Soft White Spring Research Articles

A Sustainable Management Package for Triticale in the Western Canadian Prairies

Triticale (× Triticosecale Wittmack) is a minor cereal crop in Alberta which has recently garnered interest as a biofuel feedstock. Basic agronomic information is lacking for triticale cultivars released since 1990. Field experiments were initiated in 2010 and conducted for 2 yr at four sites in central and southern Alberta to compare the impact of cultivar selection, seeding date, and seeding rate on grain yield, grain quality, and other agronomic traits. Six triticale cultivars released between 1996 and 2011, and one Soft White Spring wheat cultivar (Triticum aestivum L.) were evaluated over two seeding dates; one before and one after 15% of the total seasonal growing degree days (GDD; base = 0°C) had elapsed. The cultivars were evaluated at seeding rates of 250, 375, and 500 seeds m−2. Older triticale cultivars had higher grain yields but lower grain quality than cultivars released after 2000. The triticale cultivars produced more grain than Soft White Spring wheat in five of seven environments; however, Soft White Spring wheat exhibited better grain quality than the triticales. Yield generally increased linearly with seeding rate but the highest return on investment was observed at 375 seeds m−2. Provided there was not an early frost, triticale seeded after 15% of the seasonal GDD had elapsed could produce grain yield similar to the earlier‐seeded triticale. A sustainable management system for triticale includes modern cultivars, a seeding date that can accumulate 1750 GDD’s before frost, and a sowing density of at least 375 seeds m−2.

Phenotypic Effects of the Flowering Gene Complex in Canadian Spring Wheat Germplasm

Wheat (Triticum aestivum L.) has inherent genetic potential to synchronize its flowering and maturity to a broad growing period and is therefore one of the most widely adapted and grown food crops. Vernalization and photoperiod response genes are of primary importance to this adaptability. We screened 102 Canadian spring wheat cultivars and/or lines, developed between 1885 and 2008, from the Canada Western Red Spring (CWRS), Canada Prairie Spring Red (CPSR), and Canada Western Soft White Spring (CWSWS) classes and studied their phenotypic response both in the field and the greenhouse. Almost all the hard red cultivars possessed the Vrn‐A1a gene either alone or in combination with the dominant Vrn‐B1 while 74% of the higher yielding soft white lines possessed the Vrn‐B1 gene alone or in combination with other Vrn genes. The Vrn‐A1a alone or in combination with the Vrn‐B1 gene was the most potent gene conferring early maturity. Ppd‐D1a did not alter flowering and maturity in the hard red cultivars tested in the field but did in the greenhouse. Ppd‐D1a reduced days to flowering for soft white spring wheat but did not alter maturity. The photoperiod sensitive gene (Ppd‐D1b) is being replaced with the insensitive gene, Ppd‐D1a, in most modern Canadian germplasm, suggesting its adaptive advantages in the prairies. An overall analysis of the data for the hard red class revealed a declining trend of 0.04 d yr−1 in days to maturity in cultivars released from 1885 to 2008 and an increase of 8 kg ha−1 yr−1 in grain yield. The findings of this study may aid wheat breeders selecting parents with appropriate vernalization and photoperiod gene complexes.

Increased ABA sensitivity results in higher seed dormancy in soft white spring wheat cultivar ‘Zak’

As a strategy to increase the seed dormancy of soft white wheat, mutants with increased sensitivity to the plant hormone abscisic acid (ABA) were identified in mutagenized grain of soft white spring wheat "Zak". Lack of seed dormancy is correlated with increased susceptibility to preharvest sprouting in wheat, especially those cultivars with white kernels. ABA induces seed dormancy during embryo maturation and inhibits the germination of mature grain. Three mutant lines called Zak ERA8, Zak ERA19A, and Zak ERA19B (Zak ENHANCED RESPONSE to ABA) were recovered based on failure to germinate on 5μM ABA. All three mutants resulted in increased ABA sensitivity over a wide range of concentrations such that a phenotype can be detected at very low ABA concentrations. Wheat loses sensitivity to ABA inhibition of germination with extended periods of dry after-ripening. All three mutants recovered required more time to after-ripen sufficiently to germinate in the absence of ABA and to lose sensitivity to 5μM ABA. However, an increase in ABA sensitivity could be detected after as long as 3years of after-ripening using high ABA concentrations. The Zak ERA8 line showed the strongest phenotype and segregated as a single semi-dominant mutation. This mutation resulted in no obvious decrease in yield and is a good candidate gene for breeding preharvest sprouting tolerance.

The distal portion of the short arm of wheat (Triticum aestivum L.) chromosome 5D controls endosperm vitreosity and grain hardness

Kernel vitreosity is an important trait of wheat grain, but its developmental control is not completely known. We developed back-cross seven (BC(7)) near-isogenic lines in the soft white spring wheat cultivar Alpowa that lack the distal portion of chromosome 5D short arm. From the final back-cross, 46 BC(7)F(2) plants were isolated. These plants exhibited a complete and perfect association between kernel vitreosity (i.e. vitreous, non-vitreous or mixed) and Single Kernel Characterization System (SKCS) hardness. Observed segregation of 10:28:7 fit a 1:2:1 Chi-square. BC(7)F(2) plants classified as heterozygous for both SKCS hardness and kernel vitreosity (n = 29) were selected and a single vitreous and non-vitreous kernel were selected, and grown to maturity and subjected to SKCS analysis. The resultant phenotypic ratios were, from non-vitreous kernels, 23:6:0, and from vitreous kernels, 0:1:28, soft:heterozygous:hard, respectively. Three of these BC(7)F(2) heterozygous plants were selected and 40 kernels each drawn at random, grown to maturity and subjected to SKCS analysis. Phenotypic segregation ratios were 7:27:6, 11:20:9, and 3:28:9, soft:heterozygous:hard. Chi-square analysis supported a 1:2:1 segregation for one plant but not the other two, in which cases the two homozygous classes were under-represented. Twenty-two paired BC(7)F(2):F(3) full sibs were compared for kernel hardness, weight, size, density and protein content. SKCS hardness index differed markedly, 29.4 for the lines with a complete 5DS, and 88.6 for the lines possessing the deletion. The soft non-vitreous kernels were on average significantly heavier, by nearly 20%, and were slightly larger. Density and protein contents were similar, however. The results provide strong genetic evidence that gene(s) on distal 5DS control not only kernel hardness but also the manner in which the endosperm develops, viz. whether it is vitreous or non-vitreous.

Economics of Alternative Management Practices for Jointed Goatgrass in Winter Wheat in the Pacific Northwest

Jointed goatgrass (JGG) (Aegilops cylindrica) is an invasive annual grass weed that reduces winter wheat yield and quality. In the past 20 to 30 years, there has been much research conducted on jointed goatgrass; however, there has never been an empirical economic evaluation of jointed goatgrass in wheat during this time. This 7-year study evaluated the agronomic benefits and economic returns of twelve integrated weed management (IWM) systems based on crop yield and quality, jointed goatgrass populations, and dockage penalties. The twelve systems were all combinations of burn (B) and no burn (N) treatments; three crop rotations of soft white winter wheat-fallow-winter wheat-fallow (WW-F-WW-F), soft white spring wheat-fallow-winter wheat-fallow (SW-F-WW-F) and spring barley-fallow-winter wheat-spring barley (SB-F-WW); and two methods of winter wheat seeding, integrated (I) and standard (S). By far, the best systems for improving crop yield and quality and reducing jointed goatgrass populations and dockage were either B:SW-F-WW-F:S or N:SW-F-WW-F:S. These systems also had the highest profitability. If growers in the wheat-fallow region would adopt these two systems, they would increase profitability and sustainability and decrease herbicide resistance in jointed goatgrass.

Chromosomes 3B and 4D are associated with several milling and baking quality traits in a soft white spring wheat (Triticum aestivum L.) population

Wheat is marketed based on end-use quality characteristics and better knowledge of the underlying genetics of specific quality parameters is essential to enhance the breeding process. A set of 188 recombinant inbred lines from a 'Louise' by 'Penawawa' mapping population was grown in two crop years at two locations in the Pacific Northwest region of the United States and data were collected on 17 end-use quality traits using established quality analysis protocols. Using an established genetic linkage map, composite interval mapping was used to identify QTL associated with 16 of the 17 quality traits. QTL were found on 13 of the 21 wheat chromosomes. A large number of QTL were located on chromosomes 3B and 4D and coincided with traits for milling quality and starch functionality. Chromosome 3B contained 10 QTL, which were localized to a 26.2cM region. Chromosome 4D contained 7 QTL, all of which were located on an 18.8cM region of this chromosome. The majority of the alleles for superior end-use quality were associated with the cultivar Louise. The identified QTL detected remained highly significant independent of grain yield and protein quantity. The identification of these QTL for end-use quality gives key insight into the relationship and complexity of end-use quality traits. It also improves our understanding of these relationships, thereby allowing plant breeders to make valuable gains from selection for these important traits.

New breeding tools impact Canadian commercial farmer fields

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 Canadian Food Inspection Agency. These DH cultivars accounted for more than one third of the Canadian wheat acreage in 2009. The DH cultivar Lillian, eligible for grades of Canada Western Red Spring class and currently the most widely grown wheat cultivar in Canada, was developed using MAB to improve grain protein content with the Gpc-B1/Yr36 on chromosome 6BS introgressed from Triticum turgidum L. (Zhuk.) dicoccoides (Körn. Ex Asch. & Graebn). AC Andrew, a Canada Western Soft White spring DH cultivar, was the most widely grown cultivar in its class for the last two years. The new market class, Canada Western Hard White Spring wheat, is based entirely on DH cultivars. Goodeve, one of the first Canada Western Red Spring cultivars released with the gene Sm1 on chromosome 2BS for resistance to the orange wheat blossom midge (Sitodiplosis mosellana (Géhin)) was selected by application of the DNA marker WM1. Glencross, the first cultivar in the Canada Western Extra Strong wheat class with Sm1, was selected using the WM1 marker on haploid plants prior to doubling. Development of the durum wheat cultivars CDC Verona and Brigade involved the use of a marker for Cdu1, a major gene on chromosome 5B that regulates grain cadmium concentration. Marker technology permits a more strategic and integrated approach to breeding by quantifying the introgression of various key genes into advanced breeding material, identifying targeted loci in parents and following up with MAB in the progeny.

Bhishaj soft white spring wheat

Randhawa, H. S., Sadasivaiah, R. S., Graf, R. J. and Beres, B. L. 2011. Bhishaj soft white spring wheat Can. J. Plant Sci. 91: 805–810. Bhishaj is a soft white spring wheat (Triticum aestivum L.) that meets the end-use quality specifications of the Canada Western Soft White Spring class. Bhishaj is well-adapted to the wheat growing regions of southern Alberta and southern Saskatchewan. Based on data from the Western Soft White Spring Wheat Cooperative Registration Test from 1999 to 2001 and 2006 to 2009, Bhishaj exhibited high grain yield, mid-season maturity, semi-dwarf stature with moderate straw strength, and good resistance to shattering. Bhishaj expressed resistance to the prevalent races of leaf rust, stripe rust and powdery mildew, intermediate response to loose smut, susceptibility to stem rust, common bunt, and Fusarium head blight. Based on end-use quality analysis performed at the Grain Research Laboratory of the Canadian Grain Commission, Bhishaj had similar milling and baking performance as the check cultivars AC Reed and AC Phil.

Characterization of the Influence of Moisture Content on the Morphological Features of Single Wheat Kernels Using Machine Vision

The objective of this study was to quantify changes in morphological features of kernels of western Canadian wheat classes caused by moisture increase using a machine vision system. One hundred single wheat kernels for each of eight western Canadian wheat classes were successively conditioned from 12% to 20% (wet basis) moisture contents using potassium hydroxide (KOH) concentrations which regulated relative humidity. A digital camera of 7.4 7.4-m pixel resolution with an inter-line transfer charge-coupled device (CCD) image sensor was used to acquire images of single kernels. A machine vision algorithm developed at the Canadian Wheat Board Centre for Grain Storage Research, University of Manitoba, was implemented to extract seven morphological features (area, perimeter, major axis length, minor axis length, maximum radius, minimum radius, and mean radius) from the wheat kernel images. All the seven features of Canada Western Red Spring, Canada Western Amber Durum, Canada Prairie Spring White, Canada Prairie Spring Red, Canada Western Extra Strong, Canada Western Red Winter, Canada Western Hard White Spring, and Canada Western Soft White Spring wheat kernels were significantly (a = 0.05) different as the moisture content increased from 12% to 20%. All seven features showed a linearly increasing trend with an increase in moisture content.

Identification of wheat classes at different moisture levels using near-infrared hyperspectral images of bulk samples

Wheat classes at different moisture levels need to be identified to accurately segregate, properly dry, and safely store before processing. This paper introduces a new method using a near infrared (NIR) hyperspectral imaging system (960–1,700 nm) to identify five western Canadian wheat classes (Canada Western Red Spring (CWRS), Canada Western Extra Strong (CWES), Canada Western Red Winter (CWRW), Canada Western Soft White Spring (CWSWS), and Canada Western Hard White Spring (CWHWS)) and moisture levels, independent of each other. The objectives of this research also included identification of each wheat class at specific moisture levels of 12, 14, 16, 18, and 20%. Bulk samples of wheat were scanned in the 960–1,700 nm wavelength region at 10 nm intervals using an Indium Gallium Arsenide (InGaAs) NIR camera. Spectral feature data sets were developed by calculating relative reflectance intensities of the scanned images. Principal components analysis was used to generate scores images and loadings plots. The NIR wavelengths in the region of 1,260–1,360 nm were important based on the loadings plot of first principal component. In statistical classification, the linear and quadratic discriminant analyses were used to classify wheat classes giving accuracies of 61–97 and 82–99%, respectively, independent of moisture contents. It was also found that the linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) could classify moisture contents with classification accuracies of 89–91 and 91–99%, respectively, independent of wheat classes. Once wheat classes were identified, classification accuracies of 90–100 and 72–99% were observed using LDA and QDA, respectively, when identifying specific moisture levels. Spectral features at key wavelengths of 1,060, 1,090, 1,340, and 1,450 nm were ranked at top in classifying wheat classes with different moisture contents. This work shows that hyperspectral imaging techniques can be used for rapidly identifying the wheat classes even at varying moisture levels.

Increased Wheat Grain Hardness Conferred by Novel Puroindoline Haplotypes from Aegilops tauschii

ABSTRACTThe Puroindoline genes (Pina and Pinb) together comprise the wheat (Triticum aestivum L.) Hardness locus (Ha) located on chromosome 5D and control grain texture. While hard wheats contain a mutation in either Pina or Pinb, there is no puroindoline allelic diversity among soft hexaploid wheats as all carry the Pina‐D1a/Pinb‐D1a alleles. However, Pina and Pinb allelic variation exists within synthetic hexaploid wheats created using novel D genome donors. Here we tested the effects of four Aegilops tauschii‐derived Ha locus haplotypes (Pina‐D1c/Pinb‐D1h, Pina‐D1e/Pinb‐D1i, Pina‐D1a/Pinb‐D1i, and Pina‐D1j/Pinb‐D1i) found in synthetic wheats by crossing them into the soft white spring wheats ‘Alpowa’ and ‘Vanna’. The effect of each Ha haplotype on grain hardness was measured by analyzing backcross or F2–derived lines. All novel Ha loci increased grain hardness while still conditioning soft wheat texture independent of durum or Ae. tauschii synthetic wheat parent line. The Pina‐D1c/Pinb‐D1h haplotype was found to increase grain hardness relative to the wild‐type Ha locus by an average of 6.5 units, Pina‐D1e/Pinb‐D1i by 5.6 units, Pina‐D1a/Pinb‐D1i by 12.6 units, and Pina‐D1j/Pinb‐D1i by 3.8 units. None of the novel Ha locus haplotypes significantly affected Pina or Pinb transcript or protein expression levels. The results indicate that Ae. tauschii derived novel Ha loci could be useful in modifying soft wheat grain texture and end product quality.

Influence of Commodity Type, Percentage of Cracked Kernels, and Wheat Class on Population Growth of Stored-Product Psocids (Psocoptera: Liposcelidae)

Differences in stored-product psocid progeny production as a function of commodity type, percentage of cracked kernels, and wheat class were examined using laboratory bioassays. Population growth of Liposcelis bostrychophila Badonnel, Liposcelis decolor (Pearman), Liposcelis paeta Pearman, and Liposcelis entomophila (Enderlein) (Psocoptera: Liposcelididae) was highest on sorghum Sorghum bicolor (L.) Moench, followed by wheat, Triticum aestivum L., and rice, Oryza sativa L., whereas progeny production was negligible on wheat germ. In a second experiment that did not include L. entomophila, population growth was examined on wheat containing 0, 1, 5, 10, 20, 50, and 100% cracked kernels. Progeny production did not increase as cracked kernel content increased. Instead, progeny production peaked at 20% for L. bostrychophila adults and nymphs, at 10% for L. decolor, and at 50% for L. paeta adults; no further increases were noted beyond these levels of cracked wheat content. In a third experiment that did not include L. entomophila, progeny production was examined on eight classes of wheat: hard red winter, hard red spring, soft white winter, soft white spring, soft club, durum, soft red winter, and hard white. Overall, progeny production was higher on durum wheat than on the other classes. The results indicate that there are considerable variations in psocid population growth among the different commodities tested, and this information may be used to predict the degree to which stored commodities are susceptible to psocid infestation.

Novel Ha Locus, Pina‐D1c/Pinb‐D1h, Affects Soft White Spring Wheat Milling and Baking

ABSTRACTWheat (Triticum aestivum L.) grain hardness is controlled by the Hardness locus on chromosome 5D which consists of the linked genes Puroindoline a and b (Pina and Pinb, respectively). The Ha locus haplotype, Pina‐D1a/Pinb‐D1a, is found in all soft hexaploid wheats. While Pin diversity is low among soft wheats, several novel Ha haplotypes were reported among synthetic hexaploid wheats created using the D genome donor, Aegilops tauschii. One haplotype, Pina‐D1c/Pinb‐D1h, confers a soft phenotype with increased grain hardness over Pina‐D1a/Pinb‐D1a wheats. Here, the Pina‐D1c/Pinb‐D1h haplotype was backcrossed into the soft white spring wheat cultivars ‘Vanna’ and ‘Alpowa’. Then the effect of the two haplotypes on soft wheat milling and baking quality was compared. The effects of the Pina‐D1c/Pinb‐D1h Ha locus haplotype were similar in both the Vanna and Alpowa backgrounds. The Pina‐D1c/Pinb‐D1h lines had significantly more large and fewer small flour particles in both backgrounds and 1.51% higher flour yield in the Alpowa background. The Pina‐D1c/Pinb‐D1h haplotype group was not associated with any consistent differences in solvent retention capacities or sugar snap cookie quality parameters. The results indicate that the Pina‐D1c/Pinb‐D1h haplotype could be used to modify soft wheat milling properties without substantial effects on baking quality.

Sadash soft white spring wheat

Sadash is a soft white spring wheat (Triticum aestivum L.) that meets the end-use quality specifications of the Canada Western Soft White Spring class. Sadash is well-adapted to the wheat-growing regions of southern Alberta and southern Saskatchewan. Based on data from the Western Soft White Spring Wheat Cooperative Registration Test from 2003 to 2005, Sadash exhibited high grain yield, mid-season maturity, semi-dwarf stature with very strong straw, and good resistance to shattering. Sadash expressed resistance to the prevalent races of stem rust and powdery mildew, intermediate resistance to loose smut, moderate susceptibility to leaf rust and common bunt, and susceptibility to Fusarium head blight. Based on end-use quality analysis performed at the Grain Research Laboratory of the Canadian Grain Commission, Sadash had improved test weight over the check cultivars AC Reed and AC Phil and similar milling and baking performance.Key words: Triticum aestivum L., cultivar description, wheat (soft white spring), grain yield, quality, disease resistance

Registration of ‘Cataldo’ Wheat

‘Cataldo’ (Reg. No. CV‐1033, PI 642361) is a soft white spring wheat (Triticum aestivum L.) developed by the Idaho Agricultural Experiment Station and released in spring 2007. Cataldo was tested under experimental numbers A02215S‐B‐1 and IDO642 and has the pedigree of IDO584/4*‘Alturas’. IDO584 carries a new source of resistance to Hessian fly [Mayetiola destructor (Say)], the gene H25, originally derived from KS92WGRC 20. Cataldo was released for its novel Hessian fly resistance, conferred by the gene H25 The resistance was selected using molecular markers Xgwm610 and Xgwm397 associated with the H25 gene, together with phenotypic testing. Cataldo was released to extend the range of the Alturas genetic background into rainfed production regions of northern Idaho and eastern Washington where Hessian fly is a consistent limitation to production. Cataldo is also earlier and shorter than Alturas and has high‐temperature adult‐plant resistance to stripe rust (Puccinia striiformis Westend. f. sp. tritici Eriks.) and end‐use quality (cookie and Asian noodles) similar to Alturas.

Registration of ‘Whit’ Wheat

Stripe rust (Puccinia striiformis Westend f. sp. tritici) resistance is an essential trait for spring wheat cultivars produced in the Pacific Northwest region of the United States. The objective of this research was to develop an adapted spring wheat cultivar with high levels of resistance to stripe rust. ‘Whit’ (Reg. No. CV‐1034, PI 653841) soft white spring wheat (Triticum aestivum L.) was developed and released in July 2008 by the Agricultural Research Center of Washington State University. Whit was tested under the experimental designations SW2K067, S0300100U, and WA008008, which were assigned through progressive generations of advancement. Whit is an intermediate‐height semidwarf cultivar adapted to the intermediate to high rainfall (>380 mm of average annual precipitation), nonirrigated wheat production regions of Washington and Idaho. Whit is resistant to the Hessian fly [Mayetiola destructor (Say)], has high‐temperature, adult‐plant resistance to local races of stripe rust, is intermediate in height, is early maturing, and has high grain yield potential. Whit is a partial waxy variety with end‐use quality properties similar or superior to ‘Louise’, ‘Alpowa’, and ‘Alturas’.

A Comprehensive Genotype and Environment Assessment of Wheat Grain Ash Content in Oregon and Washington: Analysis of Variation

ABSTRACTA comprehensive analysis of the variation in wheat grain ash content has not been previously conducted. This study assessed the relative contribution of genotype and environment to variation in ash content, with a particular aim of ascertaining the potential for manipulating the trait using contemporary adapted germplasm. A total of 2,240 samples were drawn from four years of multilocation field plots grown in the wheat production areas of Oregon and Washington states. Genotypes included commercial cultivars and advanced breeding lines of soft and hard winter, and soft and hard spring wheats with red and white kernel color, several soft white club wheats, and one soft white spring waxy wheat cultivar. In addition to ash, protein content, test weight, and Single Kernel Characterization System kernel hardness, weight and size were also measured. In total, 20 separate fully balanced ANOVA results were conducted. Whole model R2 values were highly significant, 0.62–0.91. Nineteen of the 20 ANOVA results indicated significant genotype effects, but the effects were not large. In contrast, environment effects were always highly significant with F values often one to two orders of magnitude larger than the genotype F values. The grand mean for all samples was 1.368% ash. For individual data sets, genotype means across environments varied ≈0.1–0.3% ash. The genotypes judged noteworthy because they had the highest least squares mean ash content were OR9900553 and ClearFirst soft white winter, NuHills hard red winter, Waxy‐Pen and Cataldo soft white spring, and WA8010 and Lochsa hard spring wheats. Genotypes with lowest least squares mean ash were Edwin (club) soft white winter, OR2040073H hard red winter, WA7952 soft white spring, and WA8038 hard spring wheats. In conclusion, wheat grain ash is more greatly influenced by crop year and location than by genotype. However, sufficient genotype variation is present to plausibly manipulate this grain trait through traditional plant breeding.

Creation and functional analysis of new Puroindoline alleles in Triticum aestivum

The Hardness (Ha) locus controls grain texture and affects many end-use properties of wheat (Triticum aestivum L.). The Ha locus is functionally comprised of the Puroindoline a and b genes, Pina and Pinb, respectively. The lack of Pin allelic diversity is a major factor limiting Ha functional analyses and wheat quality improvement. In order to create new Ha alleles, a 630 member M(2) population was produced in the soft white spring cultivar Alpowa using ethylmethane sulfonate mutagenesis. The M(2) population was screened to identify new alleles of Pina and Pinb. Eighteen new Pin alleles, including eight missense alleles, were identified. F(2) populations for four of the new Pin alleles were developed after crossing each back to non-mutant Alpowa. Grain hardness was then measured on F(2:3) seeds and the impact of each allele on grain hardness was quantified. The tested mutations were responsible for between 28 and 94% of the grain hardness variation and seed weight and vigor of all mutation lines was restored among the F(2) populations. Selection of new Pin alleles following direct phenotyping or direct sequencing is a successful approach to identify new Ha alleles useful in improving wheat product quality and understanding Ha locus function.

The influence of moisture regime, N management, and cultivar on the agronomic performance and yield stability of soft white spring wheat

Field studies were conducted for 4 yr (2000–2003) in southern Alberta to determine the agronomic suitability and yield stability of soft white spring wheat across an array of moisture and fertility regimes. Two soft white spring wheat cultivars (AC Reed and AC Nanda) with contrasting maturity and quality profiles were compared to nine varieties representing the Canada Prairie Spring White, Canada Prairie Spring Red, and Canada Western Extra Strong wheat classes. The cultivars were managed with five varying rates of mid-row banded ammonium nitrate 0, 19, 38, 57, and 76 kg N ha-1. AC Reed matured earlier than most cultivars except AC Vista, and had the highest average yield. Yield stability analyses showed that AC Reed was well adapted to all environments but AC Nanda was less stable. AC Vista, AC Crystal, and AC Karma had average to good stability, but produced less grain than both AC Reed and AC Nanda. For non-irrigated production, yield was generally optimized at the mid-row banded rate 38 kg N ha-1 of ammonium nitrate. Response to N varied at the irrigated sites, but sites with lower initial soil NO3-N levels were responsive through the 76 kg N ha-1 rate. The soft white spring wheat class responded similarly to N in all moisture regimes, but whole-grain protein accumulation was not always lowest in the soft white spring wheat class. This study indicates that long-term sustainable production of soft white spring wheat in semi-arid, non-irrigated environments is possible, and would be most successful if cultivars were selected with yield stability, maturity and protein characteristics similar to AC Reed. Key words: Dry land production, fertility, soft white spring wheat, Triticum aestivum, yield stability, moisture regime

CANADIAN PIONEERS: John Martin Unrau

CANADIAN PIONEERS: John Martin Unrau