bluuebunny/crossref_metadata_2025 huggingface dataset:
Beam shaping of laser diode stacks for compact and efficient illumination devices at the French-German Research Institute of Saint-Louis
Authors: Lutz Yves , Laurenzis Martin
Published: February 2014

Laser diode stacks are applied for the realization of compact and efficient laser illumination devices for active imaging (e.g., laser gated viewing). An efficient use of illumination power and sensor arrays has to adapt the laser illumination to the sensor’s field of view (FOV) with a perfectly matched and homogeneous illumination field. In the past decades, ISL has studied different methods for beam shaping and homogenization of laser diode stacks. In this publication, the authors give a review of the development of different beam-shaping techniques for auto-stack, minibar stack in a specific configuration and standard laser diode stacks. The presented methods are based on the application of wedge-type waveguides, fast axis and slow axis collimation, and the rearrangement of the laser beams by polarization overlapping and virtual restacking. All presented methods have very high transmission efficiencies (>80%) and lead to a homogeneous illumination matched to the sensor’s field of view.
The interrelation between microfibril angle (MFA) and hygrothermal recovery (HTR) in compression wood and normal wood of Sugi and Agathis
Authors: Tanaka Midori , Yamamoto Hiroyuki , Kojima Miho , Yoshida Masato , Matsuo Miyuki , Lahjie Abubakar M. , Hongo Ichiro , Arizono Takeshi
Published: February 2014

Tree growth stress (GS) consists of an elastic component and a viscoelastic locked-in component. The elastic component is released instantaneously by cutting wood, whereas the locked-in component remains. The latter can be released by hot water treatment, which is known as hygrothermal recovery (HTR). In this paper the mechanism behind HTR is described and interpreted in terms of the microfibril angle (MFA) in the cell wall as follows: during cell-wall maturation, axial tensile stress is generated in the cellulose microfibrils (CMF), whereas isotropic compressive stress is generated in the matrix of lignin-hemicellulose (MT). Some amount of microscopic stresses remains following the removal of the wood from the living stem. Hygrothermal (HT) treatment induces recovery of remaining compressive stress in the MT, which causes its expansion. Axial tensile stress in the CMF are released by HT softening of the MT. This causes the CMF to contract along its length and to expand laterally. The combined effect of the expansions of the MT and contraction of the CMF causes the wood to deform anisotropically. This is the HTR of wood. The degree of anisotropy is determined by the MFA on the basis of reinforced-matrix theory.
Energy metabolism and hindbrain AMPK: regulation by estradiol
Authors: Briski Karen P. , Ibrahim Baher A. , Tamrakar Pratistha
Published: February 2014

Nerve cell energy status is screened within multiple classically defined hypothalamic and hindbrain components of the energy balance control network, including the hindbrain dorsal vagal complex (DVC). Signals of caudal DVC origin have a physiological role in glucostasis, e.g., maintenance of optimal supply of the critical substrate fuel, glucose, through control of motor functions such as fuel consumption and gluco-counterregulatory hormone secretion. A2 noradrenergic neurons are a likely source of these signals as combinatory laser microdissection/high-sensitivity Western blotting reveals expression of multiple biomarkers for metabolic sensing, including adenosine 5′-monophosphate-activated protein kinase (AMPK). Hypoglycemia elicits estradiol-dependent sex differences in A2 AMPK activation as phospho-AMPK (pAMPK) expression is augmented in male and ovariectomized (OVX) female, but not estrogen-replaced, OVX rats. This dichotomy may reflect, in part, estradiol-mediated up-regulation of glycolytic and tricarboxylic acid cycle enzyme expression during hypoglycemia. Our new model for short-term feeding abstinence has physiological relevance to planned (dieting) or unplanned (meal delay) interruption of consumption in modern life, which is negatively correlated with appetite control and obesity, and is useful for investigating how estrogen may mitigate the effects of disrupted fuel acquisition on energy balance via actions within the DVC. Estradiol reduces DVC AMPK activity after local delivery of the AMP mimic, 5-aminoimidazole-4-carboxamide-riboside, or cessation of feeding for 12 h but elevates pAMPK expression when these treatments are combined. These data suggest that estrogen maintains cellular energy stability over periods of suspended fuel acquisition and yet optimizes, by DVC AMPK-dependent mechanisms, counter-regulatory responses to metabolic challenges that occur during short-span feeding abstinence.
Speaker Verification Under Degraded Conditions Using Empirical Mode Decomposition Based Voice Activity Detection Algorithm
Authors: Rudramurthy M. S. , Prasad V. Kamakshi , Kumaraswamy R.
Published: February 2014

The performance of most of the state-of-the-art speaker recognition (SR) systems deteriorates under degraded conditions, owing to mismatch between the training and testing sessions. This study focuses on the front end of the speaker verification (SV) system to reduce the mismatch between training and testing. An adaptive voice activity detection (VAD) algorithm using zero-frequency filter assisted peaking resonator (ZFFPR) was integrated into the front end of the SV system. The performance of this proposed SV system was studied under degraded conditions with 50 selected speakers from the NIST 2003 database. The degraded condition was simulated by adding different types of noises to the original speech utterances. The different types of noises were chosen from the NOISEX-92 database to simulate degraded conditions at signal-to-noise ratio levels from 0 to 20 dB. In this study, widely used 39-dimension Mel frequency cepstral coefficient (MFCC; i.e., 13-dimension MFCCs augmented with 13-dimension velocity and 13-dimension acceleration coefficients) features were used, and Gaussian mixture model–universal background model was used for speaker modeling. The proposed system’s performance was studied against the energy-based VAD used as the front end of the SV system. The proposed SV system showed some encouraging results when EMD-based VAD was used at its front end.
Thermotropic overheating protection glazings: effect of functional additives and processing conditions on the overheating protection performance
Authors: Weber Andreas , Resch Katharina
Published: February 2014

Within this study, the effect of functional additives and processing conditions on the overheating protection performance of thermotropic systems with fixed domains (TSFD) for overheating protection purposes was evaluated. The focus was on improving the overheating protection performance of a prototype TSFD based on a UV curable acrylate resin by optimization of the material constitution (addition of functional additives like surfactants and nucleating agents) and the processing conditions (temperature conditions during manufacturing, annealing). For the evaluated system, an effect of the nucleating agent on the overheating protection performance was ascertained. Furthermore, omission of an annealing step improved the overheating protection performance slightly.
Growth of Bi2Se3 Films by Chemical Bath Deposition at Room Temperature
Authors: Phok Sovannary , Al Wahshi Fatima Subait , Al Baity Shifaa Mohsen , Abdulla Yalyali Saeed Ali
Published: February 2014

Bismuth selenide (BixSey) films are deposited onto glass substrate using chemical bath deposition at room temperature. The reacting bath contained bismuth nitrate, triethanolamine and sodium selenosulfate as selenium (Se) source. Ammonium hydroxide is used to adjust the pH of the bath. The films deposited in solutions containing Se source solution of 10 ml and 15 ml are characterized by surface morphological, compositional and structural, properties. The optimum deposition time is about 3 hours for both solutions. Films deposited up to 24 hours in bath with 10 ml Se source solution had thickness ranging up to 232 nm. The deposition rate is found to increase up to 61 nm/h for 3-hour deposition. In the case of bath with 15 ml Se source solution, the film thickness ranged from 45 nm to 632 nm for 1-hour to 24-hour deposition, respectively; with a deposition rate increasing up to 123 nm/h for 3-hour deposition. Film roughness of about 6.6 nm to 22.8 nm is measured by atomic force microscope for films deposited in bath containing 10 mL Se source and 15 ml of Se source, respectively. Crack free layers are observed with randomly large plate-like particles on top of the layer for some films. The films with typical composition of Bi21.8Se78.2 are found to be rich in Se when deposited for 6 hours, whereas the composition of a film deposited in the same bath (10 mL Se source) for 3 hours is found at Bi60.3Se39.6. Additionally, structural analysis performed by x-ray diffraction (XRD) did not reveal well-defined XRD patterns, which indicates that BixSey films were constituted mostly of nanocrystalline grains.
Electrical Characteristics of TiW/ZnO Schottky contact with ALD and PLD
Authors: Shen Mei , Afshar Amir , Gupta Manisha , Shoute Gem , Cadien Ken , Tsui Ying Yin , Barlage Doug
Published: February 2014

An electrical and analytical study was carried out to investigate TiW/ZnO Schottky contacts with 30 nm ZnO thin film layers deposited by pulsed laser deposition (PLD), plasma enhanced atomic layer deposition (PEALD), and thermal atomic layer deposition (TALD). Devices with ZnO layer deposited by TALD exhibit approximately linear behavior in their I-V measurements. However, both devices with ZnO layers deposited by PEALD and PLD behaved like Schottky rectifiers with barrier heights between TiW and ZnO of 0.51 eV and 0.45 eV respectively and ideality factors of 2.0 and 2.3 respectively. The PEALD deposited ZnO Schotty diodes demonstrated an on/off rectifying ratio of about 25 at ±1 V. The leakage current values of the PLD deposited ZnO Schottky diodes are significantly larger than those of PEALD, leading to a poor on/off rectifying ratio of ∼4. Due to the small thickness, a critical breakdown strength of 1.3 MV/cm was estimated for PEALD-ZnO thin films.
A 2D Covalently Bound Continuous Protein Gradient Assay
Authors: Mintz Benjamin , Cooper James A.
Published: February 2014

Traditional methods of quantifying cell movement in response to a chemotactic factors provide either a binary count of cell migration in response to a known concentration of the factor of interest in solution, as in Boyden chamber assays, or a method of tracking cells to determine velocities across a solubilized protein gradient where exact concentrations vary over time and are difficult to define, as in the Ibidi chemotaxis gradient assay. Using a silane self-assembling monolayer (SAM)-based procedure pioneered by V Hlady and associates, we have developed an assay capable of covalently binding a wide variety of proteins to an optically transparent surface in a 2D pattern via amine linkages. The pattern was then verified by contact angle and Raman and X-ray photoelectron spectroscopy. This new assay provides greater control of protein concentration and gradient intensity than when using only solubilized proteins.
Nutrient enrichment is related to two facets of beta diversity for stream invertebrates across the United States
Authors: Bini Luis Mauricio , Landeiro Victor Lemes , Padial André Andrian , Siqueira Tadeu , Heino Jani
Published: February 2014

Beta diversity, the spatial or temporal variability of species composition, is a key concept in community ecology. However, our ability to predict the relative importance of the main drivers of beta diversity (e.g., environmental heterogeneity, dispersal limitation, and environmental productivity) remains limited. Using a comprehensive data set on stream invertebrate assemblages across the continental United States, we found a hump‐shaped relationship between beta diversity and within‐ecoregion nutrient concentrations. Within‐ecoregion compositional dissimilarity matrices were mainly related to environmental distances in most of the 30 ecoregions analyzed, suggesting a stronger role for species‐sorting than for spatial processes. The strength of these relationships varied considerably among ecoregions, but they were unrelated to within‐ecoregion environmental heterogeneity or spatial extent. Instead, we detected a negative correlation between the strength of species sorting and nutrient concentrations. We suggest that eutrophication is a major mechanism disassembling invertebrate assemblages in streams at a continental scale.
Prioritizing winter habitat quality for greater sage‐grouse in a landscape influenced by energy development
Authors: Smith Kurt T. , Kirol Christopher P. , Beck Jeffrey L. , Blomquist Frank C.
Published: February 2014

Prioritizing habitats that provide the best options for the persistence of sensitive species in human‐modified landscapes is a critical concern for conservation. Linking occurrence and fitness parameters across multiple spatial scales provides an approach to address habitat prioritization for species of concern in disturbed habitats. To demonstrate the usefulness of this approach, we generated resource selection and survival risk models as a framework to quantify habitat value for wintering female greater sage‐grouse (Centrocercus urophasianus) inhabiting a 6,093‐km2 study area in northwest Colorado and south‐central Wyoming, USA, being developed for oil and natural gas reserves. Our approach allowed us to evaluate the relative influence of anthropogenic development and environmental attributes characterizing a large landscape on habitat selection and habitat‐specific survival in winter for female sage‐grouse. When combined, these models provided a spatial representation of habitat quality to inform management and conservation of critical wintering habitats. We used 537 locations from 105 radio‐marked female grouse obtained from 18 fixed‐wing flights across winters 2007–2008, 2008–2009, and 2009–2010. Wintering sage‐grouse selected areas with higher wetness potential (0.75‐km2 scale), intermediate (quadratic form) total shrub cover (18.83‐km2 scale), higher variability in shrub height (18.83‐km2 scale), and less heterogeneity in Wyoming big sagebrush (Artemisia tridentata wyomingensis; 4.71‐km2 scale) cover and total shrub cover (18.83‐km2 scale). Anthropogenic surface disturbance (0.75‐km2 scale) was negatively associated with occurrence. Winter survival for female grouse was positively correlated with heterogeneity in big sagebrush cover at the 0.75‐km2 scale, but negatively correlated with heterogeneity in total shrub cover at the 18.83‐km2 scale. We did not detect an association between anthropogenic variables and female winter survival. However, displacement of sage‐grouse in the energy extraction area may have masked our ability to identify anthropogenic variables potentially influencing survival. Our winter habitat quality map indicated highly effective winter habitat (high occurrence‐low survival risk) was limited, only representing 17.1% of our study area. Consequently, displacement from these limited, high‐quality winter habitats could have profound consequences to population persistence.
Comparison of Rye and Legume–Rye Cover Crop Mixtures for Vegetable Production in California
Authors: Brennan E. B. , Boyd N. S. , Smith R. F. , Foster P.
Published: February 2014

Rye (Secale cereale L.) is an important cover crop in high‐value vegetable production in California. A 2‐yr winter study on organic farms in Salinas and Hollister, CA evaluated cover crop population densities, ground cover, aboveground dry matter (DM), and N content of rye and five legume–rye mixtures. Mixtures had 60 or 90% legumes by seed weight and included two or more of the following legumes: faba bean (Vicia faba L.), vetches (V. benghalensis L., V. dasycarpa Ten., V. sativa L.), and pea (Pisum sativum L.). Seeding rates were 90 (rye) and 140 (mixtures) kg ha−1, and densities were 142 to 441 plants m−2 Early‐season ground cover was usually greater in monoculture rye and the 60% legume mixtures than the 90% legume mixtures. Total DM, and legume and rye DM in mixtures differed by year, site, harvest, and cover crop. Total DM was usually at least two times higher at season end than mid‐season. The 90% legume mixtures generally produced more legume DM than the 60% legume mixtures, but legume DM usually declined after mid‐season. Rye DM increased with rye density. Total cover crop N uptake was greater in Hollister than Salinas; however, legume DM and legume N uptake were greater in Salinas. Interactions between site, year, cover crop, and harvest illustrate the complex growth dynamics of legume–rye mixtures. The 90% legume mixtures appear most suitable for vegetable production in California because they had a better balance of legume and rye DM at season end.
Performance of Sulfur Diagnostic Methods for Corn
Authors: Pagani Agustín , Echeverría Hernán E.
Published: February 2014

Sulfur availability indicators are necessary for rational use of S fertilizers. There are disagreements, however, about which S diagnostic method provides the best results for many crops. This work evaluates the performance of different S diagnostic methods for corn (Zea mays L.). Five field experiments with different rates of S and sufficiency of other nutrients were conducted in two contrasting areas in the Argentinean Pampas region. Measurements of some soil properties, grain yield, N and S concentration in total biomass, and chlorophyll meter readings (CMR) at upper and middle layers of the canopy were performed. Sulfur application significantly increased grain yield in four of the five experiments. Fertilization with S also increased total biomass, S concentration, and CMR depending on the experiment and crop stage, but rarely N concentration in total biomass. Soil indicators (especially sulfate‐S availability) did not perform well as predictors of S response. Total S concentration and N/S ratio in biomass could be used to help characterize the S nutritional status at physiological maturity, since 89 and 72% of the samples were correctly characterized considering thresholds of 0.0095 g kg−1 and 11:1, respectively. Leaf greenness intensity could have a high potential as a predicting/characterization methodology of corn S status since acceptable linear relationships were found between corn relative yield (RY) and a new sulfur sufficiency index (SSI), based on CMR (R2 = 0.56 and 0.75 for the middle and the upper crop layer, respectively). Further research in areas with high levels of S deficiency will have to be done to validate the findings presented in this study.
Optimizing Timing of Chemical Harvest Aid Application in Cotton by Predicting Its Influence on Fiber Quality
Authors: Bange Michael P. , Long Robert L.
Published: February 2014

To optimize yield and fiber quality, boll cutting is used by cotton (Gossypium hirsutum L.) managers to determine when crops are mature and ready for chemical harvest aid application. While it is accepted that the maturity of bolls is defined using seed coat color, we found no investigations of this definition on overall crop fiber quality. Three field experiments were undertaken in different seasons that systematically varied the timing of harvest aid application to vary the amount of immature, mature, and open bolls to assess (i) fiber quality of open, mature, and immature bolls; (ii) the variation that exists within and across seasons; and (iii) if quality at the time of harvest aid application of immature, mature, and open bolls is related to final micronaire. Within seasons, quality varied by up to 1.06 to 1.53 for micronaire, 0.13 to 0.14 for maturity ratio, and 28.2 to 30.7 μg m−1 for linear density among immature, mature, and open bolls. When data were combined across all seasons relationships were developed that predicted micronaire at harvest using micronaire (r2 > 0.73) and its components together (maturity and linear density) (r2 > 0.81) of the immature bolls measured at harvest aid application. Relationships were improved when percent open bolls was included as a factor in the regressions (r2 > 0.88). The ability to estimate harvest aid timing influences on micronaire may help avoid discounts. This concept requires more testing with multiple cultivars and would be enhanced with access to reliable and simple methods to measure quality of small field samples.
Climate Impacts on Agriculture: Implications for Crop Production
Authors: Hatfield J. L. , Boote K. J. , Kimball B. A. , Ziska L. H. , Izaurralde R. C. , Ort D. , Thomson A. M. , Wolfe D.
Published: February 2014

Changes in temperature, CO2, and precipitation under the scenarios of climate change for the next 30 yr present a challenge to crop production. This review focuses on the impact of temperature, CO2, and ozone on agronomic crops and the implications for crop production. Understanding these implications for agricultural crops is critical for developing cropping systems resilient to stresses induced by climate change. There is variation among crops in their response to CO2, temperature, and precipitation changes and, with the regional differences in predicted climate, a situation is created in which the responses will be further complicated. For example, the temperature effects on soybean [Glycine max (L.) Merr.] could potentially cause yield reductions of 2.4% in the South but an increase of 1.7% in the Midwest. The frequency of years when temperatures exceed thresholds for damage during critical growth stages is likely to increase for some crops and regions. The increase in CO2 contributes significantly to enhanced plant growth and improved water use efficiency (WUE); however, there may be a downscaling of these positive impacts due to higher temperatures plants will experience during their growth cycle. A challenge is to understand the interactions of the changing climatic parameters because of the interactions among temperature, CO2, and precipitation on plant growth and development and also on the biotic stresses of weeds, insects, and diseases. Agronomists will have to consider the variations in temperature and precipitation as part of the production system if they are to ensure the food security required by an ever increasing population.
Controlled Release Urea Improved Nitrogen Use Efficiency, Yield, and Quality of Wheat
Authors: Yang Yue-Chao , Zhang Min , Zheng Lei , Cheng Dong-Dong , Liu Ming , Geng Yu-Qing
Published: February 2014

The effects of newly developed controlled release urea (CRU) and its placement method on the N use efficiency and nutritional quality of winter wheat (Triticum aestivum L.) grown on a loam soil were investigated during 2 yr. The winter wheat was grown on a loam soil. The CRU was applied at 0, 75, 150, and 225 kg N ha−1 and the urea was applied at 225 kg N ha−1 The CRU was applied with wheat seeds during sowing while the urea treatment was split into two applications: two‐thirds applied during sowing and one‐third at the 5‐tiller stage (Z25). Results showed that N release rates of CRU fit N requirements of wheat and the placement of wheat seeds with CRU improved wheat's apparent N uptake efficiency by 28.5% compared to urea treatment. Although the CRU treatment at 150 kg N ha−1 had one‐third less supplied N than that of conventional urea treatment (225 kg N ha−1), the wheat with CRU at 150 kg N ha−1 produced 6.5% more grain. In addition, at the same or one‐third reduced amount of N compared with the conventional urea treatment, CRU significantly increased the contents of Fe and Mn, providing additional nutrition and quality to the wheat grain.
Leaf Nitrogen Status as a Main Contributor to Yield Improvement of Soybean Cultivars
Authors: Jin Jian , Liu Xiaobing , Wang Guanghua , Liu Judong , Mi Liang , Chen Xueli , Herbert Stephen J.
Published: February 2014

The N demand would increase with genetic improvement of soybean [Glycine max (L.) Merr.] yield. Since yield improvement largely attributes to photosynthetic rate, which requires considerable N‐derived enzymes to activate the photosynthetic metabolism, the variation of leaf N status over time and its association with nodulation are essential for understanding the mechanism of genetic gain of yield. In agronomic practice, this is also necessary for developing N management in combination with newly released cultivars to increase N use efficiency and yield. However, these issues have not been addressed in Northeast China, where is a major area of soybean production. A field experiment was conducted with 45 representative soybean cultivars, from maturity groups (MG) 00 to 0, released from 1950 to 2006 in Northeast China. The leaf N concentration and content at R5 had positive correlations with the year of release (P < 0.001) with 23.0 and 39.3% of rises over the period, respectively. Nitrogen content per unit area had been improved significantly (P < 0.01), resulting in a 1.08% increase per year. Both photosynthetic rate and C assimilation had significantly positive association with leaf N concentration or N content per unit area, which suggests that both indicators of leaf N status could be essential contributors to genetic yield improvement. The stable content of leaf N across different environments was enhanced over years, which could contribute to yield stability. Among soybean cultivars released across 56 yr, nodule number and fresh weight were progressively increased and a close and significant correlation between leaf N concentration and nodule fresh weight was observed. This indicates that modern cultivars have a better leaf status that poses superior nodulation ability than their predecessors.
Re‐Evaluating Diagnostic Phosphorus Tests for Rice Systems Based on Soil Phosphorus Fractions and Field Level Budgets
Authors: Linquist Bruce , Ruark Matthew
Published: February 2014

The efficient management of P fertilizer in rice (Oryza sativaL.) systems is essential in ensuring optimal yields while also avoiding problems related to over application. Identifying P deficient soils is critical to developing efficient P recommendations. The objectives of study were to determine the extent of P deficiencies in California rice systems, evaluate diagnostic P tests, and identify soil P fractions that contribute to crop P nutrition. On‐farm P‐omission experiments were conducted at 64 sites where we measured Y‐leaf P concentration, P uptake, and grain yield. Soil samples were collected and analyzed for Olsen and Bray‐P as well as being subjected to a sequential P fractionation scheme to determine NaHCO3, NaOH, and HCl inorganic (Pi) and organic (Po) P. From grower interviews, an annual input/output P budget was constructed for each site that accounted for P fertilizer inputs and outputs (P removed at harvest) over the previous 5 yr. Olsen‐P (critical value: 6 mg kg−1) and Y‐leaf P tests (critical value: 0.2%) were reasonable at predicting P deficiencies across a wide range of soil types. The P budget, correlated with Olsen and Y‐leaf P, was also helpful in determining if the grower applied P rates were adequate as the only P deficient sites had a P budget of 0.5 kg P ha−1yr−1or less. Sodium bicarbonate inorganic P (NaHCO3–Pi), NaOH‐, and HCl‐Pi and ‐Po fractions were all correlated with Y‐leaf P concentrations. The only Po fraction correlated with Y‐leaf P and the P budget was HCl‐Po. The primary sinks for excess applied P fertilizer were the NaHCO3–Pi and NaOH‐Pi fractions.
Marker Assisted Evaluation of Fusarium Head Blight Resistant Wheat Germplasm
Authors: Liu Sixin , Anderson J. A.
Published: February 2014

A major QTL (quantitative trait locus) for Fusarium head blight (FHB) resistance, Qfhs.ndsu‐3BS, derived from ‘Sumai 3’, has been identified and verified by several research groups via molecular marker analysis. Further study of this QTL is worthwhile because it explains a large portion (25–60%) of the variation in FHB resistance in the reported studies. The objectives of this study were to (i) identify additional molecular markers for Qfhs.ndsu‐3BS, (ii) construct a cytologically based physical map of chromosome 3BS, and (iii) identify germplasm with novel FHB resistance genes with SSR markers near Qfhs.ndsu‐3BS Two new simple sequence repeat (SSR) markers (XBARC133 and XBARC102), two sequence tagged site (STS) markers (XSTS3B1 and Xsun2), and one restriction fragment length polymorphism (RFLP) marker (Xfbb185), were mapped to the Qfhs.ndsu‐3BS region. On the basis of deletion line analysis, this major QTL is likely located on the deletion bin 3BS 0.78‐0.87. Fifty‐four FHB resistant lines from throughout the world and 20 North American spring wheat (Triticum aestivum L.) lines of historical prominence were genotyped by five SSR markers (Xgwm389, Xgwm533, XBARC133, Xgwm493, and XBARC102) associated with Qfhs.ndsu‐3BS The Sumai 3 haplotype is rare. Only 25 out of 54 FHB resistant lines and one North American spring wheat line have Sumai 3‐type alleles for at least one of these five SSR markers. Twelve FHB resistant lines have the same SSR allele as Sumai 3 for at least four of the five SSR markers, and therefore most likely contain this major QTL. The other 42 FHB resistant lines may carry novel FHB resistance genes, and are worthy of further genetic study.
Exploiting Heterosis in Pearl Millet for Population Breeding in Arid Environments
Authors: Presterl T. , Weltzien E.
Published: February 2014

In the desert region of Rajasthan, India, farmers mainly grow pearl millet [Pennisetum glaucum (L.) R. Br.] landraces. The adoption of modern cultivars is generally low because of their poor adaptation to extreme drought stress. The objective of this study was to evaluate the performance of six elite breeding populations and three landraces and to determine the heterotic pattern among the 36 diallel crosses of those populations. Field experiments were conducted in eight environments in India. Mean grain yields (GYs) in the three environments with favorable growing conditions were double to threefold those in the three arid environments. The elite populations generally showed higher GY than the landraces; stover yield (SY) was similar in both population types. The landraces flowered earlier, had a higher tillering potential, and smaller seeds. Mean level of midparent heterosis was generally low, ranging from 0.85% for time to flowering (TF) to 6.57% for SY. For GY, expression of heterosis for individual population crosses was between −14 and +30% under drought stress, and between −9 and +17% in the favorable environments. For SY, mean heterosis was always positive and higher than for GY. The elite × landrace population crosses with high mean GY and high levels of heterosis under drought stress could be beneficial to widen the germplasm base and to combine the high yield potential of elite materials with the good adaptation of the landraces.
Genetic Analysis of Inbred and Hybrid Grain Yield under Stress and Nonstress Environments in Tropical Maize
Authors: Betrán F. J. , Beck D. , Bänziger M. , Edmeades G. O.
Published: February 2014

Drought and low soil N cause significant yield reductions in maize (Zea mays L.) grown in the tropics. Understanding the genetic basis of hybrid performance under these stresses is crucial to designing appropriate breeding strategies. This study evaluates under optimal, drought and low N stress conditions (i) the performance, combining abilities and stability of a group of tropical white inbred lines; (ii) the genetic control and modes of gene action for grain yield; and (iii) the relationship between line per se and hybrid performance. Seventeen lowland white‐grained tropical maize inbred lines were used in a diallel study. Lines and their hybrids were evaluated separately in trials under drought stress, low N, and optimal conditions in a total of 12 environments. The differences in grain yield between hybrids and inbreds (i.e., heterosis) increased with the intensity of drought stress. Significant interactions were observed for combining abilities under low and high N. The type of gene action appeared to be different under drought than under low N, with additive effects more important under drought and dominance effects more important under low N. The importance of additive effects increased with intensity of drought stress. This suggests the need for drought tolerance in both parental lines to achieve acceptable hybrid performance under severe drought. Inbreds derived from the population ‘La Posta Sequía’ exhibited the highest GCA effects, stability coefficients, and frequency of dominant alleles for grain yield. Good performance across stress levels can be achieved in tropical maize hybrids.
Combining Ability of Maize Inbreds for Carotenoids and Tocopherols
Authors: Egesel C. O. , Wong J. C. , Lambert R. J. , Rocheford T. R.
Published: February 2014

Carotenoids (provitamin A) and tocopherols (vitamin E) are lipid soluble antioxidants associated with decreased risk of several degenerative diseases. Both vitamins occur naturally in corn (Zea mays L.) grain. Corn grain is a major component in diets of humans and animals, and may have added value with increased levels of carotenoids and tocopherols. To estimate genetic variation among a group of inbreds and their breeding potential, we estimated combining abilities of four carotenoids and two tocopherols in a diallel of 45 corn hybrids. Ten inbreds were chosen that varied in endosperm color (yellow to orange), tocopherol levels and oil content. Plants were grown for two years (1998, 1999) at Urbana, IL, in an RCB design with three replications. High pressure liquid chromatography was used to assay for four carotenoids (lutein, zeaxanthin, β‐cryptoxanthin, and β‐carotene) and two tocopherols (α‐tocopherol and γ‐tocopherol). Good agreement between year means for the six compounds was observed indicating minor environmental effects. Diallel analyses indicated, between 72 to 87% of the total sums of squares for hybrids for the six compounds was attributable to GCA effects. Significant SCA effects were found for several crosses. Estimates of GCA effects indicated A619 had high values for lutein, β‐cryptoxanthin, and total carotenoids. Inbred R84 was a poor genotype for xanthophyll pigments but a significant contributor for β‐carotene and γ‐tocopherol, and total tocopherol. These genetic stocks indicate corn hybrids can be developed with higher levels of provitamin A and vitamin E.
Inheritance of Seed Dormancy in Weedy Rice
Authors: Gu Xing‐You , Chen Zong‐Xiang , Foley Michael E.
Published: February 2014

Seed dormancy contributes to the adaptability of plants in nature and is of considerable importance in agriculture. The weedy rice (Oryza sativa L.) strains LD, SS18‐2, and TKN12‐2 and cultivar ‘N22’ were selected to investigate the inheritance of dormancy in controlled conditions. Initial investigations using intact seeds, caryopses, caryopses with pericarp/testa removed, and excised embryos demonstrated that seed dormancy was imposed by the hull in SS18‐2 and TKN12‐2, and by the hull and pericarp/testa in LD and N22. Seed dormancy at 0 d after harvest (DAH) was dominant with average degree of dominance (ADD) > 0.8 in the crosses with weedy strains. Dominance for duration of seed dormancy was incomplete when judged by days to 50% germination. Broad‐sense heritability (h2b) for seed germination was lower at 0 DAH and highest at 20 DAH in all the crosses. The weedy strain‐derived F2 populations maintained a higher h2b during afterripening. The effects of three and two major genes on seed germination at 20 DAH were detected in the SS18‐2‐ and N22‐derived F2 populations, respectively. A positive ADD, a high h2b, and major gene effect for caryopsis germination at 0 DAH were detected only in the cross with LD. Seed or caryopsis dormancy was correlated with the characteristics awn and black hull or red pericarp colors in the SS18‐2‐ or LD‐derived F2 populations. This research demonstrates that weedy rice provides ideal gene resources to elucidate mechanisms of dormancy and to improve resistance to preharvest sprouting.
Quantitative Trait Loci Conditioning Resistance to Fusarium Head Blight in Wheat Line F201R
Authors: Shen Xiaorong , Ittu Mariana , Ohm Herbert W.
Published: February 2014

Fusarium head blight (FHB) of wheat (Triticum aestivum L.) is a devastating disease in wheat production worldwide. Identifying resistance genes and understanding the genetic basis of resistance to FHB are prerequisites to developing cultivars that can avoid losses from FHB. This investigation of quantitative trait loci (QTL) was performed in a recombinant inbred (RI) population derived from a cross between the FHB‐moderately susceptible cv. Patterson and the FHB‐resistant line Fundulea 201R (F201R). Bulk DNAs from the 11 most resistant and 12 most susceptible lines of the phenotypic distribution of the RI population, together with the parental lines, were screened with simple sequence repeat (SSR) markers. Regional QTL mapping identified four interval regions, located on chromosomes 1B, 3A, 3D, and 5A, that conferred resistance to FHB. The QTLs located on chromosomes 1B and 3A, contributed by F201R, had large effects and were consistently expressed in three environments. The four QTLs together accounted for 32.7% of the phenotypic variation, or 43.0% of the genotypic variation. The QTL on chromosome 3A is located in the same region as a QTL that was detected in wild tetraploid wheat T. dicoccoides (Koern. ex Asch. & Graebner) Aarons. The possibility that the FHB resistance QTLs of F201R and that of T. dicoccoides on chromosome 3A have the same origin is discussed.
Both Promoters and Inhibitors Affected Flowering Time in Grafted Soybean Flowering‐Time Isolines
Authors: Cober Elroy R. , Curtis Daniel F.
Published: February 2014

Understanding the control of flowering time in photoperiod‐sensitive plants has been furthered by grafting experiments. In soybean [Glycine max (L.) Merr.], genes which control flowering time have been identified and their responses to photoperiod characterized. Grafting experiments allow the study of interactions between genotypes. The objective of our study was to characterize the flowering response of scions from a grafted series of early‐ to late‐flowering soybean near‐isogenic lines. Seedling scions were grafted to 1‐wk‐older rootstocks and grown under noninductive 16‐h days. Rootstocks were allowed to develop a single axillary shoot to allow interaction between rootstock and scion shoots. Late‐flowering rootstocks did not delay flowering of the earliest‐flowering isolines but delayed flowering of intermediate‐flowering isolines. Some floral inhibition was also seen within scions since defoliated late‐flowering scions grafted to early‐flowering rootstocks flowered earlier compared with nondefoliated scions of the same graft combination. Early‐flowering rootstocks promoted flowering of late‐flowering scions both within and across genetic backgrounds. Early‐flowering scions flowered early (27 to 30 d) regardless of rootstock genotype. This early flowering was observed even when the scions were defoliated, indicating that floral promoters might be produced or sensed in unexpanded leaves or buds. The activity of floral promoters and inhibitors was demonstrated in soybean and these factors appeared to mediate flowering time antagonistically.
High‐Yielding Rice Cultivars Perform Best Even at Reduced Nitrogen Fertilizer Rate
Authors: Hasegawa Hiroshi
Published: February 2014

A production system consisting of high‐yielding cereal crop cultivars, together with high inputs of fertilizers, chemicals, and irrigation has increased yields in developed and developing countries during the past decades. This has led many to believe that high‐yielding cereal cultivars may not be used in alternative cropping systems in which external inputs and adverse environmental effects are minimized. The objective of this study was to test the hypothesis that high‐yielding temperate rice (Oryza sativa L.) cultivars do not perform well under a reduced N fertilizer rate. A field experiment was conducted from 1992 through 1994 at Hokuriku National Agricultural Experiment Station, Japan, on soil classified as clayey montmorillonitic, mesic Typic Endoaquepts. Thirteen rice cultivars released between 1893 and 1995 and one breeding line were grown at conventional (120 kg ha−1) and reduced (40 kg ha−1) N fertilizer rates, with a sufficient supply of other nutrients and water. Insects, diseases, and weeds were controlled by agrochemicals. In spite of contrasting weather from 1992 through 1994, there were highly positive correlations in grain yield of the rice cultivars between conventional and reduced N rates. At the reduced N rate, high‐yielding cultivars Akichikara, Fukuhibiki, Habataki, Hokuriku 153, and Xin Ging Ai 1 consistently surpassed others not only in grain yield (P < 0.01), but also in aboveground dry matter (DM), harvest index (HI), N utilization efficiency (NUE), and sink capacity (P < 0.01) with two exceptions. There are significant advantages to the use of high‐yielding rice cultivars at reduced N fertilizer rates, giving such cultivars potential benefits in alternative cropping systems for temperate regions.
Response of Eastern Gamagrass Seed to Gibberellic Acid Buffered below Its pKa
Authors: Tian X. , Knapp A. D. , Gibson L. R. , Struthers R. , Moore K. J. , Brummer E. C. , Bailey T. B.
Published: February 2014

Eastern gamagrass [Tripsacum dactyloides (L.) L.] seed are usually dormant, often causing seedling establishment difficulties. This study was conducted to assess the effect of gibberellic acid (GA3) buffered below its pKa (3.8) on seed germination of eastern gamagrass. In one experiment, concentrations of 0.001‐, 0.005‐, and 0.01 M buffered GA3 solutions were applied to seed with cupules removed from six commercial seed lots produced in three different years. After 28 d of germination, GA3 application increased total seed germination by 25 to 47 percentage points. The three GA3 concentrations were equally effective in promoting germination in all seed lots except one, where 0.001 M GA3 was more effective than 0.01 M GA3 The germination rate was accelerated by GA3 application during the germination process but did not result in germination of all the viable seeds. An average 10% of the viable caryopses remained dormant at the end of the germination test. A second experiment evaluated the germination of intact cupules after treatment for 24 or 48 h in distilled water, 0.001 M GA3 solution, buffer solution, or buffered 0.001 M GA3 solution. Buffered GA3 was not effective at enhancing germination of eastern gamagrass seed when cupules were left intact. These results suggest that there may be multiple dormancy mechanisms in eastern gamagrass. At least one mechanism involves the caryopsis and is affected by GA3 application. Furthermore, the cupule‐mediated dormancy mechanism(s) and the caryopsis‐mediated mechanism(s) must be addressed to obtain complete germination of dormant seed.
Quantifying Turfgrass Color Using Digital Image Analysis
Authors: Karcher Douglas E. , Richardson Michael D.
Published: February 2014

Color is a major component of the aesthetic quality of turf and often evaluated in field studies. Digital image analysis may be an improved, objective method to quantify turf color. Studies were conducted to determine if digital image analysis with SigmaScan software (SPSS, Chicago, IL) was capable of: (i) accurately determining the hue, saturation, and brightness (HSB) levels of Munsell Plant Tissue color chips, (ii) quantifying visual color differences among zoysiagrass (Zoysia japonica Steud.) and creeping bentgrass {Agrostis palustris Huds. [= A. stolonifera var. palustris (Huds.) Farw.]} plots receiving various N treatments, and (iii) quantifying genetic color differences among bermudagrass (Cynodon spp.) cultivars. Digital images of turf plots were analyzed with SigmaScan software to determine average HSB levels for each image. A dark green color index (DGCI) was created from HSB values for direct comparison with visual ratings. Digital image analysis accurately quantified the HSB levels (r2 = 0.99, 0.96, and 0.97, respectively) of Munsell color chips corresponding to turf colors. Significant HSB differences were present among N treatments in creeping bentgrass, while only significant hue differences existed in zoysiagrass. Significant hue and saturation differences were present among bermudagrass cultivars. There was strong agreement between DGCI values and visual ratings. The relative variances of the HSB and DGCI were significantly less than the variance associated with multiple raters. This evaluation technique may facilitate objective comparisons of turf color across researchers, locations, and years when images are collected under equal lighting conditions (i.e., the use of an artificial light source at night or in an enclosed system).
Plant Growth Regulators Can Enhance the Recovery of Kentucky Bluegrass Sod from Heat Injury
Authors: Zhang Xunzhong , Ervin E. H. , Schmidt R. E.
Published: February 2014

A primary economic concern of sod producers is loss of sod quality during the transportation, storage, and transplant stages of sale. Although a number of cultural methods have been documented for potentially reducing sod heating, many of the biological mechanisms are yet to be investigated. This study investigated the influences of selected plant growth regulators (PGRs) on sod tolerance to stress during storage by examining the relationship between preharvest photochemical efficiency (PE) and transplant rooting of Kentucky bluegrass (Poa pratensis L., KBG) sod. The PGRs, including propiconazole (propiconazole [1‐(2‐(2,4‐dichloropheny)‐4‐propyl‐1,3‐dioxolan‐2yl)methyl‐1‐H‐1, 2,4‐triazole]; PPC), and seaweed (Ascophyllum nodosum Jol) extract (SWE) plus humic acid (93% a.i.; HA), were applied alone, or in combination, to the KBG 2 wk before harvest in 1999 and 2000. Photochemical efficiency was measured immediately before harvest. The harvested sod was subjected to high temperature stress (37°C) for 72 or 96 h. The heated sod was replanted in the field and transplant visual turf injury and rooting were determined. Foliar application of SWE at 0.5 kg ha−1 plus HA at 1.50 kg ha−1, PPC at 0.44 kg ha−1 alone, or a combination of SWE + HA with 0.22 kg ha−1 PPC, enhanced PE of preharvest sod in both years. Extension of heat duration from 72 to 96 h caused significantly more injury to the sod in 1999. All PGR treatment combinations reduced visual turf injury. On average in 1999 and 2000, SWE + HA, PPC, and SWE + HA + PPC enhanced transplant rooting by 21.8, 34.7, and 44.2%, respectively. Regression analysis indicated that KBG with higher preharvest PE suffered less turf injury and produced greater rooting after transplantation. The data suggest that foliar application of SWE + HA, PPC alone, or in a combination, may improve shelf life and transplant rooting of KBG sod.