ITEMS FROM THE UNITED STATES

WASHINGTON

USDA-ARS, WHEAT GENETICS, QUALITY, PHYSIOLOGY AND DISEASE RESEARCH UNIT AND WASHINGTON STATE UNIVERSITY

Departments of Crop & Soil Sciences, Food Science and Human Nutrition, and Plant Pathology, Washington State University, Pullman, WA 99164, USA.

Epidemiology and Control of Wheat Rusts in the Western United States, 2002. [p. 227-229]

Xianming Chen, David A. Wood, Mary K. Moore, Paul Ling, and Vihanga Pahalawatta.

Rust monitoring, loss assessment, and race identification. Wheat stripe rust, leaf rust, and stem rust were monitored throughout the PNW using trap plots and field surveys in 2002. Stripe rust was predicted accurately for the PNW using monitoring data and predictive models based on susceptibility of wheat cultivars and environmental factors such as temperature and precipitation. Through collaborators in other states, wheat stripe rust was monitored throughout the United States. Wheat stripe rust occurred from California and the PNW to Georgia and Virginia and from Louisiana and Texas to Wisconsin and Ohio. Severe yield losses caused by stripe rust occurred in Arkansas, California, and the PNW. In 2002, stripe rust epidemics caused wheat yield losses about 8 x 106 bushels plus multi-million dollars on fungicide application in the United States.

In the PNW, 2002 was the most severe year of wheat stripe rust probably for the last 10 years. The stripe rust epidemics were more severe in the higher rainfall regions in eastern Washington and northern Idaho, mainly on spring wheat. Severe stripe rust occurred in nurseries of common and durum wheat in Oregon. In Washington state, the 2002 stripe rust epidemic affected about 440,000 acres (70 %) of spring wheat and 45,000 acres (2.5 %) of winter wheat. Acreage affected by stripe rust was about 20 % of the total wheat acreage. Over 170, 000 acres of spring wheat were sprayed with fungicides at a cost of over $2.5 x 106 USD. Without the fungicide control, stripe rust could have caused 20-25 % (about 5.7-7.1 x 106 bushels) yield losses. The fungicide applications saved $17 to 30 x 10^6^ USD for Washington wheat growers. The severe stripe rust epidemics on spring wheat were due to the favorable weather conditions, new races of the pathogen, and widely grown susceptible cultivars. The 2001-02 winter temperatures were higher and the 2002 spring temperatures were lower than normal, favoring stripe rust development. Precipitation was frequent in May and June and provided adequate moisture for stripe rust infection over a long period. A group of new races and races that were detected in 2000-01 in California and east of the Rocky Mountains attacked Zak and some other spring wheat cultivars that were grown over 150,000 acres in eastern Washington and northern Idaho. The durable, high-temperature, adult-plant resistance that is in most winter wheat cultivars and some spring wheat cultivars grown prevented wheat crops from epidemics that could have caused much worse damages. The multiline cultivar Rely, with various seedling-resistance genes, has been grown for more than 10 years and was the number one club wheat cultivar from 1994-2000 and the second most-grown club wheat cultivar in 2002, still showed excellent resistance to stripe rust.

Through collaborators, a total of 314 samples of wheat stripe rust were obtained from 16 states (AL, AR, CA, CO, GA, ID, IN, KS, LA, MO, OH, OR, TX, VA, WA, and WI) in 2002. More than 20 races of P. striiformis f. sp. tritici were detected. Races PST-78 (virulent on Lemhi, Heines VII, Lee, Fielder, Express, Yr8, Yr9, Clement, and Compair), PST-80 (the same virulences of PST-78 plus virulence on Produra), and two new races (the same virulences of PST-78 or PST-80 plus virulence on Stephens) were predominant throughout the United States except northwestern Washington. This group of races caused the epidemics in Arkansas, California, and Washington.

In 2002, wheat leaf rust was light in the PNW, probably because of the wide application of fungicides to control stripe rust that also controls leaf rust and stem rust. Only trace stem rust was found in commercial fields. Yield losses due to leaf rust and stem rust were minimal. Leaf rust and stem rust samples were sent to the USDA-ARS Cereal Disease Laboratory, University of Minnesota, for race identification . Two races, MBGJ (virulent on Lr1, Lr3a, Lr10, Lr11, and Lr14a) and MBBS (virulent on Lr1, Lr3a, LrB, Lr10, and Lr14a), of P. triticina were detected in Washington state. These races were different from MDBJ (virulence on Lr1, Lr3a, Lr10, Lr14a, and Lr24), the only race detected in 2001. Virulences of the 2002 Washington races were similar to those of the most predominant race MBDS (virulent on Lr1, Lr3a, Lr10, Lr14a, Lr17, and LrB).

Evaluation of wheat germ plasm and breeding lines for resistance to stripe rust. In 2002, more than 8,000 entries of wheat germ plasm and breeding lines from the NSGC and wheat breeders were evaluated for stripe rust resistance in fields under natural infections and in the greenhouse with selected races to cover all possible virulences. The evaluation data were provided to the NSGC for the germ plasm database and to breeders for developing and releasing resistant cultivars. Resistant germ plasm was selected for characterizing resistance, determining genetics of resistance, and mapping genes conferring resistance.

Determining the genetics of stripe rust resistance and developing wheat germ plasm with superior resistance to stripe rust. To determine genetics of stripe rust resistance in wheat cultivars Alpowa, Express, ID377s. and Zak, crosses and backcrosses of these cultivars with susceptible cultivars Avocet Susceptible (AVS) were made in the field and greenhouse. Seed of F1, F2, and BC1 were obtained for developing RILs for genetic studies and molecular-marker development. Advanced backcrosses will be made for developing NILs for determining the virulences of the pathogen, study host-pathogen interactions, and to improve genetic resistance. To fix the problem of susceptibility in Zak to stripe rust and improve the level of resistance in Alpowa, both Zak and Alpowa were crossed with the Yr5, Yr15, and Yr18 NILs that were developed in the Plant Breeding Institute, University of Sydney, Australia. F1 seed were obtained for all these crosses and also obtained from four-way crosses (Zak/Yr5//Zak/Yr15 and Alopwa/Yr5//Alpowa/Yr15). Molecular markers we developed for Yr5 and Yr15 will be used to screen backcross progeny and to accelerate the introgression of the effective resistance genes into the Zak and Alpowa backgrounds. We also made crosses between the Yr18 NIL with AVS for developing molecular markers for the durable APR gene and use the markers to incorporate Yr18 into Zak and Alpowa, which would bring durable resistance into Zak and improve the level of durable resistance in Alpowa.

To determine wheat resistance to the barley stripe rust pathogen, crosses were made between Lemhi and PI 478214. Lemhi is susceptible to all races except PST-21 of P. striifromis f. sp. tritici but resistant to all races of P. striifromis f. sp. hordei. PI 478214, an Ethiopian spring wheat genotype, is susceptible to both P. striiformis f. sp. tritici and f. sp. hordei. Preliminary results indicate that Lemhi has a single dominant gene for resistance to the barley stripe rust pathogen. Similarly, the barley cultivar Steptoe, which is susceptible to all races of P. striifromis f. sp. hordei, has a single dominant gene conferring resistance to P. striiformis f. sp. tritici. Currently, F2, F3, and BC1 progeny are being tested with appropriate and inappropriate races to determine the relationship between the Lemhi gene for resistance to P. striiformis f. sp. hordei and its Yr21 for resistance to PST-21 of P. striiformis f. sp. tritici. Molecular markers are being developed to map these genes.

Developing molecular markers for stripe rust-resistance genes and constructing BAC libraries for cloning resistance genes. To incorporate Yr5 and Yr15 resistance against all races of P. striiformis f. sp. tritici identified in the U.S. into wheat cultivars, the resistance-gene analog polymorphism (RGAP) technique was used to identify markers for the genes. The Yr5 and Yr15 NILs were backcrossed to AVS to develop mapping populations. We constructed a high-density map for Yr5 with 16 RGAP markers using 202 BC7:F3 lines. Six of the markers were completely associated with the Yr5 locus. Sequence analyses revealed that two codominant and Yr5-cosegregating markers, Xwgp-17 and Xwgp-18, had 98 % homology with each other and had significant homology with many plant resistance genes, resistance gene analogs, and expressed sequence tags. We developed STS markers with primers based on the sequences of Xwgp-17 and Xwgp-18. The STS markers worked well in some, but not all, F1 progeny of crosses and cultivars. Through collaborating with Jorge Dubcovsky at U.C. Davis, we further developed CAPS markers for Yr5 by digesting the STS fragments with the DpnII enzyme. The CAPS markers worked well with F1 progeny of all tested crosses and cultivars. For Yr15, we constructed a high-density map with 11 RGAP markers using 196 BC7:F4 lines, one marker completely co-segregated with and the others were linked to Yr15. We used five of the markers to determine presence or absence of Yr15 in breeding lines. Both marker and disease tests clearly indicated Yr15 in one of 13 lines tested. The markers are used to combine Yr5 and Yr15 into elite-breeding lines.

Toward cloning Yr5 and other wheat genes for resistance to stripe rust, we have been constructing a BAC library using the genomic DNA from the Yr5 NIL digested with HindIII. The library now contains 200,000 clones with an average size between 120 and 130 kb, equivalent of 2X hexaploid wheat genome. The Yr5-cosegregating RGAP markers will be used to screen the library to identify clones containing the Yr5 gene.

Evaluating fungicides for integrated control of stripe rust. Foliar fungicides were evaluated for controlling stripe rust in spring wheat plots near Pullman, WA. Susceptible Fielder and moderately susceptible Vanna spring wheat cultivars were planted on 30 April, 2002. Seven fungicide treatments were conducted on 25 June at early boot stage. Plots that were not sprayed were used as untreated check. A randomized-block design was used with four replications for each treatment. Data on stripe rust severity (percent foliage with stripe rust) were recorded on 19 July at milk stage and on 26 July at soft-dough stage. Yields were determined from plots harvested in September. All the fungicide treatments effectively reduced stripe rust severity. Folicur, Quadris, and A 13705 SC 200 applied at 2.6 and 1.96 fl oz significantly increased grain yield compared to the untreated checks on Fielder. Only A13705 SC 200 applied at 1.96 fl oz significantly increased grain yield in Vanna.

To determine the yield gain in cultivars with various levels of resistance/susceptibility from fungicide application to control stripe rust, 24 cultivars were used in the winter wheat experiment and 16 cultivars were used in the spring wheat experiment using a randomized split-plot design with four replications. The fungicide Quadris was sprayed at the rate of 6.2 oz/acre when the winter crops were in late heading stage and the spring crops were in late boot to early heading stage and highly susceptible cultivars had 10 % stripe rust. Stripe rust occurred naturally in the nonfungicide-treated plots. Rust severities were recorded 33 and 25 days after the fungicide spray in the winter wheat and spring fields, respectively. Stripe rust severities developed in the winter wheat field to 80-85 %, 50-60 %, 10-30 %, and 0-9 % on the susceptible, moderately susceptible, moderately resistant, and resistant cultivars, respectively; and in the spring wheat field to 85­95 %, 70­80 %, 38-45 %, and 0-5 % on the susceptible, moderately susceptible, moderately resistant, and resistant cultivars, respectively. The fungicide application increased yield by over 45 %, 20-40 %, 10-18 %, and 0-9% for the susceptible, moderately susceptible, moderately resistant, and resistant winter wheat cultivars, respectively; and by 40-83 %, 25-39 %, 10-20 %, and 4-8 % for the susceptible, moderately susceptible, moderately resistant, and resistant spring wheat cultivars, respectively. These data can be used to make appropriate recommendations for fungicide application according to cultivars.

Near-isogenic lines differing for morphological and physiological traits. [p. 229-231]

R.E. Allan.

Several sets of NILs have been developed, described and deposited into the USDA-ARS National Plant Germplasm System. Genetic traits for which they differ and their PI numbers are provided. To date these sets have not been registered with Crop Science Society of America.

NILs differing for heading date. Paha is a soft white winter club wheat cultivar having a midseason heading date and excellent club wheat quality. Paha was grown in the U.S. PNW in the 1970s.

• Suweon 185/7*Paha.
• PI631404, PI631405, PI631406. These NILs head 6­7 days earlier than Paha deriving earliness from Suweon 185.
• PI631403, PI631407, and PI631408. These NILs are similar to Paha for heading date.
• Early Blackhull/7*Paha.
• PI631409, PI631410, and PI631411. These NILs head 7 days earlier than Paha deriving earliness from Early Blackhull.
• PI1631412, PI631413, and PI631414. These NILs are similar to Paha for heading date.

Nord Desprez NILs differing for reduced height. Nord Desprez is an old soft red French winter wheat cultivar that has been used as a parent in several U.S. PNW breeding programs. 'Norin 10/Brevor 14' contributed RhtB1b and RhtD1b genes.

• 'Norin 10/Brevor 14' and 'CI13253//7*Nord Desprez'
• PI608358, PI608359, PI608360, and PI608361. These NILs have RhtBlb RhtDlb and are 47­51 % shorter than Nord Desprez.
• PI608363, PI608366, PI608368, and PI608369. These NILs have RhtB1b RhtD1a and are 9­13 % shorter than Nord Desprez.
• PI608362, PI608364, PI608365, and PI608367. These NILs have RhtBla RhtDlb and are 18­20 % shorter than Nord Desprez.
• PI603870, PI608371, PI608372, and PI608373. These NILs have RhtB1a RhtD1a and are similar to Nord Desprez (98 cm) for plant height.

Soft white winter NILs differing for reduced height and awn expression. 'Norin 10/Brevor 14' and 'CI13253/7*Brevor'. CI13253 has genes RhtB1b RhtD1b for reduced height and a gene for awnedness. Brevor has RhtB1a BhtD1a for normal plant height (103 cm) and a gene for awnlessness. Brevor was an important SWWW grown in the U.S. PNW during 1952-64.

• Awnless RhtB1b RhtD1b NILs: PI631090, PI631091, and PI631092.
• Awned RhtB1b RhtD1b NILs: PI631093, PI631094, and PI631095.
• Awless RhtB1b RhtD1a NILs: PI631108, PI631112, and PI631113.
• Awned RhtB1b RhtD1a NILs: PI631109, PI631110, and PI631111.
• Awnless RhtB1a RhtD1b NILs: PI631105, PI631106, and PI631107.
• Awned RhtB1a RhtD1b NILs: PI631102, PI631103, and PI631104.
• Awnless RhtB1a RhtD1a NILs: PI631096, PI631097, and PI631098.
• Awned RhtB1a RhtD1a NILs: PI631099, PI631100, and PI631101.

Tom Thumb reduced-height NILs. Growth habit, market class, plant height, and plant height genes of the recurrent parents of these NILs are Brevor (SWWW, 106 cm, RhtB1a RhtD1a), Moro (soft white winter club, 110 cm, RhtB1a RhtD1a), Olympia (SWWW, 140 cm, RhtB1a RhtD1a), Stephens (SWWW, 82 cm, RhtB1b RhtD1a), Daws (SWWW, 87 cm, RhtB1a RhtD1b), and Tres (soft white winter club, 92 cm, RhtB1a RhtD1b). 'Tom Thumb/7*Burt' contributed the RhtB1c gene.

• Brevor*4///Tom Thumb/7*Burt//3*Brevor.
  
  • PI615589, PI615590, PI615591, PI615592, and PI615593. These NILs have RhtB1c RhtD1a and are 65­68 % shorter than Brevor.
  • PI615594, PI615595, PI615596, PI615597, and PI615598. These NILs have RhtB1a RhtD1a and are similar to Brevor in plant height.
• Moro*5///Tom Thumb/7*Burt//2*Moro.
  
  • PI615599, PI615600, PI615601, PI615602, and PI615603. These NILs have RhtB1c RhtD1a and are 49­53 % shorter than Moro.
  • PI615604, PI615605, PI615606, PI615607, and PI615608. These NILs have RhtB1a RhtD1a and are similar to Moro in plant height.
• Olympia*5///Tom Thumb/7*Burt//2*Olympia.
  
  • PI615629, PI615630, PI615631, PI615632, and PI615633. These NILs have RhtB1c RhtD1a and are 51­55 % shorter than Olympia.
  • PI615634, PI615635, PI615636, PI615637, and PI615638. These NILs have RhtB1a RhtD1a and are similar to Olympia in plant height.
• Stephens*5///Tom Thumb/7*Burt//2*Stephens.
  
  • PI615634, PI615635, PI615636, PI615637, and PI615638. These NILs have RhtB1c RhtD1a and are 46­50 % shorter than Stephens.
  • PI615644, PI615645, PI615646, PI615647, and PI615648. These NILs have RhtB1b RhtD1a and are similar to Stephens for plant height.
• Daws*5///Tom Thumb/7*Burt//2*Daws.
  
  • PI615609, PI615610, PI615611, PI615612, and PI615613. These NILs have RhtB1c RhtD1b and are 64­67 % shorter than Daws.
  • PI615614, PI615615, PI615696, PI615617, and PI615618. These NILs have RhtB1a RhtD1b and are similar to Daws for plant height.
  • PI615619, PI615620, PI615621, PI615622, and PI615623. These NILs have RhtB1c RhtD1a and are 39­43 % shorter than Daws.
  • PI615624, PI615625, PI615626, PI615627, and PI615628. These NILs have RhtB1a RhtD1a and are 39­49 % taller than Daws.
• Tres*5///Tom Thumb/7*Burt//2*Tres
  
  • PI615649, PI615650, PI615651, PI615662, PI615653. These NILs have RhtB1c RhtD1b and are 62% shorter than Tres
  • PI615659, PI615660, PI615661, PI615662, PI615663. These NILs have RhtB1a RhtD1b and are similar to Tres for plant height.
  • PI615654, PI615655, PI615656, PI615657, PI615658. These NILs have RhtB1c RhtD1a and are 49 to 52 % shorter than Tres.
  • PI615664, PI615665, PI615666, PI615667. These NILs have RhtB1a RhtD1a and are 16 to 18 % taller than Tres.

Spring versus winter growth habit NILs. The recurrent parent Marfed is a SWSW that was widely grown in the U.S. PNW during 1956-76. Coldhardiness of these NILs was reported by Storlie et al. Crop Sci 38:483-488, 1998.

• Suweon 185/6*Marfed.
  • PI631514, PI631516, PI631519, PI1631522, and PI631524. These NILs have spring growth habit and likely the Vrn1 allele of Marfed.
  • PI631515, PI631517, PI631518, PI631520, PI631521, PI631523, PI631525, and PI631526. These NILs have winter growth habit and likely the vrn1 allele of Suweon 185.
• Chugoku 81/6*Marfed
  • PI631527, PI631529, PI631531, PI631533, and PI631536. These NILs have spring growth habit and likely the Vrn1 allele of Marfed.
  • PI631528, PI631530, PI631532, PI631534, PI631535, and PI631537. These NILs have winter growth habit and likely the vrn1 allele of Chugoku 81.

Evaluation of Wanser and Daws vernalization near-isogenic lines for cold hardiness. [p. 231-232]

Kimberly Garland Campbell, Robert E. Allan, Todd Linscott, Kay Walker-Simmons, and Eric Weir.

Our objective was to compare the response to artificial freezing for near-isogenic wheat genotypes differing for vernalization (Vrn) loci. We regularly conduct artificial freezing tests in growth chambers in the WSU Plant Growth Center that are able to cool to -25 C. The basic test is as described in Storlie (Storlie et al. 1998) and the result is an LT50 value (or temperature at which 50 % of the plants are survive).

R.E. Allan has developed two sets of NILs for each of four Vrn genes in a winter wheat background. Each set used the Triple Dirk NILs developed by Pugsley (Zeven et al. 1986) as Vrn-gene donors (see Table 1). Two SWWW cultivars were used as recurrent parents: Daws (Peterson et al. 1977) with good winter hardiness and Wanser with less winter hardiness. In our tests, the LT50 of Daws has consistently been 3 C less (colder) than that of Wanser.

Each Triple Dirk NIL initially was backcrossed twice to each recurrent parent with selection for the presence of the Vrn allele. Six more backcrosses were made using the recurrent parent as a male and a spring-habit progeny from the previous generation as a female (for example: Daws*2/Triple DirkD)*6//Daws). Within the progeny of each of four or five BC7 families/cross, a winter and a spring sibling was identified. Each sibling was selfed and its growth habit was checked in both a greenhouse and field environment during 1999 and 2000. Spring-habit NILs were retained only if they were homozygous for spring habit. Thus, each NIL set is comprised of each of the four Vrn loci as 4-5 families possess ing both a winter and spring sib for a total of 36-40 NILs/recurrent parent. Theoretically, Triple Dirk alleles make up 0.37 % of the genome of each NIL.

The LT50 values of the Daws NILs were determined. All Vrn loci resulted in LT50 values similar to the recurrent parent except for Vrn-A1 (Table 1) (spring habit). The presence of the Vrn-A1 allele caused a major reduction in cold hardiness, supporting previous research that noted the major effects of chromosome 5AL on cold hardiness. Because of the effects of the Vrn-A1 allele, the mean LT50 values for spring-habit NILs were higher than the mean for winter-habit NIls. There was no change in LT50 values associated with the vrn-a1 allele (winter habit) in the Daws NILs. The reduction in cold hardiness associated with Vrn-A1 is either extremely closely linked to Vrn-A1 or an effect of Vrn-A1 itself. There were no differences in LT50 values among any of the other Vrn alleles. This indicates that we can develop winter hardy spring habit wheat cultivars by using Vrn-B1 or Vrn-D1. Those facultative-habit cultivars are useful in dry-cropping situations when planting is depending upon moisture. These results also indicate that the Vrn loci and loci closely linked to them are not likely to be important sources of improved winter hardiness in winter wheat.

Expression levels of antioxidant enzymes during cold acclimation in near-isogenic lines of winter and spring wheat. [p. 232-233]

Daniel Z. Skinner and Kwang-Hyun Baek.

The expression levels of antioxidant enzyme genes were monitored in winter and spring wheat NILs during cold acclimation. The 442 (winter wheat) and 443 (spring wheat) NILs developed by Dr. R.E. Allen differed only in the Vrn1A-Fr1 region of chromosome 5A. Total RNA was extracted from wheat grown at a constant 20 C for 2 weeks, then at 2 C for 1, 2, or 4 weeks. Using gene-specific primers, quantitative RT-PCR was used to measure the levels of RNA transcripts from 11 genes. The antioxidant genes monitored were mitochondrial MnSOD, chloroplastic Cu, ZnSOD, Fe­SOD, CAT, ascorbate peroxidase (APX), gutathione reductase (GR), glutathione peroxidase (GP), mono-dehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR). The expression levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and b-actin also were monitored during cold acclimation to evaluate these genes as possible constant-expression standards for wheat cold-acclimation studies.

The expression levels of the antioxidant enzyme genes were up-regulated (MnSOD, MDHAR, AP, DHAR, GP, and GR), down-regulated (CAT), or maintained constant expression (FeSOD and Cu, ZnSOD). The genes that were up-regulated reached their highest expression levels after 2 weeks, then declined or maintained constant expression to 4 weeks. The Vrn1A-Fr1 region seemed to play a role in regulating the expression level of some of the antioxidant enzyme genes in low temperature. NIL 442 has significantly higher expression levels of MnSOD, CAT, and APX than NIL 443 after 4 weeks of cold exposure. GAPDH and b-actin had significantly higher expression levels during cold acclimation, therefore, those enzymes cannot be used as standards in these studies.

These results suggested that antioxidant enzyme genes may play a role in cold response of wheat plants. The response appears to manifest to its highest level within the first week of exposure to cold, and appears to be influenced by the alleles present at the Vrn1A-Fr1 region.

Publications. [p. 233]

• Chen XM. 2002. Resistance gene analog polymorphism, a powerful technique for developing molecular markers for disease resistance genes. Phytopathology 92:S106.
• Chen XM, and Moore MK. 2002. Epidemics and races of Puccinia striiformis in North America in 2001. Phytopathology 92:S14-15.
• Chen XM, Moore MK, Milus EA, Long DL, Line RF, Marshall D, and Jackson L. 2002. Wheat stripe rust epidemics and races of Puccinia striiformis f. sp. tritici in the United States in 2000. Plant Dis 86:39-46.
• Chen XM, Moore MK, and Wood DA. 2003. Epidemiology and control of stripe rusts of wheat and barley in the United States. In: Abstr 8th Internat Cong Plant Pathol Solving problems in the real world. 2-7 February, 2003, Christchurch, New Zealand. 2:118.
• Chen XM, Moore MK, Wood DA, and Line RF. 2002. Control of wheat and barley rusts, 2001 progress report. Cooperative Extension, Washington State University, Department of Crop and Soil Sciences. Technical Report 02-1:30-34.
• Chen XM, and Wood DA. 2002. Control of stripe rust of spring wheat with foliar fungicides, 2001. Fungicide and Nematicide Tests 57:CF03.
• Chen XM, and Wood DA. 2003. Control of stripe rust of spring wheat with foliar fungicides, 2002. Fungicide and Nematicide Tests 58:in press.
• Chen XM, Wood DA, Moore MK, Yan GP, and Line RF. 2002. Control of wheat rusts in the western United States, 2001. Ann Wheat Newslet 48:267-269.
• Chen XM, and Yan GP. 2002. Development of RGAP markers for stripe rust resistance gene Yr15 and use of the markers to detect the gene in breeding lines. Phytopathology 92:S14.
• Chen XM, Yan GP, and Line RF. 2002. Direct markers for the wheat stripe rust resistance gene Yr5 identified using resistance gene analog polymorphism have high homology with plant resistance genes. In: PAMG X p. 144.
• Chen XM, Yan GP, Soria MA, and Dubcovsky J. 2003. Development of molecular markers for the Yr5 and Yr15 resistance to wheat stripe rust. In: Abstr 8th Internat Cong Plant Pathol Solving problems in the real world. 2-7 February, 2003, Christchurch, New Zealand. 2:297.
• Del Blanco IA, Campbell KG, Chen XM, and Allan RE. 2003. Mechanisms of resistance to stripe rust in the club wheat multilines 'Rely'. PAMG X p. 388.
• Kidwell KK, Shelton GB, Demacon VL, Burns JW, Carter BP, Morris CF, Chen XM, and Hatchett JH. 2002. Registration of 'Tara 2000' wheat. Crop Sci 42:1746-1747.
• Yan GP, Chen XM, Line RF, and Wellings CR. 2003. Resistance gene analog polymorphism markers co-segregating with the Yr5 gene for resistance to wheat stripe rust. Theor Appl Genet 106:636-643.
  

USDA-ARS WESTERN WHEAT QUALITY LABORATORY [p. 234-235]
E-202 Food Science & Human Nutrition Facility East, Washington State University, Pullman, WA 99164, USA.

Craig F. Morris, A.D. Bettge, D.A. Engle, M.L. Baldridge, R.L. Engle, G.E. King, G.L. Jacobson, A.N. Masa, I. Eujayl, E.P. Fuerst, K.R. Gedye, C.C. Burke, J.F.Connett, W.J Kelley, M.J. Freston, P.K. Boyer, L. Nguyen, E.E. Galli, S.M. Finnie, C.A. Oliver, S.M. Leach, and Y. Haruta.

The mission of the lab is two-fold: conduct milling, baking and end-use quality evaluations on wheat breeding lines and conduct research on wheat grain quality and utilization. The lab continues to move into web-based information transfer and has added extensive enhancements to our web site, http://www.wsu.edu/~wwql/php/index.php. To provide greater access to our research, we developed a database of wheat cultivars relating kernel hardness and puroindoline allele. We are in the process of placing our research publications on our web site.

We are serving as curator of the Grain Hardness, Puroindoline and GSP-1 gene sections of the Catalogue of Gene Symbols in Wheat. Several new alleles have been documented in Ae. tauschii and other diploid taxa.

C.F. Morris and D.A. Engle lead the PNW Wheat Quality Council, a consortium of collaborators who evaluate the quality of new cultivars and advanced-breeding lines.

A.D. Bettge currently serves as chairman of the AACC Soft Wheat and Flour Technical Committee. New methodology for the analysis of end-use characteristics of wheat is studied by this committee for inclusion in the AACC's Approved Methods manual. Recent methods that have been studied collaboratively and approved include solvent-retention capacity, which estimates a number of end-use quality factors such as protein quality, starch damage, and pentosan content, and flour-swelling volume, which measures starch swelling and the impact of granule-bound, starch-synthase allelic state. Currently, the committee is studying an L-DOPA substrate-based method for estimation of polyphenol oxidase content of wheat, a contributor to Asian noodle discoloration.

Post-doctoral research associates include A.N. Masa, Eujayl, E.P. Fuerst, K.R. Gedye, and C.C. Burke. Y. Haruta is a visitor from a Japanese milling company.

Publications. [p. 234-235]

• Anderson JV and Morris CF. 2003. Purification and analysis of wheat grain polyphenol oxidase protein. Cereal Chem 80(2):in press.
• Beecher B, Bettge AD, Smidansky E, and Giroux MJ. 2002. Expression of wild-type pinB sequence in transgenic wheat complements a hard phenotype. 2002. Theor Appl Genet 105:870-877.
• Beecher B, Bowman J, Martin JM, Bettge AD, Morris CF, Blake TK, Giroux MJ. 2002. Hordoindolines are associated with a major endosperm texture QTL in barley (Hordeum vulgare L.). Genome 45:584-591.
• Bettge AD. 2003. Collaborative study on flour swelling volume (AACC Method 56-21). Cereal Foods World (Jan/Feb) (in press).
• Bettge AD, Morris CF, DeMacon VL, Kidwell KK. 2002. Adaptation of AACC Method 56-11, Solvent Retention Capacity, for use as an early generation selection tool for cultivar enhancement. Cereal Chem 79:670-674.
• Carter B, Campbell KG, Kidwell KK, Morris CF, Gains C. 2002. Improving gains from selection for end use quality in wheat. In: Proc 5th Ann Natl Wheat Industry Res Forum, 17 January, 2002, Orlando, FL. National Assn Wheat Growers. p. 39.
• Demeke T and Morris CF. 2002. Molecular characterization of wheat polyphenol oxidase (PPO). Theor Appl Genet 104:813-818.
• Engle, D A, Morris CF and Carter BP. 2003. Genotype and environment study, 6-year summary, 1997-2002 crop years. Published to http://www.wsu.edu/~wwql/php/index.php 18 February 2003. USDA-ARS Western Wheat Quality Laboratory and Washington State University.
• Epstein, J, Morris CF, Huber KC. 2002. Instrumental texture of white salted noodles prepared from recombinant inbred lines of wheat differing in the three granule bound starch synthase (Waxy) genes. J Cereal Sci 35:51-63.
• Kidwell KK, Shelton GB, DeMacon VL, Burns JW, Carter BP, Morris CF, Chen X, Hatchett JH. 2002. Registration of 'Tara 2000' Wheat. Crop Sci 42:1746-1747.
• Kidwell KK, Shelton GB, DeMacon VL, Morris CF, Engle DA, Burns JW, Line RF, Konzak CF, Hatchett J. 2002. Registration of 'Zak' Wheat. Crop Sci 42:661-662.
• Lillemo M, Simeone MC, Morris CF. 2002. Analysis of puroindoline a and b sequences from Triticum aestivum cv. 'Penawawa' and related diploid taxa. Euphytica 126:321-331.
• Morris CF. 2002. Puroindolines: the molecular genetic basis of wheat grain hardness. Plant Mol Biol 48:633-647.
• Morris CF. 2002. The Pacific Northwest­Land of milk and honey (and white wheat). In: Proc 5th Ann Natl Wheat Industry Res Forum, 17 January, 2002, Orlando, FL. National Assn Wheat Growers. p. 28-31.
• Morris CF and King GE. 2002. Registration of soft and hard red winter wheat near-isogenic sister lines of 'Weston'. Crop Sci 42:2218-2219.

WASHINGTON STATE UNIVERSITY
Departments of Crop and Soil Sciences, Food Science and Human Nutrition, and Plant Pathology, Pullman, WA 99164-6420, U.S.A.

Spring wheat breeding and genetics. [p. 235-236]

K. Kidwell, G. Shelton, V. DeMacon, M. McClendon, J. Baley, and R. Higgonbotham.

Overview. The overall goal of wheat breeding efforts at WSU is to enhance the economic and environmental health of wheat production in the PNW by releasing genetically superior cultivars for commercial production. Traditional breeding methods and molecular genetic technology are combined to reduce production risks associated with abiotic and biotic stresses by incorporating genetic insurance into adpated, elite varieties.

Seven hundred crosses were made in 2002, and 27,334 breeding lines were evaluated in field trials at 1 to 16 locations in Washington state. Grain samples from 522 breeding lines with superior agronomic performance were sent to the USDA-ARS Western Wheat Quality Laboratory for end-use quality assessment. Two cultivars, Macon (HWSW) and Eden (spring club) were approved for release. Macon is a Hessian fly-resistant cultivar with exceptional bread-baking and noodle-making properties. Eden has outstanding grain yield potential, traditional club quality, and excellent stripe rust resistance. Research efforts were initiated to 1) incorporate a high protein region and stripe rust resistance genes into adapted spring wheat cultivars using MAS, 2) assess broadly adapted wheat germ plasm for resistance to Phythium, and 3) assess soilborne disease pressure in glyphosate tolerant wheat production.

New cultivar prereleases and releases. Scarlet, a 1998 WSU release, was the primary HRWW in commercial production in Washington State in 2002. Scarlet was released for the semiarid production region as a replacement for Butte 86 and Kulm, however, the cultivar has broad adaptation and acreage has extended well beyond the targeted region into the intermediate-rainfall zone. Although Scarlet has performed well in the semiarid region of Washington state, it has relatively low test weight when stressed and is not excessively tall cultivar. Scarlet also is moderately susceptible to the race of stripe rust that prevailed in the region in 2002 and is susceptible to the Hessian fly. Originally, our goal was to develop a cultivar specifically for the semiarid region with the yield potential of Scarlet but that is taller, and has higher test weight, higher grain-protein content, and improved bread-baking quality compared to those of Scarlet. The agronomic performance and phenotypic characteristics of WA007859 align nicely with these requirements. WA007859 also is resistant to current races of stripe rust in the region, and is resistant to local Hessian fly biotypes, which improves its suitability for direct seed production in the low- and intermediate-rainfall zones. In 7 out of 8 site-years in cultivar-testing trials at Lind and Horse Heaven, WA, grain yields of Scarlet were statistically similar to those of WA007859. Based on 23 site years of data from the low-rainfall zone, WA007859 has a 0.6 lb/bu test weight advantage over Scarlet, and the grain protein content of WA007859 is 0.4 % higher than that of Scarlet. The bread-baking quality of WA007859 also is superior to that of Scarlet. WA007859, which will be named Hollis, was approved for cultivar release. Foundation seed of this cultivar will be produced in 2003.

Nearly 100,000 acres of the SWSW Zak were grown in Washington State in 2002, its first year in commercial production. Based on its high yield potential, superior end-use quality and Hessian fly resistance, Zak was projected to be an ideal replacement for Wawawai and Alpowa in the high-rainfall zone. In previous years, Zak demonstrated resistance to stripe rust races present in the region; however, Zak, along with many other SWSWs in commercial production, was highly susceptible to the race that prevailed in the region in 2002. Costs associated with spraying fungicide to control stripe rust reduce the profit potential of this cultivar and increase the risk of environmental contamination. The highest priority for the spring wheat-breeding program is to release a stripe rust-resistant replacement for Zak with equivalent or superior grain-yield potential and end-use quality characteristics. We also would like to replace a substantial proportion of the Alpowa acreage in the high-rainfall zone with a cultivar that has improved end-use quality, Hessian fly resistance, and better emergence under direct-seed production conditions. WA007921 has excellent potential as the Zak and Alpowa replacement in areas receiving more that 15 inches of average annual precipitation. WA007921 was rated as having moderate resistance to stripe rust in 2002 and is partially resistant (65 %) to the Hessian fly. The grain-yield potential of WA007921 was equal to or better than those of Zak, Alpowa, and Wawawai in a majority of the dryland field trials conducted from 1999 to 2002. The end-use quality of WA007921 is equivalent or superior to that of Zak, and this cultivar is a dramatic end-use quality improvement over Alpowa. WA007921 was approved for prerelease and Breeder seed of this cultivar will be produced in 2003.

In 2002, 16,000 acres of SWSW were grown in Washington state. A majority of this acreage was sown to Idaho 377s, which was licensed by the University of Idaho to a grower coöperative. Although ADM Spokane successfully produced Idaho 377s locally on contract in 2002, many growers are interested in obtaining hard white wheat cultivars through public release channels to reduce seed costs and to create flexibility in production and marketing strategies. Although Idaho 377s has excellent yield potential and superior noodle color, it does not mill particularly well and has suboptimal bread-making quality. In 2002, we released Macon, a dual-purpose, HWSW suitable for noodle and bread making with acceptable but not exceptional agronomic performance. Macon is resistant to local biotypes of the Hessian fly; however, it is moderately susceptible to the new race of stripe rust that prevailed in the region in 2002. Our goal is to release a public cultivar to replace Idaho 377s and to identify a stripe rust resistance compliment for Macon that has superior grain-yield potential, a broad adaptation range, and dual-purpose quality. WA007931 has outstanding grain-yield potential that equals or exceeds those of Idaho 377s and Macon across production zones. WA007931 has far better bread-making quality than that of Idaho 377s, and it has excellent noodle color. However, the bread-making quality of Macon is superior to that of WA007931. WA007931 would be an outstanding compliment to Macon in that it is much taller and has higher test weight, making it more suitable for production in the semiarid and intermediate-rainfall zones. WA007931 also is moderately resistant to stripe rust and is partially resistant to the Hessian fly. WA007931 is a partial waxy type, which might make it suitable for producing different types of noodles than which Macon is suited. Releasing cultivars with complimentary quality attributes will broaden the market range for PNW hard white wheat.

Marker-assisted backcross breeding. [p. 236-237]

M. McClendon and K. Kidwell.

High protein gene introgression. Increasing grain protein content by applying high rates of N fertilizer can be effective, but it is inefficient. Instead of relying solely on fertility management to increase grain-protein content of HRS, avenues to genetically enhance this trait through traditional breeding methods are now available. A promising genetic source of high grain-protein content (HGPC) was detected in a wild relative of wheat. Researchers speculate that a grain-protein content increase of 1-2 % can be expected if the HGPC region is introgressed into a bread wheat cultivar, and this protein content increase is expected to occur without additional nitrogen fertilizer requirements. The objective of this project is to increase GPC of the hard red varieties Scarlet and Tara 2002 by introgressing the region into these lines through marker-assisted backcross breeding. BC5F3 and BC6F2 lines, containing > 99 % of the genes from the WSU lines and < 1 % of the genes from the donor parents, including the high protein segment, were developed using this strategy, and this material was evaluated in the field in 2002.

Over 100 isolines (BC5F3), containing 99 % of the genes from the Scarlet or Tara 2002 with 1 % of the genes from Glupro, with or without the HGPC segment, were evaluated in a nonreplicated field trial at WSU's Spillman Farm in 2002. A soft white fertility regime (2.5 lb N/expected bu) was used to maximize fertility response differences among isolines. This trial was heavily infested with stripe rust, and susceptible lines were eliminated from consideration. Even though nonreplicated data from a single site-year must be interpreted with extreme caution, several isolines appear to have excellent potential as high protein replacements for Scarlet and Tara 2002. Replicated field trials will be initiated in 2003 to assess the impact of incorporating the HGPC region into these cultivars.

Stripe rust resistance. Zak, a Hessian fly-resistant SWSW was slated to replace Wawawai, Penawawa, and perhaps some Alpowa acreage in the high-rainfall region based on its excellent yield potential and superior end-use quality. Prior to 2002, Zak had demonstrated excellent resistance to stripe rust races prevalent in the field. In commercial production in 2002, Zak showed high levels of susceptibility to stripe rust, indicating that recently developed races have circumvented the resistance in Zak. Incorporating new rust resistance genes into Zak is a high priority since this cultivar would have been the premiere SWSW in commercial production in the region if its stripe rust resistance had held. Stripe rust resistance genes Yr5 and Yr15 are effective against all races identified so far in the U.S., and tightly linked molecular markers for these genes have been developed. The primary goal of this project is to introgress Yr5 and Yr15 into Zak as quickly and efficiently as possible by utilizing the recurrent enriched backcrossing breeding scheme.

Gene discovery. [p. 237]

R. Higginbotham, T. Paulitz, and K. Kidwell.

Pythium root rot, a fungal pathogen of wheat, causes yield losses in virtually every field in Washington. Even though Pythium damage is well-documented, limited information about which isolates are most responsible for disease occurrence is available. Nineteen Pythium isolates were tested for pathogenicity on two spring wheat cultivars. A complete random design was used to evaluate cultivars in inoculated and non-inoculated treatments in a growth chamber maintained at 16°C with ambient humidity. Plant height, length of the first true leaf, number of seminal roots, and crown root number were recorded, and roots were digitally scanned into computer files that were analyzed using WinRhizo software. Preliminary results indicated all of the Pythium isolates caused a significant reduction in the number of root tips (P < 0.0001), root surface area (P = 0.0001) and root length (P = 0.0001), whereas average root diameter increased (P = 0.001) due to a reduction in the number of fine secondary roots. Virulence level varied among species, and isolates with the highest pathogenicity levels will be used to assay a broad range of germ plasm for tolerance/resistance.

Transgene assessment. [p. 237-238]

J. Baley, T. Paulitz, and K. Kidwell.

Glyphosate tolerant wheat will permit 'in crop' weed control while maintaining the intrinsic environmental and economic benefits associated with no-till crop production. However, potential yield gains may be lost because of increased activity of soilborne pathogen on dying weeds within a glyphosate tolerant wheat crop. The objective of this study is to proactively determine the risks of incorporating glyphosate tolerant wheat into no-till production systems. Bobwhite and Westbred 926 NILs with and without glyphosate tolerance were evaluated under direct-seed conditions in three agroclimatic zones in eastern Washington. A mixture of spring barley and sterilized oat seed inoculated with Rhizcotonia solani/oryzae or Gaeumannomyces graminis var. tritici (GGT) were direct seeded into the field plots prior to planting the NILs to simulate greenbridge volunteer. A no greenbridge control also was included. NILs from three treatments (RoundUp, Buctril/Harmony Extra, and a no-spray, hand-weeded control) were evaluated for disease severity and agronomic performance. Roots were digitally scanned and analyzed using WinRhizo software to assess morphological changes within treatments. All NILs were evaluated with the Buctril/Harmony Extra and no-spray treatments, but only the glyphosate tolerant varieties were treated with glyphosate.

Regardless of disease treatment or location, glyphosate treated Roundup Ready® (RR) spring wheat, produced significantly (P = 0.001) more grain than NILs treated with Buctril/Harmony Extra or the no-spray control, suggesting that greenbridge transmission of Rhizoctonia and GGT due to Roundup application may not occur at high enough levels to suppress yields of RR cultivars. Rhizcotonia and GGT naturally prevail in areas receiving low and high levels of precipitation, respectively. In trials planted in the low and high rainfall zones, grain yields of NILs treated with Buctril/Harmony Extra were significantly (P = 0.05) lower than NILs treated with Roundup or the no-spray control. High levels of yield depression with this treatment was unexpected since wheat producers in the PNW typically use Buctril/Harmony Extra for broadleaf weed control. However, Harmony Extra is a sulfonylurea herbicide, which is a group of herbicides that have been shown to increase the incidence of R. solani and GGT in wheat, which may have impacted these results.

An interesting herbicide-pathogen interaction was noted in a trial that was heavily infested with stripe rust. Bobwhite NILs that had not been treated with Roundup had a more severe incidence of stripe rust than Roundup-treated NILs. Bobwhite NILs sprayed with Buctril/Harmony Extra or in the no spray control displayed severe stripe rust-susceptibility symptoms and matured 2-3 weeks earlier than NILs treated with Roundup. Buctril/Harmony Extra treated RR Bobwhite produced significantly (P = 0.01) less grain, than the RR Bobwhite treated with Roundup, regardless of root disease treatment. Visual differences in stripe rust severity were not apparent until 21 days after herbicide application. These results suggest that glyphosate within a RR-wheat plant may remain active for extended time periods, thereby hindering the colonization of leaf tissue by foliar pathogens. If true, residual in-plant glyphosate activity also may be responsible for increased grain yields detected for Roundup treated RR NILs across locations, regardless of disease treatment. Additional field trials, along with concurrent growth chamber analysis of root structure, defense enzymes and products, will be conducted to elucidate the effects of Roundup application on the transmission of soilborne pathogens to herbicide-resistant wheat.

Publications. [p. 238]

• Baley GJ, Kidwell KK, Paulitz TC, Yenish J, and Campbell K. 2002. Assessment of soilborne disease pressure in glyphosate tolerant wheat production. Agron Abstr:320.
• Barrett BA, Bayram ME, and Kidwell KK. 2002. Identifying AFLP and microsatellite markers for vernalization response gene Vrn-B1 in wheat (Triticum aestivum L.) using reciprocal mapping populations. Plant Breed 121:400-406.
• Bettge AD, Morris CF, DeMacon VL, and Kidwell KK. 2002. Adaptation of AACC method 56-11, solvent retention capacity, for use as an early generation selection tool for cultivar development. Cereal Chem 79(5):670-674.
• Higginbotham RW, Kidwell KK, and Paulitz TC. 2002. Pathogenicity assessment of Pythium spp. collected from cereal grain fields of eastern Washington. Agron Abstr:336.
• Kidwell KK, Shelton GB, DeMacon V, Morris CF, Engle DA, Burns JW, Line RF, Konzak CF, and Hatchett J. 2002. Registration of 'Zak' wheat. Crop Sci 42:661-662.
• Kidwell KK, Shelton GB, DeMacon VL, Burns JW, Carter BP, Morris CF, Chen X, and Hatchett JH. 2002. Registration of 'Tara 2000' wheat. Crop Sci 42:1746-1747.
• Seefeldt SS, Kidwell KK, and Waller JE. 2002. Base growth temperatures, germination rates and growth response of contemporary spring wheat (Triticum aestivum L.) cultivars from the U.S. Pacific Northwest. Field Crops Res 75:47-52.