COLORADO
COLORADO STATE UNIVERSITY
Department of Soil and Crop Sciences, Ft. Collins, CO 85023, USA.
S. Haley, J. Stromberger, B. Clifford, S. Clayschulte, T. Mulat, E. Ball, and A. Brown.
Production conditions, test sites, and variety distribution. Total winter wheat production in 2001 was estimated at 66 million bushels, a 3.2 % decrease from the 2000 crop. The average grain yield, at 33 bushels/acre, was 13.8 % higher than in 2000 but 6.2 % lower than the 5-year average. The area harvested for grain was estimated at 2 million acres, down from 2.35 million in 2000.
In 2000-01, the breeding program conducted field trials at four main locations in eastern Colorado (Walsh, Burlington, Akron, and Julesburg) in addition to the main site located at the ARDEC research facility near Fort Collins. Overall, environmental conditions experienced at these locations were highly variable, complicating both evaluation and selection. At Burlington, timely planting and good moisture led to excellent establishment and autumn growth, which, unfortunately, was followed by severe drought stress from jointing through harvest that significantly limited expression of yield differences. At Walsh, dry soil conditions in September delayed planting until late October (still in dry soil); poor emergence and growth in the autumn, some of which occurred in the spring, resulted in a high level of variability within the nurseries. At Akron, 2 inches of rain immediately after planting led to soil crusting and very poor emergence in preliminary and advanced-generation breeding trials. At Julesburg, the variety trial (UVPT) was replanted in early October (following crusting after planting in mid September) and abnormally cold temperatures beginning in early November limited autumn growth. The Fort Collins breeding-trial location was the only successful location with very high yields achieved as a result of favorable environmental conditions and optimal irrigation.
In coöperation with the CSU Variety Testing Program under the direction of Dr. Jerry Johnson, varieties and experimental lines also were tested in Colorado at six dryland (Bennett, Briggsdale, Cheyenne Wells, Genoa, Lamar, and Sheridan Lake) and two irrigated-trial locations (Haxtun, Rocky Ford). Growing conditions at many of the sites was very similar to the four breeding locations, with problems caused by poor emergence and autumn growth contributing to high levels of variability within the trials and generally low yields. The plots at Bennett and Rocky Ford were not harvested because of severe hailstorms prior to harvest, whereas the Sheridan Lake location was not harvested because of very poor stands and soil blowing in the spring.
Virtually no virus (BYDV or WSMV) or insect (RWA, greenbug, or Bird cherry-oat aphid) problems were observed at any of the wheat-trial locations. A high level of stripe rust infection was observed by mid June at several locations (Akron, Fort Collins, Genoa, Haxtun, Julesburg, Lamar, and Walsh). Data were collected on stripe rust resistance of standard varieties and experimental breeding lines. In many materials that showed a very susceptible reaction, yields and test weights were adversely affected.
Planted acreage estimates for the 2001 crop were as follows: Tam 107 - 24.9 %; Akron - 24.4 %; Prairie Red - 11.5 %; Halt - 5.1 %; Yumar - 4.6 %; Lamar - 4.4 %; Yuma - 3.2 %; Prowers - 2.9 %; Jagger - 2.9 %; T-13 - 1.5 %; TAM 110 - 1.2 %, Prowers 99 - 1.1 %; and Alliance - 1.0 %.
New releases. In 2001, one new winter wheat germ plasm line and three new winter wheat cultivars were formally released. The germ plasm line, CO960293-2 (PI 222668/TAM 107//CO850034 pedigree), was released for its combined resistance to WSMV and RWA. The source of these resistance genes is the PI 222668 parent. The RWA-resistance gene is different from those previously deployed in CSU cultivars and the recent Kansas State University release Stanton. Though distinct from the wheatgrass-derived WSMV resistance being deployed by several Great Plains breeding programs, it confers a high level of resistance (near-immunity) very similar to the wheatgrass source. We have used CO960293-2 extensively in recent crossing efforts to transfer the WSMV and RWA resistance to other backgrounds and combine its WSMV resistance with the wheatgrass WSMV-resistance source.
Two of the new cultivars released, Above and AP502 CL, are HRWW cultivars with nontransgenic tolerance to the new imidazolinone herbicide BEYOND™ from BASF Corporation. The first publicly developed CLEARFIELD™ winter wheat cultivars, Above and AP502 CL will allow selective control of winter annual grass (e.g., goatgrass, brome and cheat, and feral rye) and broadleaf weeds that are problematic in Colorado and other wheat-production areas. The genetic backgrounds of Above and AP502 CL are very similar, each coming from backcross introgression of imidazolinone tolerance into germ plasm adapted in the west central Great Plains.
Above is an awned, white-glumed, early maturing (1.8 days later than TAM 107 and 3.6 days earlier than Akron) semidwarf (0.5 inches taller than TAM 107 and 1.2 inches shorter than Akron) HRWW. Above was derived from the cross 'TAM 110*4/FS2' made in 1996 at Amarillo, TX. The wheat germ plasm line FS2 was developed by BASF Corporation (formerly American Cyanamid) through induced mutagenesis, with sodium azide and the French wheat cultivar Fidel, to obtain tolerance to the imidazolinone class of herbicides. Above was tested in the Colorado Dryland Variety Performance Trials in 2000 and 2001. Averaged over 15 trial locations (seven locations in 2000 and eight locations in 2001), Above (41.8 bu/acre) yielded less than Trego (45.1 bu/acre), the same as Jagger and Alliance, and greater than Akron (40.9 bu/acre), TAM 107 (39.9 bu/acre), and TAM 110 (39.0 bu/acre). Average test weight for Above (56.0 lb/bu) in these trials was less than those of Trego (59.0 lb/bu), TAM 107 (56.4 lb/bu), and Akron (56.3 lb/bu); the same as that of Jagger; and greater than that of TAM 110 (55.5 lb/bu). Above is resistant to stem rust, susceptible to leaf rust, and moderately susceptible to both WSMV and BYDV. Above is resistant to greenbug and susceptible to RWA and the Great Plains biotype of Hessian fly. Milling and bread-baking characteristics of Above were determined from composite grain samples from unreplicated yield trials in 1999 and the Colorado Dryland Variety Performance Trials in 2000. Relative to the broadly adapted check cultivar TAM 107, Above had higher grain volume weight, kernel weight, and flour yield, with lower flour protein content and higher ash content. In bread-baking tests, Above had lower bake water absorption, shorter mixograph mixing time, lower loaf volume, lower crumb grain and texture score, and the same mixograph-tolerance score compared to TAM 107. Ownership of Above was transferred from Colorado State University to the Colorado Wheat Research Foundation (CWRF).
The second the two CLEARFIELD™ wheats, AP502 CL, is an awned, red-glumed, early maturing (similar to TAM 107 and 5 days earlier than Akron) semidwarf (similar to TAM 107 and 1 inch shorter than Akron) HRWW. AP502 CL was derived from the cross 'TXGH12588-26*4/FS2' made in 1996 at Amarillo, TX. The wheat germ plasm line FS2 was developed by BASF Corporation (formerly American Cyanamid) through induced mutagenesis, with sodium azide and the French wheat cultivar Fidel, to obtain tolerance to the imidazolinone class of herbicides. TXGH12588-26, an unreleased experimental line from the Texas A&M University-Amarillo wheat-breeding program, is a sister line to TAM 110. AP502 CL was tested in Colorado Dryland Variety Performance Trials in 2000 and 2001. Averaged over 15 trial locations (seven locations in 2000 and eight locations in 2001), AP502 CL (40.1 bu/acre) yielded less than Trego (45.1 bu/acre), Jagger (42.4 bu/acre), Alliance (42.3 bu/acre), and Akron (40.9 bu/acre); similar to TAM 107 (39.9 bu/acre); and greater than TAM 110 (39.0 bu/acre). Average grain volume weight for AP502 CL (55.3 lb/bu) in these trials was less than those of Trego (59.0 lb/bu), TAM 107 (56.4 lb/bu), Akron (56.3 lb/bu), Jagger (56.1 lb/bu), and TAM 110 (55.5 lb/bu). AP502 CL is resistant to stem rust, susceptible to leaf rust, and moderately susceptible to both WSMV and BYDV. Above is resistant to greenbug and susceptible to RWA and the Great Plains biotype of Hessian fly. Milling and bread-baking characteristics of AP502 CL were determined from composite grain samples from unreplicated yield trials in 1999 and the Colorado Dryland Variety Performance Trials in 2000. Relative to the broadly adapted check cultivar TAM 107, AP502 CL had higher test weight, the same kernel weight, lower flour yield and flour protein content, and higher ash content. In bread baking tests, AP502 CL had lower bake-water absorption, shorter mixograph mixing time, lower loaf volume, lower crumb grain and texture score and the same mixograph-tolerance score compared to TAM 107. Ownership of AP502 CL was transferred from the CWRF to AgriPro Wheat.
The third cultivar released to seed producers, named Avalanche, is an awned, white-glumed, early maturing (4 days later than TAM 107, 1 day earlier than Akron, and 2 days earlier than Trego) semidwarf (1.1 inches taller than TAM 107 and similar to both Akron and Trego) HWWW. Avalanche was selected from the cross 'KS87H325/Rio Blanco' made in 1988 at Hays, KS, and is a sister selection to Trego. Avalanche was tested in Colorado Dryland Variety Performance Trials from 1998-2001. Averaged over 35 trial locations between 1998-2001, Avalanche (50.8 bu/acre) yielded less than Alliance (52.2 bu/acre), similar to Akron (51.0 bu/acre), and greater than TAM 107 (48.7 bu/acre). In comparison with other HWWW cultivars available in Colorado, Avalanche has yielded less than Trego (51.6 versus 49.5 bu/acre; 25 locations, 1999-2001) but greater than both Lakin (41.1 versus 38.9 bu/acre; 15 locations, 2000-01) and Nuplains (41.1 versus 37.6 bu/acre; 15 locations, 2000-01). Average test weight for Avalanche (58.7 lb/bu; 26 locations, 1999-2001) in these trials has been very high, slightly less than that of Trego (59.1 lb/bu) but greater than those of Akron (57.1 lb/bu) and TAM 107 (56.9 lb/bu). Avalanche is resistant to stem rust, moderately susceptible to leaf rust, and moderately susceptible to both WSMV and BYDV. Avalanche is susceptible to the Great Plains biotype of Hessian fly, greenbug, and RWA. Milling and bread-baking characteristics of Avalanche were determined from composite grain samples from eight subregional production zones from the 1999 and 2000 USDA Southern Regional Performance Nurseries and from the 1999 and 2000 Colorado Dryland Variety Performance Trials. Relative to the broadly adapted check cultivar TAM 107, Avalanche had higher test weight, kernel weight, and flour yield with similar flour protein and ash content. In bread-baking tests, Avalanche had better crumb grain and texture scores and slightly lower bake-water absorption than TAM 107. Mixograph mixing time, mixograph tolerance score, and loaf volume were similar for Avalanche and TAM 107. Ownership of Avalanche was transferred from Colorado State University to the CWRF.
In 2000-01, eight advanced experimental lines were on breeder seed increase and simultaneous RWA-resistance purification in Yuma, AZ. Five of these lines were RWA-resistant, backcross-derived versions of the popular variety Akron that were in their first year of testing in the UVPT. The other three lines (CO950043, CO970498, and CO970547) were RWA-resistant, experimental lines that had performed well in variety trials in previous years and showed promise as potential replacements for RWA-resistant cultivars currently in production. Based on yield performance in dryland (UVPT) and irrigated (IVPT) state variety trials, and various milling and baking quality evaluations, two of the RWA-Akron lines (CO99508 and CO99534) and one of the other lines (CO970547) were retained for further variety trial testing and seed increase. Of the other lines on increase, both CO950043 and CO970498 were dropped from further consideration. Although yield performance of CO950043 has been excellent in both dryland and irrigated trials, several independent baking quality evaluations (Wheat Quality Council, ConAgra Flour Milling, and the USDA-ARS) suggested that its overall baking quality was unacceptable. In addition to poor dryland yield performance in 2001, similar quality ratings for CO970498 were received.
Performance of the two RWA-resistant Akron lines, CO99508 and CO99534, was slightly less than that of Akron, although when disregarding dryland trials with less reliable data (e.g., Walsh and Lamar), the minor differences were not statistically significant. On the positive side, several independent milling and baking-quality evaluations (e.g., USDA-ARS, Bay States Milling, and ConAgra Flour Milling) also suggest that overall quality of these two lines is superior to that of Akron, a cultivar with a less than desirable baking-quality reputation. Both of these lines are currently on Foundation Seed Increase (18 acres each) in Colorado to enable the release of one line as an improved cultivar following testing (UVPT and IVPT) in 2002. Additional milling and baking quality evaluations are being done by the USDA-ARS quality laboratory during the winter 2001-02 using seed remnants from several locations in 2001.
The remaining line on breeder seed increase, CO970547 (Ike/Halt pedigree), again performed well statewide in dryland trials and was advanced for further testing. Based on a 2-year average in the UVPT, CO970547 has been the highest yielding entry in the central and northeast Colorado locations, 1.5 bu/acre better than Jagger and Enhancer and second only to Trego statewide. Although CO970547 has excellent RWA resistance and above-average milling- and baking-quality ratings, it did not perform as well in the southeast Colorado locations where RWA resistance is of greatest concern. In an attempt to identify types within CO970547 that may show different adaptation patterns or perhaps a yield advantage over CO970547, seven pure-line, headrow reselections were made from a headrow purification in Arizona. Seed harvested from the CO970547 headrow reselections was adequate to include each line in the replicated advanced yield trial (AYT) and a simultaneous strip-increase in Arizona for generation of breeder seed. If one or more of these reselections perform well in 2002, breeder seed quantities should be sufficient to increase in autumn 2002 for potential release in 2003. The ability to conduct a concerted headrow-reselection program, which exploits the phenomenal seed increase capabilities in Arizona, promises to be a significant benefit to the program in coming years.
In 2000-01, 26 other CSU hard red experimental lines were included in the UVPT. Three of these lines were wheat-maize DHs that combined resistance to RWA and BEYOND herbicide. One of these lines, CO99D726, yielded quite will in the UVPT but unfortunately exhibited unacceptable test-weight patterns and was dropped from further consideration, along with the other two CLEARFIELD DHs (CO99D679 and CO99D695) that were in the trial.
Five of the remaining experimental lines performed well in the UVPT, as well as the IVPT at Fort Collins and were advanced for a second year of testing in the UVPT and IVPT. These five lines (CO980376, CO980719, CO980630, CO980829, and CO980607) were sent to Arizona for headrow increases for generation of pure Breeder Seed and line reselection as was done with CO970547. The addition of Fort Collins as an official IVPT location in 2001, coupled with testing of lines that are concurrently tested in the dryland UVPT, should hopefully lead to identification of lines that show exceptional yield performance under irrigation. This strategy was further advanced with addition of a site in the San Luis Valley (Center, CO) as an official IVPT location with fall 2001 planting.
In concert with the overall breeding effort, several other activities were undertaken or continued during 2000-01.
Graduate-student research. Several graduate-student research projects currently are underway. Briefly, these include determining the inheritance and chromosomal location of a new WSMV-resistance gene, assessing environmental influence and 'genotype x environment' interaction for key noodle-quality characteristics, and identifying advantages and disadvantages of semidwarfing genes (of European origin) that do not reduce coleoptile length. By summer 2002, three new graduate students will have joined the breeding program to work on other important areas of research. Although we expect that these student projects will contribute vital information to direct the breeding program, the students also benefit by receiving a strong graduate training opportunity.
Spring wheat breeding. A spring wheat breeding effort initiated in 1996 progressed to the selection of 12 spring wheat lines from advanced yield trials in 2001. These lines will be included in replicated, variety trials in eastern Colorado in 2002. Each of these lines was derived by intermating the RWA-resistant line from Montana State University (MTRWA116) with public and private wheat cultivars with primary adaptation in the northern Great Plains region.
USDA-IFAFS Project. A multi-institutional grant effort, coördinated through the University of California-Davis, to the USDA-IFAFS grant-funding agency was successful this past year. The focus of this grant, entitled Bringing Genomics to the Wheat Fields, proposes to utilize DNA-marker technology as a means to transfer desirable quality and pest resistance traits into released varieties and elite experimental lines. CSU is one of 12 public plant-breeding programs involved in this effort, with Nora Lapitan serving as our local collaborator. At CSU, we have chosen recently released varieties or advanced experimental lines (Avalanche, Above, RWA-Akron, CO970547, Stanton, and Lakin) as target parents to transfer or combine genes for WSMV and BYDV tolerance, high grain-protein content, and RWA resistance. The duration of the project is 4 years, with the release of several improved varieties and germ plasm anticipated at the end of the project.
Facilities and equipment improvements. In 2000-01, several facilities and equipment improvements were realized. These improvements include a new university greenhouse with improved climate control and increased space; a new plot planter with no-till openers, liquid starter-fertilizer setup, and automatic seed distribution; a new seed cleaner/conditioner to assist with sample preparation for planting; and a new ATV for alleyway spraying and maintenance in the field. We also recently purchased a new headrow planter that will be used for the first time in spring 2002. The Plant Science renovation is also underway, the primary benefit for our program being a renovated and expanded wheat quality laboratory that will house the bread-baking equipment from the Food Science Department. We are very excited about these important improvements and the positive impact that they promise to make to our program.