http://hdl.handle.net/1957/18801 Sun, 19 May 2013 22:16:40 GMT 2013-05-19T22:16:40Z http://hdl.handle.net/1957/38305 Cultivation and Irrigation of Fernleaf Biscuitroot (Lomatium dissectum) for Seed Production Shock, Myrtle P.; Shock, Clinton C.; Feibert, Erik B. G.; Shaw, Nancy L.; Saunders, Lamont D.; Sampangi, Ram K. Native grass, forb, and shrub seed is needed to restore rangelands of the U.S. Intermountain West. Fernleaf biscuitroot [Lomatium dissectum (Nutt.) Mathias & Constance] is a desirable component of rangelands. Commercial seed production is necessary to provide the quantity and quality of seed needed for rangeland restoration and reclamation efforts. Fernleaf biscuitroot has been used for hundreds if not thousands of years in the western United States as a source of food and medicine. Knowledge about fernleaf biscuitroot is confined to ethnobotanical reports, evaluation of some of its chemical constituents, and its role in rangelands. Products derived from fernleaf biscuitroot are sourced from wild plant populations. Little is known about fernleaf biscuitroot cultivation or its seed production. Variations in spring rainfall and soil moisture result in highly unpredictable water stress at flowering, seed set, and seed development of fernleaf biscuitroot. Water stress is known to compromise seed yield and quality for other seed crops. Irrigation trials were conducted at the Oregon State University Malheur Experiment Station at Ontario, OR, a location within the natural environmental range of fernleaf biscuitroot. It was anticipated that supplemental irrigation would be required to produce a seed crop in all years. Fernleaf biscuitroot was established through mechanical planting and cultivation on 26 Oct. 2005 in a randomized complete block design with four replicates; plot size was 9.1 m × 3.04 m wide. Irrigation treatments were 0 mm, 100 mm, and 200 mm/year applied in four equal treatments 2 weeks apart, timed to begin with flowering and continue through seed formation. First flowering occurred in the third year after planting. Seed production increased from the fourth through the sixth year. Optimal irrigation for seed production was calculated as 140 mm/year. This is a scanned version of a published article. The original can be found at: http://hortsci.ashspublications.org/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Mon, 01 Oct 2012 00:00:00 GMT http://hdl.handle.net/1957/38305 2012-10-01T00:00:00Z http://hdl.handle.net/1957/38170 Effects of elevated CO2 and temperature on seed quality Hampton, J. G.; Boelt, B.; Rolston, M. P.; Chastain, T. G. Successful crop production depends initially on the availability of high-quality seed. By 2050 global climate change will have influenced crop yields, but will these changes affect seed quality? The present review examines the effects of elevated carbon dioxide (CO₂) and temperature during seed production on three seed quality components: seed mass, germination and seed vigour. In response to elevated CO₂, seed mass has been reported to both increase and decrease in C₃ plants, but not change in C₄ plants. Increases are greater in legumes than non-legumes, and there is considerable variation among species. Seed mass increases may result in a decrease of seed nitrogen (N) concentration in non-legumes. Increasing temperature may decrease seed mass because of an accelerated growth rate and reduced seed filling duration, but lower seed mass does not necessarily reduce seed germination or vigour. Like seed mass, reported seed germination responses to elevated CO₂ have been variable. The reported changes in seed C/N ratio can decrease seed protein content which may eventually lead to reduced viability. Conversely, increased ethylene production may stimulate germination in some species. High-temperature stress before developing seeds reach physiological maturity (PM) can reduce germination by inhibiting the ability of the plant to supply the assimilates necessary to synthesize the storage compounds required for germination. Nothing is known concerning the effects of elevated CO₂ on seed vigour. However, seed vigour can be reduced by high-temperature stress both before and after PM. High temperatures induce or increase the physiological deterioration of seeds. Limited evidence suggests that only short periods of high-temperature stress at critical seed development stages are required to reduce seed vigour, but further research is required. The predicted environmental changes will lead to losses of seed quality, particularly for seed vigour and possibly germination. The seed industry will need to consider management changes to minimize the risk of this occurring. This is the publisher’s final pdf. The published article is copyrighted by Cambridge University Press and can be found at: http://www.cambridge.org/. Fri, 30 Mar 2012 00:00:00 GMT http://hdl.handle.net/1957/38170 2012-03-30T00:00:00Z http://hdl.handle.net/1957/38080 Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill] Park, Kee Woong; Kolkman, Judith M.; Mallory-Smith, Carol A. Suspected thifensulfuron resistant spiny annual sow-thistle was identified near Colfax, Washington, in two fields with a winter wheat and lentil rotation. Therefore, studies were conducted to examine resistance of spiny annual sow-thistle to thifensulfuron and cross-resistance to other acetolactate synthase inhibitors and to determine the physiological and molecular basis for herbicide resistance. Whole-plant bioassay confirmed that the biotype was highly resistant to the sulfonylurea (SU) herbicides, thifensulfuron, metsulfuron, and prosulfuron. The resistant (R) biotype was also highly resistant to the imidazolinone (IMI) herbicides, imazamox and imazethapyr. An in vivo acetolactate synthase (ALS) assay indicated that the concentrations of SU and IMI herbicides required for 50% inhibition (I₅₀) were more than 10 times greater for R biotype compared with susceptible (S) biotype. Analysis of the nucleotide and predicted amino acid sequences for ALS genes demonstrated a single-point mutation from C to T at the als1 gene, conferring the substitution of the amino acid leucine for proline in the R biotype at position197. The results of this research indicate that the resistance of spiny annual sow-thistle to SU and IMI herbicides is due to on altered target site and caused by a point mutation in the als1 gene This is the publisher’s final pdf. The published article is copyrighted by the Agricultural Institute of Canada and can be found at: http://pubs.aic.ca/journal/cjps. Thu, 01 Mar 2012 00:00:00 GMT http://hdl.handle.net/1957/38080 2012-03-01T00:00:00Z http://hdl.handle.net/1957/37903 Camelina: Seed Yield Response to Applied Nitrogen and Sulfur Wysocki, Donald J.; Chastain, Thomas G.; Schillinger, William F.; Guy, Stephen O.; Karow, Russell S. Camelina (Camelina sativa L. Crantz) has received worldwide attention in recent years as a biofuel crop and as a broadleaf option in cereal-based cropping systems. The objective of our 3-year study was to determine camelina seed yield and nitrogen use efficiency (NUE) as affected by six applied nitrogen (N) rates at four rainfed sites in the Pacific Northwest (PNW) of the United States. An N + sulfur (S) variable was also included. Seed oil content as affected by applied N and S was also evaluated in 2010. The four sites and their average annual crop-year precipitation during the three years were Lind, WA (228 mm); Pendleton, OR (421 mm); Moscow/Pullman, ID (695 mm); and Corvallis, OR (1085). The majority of precipitation occurs in the winter and summers are comparatively dry. Camelina responded differently to applied N among sites based upon precipitation and available soil N. Seed yield did not respond to N rate treatments at Lind, presumably due to sufficient soil residual N and limited precipitation. Seed yield increased with applied N at Pendleton, Moscow/Pullman, and Corvallis. Optimum applied N rates ranged from 0 to 90 kg ha-1 depending on annual precipitation and soil available N. Maximum seed yield increases attributable to applied N ranged from 19% at Pendleton to 93% at Moscow/Pullman. Camelina NUE was greatest at Moscow/Pullman although it decreased gradually with increasing applied N rates at all sites. Lind, Pendleton, and Corvallis had the same NUE of -0.06 kg seed for every kg of available N. Camelina did not respond to applied S at any site. Seed oil content was not affected by applied N or S. Based upon the results of this study, camelina requires about 12 kg N ha⁻¹ per 100 kg of expected seed yield. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/field-crops-research/. Mon, 01 Apr 2013 00:00:00 GMT http://hdl.handle.net/1957/37903 2013-04-01T00:00:00Z