bluuebunny/crossref_metadata_2025 huggingface dataset:
Time-Specific Contribution of the Supplementary Motor Area to Intermanual Transfer of Procedural Knowledge
Authors: Perez Monica A. , Tanaka Satoshi , Wise Steven P. , Willingham Daniel T. , Cohen Leonardo G.
Published: September 2008

The supplementary motor area (SMA) makes a crucial contribution to intermanual transfer: the ability to use one hand to perform a skill practiced and learned with the other hand. However, the timing of this contribution relative to movement remains unknown. Here, 33 healthy volunteers performed a 12 item sequence in the serial reaction time task. During training, each participant responded to a sequence of visual cues presented at 1 Hz by pressing one of four keys with their right hand. The measure of intermanual transfer was response time (RT) during repetition of the trained sequence with the left hand, which was at rest during learning. Participants were divided into three groups, which did not differ in their learning rates or amounts. In two groups, 1 Hz repetitive transcranial magnetic stimulation induced transient virtual lesions of the SMA during training, either 100 ms before each cue (the premovement group) or during each key press (the movement group). The third group received sham stimulation (the sham group). After training with the right hand, RTs for performance with the left (transfer) hand were longer for the premovement group than for the movement or sham groups. Thus, the most crucial contribution of SMA to intermanual transfer occurs in the interval between movements, when the memory of a previous movement plays a role in encoding specific sequences. These results provide insight into frontal lobe contributions to procedural knowledge.
Morphological and Physiological Traits Associated with Canopy Temperature Depression in Three Closely Related Wheat Lines
Authors: Balota Maria , Payne William A. , Evett Steven R. , Peters Troy R.
Published: September 2008

Wheat (Triticum aestivum L.) cultivars with high canopy temperature depression (CTD) tend to have higher grain yield under dry, hot conditions. Therefore, CTD has been used as a selection criterion to improve adaptation to drought and heat. The CTD is a result of the leaf's energy balance, which includes terms determined by environment and physiological traits. We hypothesized that one or more of several physiological traits contributed to consistent CTD differences among three closely‐related winter wheat lines grown under dryland conditions. For three years we measured several leaf traits, including CTD, leaf dimension, gas exchange rates, and carbon‐13 isotope discrimination (Δ). Soil water content was also monitored. Data showed that daytime CTD was related to the leaf size in these wheat lines. The most drought‐tolerant line, TX86A8072, had consistently smaller and narrower leaves than TX86A5606, the least drought tolerant. For TX86A8072, dryland and irrigated average noon CTD was −0.8°C, and average flag leaf area (LA) 11 cm2, for TX86A5606, values were −1.7°C and 12.5 cm2, respectively. However, TX86A8072 also had higher CTD (i.e., lower temperatures) than TX86A5606 at night, despite a theoretically greater sensible heat transfer coefficient, suggesting greater nighttime transpiration (T). Implications of these traits on nighttime leaf energy balance and possible adaptive roles of nighttime T are discussed.
Improving the Reproducibility of Soybean Standard Germination Test
Authors: LeVan Nathan A. , Goggi A. Susana , Mullen Russell
Published: September 2008

Dry, windy weather conditions during harvest can lead to very low seed‐moisture content and severe soybean [Glycine max (L.) Merr.] seed germination problems. Some low‐moisture content seed lots have particularly low and highly variable standard germination test results, presumably caused by imbibitional injury. The objectives of this study were to evaluate the influence of seed moisture content and seed composition on germination in the laboratory and field, and to evaluate standard germination test protocols for testing low‐moisture content soybean seeds. Commercial seed lots of different seed composition were equilibrated to 0.07, 0.08, and 0.12 g H2O/g fw. Four official testing media were used in the experiments: rolled paper towels (T), crepe cellulose paper (C), crepe cellulose paper covered with sand (CS), and sand germination (S). Soybean germination and emergence were affected by maturity group, seed composition, and field conditions at planting. The testing medium and seed moisture content also influenced germination in the laboratory, but seed moisture content did not affect field emergence. These results suggest that soybean imbibitional injury caused by low‐moisture seed lots occurs primarily in the laboratory. Seed analysts must consider soybean seed composition, moisture content, and their interaction with testing media when testing low‐moisture content soybeans in the laboratory.
The Effects of Crumb Rubber Topdressing on Hybrid Kentucky Bluegrass and Bermudagrass Athletic Fields in the Transition Zone
Authors: Goddard Matthew J. R. , Sorochan John C. , McElroy J. Scott , Karcher Douglas E. , Landreth Josh W.
Published: September 2008

New turfgrass varieties and management practices have introduced new options for transition zone athletic field managers. Our objectives were to determine the wear tolerance of four turfgrasses in the transition zone with and without crumb rubber under simulated athletic field conditions, and to determine if improved cool and warm‐season turfgrass species can be used for transition zone athletic fields. Field trials evaluated the use of four turfgrass species with and without crumb rubber topdressing in Knoxville, TN, and Fayetteville, AR. Experimental design was a randomized complete block with a split‐strip plot treatment arrangement. Plots containing ‘Thermal Blue’ hybrid Kentucky bluegrass (Poa pratensis L. × P. arachnifera Torr.) or ‘Riviera’ [Cynodon dactylon (L.) Pers.], ‘Quickstand’ (C. dactylon), or ‘Tifway’ (C. dactylon × C. transvaalensis Burtt‐Davy) bermudagrass were evaluated. Crumb rubber treatments were topdressed to achieve a 2‐cm depth. Traffic was applied to each plot using a Cady Traffic Simulator to simulate athletic field wear. Traffic applications coincided with actual fall athletic seasons ranging from October to December 2005. Hybrid Kentucky bluegrass proved to be acceptable for use in transition zone athletic fields, Riviera and Tifway showed comparable wear tolerance, and Quickstand showed the lowest wear tolerance of the varieties tested. Crumb rubber topdressing resulted in a significant increase in turfgrass wear tolerance, and a decrease in surface hardness, soil bulk density, and shear resistance.
Analysis of the Lr34/Yr18 Rust Resistance Region in Wheat Germplasm
Authors: Kolmer James A. , Singh Ravi P. , Garvin David F. , Viccars Libby , William Harinder M. , Huerta‐Espino Julio , Ogbonnaya Francis C. , Raman Harsh , Orford Simon , Bariana Harbans S. , Lagudah Evans S.
Published: September 2008

The Lr34/Yr18 adult plant resistance gene contributes significantly to durable leaf rust (caused by Puccinia triticina Eriks.) resistance. Simple and robust molecular markers that enable early detection of Lr34/Yr18 are a major advancement in wheat (Triticum aestivum L.) breeding. An insertion/deletion size variant located at the csLV34 locus on chromosome 7D within an intron sequence of a sulfate transporter‐like gene tightly linked to the Lr34/Yr18 dual rust resistance gene was used to examine a global collection of wheat cultivars, landraces, and D genome–containing diploid and polyploid species of wheat relatives. Two predominant allelic size variants, csLV34a and b, found among the wheat cultivars showed disparate variation in different wheat growing zones. A strong association was observed between the presence of Lr34/Yr18 and the csLV34b allele and wheat lines known to have Lr34/Yr18 that had the csLV34a allele were rare. All landraces with the exception of those from China were predominantly of the csLV34a type. Only one size variant, csLV34a, was detected among the diploid and polyploid D genome–containing species, indicating that csLV34b arose subsequent to hexaploid bread wheat synthesis. The lineage of the csLV34b allele associated with Lr34/Yr18 in modern wheat cultivars from North and South America, CIMMYT, Australia, and Russia was tracked back to the cultivars Mentana and Ardito developed in Italy by Nazareno Strampelli in the early 1900s. The robustness of the csLV34 marker in postulating the likely occurrence of Lr34/Yr18 across a wide range of wheat germplasm and its utility in wheat breeding was confirmed.
Leaching of Mineral and Organic Nitrogen from Putting Green Profiles Supporting Various Turfgrasses
Authors: Paré Karine , Chantigny Martin H. , Carey Ken , Dionne Julie
Published: September 2008

Nitrate (NO3−) leached from golf greens has the potential to impair water quality. Dissolved organic N (DON) is also increasingly recognized as a form leached from fertilized soils. A controlled experiment was conducted to determine (i) the significance of DON in total N leaching losses under simulated golf‐green profiles and (ii) the short‐term contribution of fertilizer to leaching of inorganic and organic N forms. Various turfgrasses were grown in lysimeter columns designed to simulate a golf‐green profile. Fertilizer was applied at 25 kg N ha−1 every 14 d for 55 d, and the last application was labeled with 15N. Leachates were analyzed for NO3−‐N, NH4+‐N, and DON. The 15N recovery was assessed in plant, soil, and leachates. In the presence of plants, 10 to 70% (average 40%) of total N leached was accounted for by DON. Application of 15N revealed that one‐half to two‐thirds of NO3−‐N leached in the following 14 d was derived from the fertilizer, whereas the majority of leached DON was derived from soil residual N. Nevertheless, DO15N was present in most leachate samples collected for 14 d after fertilizer application, indicating that only a few days were required to convert mineral fertilizer to leachable organic forms. We conclude that DON may be a significant component of total N leaching losses from putting greens and would account for part of the N losses traditionally attributed to volatilization and denitrification.
Temporal Trends of Variation in Italian Rice Germplasm over the Past Two Centuries Revealed by AFLP and SSR Markers
Authors: Mantegazza R. , Biloni M. , Grassi F. , Basso B. , Lu B.‐R. , Cai X. X. , Sala F. , Spada A.
Published: September 2008

The aim of this study was to characterize the Italian rice (Oryza sativa L.) gene pool, paying particular attention to its variation over time, to determine whether human activity can reduce genetic variability, and whether such a reduction actually occurred in Italian rice varieties. We analyzed 135 Italian rice accessions, representing genotypes either introduced from abroad or developed in Italy from 1880 to 2001, using two groups of molecular markers, amplified fragment length polymorphisms and simple sequence repeats. These accessions were divided into four groups for which different statistical analyses were performed. The levels of gene diversity, from 0.1023 to 0.1921, and genetic richness, from 0.1579 to 0.3064, increased over time. Genetic structure, as estimated by analysis of molecular variance, revealed that the within‐component was overwhelmingly dominant (92%) compared with the among‐component. These results show that the level of genetic diversity in Italian rice accessions has remained high since 1850 and continues to increase. This is most likely the result of Italian breeding programs that developed new cultivars and introduced others from abroad, without substituting previous accessions. Our results show that the management and improvement of rice germplasm in Italy have been successful in maintaining sufficient genetic diversity.
Inheritance of Soybean Aphid Resistance in PI 567541B and PI 567598B
Authors: Mensah Clarice , DiFonzo Christina , Wang Dechun
Published: September 2008

In a previous study, two soybean [Glycine max (L.) Merr.] plant introductions (PIs), PI 567541B and PI 567598B, were found to possess antibiosis‐type resistance to the soybean aphid (Aphis glycines Matsumura). Plants with antibiosis resistance negatively interfere with the reproduction of the aphid and thus control the insect effectively. Field studies were conducted to determine the inheritance of antibiosis resistance in PI 567541B and PI 567598B. The two resistant PIs were crossed with one or two susceptible soybean lines and the F1 and F2 plants and F2:3 families were evaluated for aphid resistance. All F1 plants were found to be susceptible to soybean aphids. The plants in seven F2 populations segregated in a 15:1 susceptible/resistant ratio, which is the expected ratio for a trait controlled by two recessive genes. The F2:3 families also segregated in a 15:1 susceptible/resistant ratio. Therefore, the segregation data suggest that two major recessive genes are involved in the resistance in PI 567541B and PI 567598B. This information will be useful to breeders for designing efficient breeding schemes for developing soybean cultivars with antibiosis resistance to aphids.
Toxic Properties of Urease
Authors: Carlini Célia R. , Polacco Joe C.
Published: September 2008

Plant ureases have long been known for their ureolytic activities, dependent on a Ni metallocenter active site. We report here on more recently discovered novel toxic properties of ureases—properties independent of enzyme activity. Plant ureases have potent toxicity against insects that are not affected by Bt toxins. Entomotoxicity relies on an internal peptide released by insect digestive enzymes. Plant ureases are fungitoxic—in the absence of ureolytic activity—a property shared with some microbial ureases. We have found that both plant and microbial ureases also induce secretion in animal cells (and thus might be defense and pathogen factors, respectively). We suggest that in the soil, bacterial urease‐induced secretion by plant roots may play a role in rhizosphere relationships. While ureases of plant, fungi, and bacteria align with greater than 50% amino acid identity, toxicity and signaling may be due to more divergent domains, such as that for the insecticidal sub‐peptide. These domains are potential targets for manipulation to improve plant defense against herbivores and pathogens.
Fungal Endophyte Removal Does Not Reduce Cold Tolerance of Tall Fescue
Authors: Casler Michael D. , van Santen Edzard
Published: September 2008

Tall fescue [Schenodorus phoenix (Scop.) Holub.] has historically been of minor importance to livestock agriculture in cooler regions of the temperate zone. As its use in these regions expands, it becomes increasingly important to understand the effect of infection by its fungal endophyte (Neotyphodium coenophialum Morgan‐Jones and Gams) on agronomic fitness of tall fescue. Our objective was to determine the effect of endophyte infection status on forage yield and survival of tall fescue under field conditions in which freezing temperatures, combined with lack of persistent snow cover, constitute the most significant stress factor. In Experiment 1, we evaluated 427 half‐sib families of four tall fescue cultivars, half endophyte‐infected (E+) and half endophyte‐free (E−), for forage yield and survival. There was no effect of endophyte removal on either forage yield or survival, despite complete stand loss of one cultivar during two winters. In Experiment 2, we evaluated 640 clones of confirmed endophyte status, half E+ and half E−, for survival under two management regimes at four Wisconsin locations. Results were nearly identical to those for Experiment 1, with complete mortality in the unadapted cultivar and high survival rates in the three adapted cultivars, regardless of endophyte status, management, or location. In conclusion, we found no evidence that endophyte removal resulted in any disadvantage to tall fescue host‐plant survival under harsh winter conditions. In regions where freezing temperatures and desiccating winds provide the only or most important abiotic stress factor, removal of endophytic fungi do not appear to reduce fitness of their tall fescue host.
Day–Night Variation in Fatty Acids and Lipids Biosynthesis in Sunflower Seeds
Authors: Pleite Rafael , Rondanini Deborah , Garcés Rafael , Martínez‐Force Enrique
Published: September 2008

It is well known that fatty acid biosynthesis in leaves is closely related to photosynthesis; although a residual synthesis is also detected at night. But less known is the effect of the day–night cycle in fatty acid biosynthesis in heterotrophic tissues such as developing seeds. Through the use of radioactive precursors, we detected variations in the metabolism of fatty acids and lipids during the day–night period in sunflower (Helianthus annuus L.) seeds. These oscillations have been observed both in the fatty acids bound to triacylglycerols and in polar lipids, indicating a fine regulation of the lipids biosynthetic activities in sunflower developing seeds. Additionally, in the triacylglycerol fraction, periodic variations were observed in the oleic and linoleic acids content as a consequence of qualitative variations in the biosynthetic machinery during the day–night period related to temperature changes. Analyzing the rate of oleic acid desaturation, we observed a significant increase in activity in the middle of the night, indicative of the importance of nocturnal desaturation. Similar variations were also observed in the stearoyl‐acyl carrier protein (ACP) desaturase activity. This study has shown the variation in the lipid biosynthetic capacity in sunflower developing seeds during the day–night cycle—including control over individual enzymes such as the stearoyl‐ACP desaturase—and the influence of diurnal and nocturnal temperatures in the quality (oleic/linoleic ratio) of the oil.
A Rapid and Effective Method for Screening Salt Tolerance in Soybean
Authors: Valencia Ruben , Chen Pengyin , Ishibashi Tetsuaki , Conatser Matthew
Published: September 2008

Salinity has been recognized as a constraint for soybean [Glycine max (L.) Merr.] production in many regions worldwide. Fortunately, genetic variation in salt tolerance is available in the soybean germplasm bank. However, current screening methodologies for salt‐tolerant genotypes are time‐consuming and often ineffective because of their limitations in detecting and measuring plant response to salinity. The objective of this study was to develop a rapid visual method for screening soybean genotypes in response to salt stress based on foliar symptoms. Soybean seedlings were grown in hydroponics with 0, 40, 80, 120, or 160 mM NaCl. Visual foliar symptoms of excessive NaCl were evident at 26 d after planting (14 d in 120 and 160 mM NaCl treatment). The NaCl level of 120 mM was most effective for salt‐tolerance screening based on visual foliar symptoms on a group of differential genotypes. Chloride includers (‘Williams’, ‘Clark’, ‘HBK R4924’, and ‘Dare’) exhibited interveinal chlorosis, while Cl excluders (‘S‐100’, ‘Lee 68’, and ‘HBK R5525’) showed no chlorosis at the 120 mM NaCl level. At this critical selection level (120 mM NaCl), average leaf Na and Cl− contents were 2.64 and 1.96 times higher, respectively, for Cl includers than for Cl excluders. Plant damage was more evident at 120 and 160 mM NaCl, as demonstrated by the decreased shoot and root biomass and near maximum accumulation of Na and Cl− in the tissue. There was a significant and negative correlation (r = −0.69, p = 0.0006) between relative root dry weight and Cl− concentration in the leaf. This methodology is simple, rapid, and effective for selection of Cl tolerant genotypes with a minimum investment of cost and time.
Use of an Advanced Intercross Line Population for Precise Mapping of Quantitative Trait Loci for Gray Leaf Spot Resistance in Maize
Authors: Balint‐Kurti Peter J. , Wisser Randall , Zwonitzer John C.
Published: September 2008

Gray leaf spot [GLS, causal agent Cercospora zeae‐maydis (Tehon and E. Y. Daniels)] is an important fungal disease of maize in the U.S. and worldwide. The IBM population, an advanced intercross recombinant inbred line population derived from a cross between the maize lines Mo17 (resistant) and B73 (susceptible), was evaluated in three environments (Andrews, NC in 2005, 2006, and 2007) for resistance to GLS and for days from planting to anthesis (DTA). A conventional recombinant inbred line population derived from the same two parents (the “Stuber” population) was also assessed for GLS resistance in two environments (Andrews NC, 2004 and 2005). Quantitative trait loci (QTL) for GLS resistance were detected in each population. Five significant QTL were detected in the IBM population in bins 1.05, 2.04, 4.05, 9.03, and 9.05. In each case the QTL were localized to regions less than 3 centiMorgans (cM). Two QTL for GLS resistance were identified in the Stuber population in bins 2.04 and 7.05. The GLS QTL in bin 2.04 was previously identified as a QTL for southern leaf blight resistance in the IBM population. These results were compared with results from five previous GLS QTL studies and two potential GLS QTL “hotspots” were identified in bins 1.05–1.06 and 2.03–2.05. As expected, QTL were identified with much more precision in the IBM population compared to the Stuber population and to previous studies. There was no significant correlation between disease resistance and days to anthesis. Three DTA QTL were detected in bins 4.09, 8.05, and 9.02, which did not co‐localize with GLS QTL.
Recurrent Selection to Alter Grain Methionine Concentration and Improve Nutritional Value of Maize
Authors: Scott M. Paul , Darrigues Audrey , Stahly Timothy S. , Lamkey Kendall
Published: September 2008

Methionine is an essential amino acid that is limiting in maize‐ (Zea mays L.) based diets. The objective of this work was to determine whether we could alter grain methionine concentration in random‐mated maize populations by mass selection for methionine concentration using a microbial assay. In one study, we developed two populations by selecting for high or low methionine concentration (HM or LM, respectively) for three generations starting from the random‐mated population BS11. Grain from these populations was used to formulate diets for a feeding trial in which 15 rats were fed HM grain and 15 rats were fed LM grain. Rats on the HM diet had a 0.018 higher feed efficiency (g gain/g feed) than rats on the LM diet. In a second study, we performed three cycles of selection for high or low methionine concentration starting with two random‐mated populations, BS11 and BS31. We evaluated each cycle of selection in a field trial with two replications in each of two years. Methionine concentration was significantly correlated with the cycle of selection, changing on average 0.004 g methionine/100 g grain per cycle. Kernel mass, %N, oil, protein, starch, tryptophan, and lysine concentration did not exhibit significant correlations with cycle of selection. We conclude that recurrent selection for grain methionine concentration using a microbial assay is an effective method to alter methionine content.
Stability of Oleate Content in Soybean Lines Derived from M23
Authors: Scherder Curtis W. , Fehr Walter R. , Shannon J. Grover
Published: September 2008

M23 is a soybean [Glycine max (L.) Merr.] line with elevated oleate content that has been used to develop lines with elevated oleate combined with low saturated fatty acids (MO/LS), 1% linolenate (MO/LLN), or both low saturates and 1% linolenate (MO/LS/LLN). The objective of this study was to determine the stability of oleate content of eight MO/LS lines, nine MO/LLN lines, nine MO/LS/LLN lines, and four cultivars with conventional oleate content when grown in one Missouri and four Iowa environments during each of 2 yr. Averaged across the 10 environments, the mean oleate content was 590 g kg−1 for the MO/LS lines, 521 g kg−1 for the MO/LLN lines, 557 g kg−1 for the MO/LS/LLN lines, and 269 g kg−1 for the four cultivars. The mean oleate content of all lines was significantly greater in 2005 (545 g kg−1) than in 2006 (489 g kg−1) and the earliest planting date had the greatest oleate content both years. Stability of the individual lines based on either a regression analysis or on the range of their oleate content over environments indicated that the lines with the greatest oleate content generally had the most variation across environments. However, the lines with the greatest mean oleate content had the highest likelihood of meeting or exceeding 500 g kg−1 across environments.
Analysis of Flavonoids in Flower Petals of Soybean Flower Color Variants
Authors: Iwashina Tsukasa , Oyoo Maurice E. , Khan Nisar A. , Matsumura Hisakazu , Takahashi Ryoji
Published: September 2008

We previously identified two anthocyanins, malvidin 3,5‐di‐O‐glucoside and delphinidin 3,5‐di‐O‐glucoside, in flower petals of soybean cultivars with purple flowers, ‘Harosoy’ and ‘Clark’. However, two other anthocyanins found by high performance liquid chromatography (HPLC) analysis could not be identified. We further evaluated the effects of flower color genes W1, W3, W4, and Wm on flavonoid components using near‐isogenic lines for these genes. The first objective of this study was to determine the two unidentified anthocyanins in flower petals of Clark. The second objective was to evaluate the effects of Wp for pink flower and W2 for purple‐blue flower on flavonoid biosynthesis using purple‐blue flowered cultivars Nezumisaya, Yogetsu‐1‐blue, and w2‐20, and a pink flowered line LD05–15019‐pink. Chemical analysis revealed that the two remaining anthocyanins were petunidin 3,5‐di‐O‐glucoside and delphinidin 3‐O‐glucoside. Composition and amount of flavonoids in purple‐blue flowers were generally similar to those of Clark suggesting that anthocyanin structure or copigmentation with other flavonoids may not be responsible for the color. Pink flowers contained 72% of total anthocyanins, 9% of the total flavonol glycosides, and 28% of aromadendrin 3‐O‐glucoside relative to Clark. Further, pink flowers lacked kaempferol 3‐O‐glucoside. It is uncertain whether the reduction in flavonol glycosides in combination with lower anthocyanin levels might fully explain the low intensity of pigmentation in pink flowers.
Agronomic and Seed Characteristics of Soybean Lines with Increased Oleate Content
Authors: Scherder Curtis W. , Fehr Walter R.
Published: September 2008

Soybean [Glycine max (L.) Merr.] lines have been developed with the ol allele for elevated oleate from the mutant line M23 and alleles for reduced linolenate as a means of increasing stability of the oil. The purpose of this study was to evaluate the influence of elevated oleate content on agronomic and seed traits. From each of three segregating populations, 27 low‐linolenate lines with a mean oleate content >500 g kg−1 and 27 low‐linolenate lines with a mean oleate content <280 g kg−1 were selected for evaluation in three Iowa environments in 2007. The mean seed yield of the mid‐oleate (MO) lines was significantly less by 12% than the lines with conventional oleate (CO) content and the highest yielding lines in each population were of the CO type. The mean protein content of the MO lines was significantly greater by 14 g kg−1 and their mean oil content significantly less by 7 g kg−1 than the CO lines. The mean differences between the MO and CO lines were <1 d for time of maturity, 3 cm for plant height, 0.3 for lodging score, and 8 mg seed−1 for seed weight. The primary challenge for developing commercially acceptable MO lines derived from M23 will be to overcome the difference in yield compared with CO lines.
Heritability of Oleic Acid Content in Soybean Seed Oil and Its Genetic Correlation with Fatty Acid and Agronomic Traits
Authors: Bachlava Eleni , Burton Joseph W. , Brownie Cavell , Wang Sanbao , Auclair Jérôme , Cardinal Andrea J.
Published: September 2008

Oleate content is important for the nutritional value and oxidative stability of soybean [Glycine max (L.) Merr.] seed oil. Response to selection for higher oleate content depends on its heritability in breeding populations, and correlated responses of other fatty acid and agronomic traits to selection for oleate content depend on their genetic correlations with oleate. The objective of this study was to estimate the heritability of oleate content and to determine the correlation of oleate with other fatty acid and agronomic traits in three soybean populations segregating for major and minor oleate genes grown in multiple environments. One of the populations consisted of 721 lines, providing excellent precision for estimation of the genetic parameters. The results of this study indicated that heritability for oleate content was sufficiently high that early generation selection can be effective when practiced on unreplicated lines grown at a single environment. Significant negative correlations were observed between oleate and linoleate, oleate and linolenate, as well as oleate and palmitate in all three populations. Significant positive correlations were detected between palmitate and stearate in one population segregating for oleate genes and fapnc and fap1 alleles, which reduce palmitate content. In the same population we also observed a significant negative correlation between yield and oleate content, and positive correlations between yield and linoleate, and linolenate and palmitate contents.
Heterosis among Hybrids Derived from Genetically Improved and Unimproved Alfalfa Germplasm
Authors: Madril C. M. , Pierce C.A. , Ray I.M.
Published: September 2008

Commercially competitive forage yields, and in some cases high‐parent heterosis, were previously reported for several alfalfa (Medicago sativa L.) diallel hybrids derived from nine unimproved germplasm sources that have been important contributors to North American cultivars. This study evaluated biomass production of genetically unimproved and improved sets of nine of those hybrids, and their respective parents, over three years near Las Cruces, NM. Our objectives were to determine if the performance of unimproved ancestral populations provided useful information to construct superior hybrids using more elite descendant materials, and if such improved hybrids exhibited high‐parent heterosis. All improved hybrids performed either similar to, or superior to, five check cultivars. High‐parent heterosis was detected among the top four yielding improved hybrids. Unimproved hybrid performance and midparent value rankings provided reasonable indicators of potential hybrids that should be attempted among related elite populations. The results indicated that opportunities to exploit hybrid vigor still appear to exist among some elite alfalfa populations that possess a predominating germplasm source.
Development of Extra‐Long Staple Upland Cotton
Authors: Smith C. Wayne , Hague S. , Hequet E. , Thaxton P. S. , Brown I. N.
Published: September 2008

An objective of U.S. cotton breeding programs is to provide raw material that processes efficiently and produces better textile products without compromising yield. Annual domestic consumption dropped from 10.4 million bales in 1998 to 5.5 million bales in 2007. Exports increased from 4.3 to 16.2 million bales. Increased reliance on export markets will require the United States to compete more effectively in price and quality. The desired minimum upper half mean (UHM) fiber length in international markets is 28 mm, while the traditional U.S. minimum is 27 mm. To compete at this higher UHM length expectation, breeding programs should target minimums well above the international base. Extra‐long staple (ELS) upland cotton (Gossypium hirsutum L.) germplasm lines were developed by the Cotton Improvement Lab, Dep. of Soil and Crop Sciences, Texas A&M AgriLife Research, as part of an effort to create germplasm with combinations of improved fiber quality, especially UHM length and fiber bundle strength. These ELS upland lines exhibit high volume instrument UHM length >32.0 mm, and several strains exceed 34.8 mm, which is the minimum UHM length for pima (G. barbadense L.). These ELS strains range in agronomic performance from less than to equal to that of ‘Fiber Max 832’ (PI 603955). TAM 94L‐25 (PI 631440), or its full sib 94L‐2 (unreleased), is the common parent in these ELS strains and is proposed as the major contributor of favorable allelic combinations for this exceptional UHM length.
Jasmonate and Ethylene Signaling Pathway May Mediate Fusarium Head Blight Resistance in Wheat
Authors: Li Guangle , Yen Yang
Published: September 2008

Fusarium head blight (FHB), caused by Fusarium graminearum Schw. [teleomorph: Gibberella zeae (Schw.) Petch], can be a devastating disease in small grains production. Understanding its molecular pathogenesis will help identifying key steps in disease development and developing a strategy for efficiently preventing FHB epidemics. As the first step toward our goal, gene expression in the FHB‐resistant wheat (Triticum aestivum L.) cultivar Sumai 3 and the FHB‐susceptible wheat landrace Y1193‐6 was profiled with Affymetrix Wheat Genome GeneChip in 24 h after inoculation by F. graminearum isolate Fg4 and compared. Twofold change [log2(signal ratio) = 1] in expression was set as the threshold for data selection. Comparing the FHB‐inoculated and the mock‐inoculated wheat spikelets in both Sumai 3 and Y1193‐6 revealed a total of 677 possible FHB‐responsive genes. Further analysis and comparison revealed that, among these FHB‐responsive genes, 69 were F. graminearum genes. Of the 608 wheat genes, 243 showed similar expression in both Sumai 3 and Y1193‐6; 281 and 79 significantly changed expression pattern only in Sumai 3 or Y1193‐6, respectively; and five had opposite expression pattern between the two wheat genotypes. Functional genomics and physiological analyses both suggested that FHB resistance in Sumai 3 involves defense pathways regulated by jasmonic acid and ethylene signaling, while salicylic acid–regulated systematic acquired resistance is insignificant in this process.
Explanations for Decreased Harvest Index with Increased Yield in Soybean
Authors: Board James E. , Maricherla Dinesh
Published: September 2008

Yield in soybean [Glycine max (L.) Merr.] is controlled by total dry matter (TDM) accumulation and partition of that TDM into yield as measured by harvest index (HI). Previous research indicated that yield responded to TDM at R5 (seed initiation) [TDM(R5)] in an asymptotic relationship that plateaued at about 600 g m−2 As yield rose with TDM(R5), HI declined, thus acting as a yield limiting factor. Explanation for the inverse relationship between yield and HI would help develop research strategies for yield improvement. Our objective was to determine if this negative relationship resulted from an inverse relationship between node production efficiency [node no. per gram TDM(R5)] with TDM(R5). Data for this study were collected from previous studies containing a variety of cultural treatments (planting dates, row spacings, plant populations, and waterlogging) conducted near Baton Rouge, LA (30° N lat), between 1987 and 1996 and combined into a single data set. Regression analyses between yield, TDM(R5), yield components, and production efficiencies of yield components [yield component level per gram TDM(R5)] were conducted. Results indicated that the inverse relationship between HI and yield (R2 = 0.54; b1 = P < 0.0001, b2 = P < 0.05) resulted mainly from a negative relationship between node production efficiency and TDM(R5) (R2 = 0.81; b1 = P < 0.0001, b2 = P < 0.05), which resulted in less efficient production of pods and seeds (the main yield components controlling yield) as TDM(R5) increased. In conclusion, reduced node production efficiency with increased TDM(R5) created the inverse relationship between HI and yield.
Genetic Mapping of Persistence in Tetraploid Alfalfa
Authors: Robins Joseph G. , Hansen Julie L. , Viands Donald R. , Brummer E. Charles
Published: September 2008

Persistence is a critical trait for alfalfa (Medicago sativa L.), yet the genetics of this trait are poorly understood. Herein, we characterize an F1 alfalfa population derived from the cross between the two cultivated alfalfa subpecies for persistence in three production seasons at Ames and Nashua, IA, and one production season at Ithaca, NY. Quantitative trait loci (QTLs) underlying persistence were mapped using this population utilizing single‐marker analysis and interval mapping procedures. Both parental genomes (Medicago sativa subsp. falcata and M. sativa subsp. sativa) contributed marker alleles associated with persistence, suggesting that alleles from both subspecies have potential for marker‐assisted selection. Although, linkage groups 1, 2, and 7 contained putative persistence QTLs, genotype × environment interaction and location‐specific QTLs suggest location‐specific genetic mechanisms for alfalfa persistence. Nevertheless, in some instances, the same QTLs were identified in different years at the same location. Quantitative trait loci on linkage groups (LGs) 1 and 2 were location‐specific for the Ithaca and Ames locations, respectively. The majority of alleles on LG 7 associated with persistence also exhibited association with biomass production and suggest common genetic determinants for both traits. Of particular interest was the identification of simple sequence repeat allele al37288‐1a1, which associated positively with persistence in each environment of the study.
Dr. StrangeLoan: or How I Learned to Stop Worrying and Love the Financial Collapse
Authors: Edlin Aaron S.
Published: September 2008

Last week, on Wednesday September 17, 2008, the Bush Administration almost stumbled upon a way to eliminate the U.S. debt and even taxes. Aaron Edlin's ironic take on a world gone mad.
Questioning the Treasury's $700 Billion Blank Check: An Open Letter to Secretary Paulson
Authors: Edlin Aaron S.
Published: September 2008

The Treasury wants a blank check for $700 billion, at taxpayer expense; instead a businessman like Buffett should be given the job of making the taxpayers some money out of this mess, according to Aaron Edlin.
Auditor Resignations and Auditor Industry Specialization
Authors: Cenker William J. , Nagy Albert L.
Published: September 2008

SYNOPSIS: The increase of Big 4 auditor resignations in the newly regulated auditing environment creates a rich setting to examine the supply-side effects of auditor industry specialization. The authors estimate logistic regressions to examine whether audit firms consider industry specialization at both the local and national levels when deciding on whether to retain or resign from audit clients. The results show a negative relation between auditor industry specialization and auditor resignations when the auditor is a joint specialist (i.e., a specialist at both the national and local levels) and when the auditor is a local specialist only (i.e., a local specialist but not a national specialist). The national specialization alone variable (i.e., the auditor is a national specialist but not a local specialist) is not significant for our primary analysis; however, additional analyses reveal that the significance of this variable varies when incorporating alternative measurements for auditor specialization in the models. Thus, the overall evidence of the national specialization effect on the auditor’s resignation decision is mixed and inconclusive at this point. Based on the additional analyses, the joint and the local specialization effects generally appear to be robust. As such, we conclude that auditors perceive their firms’ industry expertise, particularly at the local level, as reducing both clientele mismatch and litigation risks, and hence improving audit quality.
Auditor Tenure and Shareholder Ratification of the Auditor
Authors: Dao Mai , Mishra Suchismita , Raghunandan K.
Published: September 2008

SYNOPSIS: Legislators and regulators have expressed concerns about the effect of long auditor tenure on audit quality. There is little direct evidence on investors’ perceptions about long auditor tenure. In this paper, we use shareholder votes on auditor ratification as a proxy for investor perceptions about audit quality. We find, using data from 635 firms during 2006, that shareholder votes against (or abstaining from) auditor ratification are positively correlated with auditor tenure. The results suggest that shareholders view long auditor tenure as adversely affecting audit quality, and provide an empirical basis for arguments related to the impact of long auditor tenures on shareholders’ perceptions of audit quality.
Management Earnings Forecasts: A Review and Framework
Authors: Hirst D. Eric , Koonce Lisa , Venkataraman Shankar
Published: September 2008

SYNOPSIS: In this paper, we provide a framework in which to view management earnings forecasts. Specifically, we categorize earnings forecasts as having three components—antecedents, characteristics, and consequences—that roughly correspond to the timeline associated with an earnings forecast. By evaluating management earnings forecast research within the context of this framework, we render three conclusions. First, forecast characteristics appear to be the least understood component of earnings forecasts—both in terms of theory and empirical research—even though it is the component over which managers have the most control. Second, much of the prior research focuses on how one forecast antecedent or characteristic influences forecast consequences and does not study potential interactions among the three components. Third, much of the prior research ignores the iterative nature of management earnings forecasts—that is, forecast consequences of the current period influence antecedents and chosen characteristics in subsequent periods. Implications for researchers, educators, managers, investors, and regulators are provided.
Assurance on XBRL for Financial Reporting
Authors: Plumlee R. David , Plumlee Marlene A.
Published: September 2008

SYNOPSIS: Since 2004, the Securities and Exchange Commission (SEC) has taken steps toward requiring eXtensible Business Reporting Language (XBRL) to be used in its filings, including a voluntary filing program. “Tagging” financial information using XBRL creates documents that are computer readable and searchable. Once XBRL is required, investors are likely to demand assurance on the tagging process. The Public Company Accounting Oversight Board (PCAOB) has issued guidance on attest engagements regarding XBRL financial information furnished under the SEC’s current voluntary filer program, which relies on the auditor “agreeing” a paper version of the XBRL-related documents to the information in the official EDGAR filing. This approach may be adequate for the current paper-oriented reporting paradigm. However, once filing in XBRL becomes required, the power of XBRL to allow individual financial datum to be extracted from the SEC’s financial database will be realized. This “data-centric” idea is a crucial extension of the traditional reporting paradigm that will alter the way financial and nonfinancial data can be used. The current audit focus on reconciling only the XBRL output with the paper submissions does not address this paradigm shift. In this commentary, we discuss the SEC’s efforts to incorporate XBRL into its filing process and provide a brief overview of the technical aspects of XBRL. The commentary’s principal focus is on several important questions that assurance guidance must address in a data-centric reporting environment, such as, what constitutes an error, or what does materiality mean when individual pieces of financial data will be used outside the context of the financial statements? It also describes some XBRL-related areas where academic research can help guide XBRL-document assurance efforts.
Stability of Maxillary Expansion and Tongue Posture
Authors: Ozbek M. Murat , Memikoglu Ufuk T. Toygar , Altug-Atac Ayse Tuba , Lowe Alan A.
Published: September 2008

Objective: To evaluate the adaptive changes and the stability in tongue posture following rapid maxillary expansion (RME) in patients without any signs or symptoms of respiratory disturbances.

Materials and Methods: Growing subjects with maxillary constrictions and bilateral buccal crossbites were included in the treatment group (n = 20). A control group (n = 20) comprised subjects with normal dentoskeletal features. RME appliances were used in the treatment group, with an average active expansion of 15 ± 2 days. Cephalometric radiographs were traced and digitized to evaluate static tongue posture before RME and 6.75 ± 0.48 months after RME. Follow-up radiographic evaluations of 17 expansion cases were also performed after an average of 29.25 ± 1.85 months. Independent and paired t-tests were conducted to evaluate changes in tongue posture within and between groups.

Results: Results revealed significant reductions of tongue-to-palate (P < .05) as well as hyoid bone-to-mandibular plane (P < .01) distances following RME. The new tongue posture was found to be stable during the follow-up period.

Conclusions: A higher tongue posture can be obtained with RME in children with no reported respiratory disturbances. (Angle Orthod. 2009:79; )
Antimicrobial Effects of Zinc Oxide in an Orthodontic Bonding Agent
Authors: Spencer Clayton Glen , Campbell Phillip M. , Buschang Peter H. , Cai John , Honeyman Allen L.
Published: September 2008

Objective: To test the null hypothesis that the addition of zinc oxide (ZnO) has no effect on the antimicrobial benefits and shear bond strength of a light-cured resin-modified glass ionomer.

Materials and Methods: ZnO was added to Fuji Ortho LC to create mixtures of 13% ZnO and 23.1% ZnO. Specimen discs of the modified bonding agent were incubated with Streptococcus mutans for 48 hours in a disc diffusion assay that was used to measure zones of bacterial inhibition. In addition, brackets were bonded to bovine deciduous incisors with the modified bonding agents, and shear bond strength was evaluated with a universal testing machine.

Results: The modified samples showed that antimicrobial activity increased as the concentration of ZnO increased. There were significant differences (P < .05) in antimicrobial activity. Post hoc tests showed that the antibacterial effects were 1.6 times greater with 23.1% ZnO than with 13% ZnO. There was no difference between Transbond and 0% ZnO (the negative control). After 1 month of daily rinsing, the antibacterial effects of 23.1% ZnO and 13% ZnO decreased 65% and 77%, respectively, but both maintained significant effects over the negative controls. There were no significant differences (P = .055) in shear bond strength between any of the mixture comparisons.

Conclusions: The incorporation of ZnO into Fuji Ortho LC added antimicrobial properties to the original compound without significantly altering the shear bond strength. ZnO holds potential for preventing decalcification associated with orthodontic treatment.