Registration of ‘Strongfield’ Durum Wheat

‘Strongfield’ spring durum wheat (Triticum turgidum L. var. durum) (Reg. no. CV-1000, PI 641223) was developed at the Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Current, SK, and received registration No.5819 from the Canadian Food Inspection Agency on 18 May 2004. It was released because of its superior agronomic performance, end-use quality attributes, and reduced grain cadmium concentration. Strongfield was granted Plant Breeder’s Rights by the Canadian Food Inspection Agency, certificate no. 2105, on 13 May 2005. Strongfield was selected from the cross ‘ACAvonlea’/DT665 made in 1994 and was developed using a modified pedigree breeding method. ACAvonlea (Clarke et al., 1999) is from our program, and DT665 derives from the cross ‘Kyle’/‘Nile’; Nile was obtained from the International Centre for Agricultural Research in the Dry Areas, Aleppo, Syria and Kyle (TownleySmith et al., 1987) is from our program. The F2 generation was grown in 1995 as individual plants in a nursery inoculated with leaf (caused by Puccinia triticina Eriks.) and stem rust (caused by Puccinia graminis Pers.:Pers. f.sp. tritici Eriks. & E. Henn.). Individual spikes from selected plants were grown in F2:3 single 3 m rows near Swift Current in 1996. The F3:4 and F5:6 generations were grown as head rows in a winter nursery near Christchurch, New Zealand to produce seed for yield tests. Unreplicated F3:5 and F5:7 yield trials were grown near Swift Current and Regina, Saskatchewan and Lethbridge, Alberta in 1997 and 1998 and selected for agronomic performance, disease resistance, and quality (protein, pigment, and gluten strength). An F5:8 line designated 9468-CL5 was evaluated in preregistration trials in 1999 (five locations), and under the designation DT712 in the Durum Cooperative Test in 2000 to 2002 (10 to 12 locations per year). Each year stem and leaf rust were evaluated in inoculated field trials near Winnipeg, Manitoba using mixtures of prevalent races. The stem rust races used were: QFC (C75), QTH (C25), TPM (C53), TMR (C10), TMR (C95), RTH (C57), RRQ (C63), and RKQ (C63). The races of leaf rust used were MCDS, MBDS, MBR, MBRJ, MGB, TJB, TJBJ, TGBJ, and 128–1 (74–2) (Kolmer, 1999, 2001). Races L1, L16, T1, T6, T13, and T19 of common bunt [caused by Tilletia laevis Kuhn in Rabenh., and T. tritici (Bjerk.) G. Wint. in Rabenh.] were used for screening of the Durum Cooperative Test entries in inoculated field trials near Lethbridge, Alberta. The race designations are those described byRoelfs andMartens (1988) for stem rust, Long and Kolmer (1989) for leaf rust, and Hoffmann and Metzger (1976) for common bunt. Strongfield is resistant to prevalent leaf rust, stem rust, and common bunt races. It is susceptible to loose smut [caused by Ustilago tritici (Pers.) Rostr.] races T32 and T33, and resistant to race T26, the races prevalent in western Canada. Grain yield of Strongfield (4030 kg ha) was greater than the checks ‘ACMorse’ (3810 kg ha), Kyle (3550 kg ha), AC Avonlea (3750 kg ha), ‘AC Melita’ (3580 kg ha), and ‘AC Navigator’ (Clarke et al., 2001) (3410 kg ha) in 34 stationyears of data from the main durum production area of western Canada (Clarke et al., 2005). Time to maturity of Strongfield (105 d) was similar to that of AC Avonlea (105 d) and AC Morse (105 d), and 1 d earlier than Kyle and AC Navigator. Strongfield has intermediate straw height (85 cm), similar to AC Avonlea (86 cm), and shorter than Kyle (97 cm). Test weight of Strongfield (79.3 kg hL) was similar to ACAvonlea (78.9 kg hL), and greater than AC Morse (77.9 kg hL). Average grain protein concentration of Strongfield (171 g kg, dry matter basis) was similar to AC Avonlea (168 g kg), and greater than Kyle (164 g kg), AC Navigator (155 g kg), and AC Morse (157 g kg) in 3 yr in the Durum Cooperative Test. Spikes of Strongfield are tapering, mid-dense to dense, midlong, erect, with white awns; glumes are mid-wide, mid-long, glabrous, and white; glume shoulders are straight to elevated, square, some slightly sloping; the glume beak is straight to moderately curved. Kernels are amber in color, midsize to small, and elliptical; cheeks are angular; crease is mid-deep to shallow, and mid-wide; brush is mid-size, short; embryo is mid-size to large. Strongfield is eligible for grades of the Canada Western Amber Durum wheat class. It has higher grain yellow pigment concentration (8.8 mg kg) than AC Avonlea (8.3 mg kg), ACMorse (8.0mg kg), andKyle (7.0mg kg), but lower than AC Navigator (9.4 mg kg) (Clarke et al., 2005). Strongfield has stronger gluten as measured by the gluten index (62%) than AC Avonlea (25%) and Kyle (27%), and similar to AC Navigator (66%) and AC Morse (56%). Average semolina yield of Strongfield (67%) was similar to AC Avonlea (67.1%) and AC Morse (66.7%), and less than AC Navigator (68.5%). Strongfield has the low cadmium allele described by Clarke et al. (1997), which reduces grain cadmium concentration to about half that of the checks. Breeder seed, originating from 133 F5:10 Breeder lines, will be maintained by the Seed Increase Unit of Agriculture and Agri-Food Canada, Indian Head, SK. S0G 2K0. Distribution and multiplication of Select, Foundation, Registered, and Certified seed stocks will be handled by SeCan, 201–52 Antares Drive, Ottawa, Ontario, K2E 7Z1. Small quantities of seed for research purposes are available from the corresponding author.