David Brian Fowler

• Doctor of Philosophy
• University of Saskatchewan

Low Temperature Stress in Cereals: An Interactive Winter Survival Model.

In plant cells, phosphatidylglycerol (PG) in the chloroplast has a characteristic trans‐∆3‐hexadecenoic acid (t16:1) at the sn‐2 position. The t16:1 content in wheat leaf tissues decreases during cold treatment, but the significance of this fatty acid compositional change and the underlying biochemical mechanism remains poorly understood. Using a l...

2001. Genotype-environment interaction of no-till winter wheat in Western Canada. Can. J. Plant Sci. 81: 7-16. Differences among cultivars in their response to changes in crop water availability are reflected in genotype-environment (GE) interactions for grain yield. With the recent expansion of the winter wheat production area in western Canada, i...

Rye ( Secale cereale L.) is an exceptionally climate-resilient cereal crop, used extensively to produce improved wheat varieties via introgressive hybridization and possessing the entire repertoire of genes necessary to enable hybrid breeding. Rye is allogamous and only recently domesticated, thus giving cultivated ryes access to a diverse and expl...

An interactive web‐based model (https://norstar.usask.ca/survivalmodel) that simulates winter survival in cereals has been developed for use by farmers, extension workers, plant breeders, and researchers. Consistent with our current understanding of low‐temperature (LT) gene regulation, the model is based on a series of equations describing phenolo...

Growing resistant wheat (Triticum aestivum L) varieties is an important strategy for the control of leaf rust, caused by Puccinia triticina Eriks. This study sought to identify the chromosomal location and effects of leaf rust resistance loci in five Canadian spring wheat cultivars. The parents and doubled haploid lines of crosses Carberry/AC Cadil...

Remorins (REMs) are plant‐specific proteins that play an essential role in plant–microbe interactions. However, their roles in vernalization and abiotic stress responses remain speculative. Most remorins have a variable proline‐rich N‐half and a more conserved C‐half that is predicted to form coils. A search of the wheat (Triticum aestivum L.) data...

Meaningful improvements in winter cereal cold hardiness requires a complete model of freezing behaviour in the critical crown organ. Magnetic resonance microimaging diffusion weighted experiments provided evidence that cold‐acclimation decreased water content and mobility in the vascular transition zone (VTZ) and the intermediate zone in rye (Secal...

Cold acclimation and winter survival in cereal species is determined by complicated environmentally regulated gene expression. However, studies investigating these complex cold responses are mostly conducted in controlled environments that only consider the responses to single environmental variables. In this study, we have comprehensively profiled...

The wheat (Triticum aestivum L.) crown is the critical organ of low temperature stress survival over winter. In cold-acclimated crowns, ice formation in the apoplast causes severe tissue disruption as it grows at the expense of intracellular water. While previous crown studies have shown the vascular transition zone (VTZ) to have a higher freezing...

The high cost of cultivar development encourages efficiencies to reduce time and costs to develop cultivars. Doubled haploid (DH) technology and marker assisted breeding (MAB) are two such tools that improve efficiencies. Since 1997, twenty five wheat cultivars in seven market classes, developed using DH methods, have been registered by the Canadia...

Key message: Rye genetic resources provide a valuable source of new alleles for the improvement of frost tolerance in rye breeding programs. Frost tolerance is a must-have trait for winter cereal production in northern and continental cropping areas. Genetic resources should harbor promising alleles for the improvement of frost tolerance of winter...

Advances in sequencing and genotyping methods have enable cost-effective production of high throughput single nucleotide polymorphism (SNP) markers, making them the choice for linkage mapping. As a result, many laboratories have developed high-throughput SNP assays and built high-density genetic maps. However, the number of markers may, by orders o...

Synchrotron techniques are powerful tools in material and environmental sciences. However, they are currently underutilized in plant research. The Canadian Light Source synchrotron on the University of Saskatchewan campus is the only such facility in Canada, open to academic, government, and industrial clients. This review introduces the potential...

Successful adaptation of a crop species is dependent upon programming critical growth stages so the plant can optimize its response to environmental conditions during the growing season. The ability of winter cereal genotypes to survive over-winter low-temperature stress is an example of an adaptation that allows the plant to position itself to thr...

Low temperature (LT) tolerance in cereals needs developmental regulation of metabolites, a process which is associated with vernalization requirement. This study was initiated to investigate the relationships among stage of phenological development, final leaf number (FLN), the activities superoxide dismutase, catalase, guaiacol peroxidase, ascorba...

Plants must respond to environmental cues and schedule their development in order to react to periods of abiotic stress and commit fully to growth and reproduction under favorable conditions. This study was initiated to identify SNP markers for characters expressed from the seedling stage to plant maturity in spring and winter wheat (Triticum aesti...

Map and markers data of Norstar by Cappelle Desprez. (XLSX)

Map and markers data of Norstar by Manitou. (XLSX)

Map and markers data of Norstar by winter Manitou. (XLSX)

Modulation of membrane lipid composition under varying environmental conditions is an important part of plant stress adaptation. Most notably, proportional changes of lipid composition in response to temperature changes are a major cellular response to requirements of membrane fluidity adjustment. In higher plants, synthesis of glycerolipids is acc...

Glycerolipid biosynthesis in plants proceeds through two major pathways compartmentalized in the chloroplast and the endoplasmic reticulum (ER). The involvement of glycerolipid pathway interactions in modulating membrane desaturation under temperature stress has been suggested but not fully explored. We profiled glycerolipid changes as well as tran...

Winter survival of cereals is dependent on complex, environmentally induced responses that affect just about every measurable morphological, physiological, and biochemical characteristic of the plant. Simulation models offer a valuable means for the integration of knowledge accumulated from detailed physiological, agronomic, genetic, and genomics s...

CDC Chase is a hard red winter wheat (Triticum aestivum L.) that is eligible for grades of the Canada Western Red Winter (CWRW) wheat class. High grain yield potential relative to the grain quality checks, CDC Buteo and Moats, is its primary strength. It has excellent stem, leaf, and stripe rust resistance, and low physiological leaf spot and very...

This book aims to provide an up-to-date state-of-the-art review on various aspects of Conservation Agriculture (CA) by reviewing the past and current research from various regions of the globe so that all others interested in CA could benefit from experiences gained under different agroclimatic and socio-economic conditions across the globe. This r...

Swainson is a medium tall, high-yielding, stem and leaf rust resistant winter wheat (Triticum aestivum L.) that is registered for production in western Canada. It is a hard red winter wheat cultivar that is eligible for grades of the Canada Western General Purpose (CWGP) wheat class, which was created in 2008 to encourage the development of cultiva...

Seasonal low temperature (LT) adversely affects growth of plants. The onset of LT in temperate zones also entails the process of cold acclimation, preparing the plants to withstand freezing temperatures. During this process of cold acclimation a number of physiological, biochemical and molecular changes occur. A differentially expressed enolase gen...

The expression of 1,613 transposable elements (TEs) represented in the Affymetrix Wheat Genome Chip was examined during cold treatment in crowns of four hexaploid wheat genotypes that vary in tolerance to cold and in flowering time. The TE expression profiles showed a constant level of expression throughout the experiment in three of the genotypes....

The Supplemental data includes (1) List of 238 probesets (Affymetrix Wheat GenomeChip) representing transposable elements and (2) the Box-plots of raw signal and normalized intensities in the 96 microarray slides used in the experiment.

Fowler, D. B. 2012. Sunrise soft red winter wheat. Can. J. Plant Sci. 92: 195-198. Sunrise is a high-yielding soft red winter wheat (Triticum aestivum L.) cultivar that is registered in the Canada Western General Purpose (CWGP) wheat class for production in western Canada. The CWGP wheat class was created in 2008 to encourage the development of cul...

Fowler, D. B. 2012. Moats hard red winter wheat. Can. J. Plant Sci. 92: 191-193. Moats is a hard red winter wheat (Triticum aestivum L.) that is eligible for grades of the Canada Western Red Winter (CWRW) wheat class. It has excellent stem and leaf rust resistance and higher grain yield and protein concentration than the Central Winter Wheat Cooper...

The traditional winter wheat (Triticum aestivum L.) production area on the North American Great Plains extended as far north as southern Alberta, Canada. This paper reviews a research and development program initiated with the objective of expanding production north and east into higher winter stress areas of the Canadian prairies. Winter survival...

Differentially expressed genes. Annotated list of 2771 differentially expressed genes that show GxT interaction.

Correlation of variance heatmap and dendogram. Correlation of variance heatmap and dendogram for the 96 × 96 matrix of pairwise comparisons between samples.

To identify the genes involved in the development of low temperature (LT) tolerance in hexaploid wheat, we examined the global changes in expression in response to cold of the 55,052 potentially unique genes represented in the Affymetrix Wheat Genome microarray. We compared the expression of genes in winter-habit (winter Norstar and winter Manitou)...

Accipiter is an intermediate height, high-yielding, winter wheat (Triticum aestivum L.) cultivar with good stem and moderate leaf rust resistance that is registered for production in western Canada. It is a hard red winter wheat cultivar that is eligible for grades of the Canada Western General Purpose (CWGP) wheat class. The CWGP class was created...

The purpose of this study is to investigate nitrogen release from various split rate applications of seed-placed environmentally smart nitrogen (ESN) and spring-applied dribble banded Agrotain-UAN (urea and ammonium nitrate solution) and broadcast Agrotain-urea in winter wheat. Cool spring soil conditions have the potential to limit nitrogen (N) re...

Low-temperature (LT) tolerance in winter wheat (Triticum aestivum L.) is an economically important but complex trait. Four selected wheat genotypes, a winter hardy cultivar, Norstar, a tender spring cultivar, Manitou and two near-isogenic lines with Vrn-A1 (spring Norstar) and vrn-A1 (winter Manitou) alleles of Manitou and Norstar were cold-acclima...

The high cost of cultivar development encourages efficiencies to reduce time and costs to develop cultivars. Doubled haploid (DH) technology and marker assisted breeding (MAB) are two such tools that improve efficiencies. Since 1997, twenty five wheat cultivars in seven market classes, developed using DH methods, have been registered by the Canadia...

Peregrine is a medium tall, highyielding, stem and leaf rust resistant winter wheat (Triticum aestivum L.) that is registered for production in western Canada. It is a hard red winter wheat cultivar that is eligible for grades of the Canada Western General Purpose (CWGP) wheat class. The CWGP class was created in 2007 to encourage the development o...

CDC Ptarmigan is a soft white winter wheat (Triticum aestivum L.) cultivar that is eligible for grades of the Canada Western General Purpose (CWGP) wheat class. The CWGP class was introduced in 2007 to encourage the development and production of cultivars for the biofuel and livestock feed markets in western Canada. CDC Ptarmigan is an intermediate...

CDC Buteo is a hard red winter wheat (Triticum aestivum L.) cultivar that is eligible for grades of the Canada Western Red Winter Wheat class. It is an intermediate height cultivar with moderate stem and leaf rust resistance and good winter hardiness and grain yield potential. It is adapted to the western Canadian prairies where its agronomic and d...

Autumn-seeded winter cereals acquire tolerance to freezing temperatures and become vernalized by exposure to low temperature (LT). The level of accumulated LT tolerance depends on the cold acclimation rate and factors controlling timing of floral transition at the shoot apical meristem. In this study, genomic loci controlling the floral transition...

In plants, the C-repeat binding factors (Cbfs) are believed to regulate low-temperature (LT) tolerance. However, most functional studies of Cbfs have focused on characterizing expression after an LT shock and have not quantified differences associated with variable temperature induction or the rate of response to LT treatment. In the Triticeae, rye...

Exposure of winter wheat (Triticum aestivum L.) to low autumn temperatures allows it to cold acclimate and withstand sub-zero winter temperatures. Winter damage/kill can however occur. Studies on low temperature (LT)-induced genes have focused on growth chamber-grown plants at constant LT. Ideally a field experiment would be more representative and...

Wheat (Triticum aestivum L.) is a widely adapted, economically important crop exhibiting winter, spring and intermediate growth habits. Winter wheat is seeded in the fall, over-winters, resumes growth in spring and is harvested in early summer. It also requires a period of low temperature (LT) exposure, experienced during the fall, to switch from t...

To acquire a competitive advantage and ensure survival when exposed to low-temperature extremes, cool season plants must be pro- grammed to respond to temperatures favorable for growth and environmental cues that signal seasonal changes. This project was initiated to determine (i) the cold acclimation threshold induction temperatures (ITs) in wheat...

A number of COR genes (COld-Regulated genes) have been implicated in the acquisition of low temperature (LT) tolerance in wheat (Triticum aestivum L.). This study compared the relative expression patterns of selected COR genes in leaf and crown tissues of wheat near-isogenic lines to increase understanding of the molecular mechanisms underlying LT...

Six barley (Hordeum vulgare L.) accessions, previously used as parents of mapping populations, were evaluated for characters potentially affecting the location of low-temperature (LT) tolerance QTLs. Three were of winter growth habit (Kompolti Korai, Nure, and Strider), one was facultative (Dicktoo) and two were spring (Morex and Tremois). Final le...

Low-temperature (LT) tolerance is a complex quantitative character that is expressed in anticipation of and during exposure of plants to temperatures that approach freezing. This environmentally induced character is determined by a highly integrated system of structural and developmental genes that are regulated by environmentally responsive, compl...

Low-temperature (LT) tolerance is an important economic trait in winter wheat (Triticum aestivum L.) that determines the plants' ability to cope with below freezing temperatures. Essential elements of the LT tolerance mechanism are associated with the winter growth habit controlled by the vernalization loci (Vrn-1) on the group 5 chromosomes. To id...

Low-temperature (LT) adaptation is determined by a complex quantitative system that is expressed by plants in anticipation of and during exposure to temperatures that approach freezing. It is controlled by a highly integrated genetic system that is regulated by environmentally responsive, complex pathways. In the last decade, a virtual flood of gen...

It is frequently observed that winter habit types are more low-temperature (LT) tolerant than spring habit types. This raises the question of whether this is due to pleiotropic effects of the vernalization loci or to the linkage of LT-tolerance genes to these vernalization loci. Reciprocal near-isogenic lines (NILs) for alleles at the Vrn-A1 locus,...

Improvements in agronomic practices and cultivars have allowed for expanded production of winter wheat (Triticum aestivum L.) on the Canadian prairies. In this study, yield and yield components were measured in dry land and irrigation trials to identify the factors deter- mining yield potential and sample uniformity. Although genotype 3 environment...

Low temperature (LT) stress is one of the primary environmental factors limiting the expansion of winter wheat (Triticum aestivum L.) production in northern temperate climates. The objective of this study was to clarify the interrelationship between developmental stage and freezing resistance (FR) in winter and spring habit cultivars acclimated und...

The in vitro competency of mature cereal embryos (winter, spring and durum wheats, oat, barley and triticale) was assessed for direct multiple shoot production on culture media containing the plant growth regulators, thidiazuron (TDZ) and/or 6–benzylaminopurine (BAP). Mature embryos of CDC Dancer oat showed the best response, with 69 shoots per exp...

Winter wheat (Triticum aestivum L.) is seeded in the fall, regrowth resumes in spring, culminating in an early summer harvest. Yield is generally 20-25% higher than spring wheat. However, winter damage/kill can reduce yield. The low fall temperature allows the wheat plant to cold acclimate-a process during which physiological and biochemical change...

Low-temperature (LT) adaptation is determined by a complex quantitative system that is expressed by plants in anticipation of and during exposure to temperatures that approach freezing. It is controlled by a highly integrated genetic system that is regulated by environmentally responsive, complex pathways. In the last decade, a virtual flood of gen...

The initiation of the reproductive phase in winter cereals is delayed during winter until favorable growth conditions resume in the spring. This delay is modulated by low temperature through the process of vernalization. The molecular and genetic bases of the interaction between environmental factors and the floral transition in these species are s...

A bacterial artificial chromosome (BAC) library was constructed from DNA of a commercially grown winter wheat cultivar (Triticum aestivum L. cv. Norstar) that is highly tolerant to low temperatures (LT50 = -24 degrees C). The library was produced from nuclear leaf DNA that was partially digested with HindIII and inserted into pCC1BAC vector. In exc...

Low-temperature (LT) stress is a major factor limiting the over-winter survival of barley (Hordeum vulgare L.). The objective of this study was to determine the relationship between vegetative/reproductive transition and expression of LT tolerance in barley cultivars acclimated under field conditions. Three cultivars with different vernalization re...

Cereal Chem. 81(6):777–784 Wheat cultivars, representing three winter and three spring wheats were grown in western Canada with six levels of nitrogen fertilizer and flours were prepared from them with an extraction rate of 65%. Using a chromameter, flour color and the color of uncooked white noodle sheets made from these flours with different rest...

Accurate and precise measurements of grain quality traits are required throughout the wheat (Triticum aestivum L. Em. Thell.) production and marketing chain to ensure that quality standards are maintained. In the present study, spring and winter wheat genotypes representing a wide range of grain quality types and protein concentration (PC) were gro...

The molecular genetics of vernalization, defined as the promotion of flowering by cold treatment, is still poorly understood in cereals. To better understand this mechanism, we cloned and characterized a gene that we named TaVRT-1 (wheat [Triticum aestivum] vegetative to reproductive transition-1). Molecular and sequence analyses indicated that thi...

Available soil N and a cultivar's genetic potential are primary factors determining grain protein concentration (GPC). This study focused on important genotypic and environmental factors that determine GPC and yield potential in common wheat (Triticum aestivum L.) and investigated the use of GPC as a practical indicator of crop N deficiencies for a...

An interactive web-based model for estimating winter survival in cereals has been developed for use by farmers, extension workers, and researchers. The model is based on a series of equations that describe acclimation, dehardening, and damage due to low-temperature stress that are consistent with recent interpretation of low-temperature gene regula...