Australian Grain Technologies

Glen Osmond, Australia

Australian Grain Technologies

Glen Osmond, Australia
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Hill C.B.,Australian Center for Plant Functional Genomics | Taylor J.D.,Australian Center for Plant Functional Genomics | Edwards J.,University of Melbourne | Mather D.,Waite Research Institute | And 3 more authors.
Plant Physiology | Year: 2013

Drought is a major environmental constraint responsible for grain yield losses of bread wheat (Triticum aestivum) in many parts of the world. Progress in breeding to improve complex multigene traits, such as drought stress tolerance, has been limited by high sensitivity to environmental factors, low trait heritability, and the complexity and size of the hexaploid wheat genome. In order to obtain further insight into genetic factors that affect yield under drought, we measured the abundance of 205 metabolites in flag leaf tissue sampled from plants of 179 cv Excalibur/Kukri F1-derived doubled haploid lines of wheat grown in a field experiment that experienced terminal drought stress. Additionally, data on 29 agronomic traits that had been assessed in the same field experiment were used. A linear mixed model was used to partition and account for nongenetic and genetic sources of variation, and quantitative trait locus analysis was used to estimate the genomic positions and effects of individual quantitative trait loci. Comparison of the agronomic and metabolic trait variation uncovered novel correlations between some agronomic traits and the levels of certain primary metabolites, including metabolites with either positive or negative associations with plant maturity-related or grain yield-related traits. Our analyses demonstrate that specific regions of the wheat genome that affect agronomic traits also have distinct effects on specific combinations of metabolites. This approach proved valuable for identifying novel biomarkers for the performance of wheat under drought and could facilitate the identification of candidate genes involved in drought-related responses in bread wheat. © 2013 American Society of Plant Biologists. All Rights Reserved.

Bennett D.,University of Adelaide | Reynolds M.,International Maize and Wheat Improvement Center | Mullan D.,International Maize and Wheat Improvement Center | Izanloo A.,University of Adelaide | And 5 more authors.
Theoretical and Applied Genetics | Year: 2012

A large proportion of the worlds' wheat growing regions suffers water and/or heat stress at some stage during the crop growth cycle. With few exceptions, there has been no utilisation of managed environments to screen mapping populations under repeatable abiotic stress conditions, such as the facilities developed by the International Wheat and Maize Improvement Centre (CIMMYT). Through careful management of irrigation and sowing date over three consecutive seasons, repeatable heat, drought and high yield potential conditions were imposed on the RAC875/Kukri doubled haploid population to identify genetic loci for grain yield, yield components and key morpho-physiological traits under these conditions. Two of the detected quantitative trait loci (QTL) were located on chromosome 3B and had a large effect on canopy temperature and grain yield, accounting for up to 22 % of the variance for these traits. The locus on chromosome arm 3BL was detected under all three treatments but had its largest effect under the heat stress conditions, with the RAC875 allele increasing grain yield by 131 kg ha-1 (or phenotypically, 7 % of treatment average). Only two of the eight yield QTL detected in the current study (including linkage groups 3A, 3D, 4D 5B and 7A) were previously detected in the RAC875/Kukri doubled haploid population; and there were also different yield components driving grain yield. A number of discussion points are raised to understand differences between the Mexican and southern Australian production environments and explain the lack of correlation between the datasets. The two key QTL detected on chromosome 3B in the present study are candidates for further genetic dissection and development of molecular markers. © 2012 Springer-Verlag.

Bennett D.,University of Adelaide | Izanloo A.,University of Adelaide | Izanloo A.,Birjand University | Reynolds M.,International Maize and Wheat Improvement Center | And 4 more authors.
Theoretical and Applied Genetics | Year: 2012

In the water-limited bread wheat production environment of southern Australia, large advances in grain yield have previously been achieved through the introduction and improved understanding of agronomic traits controlled by major genes, such as the semi-dwarf plant stature and photoperiod insensitivity. However, more recent yield increases have been achieved through incremental genetic advances, of which, breeders and researchers do not fully understand the underlying mechanism(s). A doubled haploid population was utilised, derived from a cross between RAC875, a relatively drought-tolerant breeders' line and Kukri, a locally adapted variety more intolerant of drought. Experiments were performed in 16 environments over four seasons in southern Australia, to physiologically dissect grain yield and to detect quantitative trait loci (QTL) for these traits. Two stage multi-environment trial analysis identified three main clusters of experiments (forming distinctive environments, ENVs), each with a distinctive growing season rainfall patterns. Kernels per square metre were positively correlated with grain yield and influenced by kernels per spikelet, a measure of fertility. QTL analysis detected nine loci for grain yield across these ENVs, individually accounting for between 3 and 18% of genetic variance within their respective ENVs, with the RAC875 allele conferring increased grain yield at seven of these loci. These loci were partially dissected by the detection of co-located QTL for other traits, namely kernels per square metre. While most loci for grain yield have previously been reported, their deployment and effect within local germplasm are now better understood. A number of novel loci can be further exploited to aid breeders' efforts in improving grain yield in the southern Australian environment. © 2012 Springer-Verlag.

Bennett D.,University of Adelaide | Izanloo A.,University of Adelaide | Izanloo A.,Birjand University | Edwards J.,University of Adelaide | And 7 more authors.
Theoretical and Applied Genetics | Year: 2012

In southern Australia, where the climate is predominantly Mediterranean, achieving the correct flowering time in bread wheat minimizes the impact of in-season cyclical and terminal drought. Flag leaf glaucousness has been hypothesized as an important component of drought tolerance but its value and genetic basis in locally adapted germplasm is unknown. From a cross between Kukri and RAC875, a doubled-haploid (DH) population was developed. A genetic linkage map consisting of 456 DArT and SSR markers was used to detect QTL affecting time to ear emergence and Zadoks growth score in seven field experiments. While ear emergence time was similar between the parents, there was significant transgressive segregation in the population. This was the result of segregation for the previously characterized Ppd-D1a and Ppd-B1 photoperiod responsive alleles. QTL of smaller effect were also detected on chromosomes 1A, 4A, 4B, 5A, 5B, 7A and 7B. A novel QTL for flag leaf glaucousness of large, repeatable effect was detected in six field experiments, on chromosome 3A (QW. aww-3A) and accounted for up to 52 percent of genetic variance for this trait. QW. aww-3A was validated under glasshouse conditions in a recombinant inbred line population from the same cross. The genetic basis of time to ear emergence in this population will aid breeders' understanding of phenological adaptation to the local environment. Novel loci identified for flag leaf glaucousness and the wide phenotypic variation within the DH population offers considerable scope to investigate the impact and value of this trait for bread wheat production in southern Australia. © 2011 Springer-Verlag.

Mahjourimajd S.,University of Adelaide | Kuchel H.,Australian Grain Technologies | Langridge P.,University of Adelaide | Okamoto M.,University of Adelaide
Plant and Soil | Year: 2016

Aims: The key aim was to assess the genetic variation for nitrogen (N) response and stability in spring wheat germplasm to determine the scope for improvement of nitrogen use efficiency (NUE) under water-limited, low yielding conditions. A further aim was to evaluate NUE stability and NUE-protein yield (PY) as suitable NUE-related traits for selection. Methods: The traits measured included grain yield (GY, kg ha−1) and NUE (kg GY kg−1 N) under varying N applications at all sites, and NUE for protein yield (NUE-PY), harvest index and plant height at some sites. In addition, two of the trials used two seeding rates to provide an assessment of the impact of plant density on NUE. Results: Genetic variation was significant for all traits studied. Grain yield was affected by both genotype (G) and N rate and the interaction between the two. Interestingly, harvest index and height showed no direct response to varying N applications. However, for these traits, there was a significant G effect and N response (G × N interaction). Conclusions: Increasing N inputs led to variable responses for GY at different sites. Importantly, genetic variation in N response was detected. The information and screening techniques will enable plant breeders to select wheat genotypes that show a consistent response to high N. There is clear scope to improve NUE in spring wheat grown in low yielding environments. © 2015, The Author(s).

Fleury D.,University of Adelaide | Jefferies S.,Australian Grain Technologies | Kuchel H.,Australian Grain Technologies | Langridge P.,University of Adelaide
Journal of Experimental Botany | Year: 2010

Tolerance to drought is a quantitative trait, with a complex phenotype, often confounded by plant phenology. Breeding for drought tolerance is further complicated since several types of abiotic stress, such as high temperatures, high irradiance, and nutrient toxicities or deficiencies can challenge crop plants simultaneously. Although marker-assisted selection is now widely deployed in wheat, it has not contributed significantly to cultivar improvement for adaptation to low-yielding environments and breeding has relied largely on direct phenotypic selection for improved performance in these difficult environments. The limited success of the physiological and molecular breeding approaches now suggests that a careful rethink is needed of our strategies in order to understand better and breed for drought tolerance. A research programme for increasing drought tolerance of wheat should tackle the problem in a multi-disciplinary approach, considering interaction between multiple stresses and plant phenology, and integrating the physiological dissection of drought-tolerance traits and the genetic and genomics tools, such as quantitative trait loci (QTL), microarrays, and transgenic crops. In this paper, recent advances in the genetics and genomics of drought tolerance in wheat and barley are reviewed and used as a base for revisiting approaches to analyse drought tolerance in wheat. A strategy is then described where a specific environment is targeted and appropriate germplasm adapted to the chosen environment is selected, based on extensive definition of the morpho-physiological and molecular mechanisms of tolerance of the parents. This information was used to create structured populations and develop models for QTL analysis and positional cloning. © 2010 The Author(s).

Huang C.Y.,University of Adelaide | Kuchel H.,Australian Grain Technologies | Edwards J.,Australian Grain Technologies | Hall S.,University of Adelaide | And 6 more authors.
Scientific Reports | Year: 2013

Root systems are critical for water and nutrient acquisition by crops. Current methods measuring root biomass and length are slow and labour-intensive for studying root responses to environmental stresses in the field. Here, we report the development of a method that measures changes in the root DNA concentration in soil and detects root responses to drought in controlled environment and field trials. To allow comparison of soil DNA concentrations from different wheat genotypes, we also developed a procedure for correcting genotypic differences in the copy number of the target DNA sequence. The new method eliminates the need for separation of roots from soil and permits large-scale phenotyping of root responses to drought or other environmental and disease stresses in the field.

Eagles H.A.,University of Adelaide | Cane K.,Australian Department of Primary Industries and Fisheries | Kuchel H.,University of Adelaide | Hollamby G.J.,University of Adelaide | And 4 more authors.
Crop and Pasture Science | Year: 2010

Photoperiod and vernalization genes are important for the optimal adaptation of wheat to different environments. Diagnostic markers are now available for Vrn-A1, Vrn-B1, Vrn-D1 and P pd-D1, with all four genes variable in southern Australian wheat-breeding programs. To estimate the effects of these genes on days to heading we used data from 128 field experiments spanning 24 years. From an analysis of 1085 homozygous cultivars and breeding lines, allelic variation for these four genes accounted for ∼45% of the genotypic variance for days to heading. In the presence of the photoperiod-insensitive allele of Ppd-D1, differences between the winter genotype and genotypes with a spring allele at one of the genes ranged from 3.5 days for Vrn-B1 to 4.9 days for Vrn-D1. Smaller differences occurred between genotypes with a spring allele at one of the Vrn genes and those with spring alleles at two of the three genes. The shortest time to heading occurred for genotypes with spring alleles at both Vrn-A1 and Vrn-D1. Differences between the photoperiod-sensitive and insensitive alleles of Ppd-D1 depended on the genotype of the vernalization genes, being greatest when three spring alleles were present (11.8 days) and least when the only spring allele was at Vrn-B1 (3.7 days). Because of these epistatic interactions, for the practical purposes of using these genes for cross prediction and marker-assisted selection we concluded that using combinations of alleles of genes simultaneously would be preferable to summing effects of individual genes. The spring alleles of the vernalization genes responded differently to the accumulation of vernalizing temperatures, with the common spring allele of Vrn-A1 showing the least response, and the spring allele of Vrn-D1 showing a response that was similar to, but less than, a winter genotype. © CSIRO 2010.

Cane K.,Australian Department of Primary Industries and Fisheries | Eagles H.A.,University of Adelaide | Laurie D.A.,John Innes Center | Trevaskis B.,CSIRO | And 5 more authors.
Crop and Pasture Science | Year: 2013

Photoperiod and vernalisation genes are important for the adaptation of wheat to variable environments. Previously, using diagnostic markers and a large, unbalanced dataset from southern Australia, we estimated the effects on days to heading of frequent alleles of Vrn-A1, Vrn-B1, and Vrn-D1, and also two allelic classes of Ppd-D1. These genes accounted for ∼45% of the genotypic variance for that trait. We now extend these analyses to further alleles of Ppd-D1, and four alleles of Ppd-B1 associated with copy number. Variation in copy number of Ppd-B1 occurred in our population, with one to four linked copies present. Additionally, in rare instances, the Ppd-B1 gene was absent (a null allele). The one-copy allele, which we labelled Ppd-B1b, and the three-copy allele, which we labelled Ppd-B1a, occurred through a century of wheat breeding, and are still frequent. With several distinct progenitors, the one-copy allele might not be homogenous. The two-copy allele, which we labelled Ppd-B1d, was generally introduced from WW15 (syn. Anza), and the four-copy allele, which we labelled Ppd-B1c, came from Chinese Spring. In paired comparisons, Ppd-B1a and Ppd-B1c reduced days to heading, but Ppd-B1d increased days to heading. Ppd-D1a, with a promoter deletion, Ppd-D1d, with a deletion in Exon 7, and Ppd-D1b, the intact allele, were frequent in modern Australian germplasm. Differences between Ppd-D1a and Ppd-D1d for days to heading under our field conditions depended on alleles of the vernalisation genes, confirming our previous report of large epistatic interactions between these classes of genes. The Ppd-D1b allele conferred a photoperiod response that might be useful for developing cultivars with closer to optimal heading dates from variable sowing dates. Inclusion of Ppd-B1genotypes, and more precise resolution of Ppd-D1, increased the proportion of the genotypic variance attributed to these vernalisation and photoperiod genes to ∼53%. © 2013 CSIRO.

News Article | November 30, 2015

The researchers hope that the technique will enable rapid screening of plants to assess their root growth under saline conditions, without needing to dig up and destroy them. "Soil salinity is a major problem for agriculture around the world," says project leader Dr Megan Shelden, from the ARC Centre of Excellence in Plant Energy Biology within the School of Agriculture, Food and Wine. "Within Australia it's estimated that salinity affects 5.7 million hectares and this is expected to increase to 17 million ha by 2050. About 67% of the land affected by salinity is in the cereal growing regions, particularly impacting south-western and south-eastern Australia, with an estimated cost to the local farming industry of around $1.5 billion a year through loss of yield. "If we can develop cereal crops with enhanced tolerance to salt stress and improved root growth in salt and drought conditions, plants will be able to access deeper soil layers for nutrients and water, leading to improved crop yields." Dr Shelden was awarded a Premier's Research and Industry Fund's Catalyst Research Grant for this project and is working in collaboration with the University of South Australia and Australian Grain Technologies. She is using a technique called 'electrical impedance spectroscopy' to measure the changing electrical properties of the plant under salt stress. "Basically, we are putting an electric current at different frequencies through plants," says Dr Shelden. "The pattern of electrical impedance in response to different frequencies will change with the size of the root system and membrane properties that are affected by salinity. We will be correlating the amount of root growth to the patterns of impedance. "The great benefit of this new technique is that we can use it to measure what's happening to plant growth within the soil without having to destroy the plants. This means that we can measure root growth over time on the same plants. "We hope the technology will lead to an inexpensive and rapid screening method for measuring root growth in cereal crops that could be potentially adapted to other agriculture crops." Dr Shelden is starting her measurements with commonly grown Australian wheat varieties including Mace, Scout and Gladius. When she has satisfactorily developed the technique, she will then progress to screening wheat lines from around the world to identify those that are more salt-tolerant.

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