bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small‐Scale Circulations Caused by Complex Terrain Affect Pollen Deposition
Authors: Viner Brian J. , Arritt Raymond W. 
Published: April 2012

ABSTRACTWe combined a high‐resolution atmospheric dynamical model and a Lagrangian dispersion model to assess the influence of complex terrain (e.g., mountains and valleys) on the movement of pollen from a source of genetically modified bentgrass (Agrostis stolonifera L.). We simulated 6 d (22–27 June 2003) from a reported case where gene flow in bentgrass was observed at distances greater than 20 km near Madras, OR (44°44′24″ N, 121°9′30″ W). Our model resolves the effects of complex terrain and local turbulence on pollen dispersion that were not considered by previous studies. We simulated pollen deposition over 20 km from its source and at locations where gene flow was previously observed. Our simulations showed that local terrain strongly affected deposition; for example, pollen grains were not deposited in large quantities within valleys or on the windward sides of mountains. Examination of the flow in these regions indicated that complex terrain creates local circulations that must be considered when predicting the potential for gene flow.
Development of Functional Markers for a Lipoxygenase Gene TaLox‐B1 on Chromosome 4BS in Common Wheat
Authors: Geng Hongwei , Xia Xianchun , Zhang Liping , Qu Yanying , He Zhonghu 
Published: April 2012

ABSTRACTLipoxygenase (LOX) activity in grain influences the color and processing quality of wheat (Triticum spp.)‐based products. Characterization of LOX genes and development of functional markers are of importance for marker‐assisted selection in common wheat (Triticum aestivum L.) breeding. In the present study, the full‐length genomic DNA (gDNA) sequence of a LOX gene (designated TaLox‐B1) located on chromosome 4BS was characterized by in silico cloning and experimental validation. Two complementary dominant sequence tagged site (STS) markers, LOX16 and LOX18, were developed based on the single nucleotide polymorphism (SNP) of two alleles at the TaLox‐B1 locus, amplifying 489‐ and 791‐bp fragments in cultivars with higher and lower LOX activities, respectively. The two markers were mapped on chromosome 4BS using a doubled haploid (DH) population derived from Zhongyou 9507 × CA9632, a set of Chinese Spring nullisomic–tetrasomic lines, ditelosomic line 4BS, and Langdon (LDN) 4D(4B) chromosome substitution line. Quantitative trait loci (QTL) analysis indicated that TaLox‐B1 co‐segregated with the two functional markers and was closely linked to simple sequence repeat (SSR) locus Xgwm251 on chromosome 4BS with a genetic distance of 1.8 cM. LOX16 and LOX18 were validated on 198 Chinese wheat cultivars and advanced lines and showed highly significant (p < 0.01) associations with LOX activity. These results suggested that LOX16 and LOX18, co‐segregating with TaLox‐B1, could be used for the improvement of color attributes of noodles and other wheat‐based products in wheat breeding programs.
Steer and Plant Responses to Chemical Suppression of Seedhead Emergence in Toxic Endophyte‐Infected Tall Fescue
Authors: Aiken Glen E. , Goff Ben M. , Witt William W. , Kagan Isabelle A. , Sleugh Byron B. , Burch Patrick L. , Schrick F. Neal 
Published: April 2012

ABSTRACTChaparral herbicide has been shown to suppress seedhead emergence in tall fescue [Lolium arundinaceum (Schreb.) Darbysh] and potentially mitigate the effects of fescue toxicosis. A two‐year grazing experiment evaluated steers grazed on endophyte‐infected fescue–Kentucky bluegrass (Poa pratensis L.) pastures either treated or untreated with Chaparral herbicide to determine if seedhead suppression alleviates fescue toxicosis and increases average daily gain (ADG). Treatments were assigned to six, 3.0‐ha fescue‐bluegrass pastures in a randomized complete block design with three replications. Pastures were grazed with 48 steers (2.7 steers ha−1) from 9 Apr. to 1 July 2009 and 6 Apr. to 7 July 2010. Reproductive tiller densities in treated pastures were low in both years (<7 m−2) in comparison with untreated pastures (113 and 69 tillers m−2 in 2009 and 2010, respectively). Ergovaline and ergovalinine concentrations were three‐ to sixfold greater in seeds than in leaf blades and sheaths of vegetative and reproductive tillers. Crude protein, water soluble carbohydrates, and in vitro digestible dry matter concentrations of tillers declined over time at a greater rate in untreated than in treated pastures. Steers on treated pastures had greater (P < 0.01) ADG, lower (P < 0.10) rectal temperatures, and greater (P < 0.01) serum prolactin concentrations. Results indicated that Chaparral herbicide can suppress reproductive development of fescue to increase ADG and reduce the severity of toxicosis.
Specific Adaptation and Genetic Progress for Grain Yield in Great Plains Hard Winter Wheats from 1987 to 2010
Authors: Graybosch Robert A. , Peterson C. James 
Published: April 2012

ABSTRACTA previous investigation, using region‐wide data from Great Plains wheat (Triticum aestivum L.) breeding trials, indicated a possible plateau in the rate of genetically determined yield potential. Data from the same USDA‐Agricultural Research Service (ARS) coordinated long‐term regional performance nurseries was used to further examine the rate of genetic improvement of Great Plains winter wheats in specific agro‐ecological or production zones over the time period 1987 to 2010. The absolute grain yield of all entries and of the top five most productive entries increased in the majority of production zones over this time period. The relative rate of genetic improvement, obtained by comparing grain yields to those of the long‐term control cultivar Kharkof, ranged from not significantly different from zero to 1.98% yr−1. This rate of change, however, was statistically significant (α = 0.05) in only two of the 12 zones evaluated. Variance components identified production zone and locations within production zone as being the largest sources of variation in grain yields. Variance due to either genotype or genotype × environmental factors remained both constant over the 24‐yr time period and small, relative to the environmental variances. Genetic progress for enhanced wheat yield in the region might be limited by the magnitude of these environmental variances and by constraints arising from continuous evolution of pest and pathogen populations.
Toward the Systematic Conservation of Global Crop Wild Relative Diversity
Authors: Maxted Nigel , Kell Shelagh , Ford‐Lloyd Brian , Dulloo Ehsan , Toledo Álvaro 
Published: April 2012

ABSTRACTGrowing concern over the potentially devastating impacts of climate change on biodiversity and food security, considered together with the growing world population, means that taking action to conserve crop wild relative (CWR) diversity is no longer an option—it is an urgent priority. Crop wild relatives are species closely related to crops, including their progenitors, which have the potential to contribute beneficial traits for crop improvement, such as biotic and abiotic resistances, leading to improved yield and stability. Having already made major contributions to crop improvement in the 20th century, CWR are recognized as a critical resource to sustain global food security; therefore, their systematic conservation is imperative. However, extending their conservation and promoting more systematic exploitation is hindered by a lack of understanding of their current and potential value, their diversity, and practically how they might be conserved. Therefore, the aim of this paper is to (i) demonstrate the current and potential use of CWR in crop improvement, (ii) estimate how many CWR species exist and how many are a global priority for active conservation, and (iii) describe how a global network for the in situ conservation of CWR might be established that could help to underpin future food security.
Preharvest Neutral Detergent Fiber Concentration of Temperate Perennial Grasses as Influenced by Stubble Height
Authors: Parsons David , McRoberts Keenan C. , Cherney Jerome H. , Cherney Debbie J.R. , Bosworth Sidney C. , Jimenez‐Serrano Felix R. 
Published: April 2012

ABSTRACTRegression equations were developed to estimate the preharvest neutral detergent fiber (NDF) concentration of temperate perennial grasses at variable cutting height. These equations can be used by producers to improve harvest timing to optimize the nutritive value of spring grass forages. The objective of this experiment was to develop equations that incorporate stubble height to estimate NDF concentration of pure grass stands. Stands of first‐cut orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.), and timothy (Phleum pratense L.) were sampled in experimental sites and producers’ fields in New York in 2009, cut into 5‐cm segments, and analyzed for dry matter (DM) production and NDF concentration. Predictive NDF and DM equations were developed for each segment. Equations describing the change with grass height in the contribution of each segment to the overall DM were used to develop equations for predicting whole‐plant NDF. Two evaluation data sets from Vermont and New York were used to test the equations. Dry matter loss equations were promising and merit further evaluation. Whole‐plant NDF equations had some merit but may have limited predictive capacity under conditions and years different than those used in equation development.
Pea Germplasm with Partial Resistance to Sclerotinia sclerotiorum Extends the Time Required by the Pathogen to Infect Host Tissue
Authors: Porter Lyndon D. 
Published: April 2012

ABSTRACTWhite mold, caused by the fungus Sclerotinia sclerotiorum (Lib.) de Bary, can be a serious disease in pea (Pisum sativum L.). Currently there are no pea genotypes with complete resistance to this pathogen. The objective of this research was to identify pea germplasm with partial resistance to S. sclerotiorum, focusing on initial infection and severity as influenced by environment. Selected pea genotypes from the USDA‐ARS Pisum core collection and two cultivars were assessed for the time required by S. sclerotiorum to severely infect these genotypes at all combinations of five temperatures (15.6, 18.3, 21.1, 23.9, and 29.4°C) and four periods of high relative humidity (PHRH) (12, 24, 48, and 72 h) under controlled environmental conditions. Severe infection is defined as the death of all plant tissue above a stem inoculation point, preventing reproduction. The commercial genotypes ‘Bolero’ and ‘1204‐3’ did not prevent severe infection at any temperature × PHRH combination. However, pea genotypes PI 164972, PI 169603, PI 197044, PI 240515, PI 270536, and PI 280611 prevented severe infection at 15.6, 18.3, 29.4, and either 21.1 or 23.9°C following a 12 h PHRH in repeated trials. Plant Introduction 164972, PI 169603, and PI 280611 also prevented severe infection following a 24 h PHRH but only at 29.4°C. Severe infection occurred for all genotypes after a 48 or 72 h PHRH at all temperatures tested. Plant Introduction 169603 and PI 240515 are recommended to pea breeders as the best germplasm to extend the time required for serious infection by S. sclerotiorum.
Effect of Autumn Sod Treatments on Overseeded Annual Ryegrass Production and Coastal Bermudagrass Recovery
Authors: Evers Gerald 
Published: April 2012

ABSTRACTOverseeding warm‐season perennial grasses with annual ryegrass (Lolium multiflorum Lam.) is a common practice throughout the southeastern United States to extend the grazing season with high quality forage. ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] competition to overseeded annual ryegrass was determined by light reaching the soil surface, ryegrass seedling density, and ryegrass herbage production. Treatments were 0, 56, and 112 kg ha−1 N 6 to 8 wk before planting ryegrass and sod management practices (SMPs) of a shallow disking (2.5 to 5.0 cm), applying a desiccant, and a control before planting in combination with mowing to a 2.5 or 10.0‐cm sod height (SH) for 3 yr. Applying N 6 to 8 wk before planting did not influence any of the plant parameters measured. The shallow disking SMP and 2.5‐cm SH allowed the most light to reach the soil surface and had the greatest ryegrass seedling density. At the 10‐cm SH the shallow disking SMP had a greater seedling density than the desiccant and control SMP. None of the SMP–SH combinations consistently improved first harvest or annual herbage mass yields over the control at the 2.5‐cm SH. Significant differences may have occurred if the first harvest was taken earlier. Spring bermudagrass recovery was reduced by the shallow disking SMP and 2.5‐cm SH. At a bermudagrass SH of 10 cm or less there was little advantage to disking or using a desiccant to enhance ryegrass production.
Mapping Quantitative Trait Loci for Partial Resistance to Powdery Mildew in an Australian Barley Population
Authors: Hickey Lee T. , Lawson Wendy , Platz Greg J. , Fowler Ryan A. , Arief Vivi , Dieters Mark , Germán Silvia , Fletcher Susan , Park Robert F. , Singh Davinder , Pereyra Silvia , Franckowiak Jerome 
Published: April 2012

ABSTRACTGenomic regions influencing resistance to powdery mildew [Blumeria graminis (DC.) E.O. Speer f. sp. hordei Ém. Marchal] were detected in a doubled haploid (DH) barley (Hordeum vulgare L.) population derived from a cross between the breeding line ND24260 and cultivar Flagship when evaluated across four field environments in Australia and Uruguay. Significant quantitative trait loci (QTL) for resistance to B. graminis were detected on six of the seven chromosomes (1H, 2H, 3H, 4H, 5H, and 7H). A QTL with large effect donated by ND24260 mapped to the short arm of chromosome 1H (1HS) conferring near immunity to B. graminis in Australia but was ineffective in Uruguay. Three QTL donated by Flagship contributed partial resistance to B. graminis and were detected in at least two environments. These QTL were mapped to chromosomes 3H, 4H, and 5H (5HS) accounting for up to 18.6, 3.4, and 8.8% phenotypic variation, respectively. The 5HS QTL contributed partial resistance to B. graminis in all field environments in both Australia and Uruguay and aligned with the genomic region of Rph20, a gene conferring adult plant resistance (APR) to leaf rust (Puccinia hordei Otth), which is found in some cultivars having ‘Vada’ or ‘Emir’ in their parentage. Selection for favorable marker haplotypes within the 3H, 4H, and 5H QTL regions can be performed even in the presence of single (major) gene resistance. Pyramiding such QTL may provide an effective and potentially durable form of resistance to B. graminis.
Comparative Analysis of Proteomic Responses to Single and Simultaneous Drought and Heat Stress for Two Kentucky Bluegrass Cultivars
Authors: Xu Chenping , Huang Bingru 
Published: April 2012

ABSTRACTProtein metabolism may vary in response to drought, heat, or heat and drought stress combined. The variations in the abundance of different proteins may differentially affect adaptation mechanisms of plants to these three types of stresses. The objectives of this study were to examine differential protein responses and identify stress‐responsive proteins associated with tolerance to drought, heat, or the combined stress in a perennial grass species. Plants of two cultivars of Kentucky bluegrass (Poa pratensis L.) contrasting in heat and drought tolerance (tolerant ‘Midnight’ and sensitive ‘Brilliant’) were treated with heat, drought, or a combination of the stresses in growth chambers. Physiological analysis demonstrated that Midnight maintained higher relative water content and photochemical efficiency and lower electrolyte leakage than Brilliant under all three stress treatments. Two‐dimensional electrophoresis and mass spectrometry analysis identified some common proteins responsive to drought, heat, and the combined stress. Induction of a chaperonin and heat shock proteins (HSPs) 70 and 90) and downregulation of proteins involved in photorespiration occurred under all three stresses. The two cultivars exhibited differential accumulation of proteins involved in photorespiration, cell wall loosening, antioxidant defense, and photosynthesis, and therefore these proteins could be associated with the contrasting drought tolerance characteristics of the cultivars. The results also suggest proteins involved in membrane stability, ribonucleic acid (RNA) stability, cell wall loosening, and antioxidant defense could contribute to superior heat tolerance of Midnight. Proteins involved in photorespiration and those that are associated with photosystems may play a major role in Kentucky bluegrass tolerance to combined heat and drought stress.
An Efficient Method for Flanking Sequence Isolation in Barley
Authors: Brown Ryan H. , Dahleen Lynn , Bregitzer Phil 
Published: April 2012

ABSTRACTA polymerase chain reaction (PCR)‐based adapter ligation method was developed to determine native barley (Hordeum vulgareL.) sequences flankingDissociation(Ds) insertions and barley expressed sequence tags (ESTs). This method is simple and efficient, with the majority (∼70%) of queries returning valid sequence information. The success of this method can be traced to experimental protocols that control sample cross contamination and that segregate specific products from nonspecific products. This report describes the protocol in detail, quantifies its efficiency to enable comparisons to future modifications, and discusses specific problems that may be addressed to enable further improvements to this method.
Genetic Relationship Between Maize Resistance to Corn Borer Attack and Yield
Authors: Butrón A. , Romay M. C. , Peña‐Asín J. , Alvarez A. , Malvar R. A. 
Published: April 2012

ABSTRACTSelection for reduced stalk tunnel length by the Mediterranean corn borer (MCB) (Sesamia nonagrioides Lef.) while maintaining yield under infestation has already been evaluated. Significant reductions for tunnel length were reported, but yield showed a nonsignificant tendency to decrease with selection that could be due to increased inbreeding or significant genetic correlation between yield and resistance. Simultaneously, the presence of major quantitative trait loci (QTL) for resistance in chromosome 4 has been suggested. In the present study, we investigated the genetic relationship between yield and stalk tunneling resistance by conducting one generation of selection each for yield alone, resistance alone, and yield and resistance combined in a broad‐based population. In addition, we tested the effectiveness of marker‐assisted selection at two markers on chromosome 4 for reducing tunnels by MCB. Evaluations were made for 2 yr at two locations under MCB infestation. Unfavorable genetic correlation between stalk tunnel length and yield has been confirmed and could prevent detection of major QTL for tunnel length by using selection mapping. Markers phi076 and umc1329 could be linked to QTL for plant height but are not useful markers for reducing tunnel length and hence damage caused by borers. Finally, results advise against selection for reduced tunnel length by MCB or any index involving yield and tunnel length.
Effective Resources in Wheat and Wheat–Thinopyrum Derivatives for Resistance to Heterodera filipjevi in China
Authors: Li Hongjie , Cui Lei , Li Honglian , Wang Xiaoming , Murray T.D. , Conner R.L. , Wang Lijian , Gao Xiu , Sun Yu , Sun Shancheng , Tang Wenhua 
Published: April 2012

ABSTRACTCereal cyst nematode (CCN) is becoming one of the important soil‐borne pathogens in wheat (Triticum aestivum L.) monocropping or wheat–maize (Zea mays L.)–wheat cropping systems of central China. Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984 was recently recognized as a causal agent of CCN in China, but little information is available on sources of resistance against this nematode species. The present study was initiated to determine the current status of resistance in wheat cultivars against H. filipjevi and to identify effective resources for improvement of CCN resistance in China. A 3‐yr field study of CCN resistance that involved 174 wheat cultivars or wheat–Thinopyrum derivatives was conducted in a wheat field in Xuchang, Henan Province, China, where H. filipjevi had been present for years. Greenhouse experiments were conducted with representative resistant entries from each group of accessions. None of the 78 wheat cultivars and breeding lines from China was resistant in field tests. Wheat cultivar Madsen from Washington State was most resistant among the entries tested both in field and under controlled environment. New sources of resistance to H. filipjevi were identified in some wheat–intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] and wheat–tall wheatgrass [Thinopyrum ponticum (Podp.) Barkworth & D. R. Dewey] partial amphiploids, which will diversify resistance resources in enhancing resistance of wheat against CCN.
Evaluation of Near‐Isogenic Lines for Three Height‐Reducing Genes in Hard Red Spring Wheat
Authors: Lanning S. P. , Martin J. M. , Stougaard R. N. , Guillen‐Portal F. R. , Blake N. K. , Sherman J. D. , Robbins A. M. , Kephart K. D. , Lamb P. , Carlson G. R. , Pumphrey M. , Talbert L. E. 
Published: April 2012

ABSTRACTThe most common genes for semidwarf habit in modern wheat (Triticum aestivum L.) cultivars are found at the Rht‐B1 and Rht‐D1 loci on chromosomes 4B and 4D, respectively. An alternative gene for semidwarf habit, Rht8, has shown potential as a replacement for Rht‐B1b and Rht‐D1b in some environments. The objective of the present study was to assess the impact of the height‐reducing gene Rht8 relative to Rht‐B1b and Rht‐D1b on performance of spring wheat in Montana and Washington environments characterized by terminal drought stress. Evaluation of near‐isogenic lines developed in four genetic backgrounds showed that Rht‐B1b, Rht‐D1b, and Rht8 caused height reduction of 19, 20, and 6.5%, respectively, relative to wild‐type near‐isogenic lines over 12 environments. An increase in grain yield was associated with reduced height for lines containing Rht‐B1b and Rht‐D1b based on means over the four genetic backgrounds and 10 environments. Height reduction and yield increase associated with Rht‐B1b and Rht‐D1b were significant in most environments. Lines with Rht8 yielded less than wild‐type based on means over environments and in 3 of 10 individual environments. Reduced height lines with Rht‐B1b and Rht‐D1b tended to have a higher harvest index and more seed per spike than wild‐type lines and reduced height lines with Rht8. In sum, our results suggest that Rht‐B1b and Rht‐D1b are superior to Rht8 as a source for height reduction for spring wheat in the tested environments.