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CDC McGwire


Denomination: 'CDC McGwire'
Previously Proposed Denomination: 'HB 335'
Botanical Name: Hordeum vulgare
Applicant/Holder: University of Saskatchewan
Crop Development Centre
4D36 Agriculture Building, 51 Campus Drive
Saskatoon, Saskatchewan
S7N 5A8
Breeder: Brian Rossnagel, University of Saskatchewan, Saskatoon, Saskatchewan
Agent in Canada: SeCan Association
400-300 Terry Fox Drive
Kanata, Ontario
K2K 0E3
Tel: 613-592-8600 ext.223
Application Date: 1999-04-26
Application Number: 99-1646
Grant of Rights Date: 2001-12-12
Certificate Number: 1103
Grant of Rights Termination Date: 2019-12-12

Variety Description

Varieties used for comparison: 'CDC Dawn' and 'CDC Freedom'

Summary: 'CDC McGwire' has a platform shaped collar while 'CDC Freedom' has a v-shaped collar. The lemma awns of 'CDC McGwire' have medium anthocyanin while the lemma awns of 'CDC Freedom' have weak anthocyanin. The attitude of the sterile spikelet is parallel to weakly divergent for 'CDC McGwire' while it is divergent for the reference varieties. The rachilla hairs are medium in length for 'CDC McGwire' while they are short for 'CDC Dawn' and long for 'CDC Freedom'. 'CDC McGwire' has no spiculation of the inner lateral nerves on the dorsal side of the lemma while the reference varieties have strong spiculation.


'CDC McGwire' is a two-row feed barley variety. The seedlings have a semi-erect to intermediate growth habit and green coleoptiles. At tillering the sheaths on the lower leaves have absent or very sparse pubescence. The plant growth habit is semi-erect to intermediate. At booting, there is a low frequency of the plants with recurved flag leaves. The flag leaf has weak pubescence on the blade and very weak pubescence on the sheath. Glaucosity on the sheath is medium to strong and there is weak anthocyanin colouration on the auricles. There is very weak pubescence on the auricle margins.

The spike of 'CDC McGwire' emerges mid to late season. The collar shape is platform and the lemma awns have medium anthocyanin at the tips. The spike has a semi-erect to horizontal attitude. The spike has weak to medium glaucosity, is parallel in shape and dense. The attitude of the sterile spikelet is parallel to weakly divergent. The first segment of the rachis is medium in length and weak to moderately curved. The glume and awn of the median spikelet are equal in length to the grain. The lemma awns are rough and are equal to or longer than the spike. The kernel of 'CDC McGwire' has no hull and a white aleurone layer. There is weak to medium anthocyanin colouration of the lemma nerves. The rachilla hairs are medium in length. There is absent or very weak spiculation of the inner lateral nerves of the dorsal side of the lemma and no hairiness in the ventral furrow. The lodicules are partly clasping and basal markings are transverse crease to incomplete horseshoe in shape. The kernel is medium in length and medium to wide in width.

'CDC McGwire' is moderately resistant to Common root rot (Cochliobolus sativus, Fusarium spp.), Net blotch (Pyrenophora teres), Covered smut (Ustilago hordei) and False loose smut (Ustilago nigra). It is moderately susceptible to Scald (Rhynchosporium secalis) and Stem rust (Puccinia graminis). 'CDC McGwire' is susceptible to True loose smut (Ustilago nuda) and very susceptible to Septoria speckled leaf blotch (Septoria passerinii).

'CDC McGwire' has fair resistance to lodging and good resistance to shattering. It has good tolerance to straw breaking and neck breaking and fair to good tolerance to drought.

Origin & Breeding History: 'CDC McGwire' was developed by the Crop Development Centre, University of Saskatchewan using a pedigree breeding system. It resulted from the cross TR311 x WM8412-9-2-1 made in 1989. The F1 to F4 generations were grown as bulks with the F1 and F3 generations grown in winter nurseries. 'CDC McGwire' was selected as a single head from an F4 plant in 1992. The seed from that F5 hill plot was bulked as the line which became 'CDC McGwire'. It was tested in CDC yield trials in 1993 to 1995, followed by testing in the Western Canadian Hulless Barley Coop trials during 1996 to 1998 under the experimental designation HB335.

Tests & Trials: Tests and trials for 'CDC McGwire' were conducted in 1999 and 2000 in Saskatoon, Saskatchewan. The experimental design was a Complete Block Design with two replicates per variety. Each replication consisted of two row plots for each entry that were approximately 3.7 metres long with row spacing of .30 metres. Measured characteristics were based on 40 measurements.

Comparison tables for 'CDC McGwire' with reference varieties 'CDC Dawn' and 'CDC Freedom'

Flag leaf length (cm)

  'CDC McGwire' 'CDC Dawn' 'CDC Freedom'
mean 14.59 16.72 14.35
std. deviation 3.80 3.82 3.72

Flag leaf width (mm)

  'CDC McGwire' 'CDC Dawn' 'CDC Freedom'
mean 9.88 10.38 9.40
std. deviation 1.98 1.61 1.86

Spike length (excluding awns) (cm)

  'CDC McGwire' 'CDC Dawn' 'CDC Freedom'
mean 10.22 9.95 11.10
std. deviation 0.86 0.93 1.42

Plant height (including spike) (cm)

  'CDC McGwire' 'CDC Dawn' 'CDC Freedom'
mean 94.68 93.48 96.98
std. deviation 4.77 8.17 5.13

Kernel weight (g/1000 seeds)

  'CDC McGwire' 'CDC Dawn' 'CDC Freedom'
mean 38.5 42.3 41.6
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