Registration of ‘MT1159CL’ Wheat

‘MT1159CL’ (Reg. no. CV-992, PI 641221) hard red winter wheat (Triticum aestivum L.) was developed by the Montana Agricultural Experiment Station and released in September 2004. MT1159CL is a Clearfield wheat that is licensed for production with Beyond herbicide (active ingredient imazamox (2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1Himidazol-2-yl]-5-(methoxymethyl)-3-pyridinecarboxylic acid) (BASF Corp., Research Triangle Park, NC). MT1159CL was released on the basis of its tolerance to imazamox herbicide, its adaptation to dryland production in central and south-central Montana, and improved bread baking quality relative to available Clearfield winter wheat cultivars. MT1159CL is a doubled-haploid line developed using the wheat 3 maize (Zea mays L.) hybridization method (Laurie and Bennett, 1988) from the cross FS2/‘Tiber’ (PI 517194, Kisha et al., 1992) made in 1997. Tiber is a hard red winter wheat cultivar released by Montana State University in 1988. Thewheat germplasm line FS2 (syn. FS4) was developed by the BASF Corporation using sodium azide–induced mutagenesis of the French wheat cultivar Fidel (Newhouse et al., 1992) and contains a single gene at the als1 locus for acetolactate synthesis, which conveys tolerance to imidazolinone herbicides. Twenty-six doubled haploids were generated from the F1 generation of this single cross in the greenhouse and growth chambers at Bozeman, MT, in 1998. Progeny harvested from the doubled haploid plants were evaluated for herbicide tolerance by spraying five plants per line with 67.7 mL L of imazamox herbicide in the greenhouse in 1999. Resistant lines and check cultivars were subsequently planted in nonreplicated standard yield plots (3 m) at Fort Ellis, MT, in the fall of 1999 and sprayedwith imazamox herbicide (labeled rate, 52.5 g a.i. ha) in May 2000. On the basis of herbicide tolerance, agronomic appearance, and milling and baking quality, the line subsequently denoted as MT1159CL was selected and bulk harvested in 2000. Ten heads were also taken from the line before harvest to initiate seed increase. MT1159CL was grown in preliminary yield trials at Bozeman in 2001; in WestBred, LLC yield trials at four Montana locations in 2003 and 2004; and in multilocation Montana StateUniversity Intrastate, off-station, and herbicidetolerance trials in 2004 and 2005. Seed increase of MT1159CL was initiated by harvesting a 10-member headrow family in bulk in 2001. In 2002, seed was further increased at Bozeman in a four-row, 60-m strip increase treated with imazamox herbicide (105 g a.i. ha). The strip increase was rogued carefully to remove phenotypic variants. Breeder seed was produced in 2003 in Yuma, AZ, and further increased at various MT locations in 2004 by Westbred, LLC. MT1159CL is a medium-early maturing, semidwarf hard red winter wheat. Average heading date of MT1159CL (162.4 d from 1 January, n 5 19) is similar to Rampart (PI 593889), but 1.9 and 1.5 d earlier (P , 0.05) than ‘Neeley’ (CI 17860) and Tiber, respectively. Plant height of MT1159CL is medium (81 cm,n5 39), shorter (P, 0.05) thanRampart (87 cm),Neeley (87 cm), andTiber (95 cm).Winter survival ofMT1159CL(33%) was low to moderate in seven trials exhibiting differential survival, similar to ‘Promontory’ (PI 555458, 41%) and Rampart (43%), but lower (P, 0.05) than Neeley (51%) and Tiber (53%). On the basis of limited field evaluations under natural infection in Montana, MT1159CL is susceptible to stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn), susceptible to leaf rust (caused by Puccinia triticina Eriks.), and moderately resistant to stripe rust (caused by Puccinia striiformisWestendorf f. sp. tritici).On the basis of eight Montana crop tolerance trials, tolerance of MT1159CL to Beyond herbicide is equivalent to the herbicide tolerance of ‘Above’ winter wheat (Haley et al., 2003). MT1159CL is an awned, tan-glumed cultivar. Its field appearance is most similar to Tiber, although it is much shorter. Juvenile plant growth is semi-erect. Plant color at boot stage is yellow-green compared to Neeley and Tiber which are darker green. After heading, the canopy is open and upright. The flag leaf is erect and twisted at the boot stage. The spike is tapering in shape, relatively short, andmiddense.Kernels are red colored, hard textured, and ovate in shape. MT1159CL is phenotypically uniform with exception that it contains a white-chaffed, imidazolinone tolerant variant at the frequency of 1 per 10000 plants. MT1159CL was tested at 43 trials in Montana in 2004 and 2005. In these trials, average grain yield ofMT1159CL (3205 kg ha, n 5 42) was similar to Rampart (3380 kg ha), but significantly lower (P , 0.05) than Tiber (3601 kg ha) and Neeley (3742 kg ha). Average grain volume weight for MT1159CL (749 g m, n 5 37) in these trials was similar to Neeley (759 g m) but lower than that of Rampart (772 gm) and Tiber (776 g m). Average grain protein of MT1159CL (130 g kg) was similar to that of Neeley (126 g kg) andTiber (129 g kg) but lower than Rampart (137 g kg). On the basis of composite grain samples from nine locations in 2004, milling and baking characteristics of MT1159CL are intermediate to Tiber and the imazamox tolerant cultivar Above. Brabender Automat flour extraction of MT1159CL (712 g kg) was significantly higher (P , 0.05) than both Above (677 g kg) and Tiber (678 g kg). MT1159CL had similar bake water absorption (654 g kg) to Above (655 g kg) but lower bake water absorption than Tiber (689 g kg). Bake mixing time of MT1159CL (3.6 min) was relatively short, similar to that of Above (3.1 min), and shorter than that of Tiber (5.5 min). Loaf volume of MT1159CL (945 cm) was intermediate to that of Above (893 cm) and Tiber (1023 cm). The Montana Agricultural Experiment Station will maintain Breeder seed of MT1159CL. MT1159CL has been submitted for protection under the Title V option of the Federal PVP act and will be available only as a class of Certified seed. The Clearfield trait possessed by MT1159CL which confers tolerance to imidazolinone herbicides has been patented by BASF. Any use of MT1159CL for research purposes requires a Material Transfer Agreement or a Commercial License to the trait, as well as permission from the variety originator. MT1159CL has been exclusively licensed to WestBred, LLC, Bozeman, MT, for sale of commercial seed stocks. Contact the corresponding author for all seed requests. No seed will be distributed without written permission from both BASF and theMontana State University for at least 20 yr from the date of this release (2004). The corresponding author will forward the request for seed to BASF Corporation.