specific market requirements. The degree of flour yellowness is due to the accumulation of carotenoids in grain, particularly lutein. Flour bis under polygenic control and quantitative trait loci (QTL) have frequently been reported on chromosome 7AL. Analysis of carotenoid genes showed that phytoene synthase (PSY) co-located to the QTL on 7AL but other genes at this locus are also thought to contribute flour bcolour variation. This study used the wheat genome survey sequence and identified the chromosomal location of all wheat carotenoid genes, but none other than PSY were located on 7AL and, therefore, other genes may control flour bcolour variation including oxidative genes that degrade carotenoids. An investigation of EST bin mapped to 7AL identified a gene encoding a catalase enzyme (Cat3-A1) that was phylogenetically related to other plant class III enzymes, co-located to the QTL for flour bcolour variation on 7AL in three mapping populations and expressed during seed development. Therefore, Cat3-A1 was functionally associated with flour bcolour variation. Catalase acts upon hydrogen peroxide as a substrate and it was postulated that Cat3-A1 alleles control varying degrees of bleaching action on lutein in developing wheat grain. Markers for Cat3-A1 developed in this study can be used in conjunction with other candidate gene markers including phytoene synthase and lycopene-ε-cylase to develop a molecular signature for selecting lines with specific flour bcolour values in wheat breeding. © 2013 Springer-Verlag Berlin Heidelberg.

Li D.A.,Baron Hay Ct | Li D.A.,Murdoch University | Walker E.,Baron Hay Ct | Walker E.,Murdoch University | And 2 more authors.
Molecular Genetics and Genomics | Year: 2015

Carotenoids (especially lutein) are known to be the pigment source for flour b* colour in bread wheat. Flour b* colour variation is controlled by a quantitative trait locus (QTL) on wheat chromosome 7AL and one gene from the carotenoid pathway, phytoene synthase, was functionally associated with the QTL on 7AL in some, but not all, wheat genotypes. A SNP marker within a sequence similar to catalase (Cat3-A1snp) derived from full-length (FL) cDNA (AK332460), however, was consistently associated with the QTL on 7AL and implicated in regulating hydrogen peroxide (H2O2) to control carotenoid accumulation affecting flour b* colour. The number of catalase genes on chromosome 7AL was investigated in this study to identify which gene may be implicated in flour b* variation and two were identified through interrogation of the draft wheat genome survey sequence consisting of five exons and a further two members having eight exons identified through comparative analysis with the single catalase gene on rice chromosome 6, PCR amplification and sequencing. It was evident that the catalase genes on chromosome 7A had duplicated and diverged during evolution relative to its counterpart on rice chromosome 6. The detection of transcripts in seeds, the co-location with Cat3-A1snp marker and maximised alignment of FL-cDNA (AK332460) with cognate genomic sequence indicated that TaCat3-A1 was the member of the catalase gene family associated with flour b* colour variation. Re-sequencing identified three alleles from three wheat varieties, TaCat3-A1a, TaCat3-A1b and TaCat3-A1c, and their predicted protein identified differences in peroxisomal targeting signal tri-peptide domain in the carboxyl terminal end providing new insights into their potential role in regulating cellular H2O2 that contribute to flour b* colour variation. © 2015, Springer-Verlag Berlin Heidelberg.

Crawford A.C.,Baron Hay Ct | Crawford A.C.,Murdoch University | Stefanova K.,Baron Hay Ct | Lambe W.,Baron Hay Ct | And 8 more authors.
Theoretical and Applied Genetics | Year: 2011

Flour colour measured as a Commission Internationale de l'Eclairage (CIE) b* value is an important wheat quality attribute for a range of end-products, with genes and enzymes of the xanthophyll biosynthesis pathway providing potential sources of trait variation. In particular, the phytoene synthase 1 (Psy1) gene has been associated with quantitative trait loci (QTL) for flour b* colour variation. Several Psy1 alleles on chromosome 7A (Psy-A1) have been described, along with proposed mechanisms for influencing flour b* colour. This study sought to identify evolutionary relationships among known Psy-A1 alleles, to establish which Psy-A1 alleles are present in selected Australian wheat genotypes and establish their role in controlling variation for flour b* colour via QTL analysis. Phylogenetic analyses showed seven of eight known Psy-A1 alleles clustered with sequences from T. urartu, indicating the majority of alleles in Australian germplasm share a common evolutionary lineage. In this regard, Psy-A1a, Psy-A1c, Psy-A1e and Psy-A1p were common in Australian genotypes with flour b* colour ranging from white to yellow. In contrast Psy-A1s was found to be related to A. speltoides, indicating a possible A-B genome translocation during wheat polyploidisation. A new allele Psy-A1t (similar to Psy-A1s) was discovered in genotypes with yellow flour, with QTL analyses indicating Psy-A1t strongly influences flour b* colour in Australian germplasm. QTL LOD value maxima did not coincide with Psy-A1 gene locus in two of three populations and, therefore, Psy-A1a and Psy-A1p may not be involved in flour colour. Instead two other QTL were identified, one proximal and one distal to Psy-A1 in Australian wheat lines. Comparison of Psy-A1t and Psy-A1p predicted protein sequences suggests differences in putative sites for post-translational modification may influence enzyme activity and subsequent xanthophyll accumulation in the wheat endosperm. Psy-A1a and Psy-A1p were not involved in flour b* colour variation, indicating other genes control variation on chromosome 7A in some wheat genotypes. © 2011 Springer-Verlag.

Dominiak B.C.,Locked Bag | Wiseman B.,Kalang Consultancy Services Pty. Ltd. | Anderson C.,Locked Bag | Walsh B.,Baron Hay Ct | And 2 more authors.
Crop Protection | Year: 2015

Since the 1990's, international trade has relied on pest free areas or endemic categories as the basis for market access conditions. In pest free areas, pesticides or other control measures cannot be used until an outbreak is declared. Declaration of an outbreak suspends market access, with the region reverting to the status of an endemic area until pest free status is re-established. Under new phytosanitary measures, an area of low pest prevalence may be used as an intermediate step between pest freedom and outbreak that permits the use of control measures to prevent a breeding population establishing without suspending market access. A low pest population may therefore be tolerated on the basis that breeding and subsequent infestation of fruit is extremely improbable. In this paper, we identify the trapping levels that define areas of low pest prevalence and how this new standard might operate for Queensland fruit fly. © 2015 Published by Elsevier Ltd.

Renton M.,University of Western Australia | Renton M.,CSIRO | Diggle A.,Baron Hay Ct | Manalil S.,University of Western Australia | Powles S.,University of Western Australia
Journal of Theoretical Biology | Year: 2011

Evolution of herbicide resistance in weeds is a growing problem across the world, and it has been suggested that low herbicide rates may be contributing to this problem. An individual-based simulation model that represents weed population dynamics and the evolution of polygenic herbicide resistance was constructed and used to investigate whether using lower herbicide rates or standard rates at reduced efficacy could reduce the sustainability of cropping systems by causing faster increases in weed population density as herbicide resistance develops. A number of different possible genetic bases for resistance were considered, including monogenic resistance and polygenic resistance conferred by several genes. The results show that cutting herbicide rates does not affect the rate at which weed densities reach critical levels when resistance is conferred exclusively by a single dominant gene. In some polygenic situations, cutting herbicide rates substantially reduces sustainability, due to a combination of faster increase in resistance gene frequency and reduced kill rates in all genotypes, while in other polygenic situations the effect is small. Differences in sustainability depend on combined strength of the resistance genes, variability in phenotypic susceptibility and rate delivered, level of control due to alternative measures, and degree of genetic dominance and epistasis. In the situation where resistance can be conferred by both a single dominant major gene or a number of co-dominant minor genes in combination, the difference made by low rates depends on the relative initial frequency of the major and minor genes. These results show that careful consideration of herbicide rate and understanding the genetic basis of resistance are important aspects of weed management. © 2011 Elsevier Ltd.

Woods B.,Baron Hay Ct | McInnis D.,1216 Manu Aloha St. | Steiner E.,Baron Hay Ct | Soopaya A.,Baron Hay Ct | And 4 more authors.
Florida Entomologist | Year: 2016

The Australian light brown apple moth (LBAM) (Epiphyas postvittana) (Walker) (Lepidoptera: Tortricidae) is a pest in Australia, New Zealand and now California (USA). The use of sterile insects in combination with mating disruption and biological insecticides has the potential to eradicate outbreaks in urban areas. The sexual competitiveness of irradiated insects is an important component of the effectiveness of the sterile insect technique (SIT), but standard techniques to measure the sexual competitiveness have been developed only for irradiated tephritid fruit flies. In particular, field cage trials have been used to measure the compatibility and competitiveness of irradiated fruit flies in comparison with wild fruit flies. Trials were carried out to determine if such tests could be adapted for a moth species. Parameters of quality or competitiveness evaluated were the proportion of the moths that mated, relative sterility index, index of sexual isolation, and mating competitiveness based on the egg hatch in the various crosses. Results showed that with the release of sterile moths of both sexes (bisex) there was little difference in competitiveness-expressed as the Relative Sterility Index (RSI)-between moths irradiated at 200, 250 and 300 Gy (irradiated either in the pupal or adult stages), but if a Fried competitiveness test was used to generate competitive C values then greater competitiveness was found at the lower doses of irradiation, but this difference was not statistically significant. Modified test procedures were developed in which the moths in field cages-after having had sufficient opportunity to mate-were egged individually and dissected to determine the presence of 1 or more spermatophores; then egg sterility and spermatophore presence were used to determine the mating type, e.g., wild female × irradiated laboratory male, etc. Results indicated that sterile-male-only releases have the potential to increase mating competitiveness of the released irradiated moths, but this conclusion requires additional experiments for confirmation. © International Atomic Energy Agency 2016. Published by the Florida Entomological Society. All rights reserved.

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