Search

Resistance to strawbreaker foot rot (caused by Oculimacula yallundae Crous & W. Gams and O. acuformis Crous & W. Gams), stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici iformisEriks.), and Cephalosporium stripe (caused by Cephalosporium gramineum Nisikado and Ikata) are important traits for winter wheat ( Triticum aestivum L.) cultivars produced in the Pacific Northwest region of the United States. The objective of this research was to develop an adapted winter wheat cultivar with effective resistance to these diseases. ‘Puma’ (Reg. No. CV-1097, PI 670038) soft white winter wheat ( Triticum aestivum L.) was developed and released in August 2013 by the Agricultural Research Center of Washington State University. Puma was tested under the experimental designations 5J030731, 5J030731–2, and WA008134, which were assigned through progressive generations of advancement. Puma is a semidwarf cultivar adapted to intermediate to high rainfall (>400 mm of average annual precipitation), unirrigated wheat production regions of Washington. Puma is resistant to strawbreaker foot rot, has high-temperature, adult-plant resistance to the stripe rust pathogen, is tolerant to Cephalosporium stripe, is intermediate in height, has midseason maturity, and has a high test weight and grain yield potential. Puma has end-use quality properties similar or superior to those of ‘Stephens’, ‘Brundage 96’, and ‘Xerpha’.

Many of the current soft white winter (SWW) wheat (Triticum aestivum L.) cultivars produced in Washington are adapted to specifi c environments. The objective of this research was to develop a high yielding, disease resistant SWW cultivar with competitive yield potential for all Washington winter wheat production environments. 'Xerpha' (Reg. No. CV-1045, PI 645605) SWW wheat was developed by the Agricultural Research Center of Washington State University (WSU) and released in 2008. It was selected from an 'Eltan'/'Estica' cross made in 1999 and advanced to the F 5 in the greenhouse by a modifi ed single seed descent breeding strategy. Successive progeny were advanced under fi eld conditions by a modifi ed pedigree-bulk breeding method under the experimental designations SSD01061 and eventually WA007973. Xerpha was the highest, or among the highest, yielding SWW cultivars in every precipitation zone in the WSU Extension Uniform Cereal Variety Testing Program (EUCVTP) trials in 2006, 2007, and 2008. It was released as a replacement for 'Madsen' and Eltan on the basis of its superior grain yield in Washington's low ( 500 mm AAP) precipitation zones; excellent grain volume weight; strong cold tolerance, and high-temperature, adult-plant (HTAP) resistance to stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici).

Selection of winter wheat cultivars with long coleoptiles is an important component of improving emergence, weed suppression and grain yield in low rainfall regions of the world. Seven winter wheat cultivars were hybridized in a Griffing’s half-diallel mating design, method 2 (reciprocals excluded, parents included), model 1 (fixed), and the progeny analyzed for coleoptile length in the F1 through F4 for response to selection, general combining ability (GCA), specific combining ability (SCA) and heritability. Highly significant differences existed for GCA among progeny in each generation. SCA was highly significant in the F1, F2 and F4, although SCA estimates were inconsistent among generations in each progeny population. The SCA/GCA ratio was 0.15, 0.11, 0.06 and 0.04 in the F1 through the F4, respectively, indicating that additive effects increased with homozygosity. Broad-sense heritability for coleoptile length was estimated at 0.86, 0.76, 0.60 and 0.78 for the F1 through the F4, respectively. Realized heritabilities ranged from −0.16 to 0.85 with a mean of 0.32 in the F3 and ranged from −0.68 to 0.68 with a mean of 0.13 in the F4. Spearman’s rank correlation coefficients (RS) were significant for all generation comparisons except the F1:F2, indicating that changes in rank for coleoptile length were insignificant. Cultivars with long coleoptiles and high GCA were the best parents for improving coleoptile length. Sustained selection over generations for coleoptile length was more effective than one generation of selection for genotypes both with and without reduced height genes.

Public health concerns about pathogens present in animal manure are emerging constraints to water supplies in many areas of the world. The objective of this study was to examine the microbial community composition in aquifer material impacted by contaminants from different sources. Total microbial community profiles were compared by using eubacterial primers to amplify 16S rRNA genes from total bacterial DNA and RNA. PCR and reverse transcriptase (RT) PCR were used to amplify 16S ribosomal RNA, and the products were subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis of RT-PCR products detected a subset of bands visible in the DNA-based analysis, indicating that some dominantly detected bacterial populations did not have high levels of metabolic activity. The sequences detected by the RT-PCR approach were, however, derived from a wide taxonomic range, suggesting that the activity in the aquifer sand material was not determined at broad taxonomic levels but rather was a strain- or species-specific phenomenon. Comparative analysis of DGGE profiles grouped all DNA-derived aquifer samples together in a cluster. At the end of the experimental period, the aquifer material entered a stable population state, which was characterized by a greater diversity of DNA-based fingerprints compared to viable bacteria. Our data showed that the active members of the community are a sub-population of that community that performs certain biological functions during water filtration through aquifer material. Therefore, recharging surface water through aquifer sand material may produce a microbial population quite different from the input source due to the availability of nutrients for bacterial growth.

Organic and low-input farmers often plant seed varieties that have been selected under conventional practices, traditionally including high inputs of artificial fertilizers, crop protection chemicals and/or water. In addition, these crops are often selected in environments that may or may not represent the local environment of the farmer. An evolutionary participatory breeding (EPB) method emphasizes the utilization of natural selection in combination with site-specific farmer selection in early segregating generations of a heterogeneous crop population. EPB is a combination of two specific breeding methods, evolutionary breeding and participatory plant breeding. Evolutionary breeding has been shown to increase yield, disease resistance, genetic diversity and adaptability of a crop population over time. It is based on a mass selection technique used by farmers for over 10,000 years of crop improvement. Participatory plant breeding programs originated in developing countries to meet the needs of low-input, small-scale farmers in marginal environments who were often overlooked by conventional crop breeders. The EPB method is an efficient breeding system uniquely suited to improving crop varieties for the low-input and organic farmer. The EPB method utilizes the skills and knowledge of both breeders and farmers to develop heterogeneous landrace populations, and is an effective breeding method for both traditional and modern farmers throughout the world.

Surface- and ground-water quality in the Chino-Santa Ana River Basin, California is a major source of drinking water supply for the Los Angeles metropolitan area. This water source is significantly degraded due to intensive dairy operations and the disposal of untreated wastewater into the Chino Basin. Constructed wetlands have been recognized as a treatment option for the removal of high concentrations of contaminants in agricultural waste water prior to land application. The goal of this study was to characterize the fate and transport of chemical contaminants and pathogens in a constructed wetland system and to determine the diversity of ammonia oxidizing bacteria that were responsible for nitrogen mineralization in the wetlands. Water samples were collected weekly for 11 months from two wetlands to determine the efficiency of the treatment system in removal of chemical contaminants, total/fecal coliforms and Escherichia coli. Reduction by the treatment was greatest for biological oxygen demand (BOD), suspended solids, chemical oxygen demand (COD), nitrate, and coliforms. There was only moderate removal of total nitrogen and phosphorus. The population of ammonia-oxidizing bacteria showed a higher percentage of Nitrosospira-like sequences from the wetland samples, compared to a higher percentage of Nitrosomonas-like sequences from manure, feces, raw washwater and facultative pond. These results demonstrate that the wetland system is a natural process dependent upon the development and maintenance of healthy microbial communities for optimal wastewater treatment in reducing dairy waste in the Santa Ana watershed quality

With 4 tables Abstract Perennial wheat is emerging as a potential long-term response to agroecological problems resulting from soil erosion. We conducted field scale trials of 31 F5 (2005–2006) and five F6 (2006–2007) amphiploid breeding lines derived from Thinopyrum elongatum/Triticum aestivum (cv. ‘Chinese Spring’)//T. aestivum (cv. ‘Madsen’) crosses. Here, we report results on post-sexual cycle regrowth (PSCR) and grain yield in the amphiploid lines and two annual wheat cultivars from three locations in Washington State, USA. Per cent plants per plot exhibiting PSCR varied significantly among genotypes and ranged from 18% to 81% (μ = 45%) in the amphiploids, with no PSCR apparent in the annual cultivars. The mean grain yields of the amphiploid lines were 632, 2086 and 2226 kg/ha at each location; approximately 44% (range = 20–93%) of the annual wheat. Absence of genotype × environment interactions for PSCR suggests that selection for broad adaptation of the PSCR trait across locations and years would be possible. No relationship existed between grain yield and regrowth among the lines exhibiting PSCR, indicating potential for simultaneous selection of these traits.

Four compounds analogous to the humite minerals were synthesized in the system Mg2GeO4-MgF2 by crystallization from melts and solid state reaction techniques. Precise optical and X-ray diffraction data were obtained. Several other phases were observed within the system MgO-GeO2-MgF2.

Thermodynamic and melting experiments indicate considerable potential for the use of nonstoichiometric yttria as a crucible material for cold-wall induction melting of titanium metal. Experiments have shown that substoichiometric (reduced) Y2O3−x offers more resistance to attack by molten titanium, due to lower oxygen potential, but is subject to increased uptake of yttrium into solution. Yttria reacts with and contaminates molten titanium having greater than 100 °C superheat and where the crucible temperature is equal to or exceeds the melt temperature. The yttrium taken into solution, however, scavenges oxygen from the titanium solution and precipitates as Y2O3−x, reducing interstitials to acceptable levels. Normal cold-wail induction melting, using greater metal mass to contact area in a substoichiometric yttria crucible, should yield high quality titanium metal, comparable to some grades of present commercially pure metal. Development of the crucible material is continuing with studies of larger cold-...

The vertical section Ti-ZrO2 within the Ti-Zr-O system was investigated by metallographic, X-ray diffraction, electron probe, and melting point studies. Analyses were conducted using arcmelted specimens which had been equilibrated and quenched from temperatures of 600° to 1600°C. The Ti-ZrO2 section is similar to the Zr-ZrO2 system. At high temperatures, considerable amounts of Zr and O go into solid solution in Ti, stabilizing α-Ti to 30 wt% ZrO2. From 30 to 98 wt% ZrO2 an α-Ti+ZrO2 region is defined, and at compositions above 98 wt% ZrO2, single-phase ZrO2(ss) exists. At low temperatures an α-Ti+(Ti,Zr)3O field exists from 22 to 32 wt% ZrO2; this region decreases in size with increasing temperature until it disappears at 1200°C. Above 32 wt% ZrO2, a three phase α-Ti+ (Ti,Zr)3O+ZrO2 field exists; its stability extends from 1200°C at 30 wt%

Diffusion bonding is presently under development as a manufacturing process for large complex structures. It is particularly advantageous for titanium alloy structures due to titanium’s ability to dissolve its own oxide, and it overcomes the problem associated with low hardenability and poor grain refinement in heavy sections. The size and complexity of aircraft parts frequently require immense slabs of plate material or huge forgings, the latter requiring very large presses, which in turn are machined to a small fraction of the original weight. Fabrication of a large complex shape by diffusion bonding offers the potential of immediate savings in material and machining requirements.

Within the last two decades, titanium and titanium-base alloys have been produced and metallurgically developed for critical aerospace applications. Titanium alloys, through government and industrial R&D, are now produced for structural use as well as for critical rotating engine components. The success of titanium and titanium alloys has been realized in spite of its higher cost brought on, in part, by limitations in melting technology.

The infrared spectra of oxidation films on titanium show an asymmetrical absorption band at 828 ${\mathrm{cm}}^{\ensuremath{-}1}$ not found as an infrared-active mode in single-crystal Ti${\mathrm{O}}_{2}$. It is identified as two superposed longitudinal-optical modes at approximately 828 and 809 ${\mathrm{cm}}^{\ensuremath{-}1}$ on the basis of optical tests and theoretical predictions.