Progress 09/15/06 to 09/14/07
Outputs
OUTPUTS: This report focuses on one aspect of the project, namely our efforts to determine the genetic factors that determine wheat breadmaking quality Breadmaking quality in wheat is heavily influenced by six genetic loci that encode glutenin proteins and by the 1RS chromosome arm translocation from rye. However, the relative importance of those factors in conditions similar to Colorado's wheat growing environments has not been reported. Two studies dealing with that objective are discussed in the following sections. (1) We grew a population of 190 recombinant inbred lines (RILs) derived from the cross of the winter wheats TAM107-R7 (poor quality) and Arlin (high quality) under irrigated and dryland conditions. Grain samples from replicated field plots were evaluated for several dough mixing parameters measured on a mixograph device. The same lines were also evaluated for their allelic patterns at six high and low molecular weight glutenin subunit loci and for the presence or
absence of the 1RS chromosome arm translocation from rye. Statistical associations between genotype (glutenin loci and rye translocation) and phenotype (mixograph properties) were calculated with a t-test. Results indicated that environment had a strong influence on quality and that significant variation in quality was associated with the Glu-A1, Glu-B1, Glu-D1, and Glu-A3 loci, and the 1RS translocation. (2) In a separate study we evaluated a set of 96 wheat cultivars and advanced breeding lines, mostly from the Great Plains, in three Colorado locations. These materials were evaluated for dough mixing properties and allelic variation at glutenin loci and 1RS, as in the previous study. In addition, they were genotyped at 60 microsatellite markers distributed across the wheat genome to determine genetic relationship among the lines. This last step was necessary to avoid false positive associations that are based on genetic similarities among lines. Results of this study again
demonstrated the importance of environmental conditions in determining quality. Specific allelic variants at Glu-A1, Glu-B1, Glu-D1, and Glu-B3 were shown to be associated either with better or poorer mixing properties. The 1BL.1RS translocation was found to be more detrimental to quality than the 1AL.1RS translocation. Results of the work described above were disseminated at a national professional meeting (American Society of Agronomy annual meeting, Indianapolis, IN, 12-16 Nov. 2006) and at the annual meeting of the Colorado Association of Wheat Growers (Fort Collins, CO, 3 April, 2007).
PARTICIPANTS: Participants: Scott Reid: Research Associate in Byrne's program; responsible for DNA marker and protein analyses, growing and crossing greenhouse plants, and assisting with field work. Mustapha El Ouahabi: Graduate Research Assistant in Byrne's program; responsible for field evaluation of a drought tolerance population. Debbie Badillo: Research Associate in Byrne's program; responsible for DNA marker evaluation of a drought tolerance population. Shusong Zheng: Elizabeth Castelbaum
TARGET AUDIENCES: Colorado Association of Wheat Growers: Reports by all three co-PI's at the CAWG annual meeting, followed by tours of the co-PIs' laboratory and greenhouse facilities. Wheat producers of central and eastern Colorado: Presentations by co-PI Haley at 6 to 8 field days and 3 to 4 wheat planting meetings per year.
Impacts
Our results These results suggest that selection for appropriate glutenin alleles and rye translocations can aid the development of cultivars with desirable dough properties in Colorado and similar environments.
Publications
- Botha, A.M., Y. Li, and N.L.V. Lapitan. 2005. Cereal host interactions with Russian wheat aphid: A review. J. Plant Interaction 1:211-222.
- Haley, S.D., J.J. Johnson, F.B. Peairs, J.S. Quick, J.A. Stromberger, S.R. Clayshulte, J.D. Butler, J.B. Rudolph, B.W. Seabourn, G. Bai, Y. Jin, and J. Kolmer. 2007. Registration of 'Ripper' wheat. J. Plant Reg. 1:1-6.
- Hesler, L.S., S.D. Haley, K.K. Nkongolo, and F.B. Peairs. 2007. Resistance to Rhopalosiphum padi (Homoptera: Aphididae) in triticale and triticale-derived wheat lines with resistance to Diuraphis noxia (Homoptera: Aphididae). J. Entomol. Sci. 42: 217-227
- Lapitan, N.L.V., Y. Li, J. Peng, and A.-M. Botha. 2007. Fractionated extracts of Russian wheat aphid eliciting defense responses in wheat. J. Econ. Entom. 100:990-999.
- Peng, J., H. Wang, S.D. Haley, F.B. Peairs, and N.L.V. Lapitan. 2007. Molecular mapping of Russian wheat aphid resistance gene Dn2414 in wheat. Crop Sci. 27:2418-2429.
- Botha, A.M., Y. Li, and N.L.V. Lapitan. 2006. Elicitation of the wheat defense-transcriptome in response to two Diuraphis noxia biotypes. 17th Biennial International Plant Resistance to Insects Workshop:46.
- Lapitan, N.L., Y. Li, and A.-M. Botha-Oberholster. 2005. The Russian Wheat Aphid And Its Interaction With Wheat. Plant and Animal Genome Conference XIII:W262.
- Lapitan, N.L.V., Y. Li, J. Peng, and A.-M. Botha. 2006. Deciphering the molecular interaction between wheat and the Russian wheat aphid. 17th Biennial International Plant Resistance to Insects Workshop:45-46.
- Van Eck, L., A. Myburg, N.L.V. Lapitan, and A.M. Botha-Oberholster. 2006. Profiling Russian wheat aphid (Diuraphis noxia) induced transcripts in near isogenic wheat (Triticum aestivum L.) lines using cDNA-AFLP and quantitative PCR analysis. 17th Biennial International Plant Resistance to Insects Workshop:27.
- Clayshulte, S.R., S.D. Haley, P.F. Byrne, and X. Shan. 2007. Trait associations at the Xgwm261 and Rht-B1 loci in two winter wheat recombinant inbred line populations. Crop Science 47:2346-2355.
- Shan, X., S.R. Clayshulte, S.D. Haley, and P.F. Byrne. 2007. Variation for glutenin and waxy alleles in the U.S. hard winter wheat germplasm. Journal of Cereal Science. 45:199-208.
- Xueyan Shan, Sally R. Clayshulte, Patrick F. Byrne, and Scott D. Haley. Variation for glutenin and waxy alleles in U.S. hard winter wheat germplasm. Poster 248-7, http://crops.confex.com/crops/2006am/techprogram/P26782.HTM. American Society of Agronomy Annual Meeting, 12-16 Nov. 2006, Indianapolis.
- Shusong Zheng, Xueyan Shan, and Patrick Byrne. 2006. Effects of glutenin subunit variation and 1RS.1AL translocation on dough properties of wheat grown in Colorado environments. Poster 248-9, http://crops.confex.com/crops/2006am/techprogram/P24972.HTM American Society of Agronomy Annual Meeting, 12-16 Nov. 2006, Indianapolis.
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Progress 09/15/05 to 09/14/07
Outputs
OUTPUTS: (1) 320 Iranian landraces were evaluated for Russian wheat aphid (RWA) biotype 2 resistance; 10 selections were identified and crosses made to develop mapping populations. Two resistant tetraploid wheat accessions were crossed with spring wheat to transfer the resistance to a hexaploid background. A set of backcross-derived near-isogenic lines with 10 sources of resistance in a Yuma background were developed for genetic studies. We developed a large population to separate the RWA resistance gene Dn7 from the deleterious effects of the 1BL.1RS rye translocation. (2) Resistance genes were mapped in two accessions with resistance to multiple RWA biotypes. The gene in CI2401 was mapped to chromosome arm 7DS, approximately 10 cM from marker Xgwm111. The resistance gene in 2414-11 was mapped to chromosome arm 1RS. Based on the pattern of linked markers and phenotypic response, the gene appears to be the same as, or closely linked to Dn7. (3) To identify wheat genes involved in the defense response, we used the Affymetrix Wheat GeneChip to compare gene expression patterns in response to RWA infestation in near-isogenic lines with and without Dn7. Differentially expressed genes included those involved in known defense pathways and several unknown genes. We extracted total protein from RWA salivary glands and guts, and separated it into 50 fractions by HPLC. When injected into plants, two fractions from biotype 1 and one fraction from biotype 2 gave significantly higher peroxidase activity in resistant than in susceptible plants, indicating that these fractions likely contain RWA virulence proteins. (4) For NIR calibration, we focused on prediction of measurements for single kernel characterization. 10,000 whole grain samples were analyzed for kernel hardness, weight, and diameter. A NIRSystem 6500 instrument was used to measure NIR spectra of the samples. Calibration was performed with modified partial least squares regression. Results for all three parameters revealed that the calibration model had a reasonable amount of predictive ability, with coefficients of determination greater than 0.70. (5) We evaluated six experimental transgenic spring wheat lines for field performance under well watered and moisture stress conditions in 2006 and 2007. The lines had previously been shown to be drought tolerant under greenhouse conditions. Our field trials, however, showed no significant differences in yield-related traits between these lines and their parent cultivar. We also evaluated 400 synthetic hexaploid lines under rainfed conditions in 2007. 45 lines were selected for further evaluation based on biomass, plant morphology, and kernel characteristics. (6) We developed three populations for quantitative trait locus analysis (QTL) and one for association analysis. Evaluations of one QTL population and the association analysis population resulted in identification of glutenin alleles with important influences on breadmaking quality under rainfed and irrigated conditions. Evaluations of the two other QTL populations for drought tolerance are partially complete and will continue through 2009. PARTICIPANTS: Scott Reid: Research Associate in Byrne's program; responsible for DNA marker and protein analyses, growing and crossing greenhouse plants, and assisting with field work. Debbie Badillo: Research Associate in Byrne's program; responsible for DNA marker evaluation of a drought tolerance population. Mustapha El Ouahabi: Graduate Research Assistant in Byrne's program; responsible for field evaluation of a drought tolerance population. Shusong Zheng: Ph.D. student in Byrne's program; responsible for genetic and phenotypic evaluation of breadmaking quality. Elizabeth Castelbaum: M.S. student in Byrne's program; responsible for evaluation of drought tolerant transgenic wheat. Ben Beyer: Graduate Research Assistant in Haley's program; collaborator on Russian wheat aphid resistance mapping. Jennifer Roth: Graduate Research Assistant in Haley's program; collaborator on Russian wheat aphid resistance mapping. Josh Butler: Research Associate in Haley's program; responsible for NIR calibration of breadmaking properties. Junhua Peng and Hong Wang: Research Associates in Lapitan's program; collaborator on Russian wheat aphid mapping and toxicity mechanisms. TARGET AUDIENCES: Colorado Association of Wheat Growers: Reports by all three co-PI's at the CAWG annual meeting, followed by tours of the co-PIs' laboratory and greenhouse facilities. Wheat producers of central and eastern Colorado: Presentations by co-PI Haley at 6 to 8 field days and 3 to 4 wheat planting meetings per year. Wheat scientific community: Presentations by all co-PIs, their research associates, students at national and regional professional meetings. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
In this project we have obtained results that will improve understanding of RWA resistance in wheat and contribute to development of a new generation of RWA-resistant wheat varieties for western growers. Specifically, we have (1) identified additional wheat germplasm resistant to new RWA biotypes, some of which has been incorporated into breeding materials undergoing field evaluation; (2) developed mapping populations and other germplasm materials for genetic studies of resistance; (3) improved understanding of the inheritance and gene locations of RWA resistance; and (4) detected genes involved in the defense response against RWA and narrowed down the protein fractions responsible for RWA virulence in wheat. For breadmaking quality, we have (1) developed NIR calibrations that will greatly speed up evaluations for important kernel characteristics in applied wheat breeding programs; and (2) obtained results concerning effects of glutenin alleles that can aid in the development of cultivars with desirable dough properties in Colorado and similar environments. For stress tolerance, we have (1) developed two mapping populations currently undergoing field and molecular marker evaluation; and (2) identified a subset of synthetic hexaploid accessions with apparent tolerance to drought stress, which have been crossed to adapted cultivars.
Publications
- No publications reported this period
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Progress 09/15/05 to 09/15/06
Outputs
This report focuses on progress in identifying and understanding Russian Wheat Aphid (RWA) resistance. (1) Evaluation and use of resistance sources: A group of 320 Iranian landrace selections previously identified as having RWA biotype 2 resistance was evaluated for biotype 1 resistance. Over 450 single plant selections were made from 97 different Iranian landrace accessions, increased in the greenhouse, and progeny-tested. Ten single-plant selections of diverse origin were identified and crosses made with them to develop populations for genetic studies. Two resistant tetraploid accessions were crossed with a spring wheat accession to transfer the resistance to a hexaploid background. We continued to develop a set of backcross-derived near-isogenic lines in a Yuma background with 10 different sources of resistance, for future genetic studies as well as biotype monitoring and characterization. Biotype 2-resistant lines derived from an introgression from Triticale were
field-tested in 2006. These lines have been discarded from release consideration due to poor yield and apparent instability of resistance. (2) Gene mapping: Resistance genes were mapped in two accessions with resistance to multiple RWA biotypes. The gene in accession CI2401 was mapped to chromosome arm 7DS, approximately 10 cM from marker Xgwm111. Experiments are underway to find more tightly linked markers. The resistance gene in accession 2414-11 was mapped to chromosome arm 1RS (a translocation from rye). Based on the pattern of linked markers and phenotypic response, the gene appears to be the same as, or closely linked to, the previously mapped Dn7. (3) Gene expression: To identify wheat genes involved in the defense response against RWA, we compared gene expression patterns in near-isogenic lines differing in the presence or absence of Dn7. Expression was analyzed with the Affymetrix Wheat GeneChip array. Infestation was carried out with biotypes 1 and 2, and wheat RNA samples
were collected at 5 h and 48 h post-infestation. Differentially expressed genes included those involved in biosynthesis of and response to jasmonic acid, salicylic acid, and ethylene, as well as several unknown genes. The function of these genes in RWA resistance is being tested by suppressing gene expression via virus-induced gene silencing. Results of this study may lead to development of broad-spectrum RWA resistance. (4) Virulence factors: We previously reported that injection of RWA proteins induced leaf rolling and lower levels of defense-related enzymes in susceptible plants. Therefore, we extracted total protein from salivary glands and guts of RWA biotypes 1 and 2, and separated it into 50 fractions by high pressure liquid chromatography. Each fraction was injected into resistant and susceptible plants and activity of the defense-related enzyme peroxidase was measured. Two fractions from biotype 1 and one fraction from biotype 2 gave significantly higher peroxidase activity
in resistant compared to susceptible plants, indicating that these fractions likely contain RWA virulence proteins. Identity of the proteins in these fractions will be analyzed by mass spectrometry.
Impacts
The Russian Wheat Aphid is a serious economic problem for wheat growers in the western U.S., and the appearance of new biotypes has added urgency to the search for additional sources of resistance. In this project we have (1) identified additional wheat germplasm resistant to new RWA biotypes; (2) improved understanding of the inheritance and gene locations of RWA resistance; (3) detected genes involved in the defense response against RWA; and (4) identified specific protein fractions involved in RWA virulence to wheat. These results will improve understanding of RWA resistance in wheat and contribute to development of a new generation of RWA-resistant wheat varieties for western growers.
Publications
- Haley, S.D., Johnson, J.J., Peairs, F.B., Quick, J.S., Westra, P.H., Stromberger, J.A., Clayshulte, S.R., Clifford, B.L., Rudolph, J.B., Giura, A., Seabourn, B.W., Chung, Y.J., and Kolmer, J. 2006. Registration of Bond CL wheat. Crop Sci. 46:993-994.
- Haley, S.D., Johnson, J.J., Peairs, F.B., Quick, J.S., Westra, P.H., Stromberger, J.A., Clayshulte, S.R., Clifford, B.L., Rudolph, J.B., Seabourn, B.W., Chung, Y.J., and Kolmer, J. 2006. Registration of Protection wheat. Crop Sci. 46:995-996.
- Randolph, T.L., Peairs, F.B., Koch, M., Walker, C.B., Stubbs, J.R., Quick, J.S., and Haley, S.D. 2005. Yield response and categories of resistance to Russian Wheat Aphid in four Dn4 hard red winter wheats. J. Econ. Entomol. 98:588-594.
- Haley, S.D., Quick, J.S., Johnson, J.J., Peairs, F.B., Stromberger, J.A., Clayshulte, S.R., Clifford, B.L., Rudolph, J.B., Seabourn, B.W., Chung, Y.J., and Kolmer, J. 2005. Registration of Hatcher wheat. Crop Sci. 45:2654-2655.
- Nobles,W., Byrne, P., Guenzi, A., Martin, B., Elavarthi, S., Carver, B., and Mergoum, M. 2005. Performance of four mannitol-accumulating transgenic wheat lines under moisture stress and non-stress conditions. Abstract 543b, http://crops.confex.com/crops/2005am/techprogram/P6075.HTM. American Society of Agronomy annual meeting, 6-10 Nov. 2005, Salt Lake City.
- Zheng, S., Shan, X., and Byrne, P. 2006. Effects of glutenin subunit variation and 1RS.1AL translocation on dough properties of wheat grown in Colorado environments. Abstract, http://crops.confex.com/crops/ws2006/techprogram/P20996.HTM, Western Society of Crop Science annual meeting, 19-21 June 2006, Torrington, WY.
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