AAC Paramount soft white spring wheat

AAC Paramount is a soft white spring wheat (Triticum aestivum L.) cultivar that meets the end-use quality specifications of the Canada Western Soft White Spring (CWSWS) class. AAC Paramount is adapted to the irrigated wheat growing regions of southern Alberta and southern Saskatchewan, and for dry land production in the western prairies. On average, AAC Paramount had 6% higher grain yield (under both irrigated and dry land conditions) than the check cultivar AC Andrew. AAC Paramount exhibited excellent straw strength and similar maturity to AC Andrew and Sadash but was 2 d earlier than AAC Indus. Its plant height was taller than both AC Andrew and Sadash but similar to AAC Indus. AAC Paramount exhibited high levels of resistance to the prevalent races of stripe rust, powdery mildew, and loose smut; intermediate reactions to leaf rust, stem rust, and kernel black point; was moderately susceptible to Fusarium head blight and leaf spot diseases, and susceptible to common bunt.

Investigating conditions that induce late maturity alpha-amylase (LMA) using Northwestern US spring wheat (Triticum aestivum L.)

The wheat industry rejects grain with unacceptably high α-amylase enzyme levels due to the risk of poor endproduct quality. There are two main causes of elevated grain α-amylase: (1) preharvest sprouting in response to rain before harvest and (2) late maturity α-amylase (LMA) induction in response to a cool temperature shock during late grain development. LMA induction was detected in a panel of 24 Northwestern US spring wheat lines. Thus, this problem previously described in Australian and U.K. varieties also exists in U.S. varieties. Because LMA induction results were highly variable using published methods, a characterization of LMA-inducing conditions was conducted in an LMA-susceptible soft white spring wheat line, WA8124. Problems with elevated α-amylase in untreated controls were reduced by raising the temperature, 25°C day/18°C night versus 20°C day/10°C night. LMA induction was not improved by colder temperatures (15°C day/4°C night) versus moderately cold temperatures (18°C day/7.5°C night or 10°C day/10°C night). While previous studies observed LMA induction by heat stress, it failed to induce LMA in WA8124. Thus, not all LMA-susceptible cultivars respond to heat. The timing of LMA susceptibility varied between two cultivars and within a single cultivar grown at slightly different temperatures. Thus, variability in LMA induction likely results from variability in the timing of the grain developmental stage during which cold shock induces LMA. Thus, it was concluded that the visual inspection of grain is needed to correctly identify LMA-sensitive spikes at the soft dough stage of grain development (Zadok's stage 85).

Detection of Dual Heterodera avenae Resistance plus Tolerance Traits in Spring Wheat

The cereal cyst nematode Heterodera avenae reduces wheat yield in the Pacific Northwest. Resistance and tolerance traits among spring wheat cultivars were poorly defined. Screening trials were conducted with 39 cultivars over a 2-year period in irrigated commercial fields that were infested by H. avenae. Comparisons were made between drill strips treated or untreated with aldicarb at the time of planting. Root sampling at the time of plant anthesis indicated that cultivars differed greatly in susceptibility to H. avenae, with numbers of newly produced white H. avenae females ranging from <5 to 70 per plant. Aldicarb reduced mean numbers of white females as much as 99% on the most susceptible cultivar (‘Glee’) and increased mean grain yield as much as 77% for the least tolerant cultivar (‘Cataldo’). Density of H. avenae eggs in untreated soil following harvest was significantly higher than the density in aldicarb-treated plots. Agronomically acceptable traits of resistance plus tolerance were identified in one cultivar of hard red spring wheat (‘WB-Rockland’) and two cultivars of hard white spring wheat (‘Klasic’ and ‘LCS Star’) but in none of the soft white spring wheat cultivars. This is the first report of spring wheat cultivars expressing the dual traits of resistance plus tolerance to H. avenae.

AAC Indus soft white spring wheat

Randhawa, H. S., Graf, R. J. and Sadasivaiah, R. S. 2015. AAC Indus soft white spring wheat. Can. J. Plant Sci. 95: 793–797. AAC Indus is a soft white spring wheat (Triticum aestivum L.) cultivar that meets the end-use quality specifications of the Canada Western Soft White Spring (CWSWS) class. AAC Indus is adapted to the irrigated wheat-growing regions of southern Alberta and southern Saskatchewan, and for dryland production in the western prairies. AAC Indus had higher (P≤0.05) grain yield under dryland conditions than all of the check cultivars. AAC Indus exhibited excellent straw strength and was 2 d later in maturity. AAC Indus exhibited good levels of resistance to the prevalent races of stripe rust and powdery, mildew and intermediate reactions to kernel black point and leaf rust. AAC Indus was susceptible to stem rust, common bunt, loose smut and Fusarium head blight.

AAC Chiffon soft white spring wheat

Randhawa, H. S., Graf, R. J. and Sadasivaiah, R. S. 2014. AAC Chiffon soft white spring wheat. Can. J. Plant Sci. 94: 1303–1308. AAC Chiffon is a soft white spring wheat (Triticum aestivum L.) cultivar that meets the end-use quality specifications of the Canada Western Soft White Spring (CWSWS) class. AAC Chiffon is well-adapted to the irrigated wheat growing regions of southern Alberta and southern Saskatchewan, and for rain-fed production in the western prairies. Based on data from the Western Soft White Spring Wheat Cooperative registration trials from 2008 to 2011, AAC Chiffon exhibited higher grain yield than the check cultivars, similar maturity, and taller stature with moderate straw strength. AAC Chiffon expressed resistance to the prevalent races of stripe rust, intermediate responses to powdery mildew, kernel black point and leaf rust, and susceptibility to stem rust, common bunt, loose smut and Fusarium head blight. Based on end-use quality analysis performed by the Grain Research Laboratory of the Canadian Grain Commission, AAC Chiffon was eligible for grades of CWSWS wheat.