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Ellen T. Paparozzi, Walter W. Stroup and M. Elizabeth Conley

1 Dept. of Agronomy and Horticulture. For reprint requests, email address: etp1@unl.edu 2 Dept. of Statistics. Plant material was donated by Ecke's Poinsettias Inc. This article is submitted as Nebraska Agricultural Research Division journal series

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T.R. Willard, C.M. Peacock and D.G. Shilling

1 Former Graduate Research Assistant, Dept. of Agronomy. Current address: W.R. Landis Assoc., Inc., 102 N. Lee St., Valdosta, GA 31603-5126. 2 Associate Professor, Ornamental Horticulture Dept. Current address: Dept. of Crop Science, North Carolina

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Steven J. Guldan, Charles A. Martin, Jose Cueto-Wong and Robert L. Steiner

1 Alcalde Sustainable Agriculture Science Center and Dept. of Agronomy and Horticulture. 2 Dept. of Agronomy and Horticulture. 3 Dept. of Experimental Statistics. A contribution of the New Mexico Agricultural Expt. Station, New Mexico State

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Steven J. Guldan, Charles A. Martin, Jose Cueto-Wong and Robert L. Steiner

1 Alcalde Sustainable Agriculture Science Center and Dept. of Agronomy and Horticulture. 2 Department of Agronomy and Horticulture. 3 Department of Experimental Statistics. A contribution of the New Mexico Agricultural Expt. Station, New

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I.E. Yates, E.A. Carter, T.A. Wilkins and B.W. Wood

1 Current address: Dept. of Agronomy, Texas Tech Univ., Lubbock, TX 79409. 2 Current address: Dept. of Agronomy and Range Science, Univ. of California, Davis, CA 95616. The technical expertise of Donnie Maxey in the preparation of photomicrographs

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Brian J. Just* and Philipp W. Simon

While the carotenoid biosynthetic pathway has been studied several horticultural and agronomic crops, very little information exists for this conserved pathway in carrot, a primary source of dietary carotenoids. Though orange carrots are the most familiar color to Western consumers, yellow, red, and white carrots also exist and have been historically important. Modern carrot breeders are showing renewed interest in these unusual color phenotypes. Beta- and alpha-carotene are the primary pigments in orange carrot roots. Yellow carrots accumulate xanthophylls (oxygenated carotenes), red carrots accumulate lycopene (the precursor to alpha- and beta-carotene), and white carrots accumulate no detectable pigments. Differences between these phenotypes are usually monogenic or oligogenic. Our research has focused on identifying putative genes for carotenoid biosynthetic enzymes in the carrot genome, mapping them, and examining expression patterns in various tissues and carrot root pigment phenotypes. We are using this information to create a carrot pigment biosynthesis function map incorporating biosynthetic enzymes, major carrot color genes, and gene expression information.

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J. Nienhuis, P. Skroch, M. Sass, S. Beebe, J. Tohme and F. Pedraza

The number of Phaseolus vulgaris germplasm accessions numbers more than 30,000. While the large numbers of accessions increase the probability of preserving genetic variability they simultaneously limit the efficient and routine utilization of this resource. From the approximately 4000 P. vulgaris accessions in the C.I.A.T. whole collection that were collected in Mexico, a core collection of 400 accessions was developed based on variation for agronomic performance, ecological adaptation, and seed characteristics. Random samples of 90 accessions each were drawn from the core and whole collections and evaluated for 224 polymorphic RAPD bands. Based on analysis of the RAPD data there were no significant differences in genetic diversity between the two samples. The correlation of marker frequency for the two samples was 0.984 confirming that the two samples represent the same population.

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Wes Messinger, Aaron Liston and Kim Hummer

The Pacific Northwest boasts a remarkable diversity of wild currants and gooseberries (Ribes). Of nearly 150 species worldwide, 34 occur in the region. All but two infrageneric taxa are represented, including close relatives of the black currants, red currants, and cultivated gooseberries. High ecological diversity parallels this taxonomic diversity: a Ribes species occurs in nearly every terrestrial habitat, from sea level to above treeline, and from swamp to desert. This diversity is a valuable source of agronomically important genes for the plant breeder. In addition, wild Ribes represent a relatively unexplored source of ornamental shrubs. Habit and habitat of a number of species of interest are described and illustrated. An annotated list of species, subspecies, and varieties native to the Pacific Northwest is presented with discussion of taxonomic proximity to Cultivated varieties, range, natural habitat, and ornamental potential.

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M. Rawgappa, H.L. Bhardwaj, A.I. Mohamed, M.E. Showhda and M.E. Kraemer

Thirty-five mint accessions were evaluated during 1993 for agronomic characteristics (leaf texture, color, and pubescence), plant vigor, cold hardiness, insect population interactions, and contents of essential oils, ash, and total protein. These accessions were obtained from National Clonal Germplasm Repository, Corvallis, Oregon during 1992. The rhizomes were planted in the greenhouse on April 2, 1992 and transplanted to the field on May 29, 1992 as a randomized complete block design with three replications. The chemical composition data from whole plants indicated that ash content was dependent upon location from which an accession was collected, ploidy level (diploid vs. polyploid), type of mint (peppermint vs. spearmint), and genetics (hybrid vs. non-hybrid). Diploid accessions had significantly higher essential oil content. The protein content was higher in peppermint types than spearmint types. The hybrid accessions had lower protein content in comparison to non-hybrids.

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Monica Ozores-Hampton and Deron R. A. Peach

Land application and landfilling are the most common destination for biosolids in the United States. When properly treated and managed in accordance with the existing state and federal regulations and standards, biosolids are safe for the environment and human health. Application of biosolids in vegetable production as an organic amendment to soils can increase plant growth and produce comparable crop yields with less inorganic nutrients than a standard program of commercial synthetic fertilizers. No application rate of treated biosolids alone will produce crop yields equivalent to commercial fertilizers. Biosolids may be used in conjunction with fertilizer thus lessening the application rate required. The major obstacles to public acceptance are issues concerning water pollution, risk of human disease, and odors. Additionally, heavy metals are an issue of bias with public perception. To ensure safe use of biosolids to a vegetable production systems the agronomic rate (nutrient requirement of the vegetable crop grown) should be calculated before application for the specific crop.