Registration of ‘Divide’ Durum Wheat

Dep. of Plant Sciences, North Dakota State Univ., Fargo, ND, 58105. Registration by CSSA. Received 1 May 2006. *Corresponding author (elias.elias@ndsu.edu). ’Divide’ (Reg. No. CV-1009, PI 642021), spring durum wheat (Triticum turgidum L. var. durum Desf.) was developed by the North Dakota Agricultural Experiment Station in cooperation with the USDA-ARS and released on 1 June 2005. Divide was named after Divide County, a major durum production area in northwestern North Dakota. Divide was released based on its high grain yield potential and excellent quality. Divide was tested as the experimental line D971511 and was selected from the cross ‘Ben’ (PI 596557)/D901282//’Belzer’ (PI 603286) made in 1993 (Elias and Miller, 1998) and (Elias et al., 1999). The parent D901282 was derived from the cross D84102/’Regold’. The pedigree of D84102 is D7984/D7926. The parents of D7984 are ‘Ward’ (CI 15892) and ‘Vic’ (CI 17789), (Quick et al., 1974, 1980). D7926 was derived from the cross D7456/Vic. D7456 was derived from the cross D6771/’Rugby’ (CI 17284) (Quick et al., 1975). The pedigree of D6771 is ‘Stewart 63’ (CI 12066)//Yt54/N10B (Knott, 1964). Divide was developed using the pedigree breeding method and was bulked in the F5 generation as an F4–derived line in 1997. Six thousand F4:12 heads were selected from quality drill strips at Langdon, ND, for seed purifi cation. Heads were threshed individually and seeded as headrows at Yuma, AZ, in 2004. Nonuniform rows were discarded, and the remaining rows were bulk harvested as Breeder seed. Divide is a daylength-sensitive durum wheat that is similar in heading date (65 d from seeding to when approximately 50% of the plants had heads completely emerged from the boot) to ‘Mountrail’ (Elias and Miller, 2000b) and 1 d later than ‘Ben’. Divide has an average plant height of 89 cm, which is similar to Ben and 16 cm taller than the semidwarf cultivar Plaza (Elias et al., 2001b). The culm of Divide is white, and the peduncle is erect. Divide has midlong spikes that are awned, oblong, middense, and erect. The awns are white and 15 to 16 cm long. The glumes are oblique, white, medium, and wide. The kernels are amber, hard, long, and elliptical; the germ is large; the crease is midwide and shallow; and the brush is long. Based on 38 location years of testing in the Uniform Regional Durum Nursery (URDN) from 2001 to 2004, the mean grain yield of Divide (3971 kg ha−1) was higher than Ben (3769 kg ha−1), ‘Maier’ (3722 kg ha−1) (Elias and Miller, 2000a), and ‘Pierce’ (3884 kg ha−1) (Elias et al., 2004). In those same trials, Divide had a 767.7 kg m−3 grain volume weight, which was higher than Maier (761.2 kg m−3) and 12.8 kg m−3 lower than ‘Lebsock’ (Elias et al., 2001a). Divide had a 38.7 mg kernel weight, which was greater than Maier (35.9 mg) and lower than Ben (40.1 mg). Based on 23 location years in the North Dakota Research Extension Centers’ varietal trials from 2001 to 2004, Divide had higher yield (3675 kg ha−1) than Ben (3534 kg ha−1), Maier (3440 kg ha−1), Mountrail (3635 kg ha−1), and Pierce (3554 kg ha−1). In those same trials, Divide had a 778.0 kg m−3 grain volume weight, which was similar to Maier and 12.8 kg m−3 lower than Lebsock. Grain samples from quality drill strips grown at 19 location years (2001–2003) were tested for durum wheat quality at North Dakota State University (NDSU). The semolina extraction rate of Divide (64.8%) on the Buhler-Miag laboratory mill at the Department of Cereal and Food Sciences, NDSU, was higher than Mountrail (64.2%) but lower than Ben (65.1%) and Lebsock (65.3%). Divide has strong gluten mixing characteristics (classifi cation: 7.3) as estimated by mixograph, similar to Pierce (7.2) and stronger than Mountrail (5.2). Semolina protein of Divide was 142 g kg−1, which was similar to Ben but higher than Mountrail (137 g kg−1). Pasta produced from Divide has a color score of 9.1, which is similar to Maier and Lebsock but higher than Mountrail (8.9). Divide was evaluated at the USDA-ARS, Northern Crop Science Laboratory, Fargo, ND, for wheat stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn) and was found to be resistant (reaction type 0) to pathotypes Pgt-QCCJ, -QTHJ, -RTQQ, -TMLK, -TPMK, and -HPHJ. Divide has exhibited adult plant resistance (reaction type 0 to 5R) to leaf rust (caused by P. triticina Eriks.) similar to Maier and Lebsock when evaluated in the URDN at Langdon, ND, from 2001 to 2004. On a scale of 0 to 9, where 0 is resistant and 9 is susceptible, Divide had average score of 3.2 in fi eld reaction to tan spot [caused by Pyrenophora tritici-repentis (Died.) Drechs] compared with 4.1 and 4.7 of Maier and Mountrail, respectively. Divide has lower disease severity (23%) to Fusarium head blight [caused by Fusarium Published in the Journal of Plant Registrations 1:7–8 (2007). doi: 10.3198/jpr2006.05.0281crc © Crop Science Society of America 677 S. Segoe Rd., Madison, WI 53711 USA