AAC Tomkins

Wheat

Variety Description

Varieties used for comparison: 'AAC Cirrus', 'AAC Iceberg' and 'CDC Whitewood'

Summary: The intensity of anthocyanin colouration for the coleoptile of 'AAC Tomkins' is weak whereas it is strong to very strong for 'AAC Cirrus' and 'AAC Iceberg'. At booting, the frequency of plants with recurved flag leaves is medium to high for 'AAC Tomkins' whereas 'CDC Whitewood' has a low to medium frequency of plants with recurved flag leaves. The intensity of anthocyanin colouration of the auricles on the flag leaf is absent or very weak for 'AAC Tomkins' whereas it is weak for 'AAC Iceberg' and strong for 'AAC Cirrus'. 'AAC Tomkins' has a shorter flag leaf than those of 'AAC Cirrus' and 'AAC Iceberg'. The plants of 'AAC Tomkins' head earlier than the plants of 'AAC Cirrus'. At maturity, the spike, excluding the awns, of 'AAC Tomkins' is shorter than that of 'AAC Cirrus' and 'AAC Iceberg'. The anthocyanin colouration on the straw of 'AAC Tomkins' is absent whereas anthocyanin colouration is present on the straw of 'AAC Cirrus'. The germ on the kernel of 'AAC Tomkins' is large whereas those of 'AAC Cirrus' and 'CDC Whitewood' are medium in size.

Description:

PLANT: common wheat, spring type, intermediate growth habit at 5 to 9 tiller stage, medium to high frequency of plants with recurved flag leaves, heads emerge mid-season

SEEDLING (4 LEAF STAGE): weak intensity of anthocyanin colouration of coleoptile, glabrous sheaths and blades of lower leaves

FLAG LEAF: absent or very weak intensity of anthocyanin colouration of auricles, medium glaucosity of sheath, absent or very weak glaucosity of lower side of blade, glabrous blade

CULM: absent or very sparse hairiness of uppermost node, medium degree of glaucosity at heading, curved neck
STRAW (AT MATURITY): thin pith in cross-section, no anthocyanin colouration

SPIKE: medium degree of glaucosity at heading, parallel-sided shape in profile, medium density, white at maturity, absent or very sparse hairiness of convex surface of apical segment
AWNS: shorter than spike length
LOWER GLUME SHOULDER: medium width, slightly sloping to straight
LOWER GLUME BEAK: short, slightly curved shape
LOWEST LEMMA: straight to slightly curved beak

KERNEL: hard white type, white
GERM: large

Origin & Breeding History: 'AAC Tomkins' (experimental designations H1161&BC004 and HW402) originated from the cross between 'AAC Iceberg' and 'Carberry' made in 2011 at the Swift Current Research and Development Centre of Agriculture and Agri-Food Canada in Swift Current, Saskatchewan. Double haploid lines were generated using the maize pollen method. In 2013, 36 of the 83 individual white seeded double haploid lines were inoculated with Common bunt and planted in a rust epiphytotic nursery. Two spikes were selected from the 17 disease resistant double haploid lines that also matured early and had strong stems of acceptable height. In 2013-2014, seeds from each spike grown in 2 metre long DH3 rows near Irwell, New Zealand were assessed for maturity, plant height and resistance to lodging and shattering and harvested as individual rows for subsequent trialing. In 2014, 24 selected double haploid lines were assessed as DH4 plots for agronomic performance in nurseries near Swift Current and Indian Head, Saskatchewan and Lethbridge, Alberta. Selected lines were screened for disease reaction, grain quality and kernel characteristics. Dormancy was assessed in preharvest sprouting chamber tests on spikes collected from yield trials conducted in 2014 near Swift Current. Disease responses were further assessed in specialized nurseries near Portage la Prairie, Manitoba and Swift Current whereas the seed from yield trials were assessed for grain quality and kernel characteristics in 2014. One DH4 line designated as H1161&BC004, identified as meeting all selection criteria at each stage, was evaluated in the Western Hard White B test in 2015 and as HW402 in the Hard White Wheat C Registration test from 2016 to 2018. Breeder seed production commenced in 2016 at the Agriculture and Agri-Food Canada Seed Increase Unit, Indian Head, Saskatchewan.

Tests & Trials: The comparative trials for 'AAC Tomkins' were conducted at the Agriculture and Agri-Food Canada, Swift Current Research and Development Centre during the 2018 and 2021 growing seasons. There were 4 replicates of 4.6 square metre plots arranged in an RCB Design. Each plot consisted of 4 rows, each 4 metres long, with an inter-row spacing of 23 cm. The planting density was 220 plants per metre squared, with 3200 plants per variety grown per year. Measured characteristics were based on 20 measurements per variety per year. Mean differences were significant at the 5% confidence probability level based on LSD values.

Comparison tables for 'AAC Tomkins' with reference varieties 'AAC Cirrus', 'AAC Iceberg' and 'CDC Whitewood'

Flag leaf length (cm)

Spike length (excluding awns) (cm)

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Wheat: 'AAC Tomkins' (bottom left) with reference varieties 'AAC Cirrus' (top left), 'CDC Whitewood' (top right) and 'AAC Iceberg' (bottom right)

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Wheat: 'AAC Tomkins' (left) with reference varieties 'AAC Cirrus' (centre left), 'AAC Iceberg' (centre right) and 'CDC Whitewood' (right)

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Wheat: 'AAC Tomkins' (left) with reference varieties 'AAC Cirrus' (centre left), 'AAC Iceberg' (centre right) and 'CDC Whitewood' (right)