Plant Breeding and Genetics Commons^™

Pseudomonas Syringae Type Iii Secretion System Targeting Signals And Novel Effectors Studied With A Cya Translocation Reporter, Lisa M. Schechter, Kathy A. Roberts, Yashitola Jamir, James R. Alfano, Alan Collmer

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae pv. tomato strain DC3000 is a pathogen of tomato and Arabidopsis. The hrp-hrcencoded type III secretion system (TTSS), which injects bacterial effector proteins (primarily called Hop or Avr proteins) into plant cells, is required for pathogenicity. In addition to being regulated by the HrpL alternative sigma factor, most avr or hop genes encode proteins with N termini that have several characteristic features, including (i) a high percentage of Ser residues, (ii) an aliphatic amino acid (Ile, Leu, or Val) or Pro at the third or fourth position, and (iii) a lack of negatively charged …

Activation Of A Coi1-Dependent Pathway In Arabidopsis By Pseudomonas Syringae Type Iii Effectors And Coronatine, Ping He, Satya Chintamanani, Zhongying Chen, Lihuang Zhu, Barbara N. Kunkel, James R. Alfano, Xiaoyan Tang, Jian-Min Zhou

Center for Plant Science Innovation: Faculty Publications

Gram-negative bacteria use a variety of virulence factors including phytotoxins, exopolysaccharides, effectors secreted by the type III secretion system, and cell-wall-degrading enzymes to promote parasitism in plants. However, little is known about how these virulence factors alter plant celluar responses to promote disease. In this study, we show that virulent Pseudomonas syringae strains activate the transcription of an Arabidopsis ethylene response factor (ERF) gene, RAP2.6, in a coronatine insensitive 1 (COI1)-dependent manner. A highly sensitive RAP2.6 promoter-firely luciferase (RAP2.6-LUC) reporter line was developed to monitor activities of various bacterial virulence genes. Analyses of P. syringae pv. tomato DC3000 mutants indicated …

Mapping The Fas Locus Controlling Stearic Acid Content In Soybean, M. M. Spencer, V. R. Pantalone, E. J. Meyer, D. Landau-Ellis, D. L. Hyten Jr.

Department of Agronomy and Horticulture: Faculty Publications

Increasing the stearic acid content to improve soybean [Glycine max (L) Merr] oil quality is a desirable breeding objective for food-processing applications. Although a saturated fatty acid, stearic acid has been shown to reduce total levels of blood cholesterol and offers the potential for the production of solid fat products (such as margarine) without hydrogenation. This would result in the reduction of the level of trans fat in food products and alleviate some current health concerns. A segregating F₂ population was developed from the cross between Dare, a normal stearic acid content cultivar, and FAM94-41, a high stearic …

The Pseudomonas Syringae Type Iii-Secreted Protein Hopptod2 Possesses Protein Tyrosine Phosphatase Activity And Suppresses Programmed Cell Death In Plants, Avelina Espinosa, Ming Guo, Vincent C. Tam, Zheng Qing Fu, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

The bacterial plant pathogen Pseudomonas syringae possesses a type III protein secretion system that delivers many virulence proteins into plant cells. A subset of these proteins (called Avr proteins) is recognized by the plant’s innate immune system and triggers defences. One defence-associated response is the hypersensitive response (HR), a programmed cell death (PCD) of plant tissue. We have previously identified HopPtoD2 as a type III secreted protein from P. s. pv. tomato DC3000. Sequence analysis revealed that an N-terminal domain shared homology with Avr- PphD and a C-terminal domain was similar to protein tyrosine phosphatases (PTPs). We demonstrated that purified …

Single-Nucleotide Polymorphisms In Soybean, Y. L. Zhu, Q. J. Song, D. L. Hyten, C. P. Van Tassel, L. K. Matukumalli, D. R. Grimm, S. M. Hyatt, E. W. Fickus, N. D. Young, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Single-nucleotide polymorphisms (SNPs) provide an abundant source of DNA polymorphisms in a number of eukaryotic species. Information on the frequency, nature, and distribution of SNPs in plant genomes is limited. Thus, our objectives were (1) to determine SNP frequency in coding and noncoding soybean (Glycine max L. Merr.) DNA sequence amplified from genomic DNA using PCR primers designed to complete genes, cDNAs, and random genomic sequence; (2) to characterize haplotype variation in these sequences; and (3) to provide initial estimates of linkage disequilibrium (LD) in soybean. Approximately 28.7 kbp of coding sequence, 37.9 kbp of noncoding perigenic DNA, and …

The Shca Protein Is A Molecular Chaperone That Assists In The Secretion Of The Hoppsya Effector From The Type Iii (Hrp) Protein Secretion System Of Pseudomonas Syringae, Karin V. Van Dijk, Vincent C. Tam, Angela R. Records, Tanja Petnicki-Ocwieja, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae uses a type III protein secretion system encoded by the Hrp pathogenicity island (Pai) to translocate effector proteins into plant cells. One of these effector proteins is HopPsyA. A small open reading frame (ORF), named shcA, precedes the hopPsyA gene in the Hrp Pai of P. s. syringae 61. The predicted amino acid sequence of shcA shares general characteristics with chaperones used in type III protein secretion systems of animal pathogens. A functionally non-polar deletion of shcA in P. s. syringae 61 resulted in the loss of detectable HopPsyA in supernatant fractions, consistent with ShcA acting as a …

Genomewide Identification Of Pseudomonas Syringae Pv.Tomato Dc3000 Promoters Controlled By The Hrpl Alternative Sigma Factor, Derrick E. Fouts, Robert B. Abramovitch, James R. Alfano, Angela M. Baldo, C. Robin Buell, Samuel Cartinhour, Arn K. Chatterjee, Mark D'Ascenzo, Michelle L. Gwinn, Sondra G. Lazarowitz, Na-Chun Lin, Gregory B. Martin, Amos H. Rehm, David J. Schneider, Karin V. Van Dijk, Xiaoyan Tang, Alan Collmer

Center for Plant Science Innovation: Faculty Publications

The ability of Pseudomonas syringae pv. tomato DC3000 to parasitize tomato and Arabidopsis thaliana depends on genes activated by the HrpL alternative sigma factor. To support various functional genomic analyses of DC3000, and specifically, to identify genes involved in pathogenesis, we developed a draft sequence of DC3000 and used an iterative process involving computational and gene expression techniques to identify virulence-implicated genes downstream of HrpLresponsive promoters. Hypersensitive response and pathogenicity (Hrp) promoters are known to control genes encoding the Hrp (type III protein secretion) machinery and a few type III effector proteins in DC3000. This process involved (i) identification of …

Clone Size Of Andropogon Gerardii Vitman (Big Bluestem) At Konza Prairie, Kansas, Kathleen H. Keeler, Charles F. Williams, Linda S. Vescio

School of Biological Sciences: Faculty Publications

Clone size of plants of Andropogon gerardii from Konza Prairie Biological Station, Manhattan, Kansas was estimated from spatial patterns of genetic variation, using proteins detected by starch gel electrophoresis and DNA content (ploidy) measured by flow cytometry. Unique multi-locus protein banding patterns and differences in ploidy were used to exclude plants as members of the same clone. Individual clones averaged about 2 m in diameter and areas of prairie of 100 m² were calculated to contain an average of 31.8 genetic individuals.

‘Forrest’ Resistance To The Soybean Cyst Nematode Is Bigenic: Saturation Mapping Of The Rhg1 And Rhg4 Loci, K. Meksem, P. Pantazopoulos, V. N. Njiti, D. L. Hyten, P. R. Arelli, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

Field resistance to cyst nematode (SCN) race 3 (Heterodera glycines I.) in soybean [Glycine max (L.) Merr.] cv ‘Forrest’ is conditioned by two QTLs: the underlying genes are presumed to include Rhg1 on linkage group G and Rhg4 on linkage group A2. A population of recombinant inbred lines (RILs) and two populations of near-isogenic lines (NILs) derived from a cross of Forrest × Essex were used to map the loci affecting resistance to SCN. Bulked segregant analysis, with 512 AFLP primer combinations and microsatellite markers, produced a high-density genetic map for the intervals carrying Rhg …

High-Throughput Genotyping For A Polymorphism Linked To Soybean Cyst Nematode Resistance Gene Rhg4 By Using TaqmanTm Probes, Khalid Meksem, Eliza Ruben, David L. Hyten, Michael E. Schmidt, David A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

An individual soybean breeder can generate over one hundred thousand new genotypes each year. The efficiency of selection in these populations could be improved if these genotypes were effectively screened with one DNA marker that identified an important gene, and if laboratory throughput was high and costs were low. Our aim was to develop a rapid genotyping procedure for resistance to the soybean cyst nematode. A high-throughput genotyping method was developed with fluorogenic probes to distinguish between two insertion polymorphisms in alleles of an AFLP marker that is located about 50 kbp from the Rhg4 gene candidate. The assay uses …

Conversion Of Aflp Bands Into High-Throughput Dna Markers, K. Meksem, E. Ruben, D. L. Hyten, K. Triwitayakorn, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

The conversion of AFLP bands into polymorphic sequence-tagged-site (STS) markers is necessary for high-throughput genotype scoring. Technical hurdles that must be overcome arise from genome complexity (particularly sequence duplication), from the low-molecular- weight nature of the AFLP bands and from the location of the polymorphism within the AFLP band. We generated six STS markers from ten AFLP bands (four AFLPs were from co-dominant pairs of bands) in soybean (Glycine max). The markers were all linked to one of two loci, rhg1 on linkage group G and Rhg4 on linkage group A2, that confer resistance to the soybean cyst nematode (Heterodera …

Two Large-Insert Soybean Genomic Libraries Constructed In A Binary Vector: Applications In Chromosome Walking And Genome Wide Physical Mapping, K. Meksem, K. Zobrist, E. Ruben, D. L. Hyten, T. Quanzhou, H-B. Zhang, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

Large DNA insert libraries in binary T-DNA vectors can assist in the isolation of the gene(s) under-lying a quantitative trait locus (QTL). Binary vectors facilitate the transfer of large-insert DNA fragments containing a QTL from E. coli to Agrobacterium sp. and then to plants. We constructed two soybean large-insert libraries from cv. Forrest in the pCLD04541 (V41) binary vector after partial digestion of genomic high-molecular-weight DNA with BamHI or HindIII. The libraries contain 76,800 clones with an average insert size of 125 kb, and therefore represent 9.5-fold haploid genome equivalents. Colony hybridization using a chloroplast-specific probe infers that …

Pseudomonas Syringae Hrp Type Iii Secretion System And Effector Proteins, Alan Collmer, Jorge L. Badel, Amy O. Charkowski, Wen-Ling Deng, Derrick E. Fouts, Adela R. Ramos, Amos H. Rehm, Deborah M. Anderson, Olaf Schneewind, Karin V. Van Dijk, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae is a member of an important group of Gram-negative bacterial pathogens of plants and animals that depend on a type III secretion system to inject virulence effector proteins into host cells. In P. syringae, hrpyhrc genes encode the Hrp (type III secretion) system, and avirulence (avr) and Hrpdependent outer protein (hop) genes encode effector proteins. The hrpyhrc genes of P. syringae pv syringae 61, P. syringae pv syringae B728a, and P. syringae pv tomato DC3000 are flanked by an exchangeable effector locus and …

The Pseudomonas Syringae Hrp Pathogenicity Island Has A Tripartite Mosaic Structure Composed Of A Cluster Of Type Iii Secretion Genes Bounded By Exchangeable Effector And Conserved Effector Loci That Contribute To Parasitic Fitness And Pathogenicity In Plants, James R. Alfano, Amy O. Charkowski, Wen-Ling Deng, Jorge L. Badel, Tanja Petnicki- Ocwieja, Karin Van Dijk, Alan Collmer

Center for Plant Science Innovation: Faculty Publications

The plant pathogenic bacterium Pseudomonas syringae is divided into pathovars differing in host specificity, with P. syringae pv. syringae (Psy) and P. syringae pv. tomato (Pto) representing particularly divergent pathovars. P. syringae hrp/hrc genes encode a type III protein secretion system that appears to translocate Avr and Hop effector proteins into plant cells. DNA sequence analysis of the hrp/hrc regions in Psy 61, Psy B728a, and Pto DC3000 has revealed a Hrp pathogenicity island (Pai) with a tripartite mosaic structure. The hrp/hrc gene cluster is conserved in all three strains and is flanked by a unique exchangeable …

Basic Biotechnology, Jennifer Flak, Julie Albrecht

Plant and Soil Sciences eLibrary

An introduction to traditional cross-breeding and genetic engineering of plants, and to biotechnology.

Objectives - Basic Biotechnology

After completing Nutrition Basic Biotechnology, participants should be able to:

• Describe one similarity between traditional cross-breeding and genetic engineering of plants.
• Give two limitations that are encountered with traditional cross-breeding of plants.
• Explain why genetic engineering is not limited in the same way as traditional cross-breeding.
• Define biotechnology in broad terms.
• List three plant applications of biotechnology.
• List the three areas of nutritional profiles that have been improved with biotechnology.

Modules:

• Lesson home
• Objectives - Basic Biotechnology
• Historical Uses of Biotechnology
• Basic Understanding …

Ec00-103 Nebraska Fall-Sown Small Grain Variety Tests 2000, Lenis Alton Nelson, David D. Baltensperger, Robert N. Klein, Roger Wesley Elmore, P. Stephen Baenziger, Todd Campbell

University of Nebraska-Lincoln Extension: Historical Materials

This circular is a progress report of variety trials conducted by personnel of the Agronomy Department and the South Central, West Central and Panhandle Research and Extension Centers and their associated agricultural laboraties. The 2000 estimated winter wheat yield for Nebraska was a 36 bushels per acre from 1,750,000 harvested acres. The total production of winter wheat for the state was 63,000,000 bushels. This circular reports data from winter wheat trials conducted throughout Nebraska. Entries included varieties or hybrids and promising experimental strains from Nebraska and surrounding states and private breeders. This was the ninetenth year for privately developed varieties. …

The Avr (Effector) Proteins Hrma (Hoppsya) And Avrpto Are Secreted In Culture From Pseudomonas Syringae Pathovars Via The Hrp (Type Iii) Protein Secretion System In A Temperature- And Ph-Sensitive Manner, Karin V. Van Dijk, Derrick E. Fouts, Amos H. Rehm, Angela R. Hill, Alan Collmer, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

We present here data showing that the Avr proteins HrmA and AvrPto are secreted in culture via the native Hrp pathways from Pseudomonas syringae pathovars that produce these proteins. Moreover, their secretion is strongly affected by the temperature and pH of the culture medium. Both HrmA and AvrPto were secreted at their highest amounts when the temperature was between 18 and 22°C and when the culture medium was pH 6.0. In contrast, temperature did not affect the secretion of HrpZ. pH did affect HrpZ secretion, but not as strongly as it affected the secretion of HrmA. This finding suggests that …

Comparison Of Common Cytotypes Of Andropogon Gerardii (Andropogoneae, Poaceae), Kathleen H. Keeler, Geoffrey A. Davis

School of Biological Sciences: Faculty Publications

Many plant species contain populations with more than one polyploid cytotype, but little is known of the mechanisms maintaining several cytotypes in a population. Andropogon gerardii cytotypes were compared to evaluate different models of autopolyploid cytotype coexistence. The enneaploid (90 chromosome, 9x) cytotype was found to be larger and taller than the hexaploid (60 chromosome, 6x) cytotype. Seed production is significantly more efficient in hexaploids, but seed production per area was not significantly different. The two cytotypes are not exomorphologically separable in the field because of great plasticity in response to environmental variation and wide variation …

The Pseudomonas Syringae Pv. Tomato Hrpw Protein Has Domains Similar To Harpins And Pectate Lyases And Can Elicit The Plant Hypersensitive Response And Bind To Pectate, Amy O. Charkowski, James R. Alfano, Gail Preston, Jing Yuan, Sheng Yang He, Alan Collmer

Center for Plant Science Innovation: Faculty Publications

The host-specific plant pathogen Pseudomonas syringae elicits the hypersensitive response (HR) in nonhost plants and secretes the HrpZ harpin in culture via the Hrp (type III) secretion system. Previous genetic evidence suggested the existence of another harpin gene in the P. syringae genome. hrpW was found in a region adjacent to the hrp cluster in P. syringae pv. tomato DC3000. hrpW encodes a 42.9-kDa protein with domains resembling harpins and pectate lyases (Pels), respectively. HrpW has key properties of harpins. It is heat stable and glycine rich, lacks cysteine, is secreted by the Hrp system, and is able to elicit …

Evolutionary Implications Of Meiotic Chromosome Behavior, Reproductive Biology, And Hybridization In 6x And 9x Cytotypes Of Andropogon Gerardii (Poaceae), Guillermo A. Norrmann, Camilo L. Quarín, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Andropogon gerardii, big bluestem, has 60 and 90 chromosome cytotypes. Meiosis in the hexaploid was shown to be regular, although some secondary associations of bivalents form. Meiosis in the enneaploid (2n = 9x = 90) is irregular, leading to most gametes having unbalanced chromosome complements. Both cytotypes show considerable self-incompatibility. Cytotypes crossed freely, forming a variety of fertile euploids and aneuploids. Indistinguishable exomorphology, intermixing in natural populations, and compatibility suggest that A. gerardii is best understood as a cytotypically complex single species.

Identification Of A Brazil-Nut Allergen In Transgenic Soybeans, Julie A. Nordlee, Steve L. Taylor, Jeffrey A. Townsend, Laurie A. Thomas, Robert K. Bush

Department of Food Science and Technology: Faculty Publications

Background: The nutritional quality of soybeans (Glycine max) is compromised by a relative deficiency of methionine in the protein fraction of the seeds. To improve the nutritional quality, methionine-rich 2S albumin from the Brazil nut (Bertholletia excelsa) has been introduced into transgenic soybeans. Since the Brazil nut is a known allergenic food, we assessed the allergenicity of the 2S albumin.

Methods: The ability of proteins in transgenic and nontransgenic soybeans, Brazil nuts, and purified 2S albumin to bind to IgE in serum from subjects allergic to Brazil nuts was determined by radioallergosorbent tests (four …

Movement Of Crop Transgenes Into Wild Plants, Kathleen H. Keeler, Charles E. Turner, Margaret R. Bolick

School of Biological Sciences: Faculty Publications

Despite the great potential and increasing importance of other weed control options (Turner et al. 1992) and unwanted environmental side effects of some herbicides, herbicides constitute a very important means of weed control. The escape of herbicide resistance genes to wild, weedy plants could cause more severe weed problems, and presents a very real threat to the efficacy of herbicides as a weed control option. Therefore, management strategies that prevent, or reduce the likelihood and frequency of HRG escape through containment methods are advisable, as are mitigation plans in the event of HRG escape to wild plants.

Local Polyploid Variation In The Native Prairie Grass Andropogon Gerardii, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

The microscale distribution of polyploid variants of the dominant grass big bluestem (Andropogon gerardii) in virgin tallgrass prairie was mapped using flow cytometry. The correlation between DNA content and polyploidy allows the use of flow cytometry for nondestructive determination of polyploidy in intact plants. At Konza Prairie, local plots contained from 0 to 100% hexaploid cytotypes but most showed fine-scale mixing of the polyploid variants. The relationship of cytotype frequency to moisture availability or burning history was nonsignificant

Origin And Evolution Of Defective Interfering Rnas Of Tomato Bushy Stunt Virus, David A. Knorr, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Viruses with defective genomes have been identified in association with virtually every major family of viruses and have been widely utilized as tools for investigating virus functions in animal cell culture systems (Perrault, 1981). It is generally thought that defective interfering viruses (DIs) arise through deletion, rearrangement, or recombination of a competent viral genome. DIs tack the ability for independent existence relying on their parental helper viruses to supply factors required for replication, maturation, and/or encapsidation (Huang and Baltimore, 1977). The interference attributed to DIs is thought to result from competition with the helper virus for factors required in trans …

Selection Of Stable Cultivars Using A Safety-First Rule, Kent M. Eskridge

Department of Statistics: Faculty Publications

The presence of genotype by environment interaction is of major concern to plant breeders, since large interactions can reduce gains from selection and complicate identification of superior cultivars. Numerous statistics have been proposed to characterize stability of cultivars, yet none of these methods explicitly indicate how stability may be combined with mean yield in choosing superior cultivars. It is assumed that the plant breeder prefers a cultivar with a small probability of low yield. Using a decision-theory concept known as safety-first to model such behavior, an index incorporating mean yield and stability is developed for each of four different definitions …

Can Genetically Engineered Crops Become Weeds?, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

There are significant differences if the distribution of weedy characteristics among weeds, normal plants, and crops. The world’s most serious weeds possess on the average 10 or 11 of these characters, a random collection of British plants have an average seven of the traits, and crop plants only five. For the average crop to become as “weedy” as the average weed, it would need to acquire five weedy traits. Even using the unlikely assumption that those traits are single loci in which a dominant mutation would provide the weedy character, this would require the simultaneous acquisition of five gene substitutions. …

Results Of The Thirteenth International Winter Wheat Performance Nursery Grown In 1981, S. L. Kuhr, C. J. Peterson, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the thirteenth report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station in cooperation with the Agricultural Research Service (ARS), U. S. Department of Agriculture, under contract number AID/ta-C-1093 with the U. S. International Development Corporation, Agency for International Development. The Nursery was designed to (1) test the adaptation and stability of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management regimes, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes; (3) test …

Evaluation Of Crested Wheatgrass Introductions For Forage Yield And Quality, K. P. Vogel, P. E. Reece, J. F. S. Lamb

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Crested wheatgrass, Agropyron cristatum and A. desertorum, are among the most important cool-season forage grasses in the United States and Canada, particularly for reseeding arid range sites. Further improvement in this grass by breeding depends on identifying sources of genetic variability for forage yield and quality. Foreign introductions are an obvious source of genetic variation since crested wheatgrasses are introduced species. In this study 38 accessions (PI lines) and 8 Nebraska experimental lines were evaluated for forage quality as measured by in vitro dry matter digestibility (IVDMD) and protein content and for forage yield. The cultivars 'Ruff' and 'Nordan' …

Results Of The Twelfth International Winter Wheat Performance Nursery Grown In 1980, S. L. Kuhr, C. J. Peterson, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the twelfth report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station in cooperation with the Agricultural Research Service (ARS), U.S. Department of Agriculture, under contract number AID/ta-C-1093 with the U.S. International Development Corporation, Agency for International Development. The Nursery was designed to (1) test the adaptation and stability of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management regimes, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes; (3) test the degree …

Results Of The Eleventh International Winter Wheat Performance Nursery Grown In 1979, S. L. Kuhr, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the eleventh report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station in cooperation with the Agricultural Research Service (ARS), U.S. Department of Agriculture, under contract number AID/ta-C-1093 with the U.S. International Development Corporation, Agency for International Development. The Nursery was designed to (1) test the adaptation and stability of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management regimes, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes; (3) test the degree …