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Montana Agricultural Experiment Station; Montana Wheat and Barley Committee; Hatch project (MONB00298)

The goal of this project was to determine the genetic basis for quality differences between a modern semidwarf spring wheat (Triticum aestivum L.) cultivar McNeal and a historically important standard height cultivar Thatcher. McNeal is higher yielding with lower grain protein than Thatcher, yet has stronger gluten properties important in bread making. Grain from a total of 160 recombinant inbred lines including 80 semidwarf and 80 standard-height lines grown in three environments was tested for bread-making quality. A genetic map of 609 markers was used to identify bread-making quality quantitative trait loci (QTL) influencing flour protein, dough mixing, and baking properties. The McNeal allele for semidwarf habit at Rht-D1 had the largest impact on end-use quality parameters, including flour protein and loaf volume. The primarily negative impact of this allele on quality in McNeal was mitigated by alleles for increased dough strength at other QTL. The allele with the greatest effect on strength was at Gli-B1. Other alleles for increased end-use quality, especially alleles impacting flour protein, tended to be negatively associated with previously identified alleles for grain yield and its components. In sum, this paper shows that the introduction of the Rht alleles for semidwarf habit have presented a challenge to the maintenance of superior end-use quality in modern hard red spring wheat cultivars.

‘Egan’ hard red spring wheat (Triticum aestivum L.) (Reg. No. 1102, PI 671855) was developed by the Montana Agricultural Experiment Station and released in 2014. Egan is intended for production in areas of Montana infested with the orange wheat blossom midge (OWBM) (Sitodiplosis mosellana Gehin). Egan is resistant to OWBM due to antibiosis conferred by resistance gene Sm1. Egan also contains a chromosome segment originally introgressed into wheat from T. turgidum ssp. dicoccoides containing a gene for high protein (Gpc-B1) and a gene for stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici) resistance (Yr36). Egan has shown high yield potential and high grain protein in nurseries grown under OWBM pressure in the Flathead Valley of Montana. Egan is the first hard red spring wheat cultivar with resistance to OWBM developed for Montana.

‘Warhorse’ (Reg. No. CV-1096, PI 670157) hard red winter (HRW) wheat (Triticum aestivum L.) was developed and released by the Montana Agricultural Experiment Station in September 2013. Warhorse is of unknown pedigree, derived from a composite of three topcrosses made to the same F 1 population in 2000: MT9908//‘Nuplains’/MTS9862; Nuplains/ MTS9862//MTW0047; and Nuplains/MTS9862//MTS0028. Warhorse was developed using a modified bulk breeding method and selected as an F 5:6 headrow. Warhorse was tested under the experimental number MTS0808 from 2008 to 2013 in Montana. Quality was evaluated in multilocation Montana trials since 2008. Warhorse is a solid-stem, high-yielding HRW wheat line with medium to high test weight, medium maturity, reduced height (Rht-B1b), medium to high grain protein, and acceptable milling and baking quality. Warhorse was released for its improved host plant resistance to wheat stem sawfly (Cephus cinctus Nort.) conditioned by stem solidness, along with short stature and improved yield potential relative to existing solid-stem cultivars adapted to Montana.

Molecular markers for the red grain color (R) loci controlling seed color and the polyphenol oxidase (Ppo-A1) locus controlling polyphenol oxidase (PPO) activity in seed have recently been developed. These markers provided the opportunity to convert the hard red spring wheat cultivars Choteau and Hank to white-seeded versions with high and low PPO levels, respectively. These sets of near-isogenic lines provided material to test the effects of seed color and PPO activity on a range of end-use quality traits. We tested recurrent parents Choteau and Hank, along with near-isogenic derivatives with white seed, in two replicated trials in Bozeman, Montana, for end-use quality parameters. The white-seeded lines consisted of both high- and low-PPO near-isogenic lines. The primary impact of white seed was the production of whole wheat bread with a perceived sweeter taste relative to the red-seeded lines. Noodle color was not consistently impacted by the level of PPO variation despite relatively large redu...

Polyphenol oxidase (PPO) activity is a factor in time-dependent discoloration of Asian noodles. At least two major genes Ppo - A1 and Ppo - D1 control kernel PPO activity in wheat. The goal was to determine the relative importance of allelic variation for Ppo - A1 and Ppo - D1 on Chinese raw noodle color profile and kernel and flour characteristics using a winter wheat recombinant inbred population segregating for Ppo - A1 and Ppo - D1 . Ppo - A1 allelic variation explained 80% and Ppo - D1 allelic variation explained 2% of the variation in kernel PPO activity. The low PPO allele at each locus gave noodles that were brighter (greater L*), more yellow (greater b*) and more red (greater a*) at 24 h, and noodles with less change in L* but more change in a* and b* with time (0–24 h). The two loci combined explained 27, 35, and 17% of variation in L*, a*, and b* at 24 h, and 51, 55, and 58% of the variation in change in L*, a*, and b* with time, respectively. Allelic variation at Ppo - D1 explained a larger percentage of variation than did Ppo - A1 in each case except b* at 24 h where the two loci explained equal amounts.

Consumers prefer noodles with a bright creamy color that maintains with time. High levels of polyphenol oxidase (PPO) activity and high flour protein are associated with darker noodles. A major gene on chromosome 2A in wheat controls substantial variation in PPO activity. Our goal was to determine the impact of selecting for Ppo-A1 allelic differences and high vs. low protein on white salted noodle, bread, and agronomic traits. Two winter wheat (Triticum aestivum L.) populations were created that segregated for grain protein concentration and for Ppo-A1a (high PPO) and Ppo-A1b (low PPO). Four selection populations were created by divergent selection for grain protein, followed by selection of Ppo-A1a and Ppo-A1b alleles within the high and low grain protein groups. The selection populations were evaluated in replicated trials in two environments. White salted noodle and bread quality and agronomic traits were measured using four lines from each selection population. The Ppo-A1a vs. Ppo-A1b classes differed by 0.40 ΔA 475 min -1 g -1 and the high- vs. low-protein classes differed by 17 g kg -1 in grain protein. The high-protein class yielded 8.6% less than the low-protein group. Ppo-A1 allelic class had no affect on agronomic traits. High-protein class gave higher loaf volume, but Ppo-A1 allelic class difference did not affect bread quality. Ppo-A1 allelic class did not affect noodle brightness (L*) at 0 or 24 h, but Ppo-A1a class showed greater change in L* with time. High protein gave darker noodles at both 0 and 24 h and greater change in L* with time. Ppo-A1 allelic class did not affect noodle texture, but noodles were more firm with high protein compared with low protein. Ppo-A1 allelic class and protein effects on noodle and bread traits were additive.

A negative relationship between dough strength and dough extensibility would pose a problem for breeding hard wheats, as both dough strength and dough extensibility are desirable. We derived 77 recombinant inbred lines (RIL) from a cross between hard red spring wheat cultivars McNeal and Thatcher. McNeal produces flour with stronger dough and lower extensibility than does Thatcher. RIL were evaluated for strength-related properties using mixograph analysis and extensibility parameters using the Kieffer attachment to the TA.XT2 texture analyzer. Additionally, the RIL were test baked. Measurements using the mixograph and the Kieffer attachment were highly heritable. Maximum dough extensibility (Extmax) was negatively correlated with resistance to extension (Rmax) (r = -0.74) and with mixograph tolerance (r = -0.45). Loaf volume was correlated with both Rmax (r = 0.42) and area under the extensigraph curve (r = 0.44) based on partial correlation analysis adjusted for protein differences. Extmax was ...

Polyphenol oxidase (PPO) (EC.1.14.18.1) activity has been shown to be related to time-dependent discoloration of Asian noodles. Our objective was to determine the impact of divergent selection for PPO activity on agronomic, milling, bread baking, and Chinese raw noodle quality traits in winter wheat (Triticum aestivum L.) populations. Progeny from seven winter wheat populations were selected for high or low PPO activity by the L-3,4-dihydroxyphenylalanine (L-DOPA) assay on whole kernel meal on the basis of a single replication with equal number of high and low lines in each population. The selected lines were evaluated in replicated trials in multiple environments. Agronomic, milling, bread baking, and Chinese raw noodle traits were measured for all entries. The high versus low PPO classification was confirmed from replicated trials with no overlap between low and high PPO lines for any of the populations. Divergent selection had no impact on agronomic traits except for heading date where low PPO lines averaged 1 d later to head than high PPO lines. Flour ash averaged 0.11 g kg -1 higher for low compared with high PPO lines, but flour protein and flour yield did not differ between groups. The low PPO selection group had weaker dough, as reflected by lower mixograph tolerance, and lower crumb grain scores. Chinese raw noodle texture was altered by divergent selection so that the low PPO group produced noodles that were less elastic, sticky, and chewy than the high PPO group. Chinese raw noodles became darker (lower L*), more yellow (greater b*), and more red (greater a*) with time. Low PPO lines averaged less change in L* (8.9 vs. 9.6) but more change in b* (-7.70 vs. -7.02) and a* (-0.74 vs. -0.62) than high PPO lines over 24 h. Whether these changes in noodle color and texture are desirable may depend on the type of noodle and regional and personal preferences.

The MHC class II loci encoding cell surface antigens exhibit extremely high allelic polymorphism. There is considerable uncertainty in the literature over the relative roles of recombination and de novo mutation in generating this diversity. We studied class II sequence diversity and allelic polymorphism in two populations of Peromyscus maniculatus, which are among the most widespread and abundant mammals of North America. We find that intragenic recombination (or gene conversion) has been the predominant mode for the generation of allelic polymorphism in this species, with the amount of population recombination per base pair exceeding mutation by at least an order of magnitude during the history of the sample. Despite this, patchwork motifs of sites with high linkage disequilibrium are observed. This does not appear to be consistent with the much larger amount of recombination versus mutation in the history of the sample, unless the recombination rate is highly non-uniform over the sequence or selection maintains certain sites in linkage disequilibrium. We conclude that selection is most likely to be responsible for preserving sequence motifs in the presence of abundant recombination.

The composition, transparency, refractive index, and infrared reflectance of yttria-stabilized cubic hafnia (c-HfO(2)) single crystals were measured. The material is transparent from the ultraviolet to the mid-infrared and for 9.6-mol % Y(2)O(3), the index is slightly smaller than for comparable cubic zirconia c-ZrO(2) or for diamond, but the dispersion (n(F) - n(c) = 0.02811) is larger than that of diamond. The index vs wavelength from 0.36 microm in the ultraviolet to 5.0 microm in the infrared is represented by a three-term Sellmeier formula to 1 x 10(-4). The temperature dependence of refractive index is similar to that of c-ZrO(2). The infrared reflectance spectrum is fitted in a classical dispersion analysis with seven oscillators derived from the transverse optical phonon as well as acoustic frequencies with splittings due to lowered symmetry derived from the randomly distributed stabilizer ions.

Progress in understanding the evolution of variation at the MHC has been slowed by an inability to assess the relative roles of mutation vs. intragenic recombination in contributing to observed polymorphism. Recent theoretical advances now permit a quantitative treatment of the problem, with the result that the amount of recombination is at least an order of magnitude greater than that of mutation in the history of class II genes. We suggest that this insight allows progress in evaluating the importance of other factors affecting the evolution of the MHC. We investigated the evolution of MHC class II Eβ sequence diversity in the genus Peromyscus. We find evidence for extensive recombination in the history of these sequences. Nevertheless, it appears that intragenic recombination alone is insufficient to account for evolution of MHC diversity in Peromyscus. Significant differences in silent variation among subgenera arose over a relatively short period of time, with little subsequent change. We argue that these observations are consistent with the effects of historical population bottleneck(s). Population restrictions may explain general features of MHC evolution, including the large amount of recombination in the history of MHC genes, because intragenic recombination may efficiently regenerate allelic polymorphism following a population constriction.

A computerized direct reading emission spectrometer has been constructed to perform rapid spectrochemical analyses. The four essential components include a prism-echelle spectrograph to disperse light from the source, a proximity-focus image intensifier to convert ultraviolet radiation to visible, a random-access digital television camera to measure the intensities of many wavelengths simultaneously, and a dedicated minicomputer for control, data processing, and output. At the present stage of development, the intensities of 400 analytical lines can be measured every second during the excitation of a sample and the results can be summed, averaged, or displayed as intensity vs time. Analytical working curves can be automatically constructed and displayed for inspection by the operator. Analyses are reported for Fe in beryl using a graphite powder method and a dc arc, as well as for Zn, Sn, and Pb in Cu alloys using a glow-discharge sputtering source. The analyses yield values comparable to those from more conventional equipment.

This paper discusses investigations conducted to achieve optimum sensitivity for the determination of rare earths in yttrium oxide and describes a specific technique evolved for the above analysis. A dc arc burning in a controlled atmosphere of argon and oxygen is used together with a spectrograph of very high dispersion in order to provide optimum signal-to-noise ratio. Because the excitation efficiency is not uniform along the entire height of the arc column, only the most efficient portion is transmitted to the slit. Without any treatment or concentration of the sample other than dilution with graphite powder, the above method achieves sensitivities for the rare earths in yttrium oxide ranging from about 50 ppm for the least sensitive rare earths (Pr, Ce) to about 0.5 ppm for the most sensitive rare earths (Lu, Sc, Yb).

The optical spectrum of gallium atoms produced and excited near a self‐formed high‐field emission tip of a liquid metal gallium ion source has been observed in detail. The spectrum reveals several interesting features. The dispersed neutral gallium lines exhibit asymmetric tails extending over tens of angstroms. The broadening is identified as due to quadratic stark effect. The maximum broadening is limited by field ionization of the atom from its excited state. The agreement with classical results is reasonable. A background continuum has also been observed, which may be due to transition radiation arising from collision of electrons, produced during field ionization, with the liquid‐metal tip.

A method has been developed to permit the quantitative determination of trace metals in polypropylene and other organic materials in which the total ash content ranges from 0.10 per cent to less than 0.001 per cent by weight. A small sample of the material is ashed directly in the electrode. A fixed amount of germanium internal standard solution is added to the electrode and dried Standards are prepared by adding weighed amounts of a plastic dispersion containing known amounts of the elements to be determined to specially prepared electrodes. Using a controlled atmosphere chamber the prepared electrodes are excited with a dc arc in an atmosphere of argon and oxygen and the spectra recorded photographically.