Improvements in the bread-making quality and agronomic performance of Canadian spring wheats released between 1860 and 1986

Non-Peer ReviewedTwenty eight red spring wheat cultivars ranging from "Red Fife" to "Laura" in vintage were field-tested in each of four years (1989-1992). End-use quality analyses were performed on the grain harvested from three experiments. The objective of this study was to measure the rate of cultivar improvement for agronomic and bread-making quality performance. In the absence of disease, the more modern cultivars yielded 18% more than the cultivars released at the turn of this century. The yield advantage of the modern cultivars approached 30% under leaf rust disease pressure. Yield levels are estimated to be increasing at a rate of approximately 20+ kg/ha/yr. Protein quantity and quality have improved over time as has loaf volume. Improvements in agronomic, disease resistance and value-added performance have been off-set by a slight delay in maturity

Isolation distances for minimizing out-crossing in spring wheat

Non-Peer ReviewedCurrently recommended isolation distances of three or 10 m for pedigreed seed production of spring wheat (Triticum aestivum L.) may not be sufficient for cultivars with high out-crossing (OC) rates. The detection of higher than expected OC rates in wheat has directed this research to reassess currently recommended minimum isolation distances. The objective of this study was to determine if increased isolation distances are needed for cultivars that exhibit higher than normal levels of out-crossing. In each of two years, OC rates were determined for four Canadian spring wheat cultivars at each of 15 distances (0-33 m) from a blue aleurone pollen source. Cultivars were grown in rows perpendicular to the pollinator block to the north, south, west, & east. Target rows were replicated four times within each direction. Out-crossing in ‘Katepwa’ & ‘Biggar’ was not detected beyond three meters. Cultivars ‘Roblin’ & ‘Oslo’ exhibited higher than normal OC at distances of up to 27m. For Roblin & Oslo, an isolation distance of 30m is recommended to mitigate OC-derived off-types in the subsequent generation of pedigreed seed

Maximizing pre-harvest sprouting in white- and red-seeded wheat

Non-Peer ReviewedSeed dormancy is the main factor responsible for conferring pre-harvest sprouting tolerance to wheat grain. Recently, five common wheat germplasm lines (W98616, Line 211, CDC EMDR-4, CDC EMDR-9, and CDC EMDR-14) with deep seed dormancy levels and differing genetic backgrounds were released by the Crop Development Centre, University of Saskatchewan. The objective of this presentation is to give an overview of (1) the five CDC germplasm lines, (2) the two dormancy breaking methods that effectively overcome the deep seed dormancy levels in the five CDC germplasm lines, and (3) how the two dormancy breaking method can be used by breeders to improve sprouting tolerance within their breeding programs using the five CDC germplasm lines

Stripe rust virulence on Yr genes in Saskatchewan

Non-Peer Reviewe

Identification of intergeneric and synthetic spring wheat lines with resistance to Fusarium head blight

Non-Peer ReviewedFusarium head blight (FHB) is a serious disease in many cereal crops worldwide, as it can drastically reduce both yield and quality in infected crops. Resistance to FHB is therefore a desirable trait for incorporation into new wheat cultivars. Wild relatives are a source of new genetic variation and have been shown to enhance disease resistance when hybridized with wheat. This research has focused on evaluating intergeneric and interspecific wheat lines for resistance to FHB. Intergeneric hybrids of wheat (Triticum aestivum) and Agropyron repens syn. Elytrigia repens, and synthetic wheat lines produced at CIMMYT, were evaluated under greenhouse conditions for resistance to FHB caused by Fusarium graminearum. Approximately 35% of the intergeneric lines and 15% of the synthetic lines consistently displayed moderate to high levels of Type II resistance. Pollen staining was conducted to determine the fertility levels of the intergeneric lines. 79% of the F3 lines and 72% of the F5 and F6 lines displayed fertility levels above 75%. Control cultivars displayed fertility levels ranging from 88-94%. Generally, lines that rated as moderately to highly resistant were also highly fertile. These lines could be of significant value in wheat breeding programs aimed at integrating new sources of resistance to Fusarium head blight

Development of niche market pulse crops for Saskatchewan

Non-Peer Reviewe

Seed dormancy and germination in three annual canarygrass (Phalaris canariensis L.) cultivars relative to spring wheat (Triticum aestivum L.)

Non-Peer ReviewedSeed dormancy in annual canarygrass may lead to unsatisfactory germination in seed tests. The objectives of this study were (i) to quantify the levels of seed dormancy in three morphologically diverse annual canarygrass cultivars (‘Keet’, ‘CDC Maria’, & ‘CY 184’) relative to spring wheat & (ii) to determine the effectiveness of three treatments (GA3, KNO3, & chilling) & two temperature regimes (15/25°C & 15°C) in promoting germination of dormant annual canarygrass seeds. The hard red spring wheat cultivar ‘Katepwa’ control was included as a representative of a cereal crop that has been extensively characterized with regards to seed dormancy. In 1998 & 1999, the four cultivars were grown at Saskatoon, Canada. At maturity, panicles & spikes were hand harvested & stored at –20°C. Four replications of 50 seeds per cultivar were used in each experiment. Three experiments were conducted: (i) seeds were germinated at 10, 15, 20, & 25°C for one week, (ii) seeds were stored at 24°C for zero to eight weeks prior to germination at 22°C for one week, & (iii) seeds were treated with GA3, KNO3, & chilling prior to germination at 15/25°C (16/8h) or 15°C for two weeks. For experiment one & three, a split-plot analysis was used to analyze arc sin transformed percentage germination data. Average percentage germination data in experiment two were tested to be significantly different from 98% germination (P=0.05) based on one-tailed t-tests. Annual canarygrass developed deeper dormancy than the wheat cultivar in both years, particularly when germinated at 20 & 25°C. The highest percentage germination was observed at 15°C. Two (1998) & four weeks (1999) of storage at 24°C were required to overcome dormancy in annual canarygrass. Pre-chilling or KNO3 treatment prior to germination at 15/25°C (16/8h in darkness) resulted in average germination levels of 94% (1998) & 66% (1999). Potassium nitrate treatment prior to incubation at 15°C in darkness was the most effective method of promoting germination in dormant seeds, resulting in 99% (1998) & 97% (1999) germination. Thus, we recommend the use of the latter method, instead of the former or currently recommended method (pre-chilling or KNO3 treatment prior to germination at 15/25°C [16/8h] in darkness), for testing germination levels of dormant seed of annual canarygrass

Allelic diversity of HMW and LMW glutenin subunits and ω-gliadins in Canadian hard red spring bread wheat (Triticum aestivum L.) developed over 150 years

Non-Peer ReviewedWheat (Triticum aestivum L.) is a major cereal crop that is grown around the world. Wheat based products are an important component of human diet as source of calories and proteins. The wheat grain storage proteins are made up of glutenin and gliadin subunits that form gluten in the dough, when wheat flour is mixed with water. The viscoelastic properties of wheat dough lend itself to make diverse food products consumed around the world. During the past few years, wheat gluten has been blamed for increased incidence of some chronic diseases such as obesity and associated cardiovascular ailments and type-2 diabetes. The main objective of this study was to study the diversity in wheat glutenins and gliadins, the two proteins that make up gluten, during 150 years of wheat improvement in Canada. A set of 37 hard red spring wheat cultivars were grown during 2013 and 2014, in a randomized complete block design with four replicates at the Kernen farm, University of Saskatchewan. Cultivars were selected based on the year of release from 1860 to 2007 and subdivided into historical and modern wheats. Historical cultivars included 11 entries released in Canada from 1860 until 1935 and the modern group included 26 cultivars released after 1935 and up to 2007. Gluten protein composition was determined by SDS-PAGE. Most of the genotypes in both groups had the combination Glu-A1b (2*), Glu-B1c (7+9) and Glu-D1d (5+10) for the high molecular weight glutenins (HMW-GS). Another allele that remained stable was the low molecular weight glutenin (LMW-GS) Glu-A3e present in 91% (historical) to 58% (modern) of the cultivars. Most variation was observed in the frequency of appearance of the most common subunits in the LMW-GS Glu-B3 and Glu-D3. For instance, in the historical group, the most common alleles were the Glu-B3b’ (55%) and the Glu-D3a (37%) or Glu-D3b (36%) whereas in modern cultivars Glu-B3h (58%) and the Glu-D3c (58%) were most frequent. Regarding ω-gliadins encoded by the Gli-B1, a relative high proportion of the historical genotypes carried the Gli-B1b subunit whereas in modern cultivars the Gli-B1d (58%) was common. No major alterations in the gluten subunits were observed between the Canadian historical and modern hard red spring wheat cultivars developed over the last century and half. However, subtle differences were found in the HMW-GS and the LMW-GS Glu-A3, and the frequency of appearance in the Glu-D3 and Glu-B3 (LMW-GS) and the Gli-B1 (ω-gliadins). The impact of the alterations on the incidence of Celiac disease is currently being studied

Genetic mapping of pre-harvest sprouting resistance loci in bread wheat (Triticum aestivum L.)

Non-Peer ReviewedPre-harvest sprouting (PHS) in bread wheat (Triticum aestivum L.) is the germination of mature grain while still in spike. PHS causes downgrading of grain quality which severely limits its end use. In western Canada, cool and wet weather during harvest makes the crops susceptible to PHS. Breeding for PHS tolerance in wheat is challenging on phenotypic basis because PHS is inherited quantitatively and strongly affected by environmental conditions. A mapping population of one hundred and fifty one doubled haploid (DH) lines from a cross between two spring wheat cultivars ND690 (non-dormant) and W98616 (dormant) was developed for genetic mapping of PHS resistance loci. Initially, 20 dormant and 20 non dormant lines were used for genetic mapping with SSR (Simple sequence repeat) and AFLP (Amplified Fragment Length Polymorphism) markers. A total of 550 markers (300 SSR markers and 250 AFLP) markers have been mapped on different chromosomes. Five chromosomal regions on the chromosomes 1A, 3B, 4A, 5B and 6B associated with pre-harvest sprouting were identified in this study

Identification and validation of QTLs associated with pre-harvest sprouting tolerance in bread wheat

Non-Peer ReviewedPre-harvest sprouting (PHS) is the in-spike germination of physiologically mature grain in response to relatively high humidity due to untimely rains prior to harvest. PHS in bread wheat (Triticum aestivum L.) results in substantial economic loss, as it decreases the functional quality of wheat grain. The Canadian Grain Commission sets the limit of percentage severely sprouted and total sprouted grain depending on the grade and wheat classes. Pre-harvest sprouted wheat is reduced in grade and value, depending on the quantity of sprouted kernels present in a sample. Breeding for PHS tolerance in wheat is challenging on phenotypic basis because PHS is inherited quantitatively and highly influenced by environmental conditions. Seed dormancy is the main factor responsible for conferring the PHS resistance to the grains of bread wheat. The objectives of this study were to identify and validate the major quantitative loci (QTL) for pre-harvest sprouting (PHS) resistance in bread wheat. A F1-derived doubled haploid (DH) population of 151 lines from a cross between two spring wheat cultivars ND690 (nondormant) and W98616 (dormant) was used to identify the genomic regions associated with PHS tolerance. A total of 950 polymorphic markers (369 SSR, 306 AFLP, 267 DArT and 8 EST) have been used to develop a genetic map and to identify QTLs for PHS tolerance. Interval mapping revealed a major QTL on chromosome 4A explaining 25% phenotypic variation in this mapping population. Forty two Canadian wheat cultivars and germplasm lines were screened with the DNA marker in the QTL region on chromosome 4A for validation. 113 BC1F1 plants from four different backcrosses were screened with the marker associated with PHS resistance. Marker assisted back crossing reduced the population size in BC1F1 generation by 40.7%. This information will help the plant breeders to pyramid this QTL with other QTLs from different PHS resistance sources