bluuebunny/crossref_metadata_2025 huggingface dataset:
International Postgraduate Nursing Education Exchanges: Impossible?
Authors: Cook Sarah Sheets
Published: April 2012

The possibility of meaningful international educational exchanges for nurses in postgraduate/postbasic nursing education programs might seem far-fetched. Scope of practice, registration issues and standards, even organization of schools and universities would seem difficult issues to
overcome. In 2010, a consortium of some seven schools of nursing in the United States, Ireland, Portugal, Norway, Slovenia, Denmark, and Malta opened a dialogue about curricular meeting points in postgraduate nursing education. The evolution of the European Union and the Bologna Accords (European
Commission, 2008) have created an environment where a search for curricular meeting points is possible. One such meeting point involved student exchanges. This article will explore the experience of two consortium member schools in developing and operationalizing an exchange.
Rare Manifestation of Granulomatosis With Polyangiitis
Authors: Bhattarai Manoj , Yuan Weijia , Fletcher Paul , Gersten Adam , Chang Anthony , Spiera Robert , Bass Anne , Erkan Doruk , Tarnow Dennis
Published: April 2012

Introduction: Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, is a multisystem disorder that mainly involves airways and kidneys. Oral GPA may present as ulcerations or strawberry gingivitis. Early diagnosis and intervention are crucial for overall prognosis.

Case Presentation: An unusual case of oral GPA manifested by chronic localized inflammation, leading to failure of dental implants in an elderly woman, is presented. Diagnosis was based on antineutrophil cytoplasmic testing and histopathologic evidence of necrotizing vasculitis. Disease remission was achieved with cyclophosphamide and steroids.

Conclusion: Familiarity with oral manifestations of GPA will help dentists and oral surgeons diagnose and treat early or incipient GPA without delay.
The mosasaurid (Squamata) Prognathodon in the Maastrichtian (Late Cretaceous) of the Cotentin Peninsula (Normandy, northwestern France)
Authors: Buffetaut Eric , Bardet Nathalie
Published: April 2012

Although the presence of mosasaurids in the Late Cretaceous (Maastrichtian) Baculites limestone of the Cotentin peninsula, in the western part of Normandy (France), was reported as early as 1873 by Henri-Emile Sauvage, this occurrence has largely been overlooked by subsequent authors. In this paper we review Sauvage’s original material (an isolated tooth – the type of Mosasaurus platyodon) and describe an additional, hitherto unpublished, tooth crown also from the Baculites Limestone of the Cotentin and refer both to the globidensine mosasaur Prognathodon. Mosasaurus platyodonSauvage, 1873 is considered a nomen dubium.
The snout of Halisaurus platyspondylusMarsh 1869: phylogenetic and functional implications
Authors: Polcyn Michael J. , Lamb James
Published: April 2012

New material of Halisaurus platyspondylus allows description of the snout elements for the first time. The specimen was recovered from the Late Maastrichtian New Egypt Formation in Gloucester County, New Jersey. Portions of the frontal, both prefrontals, and the left quadrate are preserved and are nearly identical to the USNM H. platyspondylus specimen. It can be excluded from H. arambourgi by the extensive sutural contact of the prefrontal and ventral frontal. The new material demonstrates development of a relatively broad short skull in H. platyspondylus as in H. arambourgi, and articulations of constituent elements reveal a strong, akinetic snout. This stands in contrast to the elongate, narrow skulls of more basal halisaurines such as Eonatator. This pattern, also seen in derived members of other mosasaurid subfamilies, suggests a shift from high velocity jaw closure for prey acquisition in more basal forms to robust skulls optimized for increased bite force in some more derived forms.
Sensitivity to Gibberellin of Dwarf Foxtail Millet Varieties
Authors: Qian Jiyue , Jia Guanqing , Zhi Hui , Li Wei , Wang Yongfang , Li Haiquan , Shang Zhonglin , Doust Andrew N. , Diao Xianmin
Published: April 2012

Dwarf mutants identified from various crop species have been extensively used as valuable resources for breeding lodging resistant elite cultivars. The response of dwarf lines to gibberellic acid 3 (GA3) is important for dwarf mutant identification and classification. Forty‐eight foxtail millet [Setaria italica (L.) P. Beauv.] dwarf lines collected from different breeding programs in China were tested for their response to GA3 at the seedling stage. Forty‐six of the samples were identified as being sensitive to GA3 treatments and two lines, 84133chunhe and Xianai, were identified as insensitive. For most sensitive lines, seedling, leaf, mesocotyl, and coleoptile showed positive reaction to GA3, increasing their length at most of the concentrations. Root responses to GA3 were diverse but mostly negative. The mesocoty1 is the most sensitive to GA3 solutions with concentrations between 30 and 50 mg kg−1 and is suggested as the best test for gibberellic acid (GA) sensitivity in foxtail millet. The results in this paper indicate that multiple dwarfing genes might exist in foxtail millet and that these dwarf lines will be useful for further studies.
Nitrogen Source Effects on Ammonia Volatilization from Warm‐Season Sod
Authors: Huckaby E.C. Knight , Wood C.W. , Guertal E.A.
Published: April 2012

Ammonia (NH3) volatilization from fertilized turfgrass may represent a worst‐case scenario: surface application without incorporation, especially if irrigation is not available. Although studied in field crop systems, field‐scale losses of NH3 from turfgrass systems have received little study. Additionally, volatilization research with slow‐release N sources is largely absent from the turfgrass literature. The objective of this study was to quantify NH3 volatilization from three N sources applied to warm‐season turfgrass, using a field‐scale mast system not yet evaluated in turfgrass settings. Treatments were applied to hybrid bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] or zoysiagrass (Zoysia japonica Steud.) sod in October 2005, May 2006, and September 2006. Fertilizer treatments were urea (46–0–0), methylene urea (40–0–0), and polymer coated urea (41–0–0) applied at a N rate of 146 kg ha−1. For 10 d NH3 was captured using a passive micrometeorological system of oxalic acid coated traps mounted on a rotating mast in the center of a 15 m diameter circular plot. In October 2005, NH3 volatilized from plots fertilized with urea was 11.7% of total N applied, which is significantly more volatilization than measured from plots receiving polymer coated urea. In May 2006 significantly more NH3 volatilized from plots fertilized with urea (11.7%) than from those fertilized with polymer‐coated urea (3.6%). The 2006 studies had similar results, with significantly more NH3 volatilized from urea fertilized plots (average of 17.9%) than from plots fertilized with methylene urea (5.8%) or polymer‐coated urea (4.4%).Of the three N sources, urea volatilized a greater proportion of applied N than the slow‐release sources methylene urea and polymer coated urea.
Direct Selection for Grain Yield under Moisture Stress in Oryza sativa cv. IR58025B × Oryza meridionalis Population
Authors: Gouda P. Kalmeshwer , Kumar Varma C. Mohan , Saikumar S. , Kiran B. , Shenoy Vinay , Shashidhar H. E.
Published: April 2012

Rice (Oryza sativa L.) is one of the important food crops drastically affected by drought. Considering the low heritability of grain yield under water stress, several secondary traits associated with drought tolerance have been used, but the success achieved in deriving cultivars with high yield potential under stress is less compared to irrigated conditions. Hence, objective of the experiment was to estimate heritability for grain yield under lowland stress and select for grain yield per se using wild species Oryza meridionalis Ng and also to identify physio‐morphological traits responsible for withstanding water stress. A population derived from O. sativa cv. IR58025B × O. meridionalis (BC2F3) was evaluated under control and stress conditions. Variability observed for yield and component traits indicated O. meridionalis to be a good source of useful alleles for drought tolerance. Broad‐sense heritability (h2) of grain yield under stress, although only 33.1%, was comparable to control 59.4%, indicating direct selection for grain yield per se can be practiced. Twenty high‐yielding selected lines and 40 random lines were evaluated under control and stress conditions to estimate selection response. Yield of selected lines outperformed random lines and checks under stress. Furthermore, 10 lines (5 high yielding and 5 low yielding) selected from the population were characterized for root morphological traits. Maximum root length (MRL) and root volume (RV) of selected high‐yielding lines recorded maximum compared with checks and low‐yielding lines indicating positive influence of drought avoidance root traits on grain yield under stress. Hence, O. meridionalis can be a good source of root traits contributing to stress tolerance and selection for grain yield under stress is an effective strategy in deriving drought tolerant lines in rice.
A Rapid, Small‐Scale Sedimentation Method to Predict Breadmaking Quality of Hard Winter Wheat
Authors: Seabourn Bradford W. , Xiao Zhihua S. , Tilley Michael , Herald Thomas J. , Park Seok‐Ho
Published: April 2012

Breeders and processors are always looking for rapid and accurate methods to evaluate wheat (Triticum aestivum L.) quality. The objective of this study was to develop a rapid, small‐scale method to accurately determine breadmaking quality for early generation hard winter wheat (HWW) breeding lines by combining the solutions used in the sodium dodecyl sulfate (SDS) sedimentation method (American Association of Cereal Chemists [AACC] 56‐70 [AACC, 2000]) and the centrifugation process found within the solvent retention capacity (SRC) method (AACC 56‐11 [AACC, 2000]). A preliminary test of the hybrid SDS‐SRC method was performed on eight HWW varieties and compared to AACC (56‐70) and in‐house Hard Winter Wheat Quality Laboratory (HWWQL) methods to show proof of concept. Further validation of the hybrid method was conducted on a diverse set of 53 HWW varieties. The hybrid method was performed in 66% less time than AACC 56‐70 and HWWQL methods. Furthermore, sample size was reduced from 6 g for the AACC method to 1 g for the hybrid method. Results obtained from the hybrid method exhibited a higher correlation to bread loaf volume (r ≥ 0.84) compared to results from the AACC method (r > 0.42) and HWWQL method (r ≥ 0.64) for wheat flour. Due to enhanced speed, accuracy, and simplicity the hybrid SDS‐SRC sedimentation method may prove useful in breeding programs, grain elevators, and other scenarios where rapid assessment of end‐use quality determination is required.
Seasonal Changes in Morphology and Physiology of Roughstalk Bluegrass
Authors: Rutledge James M. , Volenec J.J. , Hurley R.H. , Reicher Z.J.
Published: April 2012

Roughstalk bluegrass (Poa trivialis L.) (RBG) is a weed in many turf settings because it often thins, goes dormant, or dies with increasing summer temperatures. Morphology and physiology of RBG are not well understood. Our objective was to describe morphological differences and physiological changes in shoots and stolons of RBG and creeping bentgrass (Agrostis stolonifera L.) (CBG) during the growing season in Indiana. The study evaluated three grasses (‘L93’ CBG and ‘Laser’ and ‘Pulsar’ RBG) over nine harvests from field plots between April and October of 2008 and 2009. Turf quality and percent cover were consistently higher for CBG compared to RBG. However, mild summer temperatures in 2008 and 2009 likely resulted in minimal separation between RBG cultivars. Stolon production began in May for RBG and CBG after planting in August of the previous year. Specific stolon dry weights (mg cm−1) of RBG doubled compared to L93 during peak summer stress in August. Total nonstructural carbohydrate (TNC) concentration of RBG shoots decreased 26% while TNC in stolons remained unchanged. Additionally, protein and amino acid concentrations increased in stolons and decreased in shoots of RBG during summer stress, further supporting our hypothesis that stolons act as storage organs during high temperatures. Conserving protein and carbohydrates in stolons at the expense of shoots until high temperature stress subsides may be a stress tolerance mechanism of RBG.
Influence of Seeding Rate, Nitrogen Management, and Micronutrient Blend Applications on Pith Expression in Solid‐Stemmed Spring Wheat
Authors: Beres Brian L. , McKenzie Ross H. , Cárcamo Héctor A. , Dosdall Lloyd M. , Evenden Maya L. , Yang Rong‐Cai , Spaner Dean M.
Published: April 2012

The wheat stem sawfly (Cephus cinctus Norton [Hymenoptera: Cephidae]) is a serious threat to wheat (Triticum aestivum L.) and other cereal grains in the northern Great Plains. Wheat cultivars with high expression of pith in the culm of the stem (stem solidity) can minimize losses associated with sawfly infestations and subsequent stem boring of the larva. Based on the widespread area now sown to solid‐stemmed wheat, our objective was to develop an integrated nutrient and planting strategy specific to solid‐stemmed spring wheat using modern farming techniques. Five levels of banded N fertilizer (0, 30, 60, 90, and 120 kg N ha−1) were arranged in a factorial combination with three levels of sowing density (100, 300, and 500 seeds m−2) and grown at three sites in southern Alberta, Canada, from 2007 to 2009. Increased planting densities optimized yield, but an inverse relationship with pith expression (stem solidness) was observed. Low plant populations (100 seeds m−2) were often most effective at maximizing pith expression in solid‐stemmed wheat and reducing sawfly cutting damage. However, this usually required the highest rates of N fertilizer, so a system of low seeding rates and high N may not be economical based on fertilizer input costs and the generally lower grain yield response (−9%). An integrated planting and nutrient strategy for solid‐stemmed spring wheat cultivars consists of seeding rates no greater than 300 seeds m−2 and basal N applications in the range of 30 to 60 kg N ha−1.
A Modified Method to Screen for Partial Resistance to Phytophthora sojae in Soybean
Authors: Stewart Silvina , Robertson Alison E.
Published: April 2012

Phytophthora root and stem rot, caused by Phytophthora sojae Kauf and Gerd, is one of the most damaging diseases of soybean [Glycine max (L.) Merr.] in the United States. Partial resistance (PR), which is defined as the relative ability of a soybean plant to survive root infection without showing severe symptoms, is an effective way to manage this disease. A modification of the layer test method used to screen for PR to P. sojae in soybean was evaluated. Instead of the P. sojae‐colonized agar layer, which is used in the current greenhouse cup assay, P. sojae‐infested rice (Oryza sativa L.) grains were used. In addition, a dry root weight (Drw) measurement was compared to a disease severity root rot score, which uses a 1 to 10 visual scale. The rice method was not statistically different from the layer test for the variables evaluated. Advantages of the rice method include reduced cost and the ability to screen soybean germplasm with more than one pathotype of the pathogen in a single assay. A mixture of several pathotypes of P. sojae ensures compatible interactions between isolates used and all known Rps genes, thus avoiding Rps genes that could go undetected and mask PR during screening. Although collecting and handling of roots for Drw data may require more time, it is a more objective variable, which assures precise scoring, it is not rater dependent, and less training of personnel is required.
Diverse Soybean Accessions Identified with Temperature‐Sensitive Resistance to Tobacco Streak Virus
Authors: Hobbs H. A. , Jossey S. , Wang Y. , Hartman G. L. , Domier L. L.
Published: April 2012

Tobacco streak virus (TSV) is a pathogen that has been reported in soybean [Glycine max (L.) Merr.] in Brazil and the United States, for which resistance has only been reported in the “hay‐type” soybean cultivar Tanner. To find additional resistant soybean genotypes, >1000 soybean accessions from the USDA Soybean Germplasm Collection were evaluated for resistance to TSV in the greenhouse. No resistance was found in a 94‐accession ancestral set, but 19 of 926 accessions screened from a geographically diverse set of soybean accessions were resistant to TSV infection. Further investigation showed that the resistance of the soybean accessions was temperature sensitive. When TSV‐resistant plants were inoculated with TSV and grown at 24°C for 17 to 20 d in a growth chamber, only 7% of inoculated plants became infected, based on virus antigen detected in noninoculated trifoliolate leaves. In contrast, when inoculated with TSV and grown at 32°C for 17 to 20 d, 71% of TSV‐resistant plants became systemically infected with TSV, including plants of the resistant control, Tanner, which was earlier identified as resistant to TSV infection and had never shown systemic TSV movement under greenhouse conditions. Because temperatures may equal or exceed 32°C at times during the growing season in many soybean producing areas, it will be important to assess the potential usefulness of the TSV resistance under field conditions for several years before utilizing it in breeding programs.
Evaluation and Haplotype Analysis of Elite Synthetic Hexaploid Wheat Lines for Resistance to Hessian Fly
Authors: Yu Guo Tai , Wang Tao , Anderson Kirk M. , Harris Marion O. , Cai Xiwen , Xu Steven S.
Published: April 2012

Synthetic hexaploid wheat (SHW), derived from the hybrids between tetraploid wheat (Triticum turgidum L.) and Tausch's goatgrass (Aegilops tauschii Coss.), is an excellent source of resistance genes for various pests of wheat (Triticum aestivum L.). The objectives of this study were to evaluate the elite SHW lines developed at the International Maize and Wheat Improvement Center for resistance to Hessian fly and to postulate the resistance genes present in the resistance lines. A total of 118 elite SHW lines and 35 durum wheat parents were evaluated for resistance to the Great Plains (GP) biotype of the Hessian fly. Fifty‐two of the SHW lines were highly or moderately resistant to Hessian fly. Since all of the durum parents were susceptible, the resistance genes in these SHW lines were derived from the A. tauschii D genome. The 52 SHW lines were haplotyped using eight polymerase chain reaction (PCR)‐based markers closely linked to five resistance genes (H13, H22, H23, H26, and H32) previously identified in A. tauschii. The marker analysis revealed that 32 resistant SHW lines shared haplotypes with the wheat lines containing the five known resistance genes. Nineteen resistant SHW lines had different haplotypes, suggesting that these lines may contain new genes for resistance to Hessian fly. The resistant SHW lines identified in this study will be useful for the development of wheat cultivars resistant to the Hessian fly as well as for genetic and evolutionary studies of resistance genes.
Selection and Use Recommendation in Hybrids of Ornamental Banana
Authors: Santos‐Serejo Janay A. , Souza Everton H. , Costa Maria A. P. C. , Costa Junior Davi S. , Amorim Edson P. , Silva Sebastião O. , Souza Fernanda V. D.
Published: April 2012

The ornamental market is dynamic and demands constant novelties. The use of fruit crops as ornamental plants can be an interesting alternative with very differentiated and original products. The banana germplasm bank at Embrapa Cassava and Fruits has been primarily used in the breeding program for generating new cultivars as food. To diversify and expand the use of this collection, accessions with ornamental potential have been selected to obtain new hybrids. This work was aimed at characterizing the progeny of ornamental Musa L. spp. by grouping the hybrids according to the following uses: landscape plants, potted plants, cut flower, or minifruits. Forty‐two hybrids were evaluated with 14 quantitative and 12 qualitative descriptors in three production cycles. In addition, assays for resistance to black and yellow Sigatoka and to Fusarium wilt were performed. Variability was observed for all the characteristics evaluated within progenies, especially with regard to leaf color, fruit, peduncle, rachis, and heart. All evaluated hybrids were resistant to yellow Sigatoka and to Fusarium wilt and were resistant or showed reduced symptoms of susceptibility to black Sigatoka. Most hybrids (82%) presented reduced plant height. After clustering by use category, the hybrids RM 09, RM 38, RM 37, and RM 33 were selected and recommended to be used as cut flowers, minifruits, or landscaping plants.
Inheritance and Genetic Mapping of Russian Wheat Aphid Resistance in Iranian Wheat Landrace Accession PI 626580
Authors: Valdez Victoria A. , Byrne Patrick F. , Lapitan Nora L.V. , Peairs Frank B. , Bernardo Amy , Bai Guihua , Haley Scott D.
Published: April 2012

Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is a significant insect pest of wheat (Triticum aestivum L.) and has had a major economic impact worldwide, especially on winter wheat in the western United States. Development of resistant cultivars remains the most viable method for RWA control, although the continuing emergence of new RWA biotypes virulent to deployed resistance genes reinforces the need for the discovery of new sources of resistance. Iranian wheat landrace accession PI 626580 has shown high levels of resistance to RWA biotypes 1 (RWA1) and 2 (RWA2), but the inheritance and chromosomal location of this resistance is unknown. The objectives of this study were to determine the inheritance of RWA2 resistance, identify closely linked markers, and map the chromosomal location of RWA2 resistance found in PI 626580. Bulked segregant analysis was conducted with a mapping population of 154 F2 individuals derived from a single plant selection made from PI 626580 and ‘Yuma’ (a susceptible wheat cultivar). Phenotypic segregation of RWA2 resistance suggested a single dominant gene, provisionally designated Dn626580. Linkage mapping analysis identified three simple sequence repeat (SSR) markers, Xbarc214, Xgwm473, and Xgwm437, proximally linked to Dn626580 near the centromere on the short arm of chromosome 7D at distances of 1.8, 5.0, and 8.2 cM, respectively. Dn626580, a new resistance gene found in PI 626580, could be used alone or by pyramiding with other resistance genes to develop cultivars with effective RWA resistance.
Forage Accumulation, Nutritive Value, and Persistence of ‘Mulato II’ Brachiariagrass in Northern Florida
Authors: Vendramini J. M. B. , Sollenberger L. E. , Lamb G. C. , Foster J. L. , Liu K. , Maddox M. K.
Published: April 2012

‘Mulato II’ [Brachiaria spp.] is a warm‐season grass with excellent nutritive value adapted to tropical regions; however, its herbage production and persistence in subtropical locations is unknown. Grazing and clipping studies were conducted in 2008 and 2009 in Marianna and Gainesville, FL, respectively. The treatments for the grazing study were beef heifers (Bos spp.) grazing Mulato II, ‘Tifleaf 3’ pearl millet [Pennisetum glaucum (L.) R. Br.], or ‘Hayday’ sorghum‐sudangrassgrass [Sorghum bicolor (L.) Moench] pastures on a continuous stocking rate. In 2008, there were no differences in herbage allowance (HA) (0.9 kg dry matter [DM] kg−1 live weight [LW]), average daily gain (ADG) (0.5 kg d−1), and gain per hectare (168 kg) among treatments. However, Mulato II had greater HA (2.0 vs. 0.7 kg DM kg−1 LW) and ADG (0.78 vs. 0.41 kg d−1) than Tifleaf 3 and Hayday and similar gain per hectare (302 kg) in 2009. The treatments for the clipping study were Mulato II, evaluated as an annual and perennial, ‘Tifton 85’ bermudagrass (Cynodon spp.), Tifleaf 3 pearl millet, and Hayday sorghum‐sudangrass. In 2008, Hayday and Tifleaf 3 established more rapidly than Mulato II; however, Mulato II grew later in the fall. In 2009, the perennial treatments (Mulato II and Tifton 85) had overall greater herbage accumulation than the annual treatments. In the clipping study, Tifton 85 had greater ground cover than Mulato II perennial in 2009 (73 vs. 36%) and 2010 (73 vs. 12%). Mulato II may be used as a high quality, short‐lived perennial warm‐season grass in subtropical areas.
Factors Affecting the Accuracy of Genotype Imputation in Populations from Several Maize Breeding Programs
Authors: Hickey John M. , Crossa Jose , Babu Raman , de los Campos Gustavo
Published: April 2012

Genomic selection and association mapping offer great potential to increase rates of genetic progress in plants. The prediction of genomic breeding values usually requires that missing genotypes be imputed because a proportion of genotypes is usually uncalled by the genotyping algorithm, different individuals may be genotyped using different platforms, or low cost genotyping strategies can involve genotyping some individuals at high density and others at low density. The objective of this paper was to quantify the accuracy of imputation in a maize (Zea mays L.) data set and explore some of the factors that affect it. The factors studied were the density of the low‐density platform, level of linkage disequilibrium, minor allele frequency of the marker being imputed, and degree of genetic relationship between the line being imputed and the training population. The accuracy of imputation was high even when only 8774 genotypes constitute the low‐density platform. The correlation between the true and imputed genotypes was 0.87. However, there was a dramatic reduction in the accuracy of imputation when the low‐density platforms had fewer than 8774 genotypes. Genetic relatedness between an individual having its genotypes imputed and the individuals genotyped with the high‐density platform was important. The design of an information nucleus that incorporates imputation for the purposes of implementing genomic selection and association mapping in small independent breeding programs was discussed.
Organic Management Practices on Athletic Fields: Part 1. The Effects on Color, Quality, Cover, and Weed Populations
Authors: Miller Nathaniel A. , Henderson Jason J.
Published: April 2012

Many organic products have been used effectively in turfgrass management programs, but their exclusive use in athletic field maintenance and effect on playing surface quality has not been extensively researched. The objectives were to determine the effects of management regimes and overseeding during simulated traffic on (i) turfgrass color and quality, (ii) percent cover, and (iii) weed populations. The experimental design was a 2 × 6 factorial, with two overseeding levels (overseeded and not overseeded) of a perennial ryegrass (Lolium perenne L.) blend during traffic and six management regimes: (i) conventional, (ii) organic manure (OMan), (iii) organic protein (OPro), (iv) organic manure plus compost tea (OMan+CT), (v) organic protein plus compost tea (OPro+CT), and (vi) none or the control. This research was conducted over 2 yr on a mature stand of ‘Langara’ Kentucky bluegrass (Poa pratensis L.) on a Paxton sandy loam soil. Fall traffic was simulated with a Cady Traffic Simulator. The conventional treatment consistently produced higher quality turfgrass, lower weed counts, and better mid‐ to late‐fall color. Weed populations were significantly less with the conventional regime. Overseeding increased cover at the end of the traffic periods by 32% in the first year and by 103% in the second year. Overseeding was also beneficial to turfgrass color and quality and in reducing weeds. The conventional treatment also retained significantly higher turfgrass cover than the organic regimes under trafficked conditions late into the fall in 2008. However, no difference in late fall cover between the conventional and organic management regimes was observed in late fall 2009. Compost tea applications showed no enhancement of turfgrass color, quality, or cover over the entire duration of the study.
Haploid Fertility in Temperate and Tropical Maize Germplasm
Authors: Kleiber Daniel , Prigge Vanessa , Melchinger Albrecht E. , Burkard Florian , San Vicente Félix , Palomino Guadalupe , Gordillo G. Andrés
Published: April 2012

Doubled haploid (DH) technology facilitates rapid development of homozygous inbred lines for hybrid breeding in maize (Zea mays L.). However, the required artificial chromosome duplication step, which commonly involves toxic and costly chemicals, represents a bottleneck. Exploiting the haploids’ natural fertility may enable abolishment of artificial treatments and enhance efficiency of line development. We screened haploid populations derived from U.S. Corn Belt and tropical germplasm for the proportion of fertile haploids (FP) and the number of intact seeds (IS) on selfed ears and examined the effects of environments, heterotic groups, maturity groups, and population types on FP and IS. The FP ranged from 0 to 20% under field conditions and from 0 to 70% under greenhouse conditions. Tropical elite germplasm had higher median FP and mean IS than tropical landrace accessions. The Corn Belt heterotic group Stiff Stalk had higher median FP than Iodent and Lancaster while early germplasm showed higher median FP than the other maturity groups. Significant (p > 0.01) genetic variance for FP was observed among elite Corn Belt materials and heritability was 0.79, indicating that recurrent selection to increase FP is promising. We propose that artificial chromosome duplication is not necessary for DH line production from germplasm with high FP. This seems particularly relevant to enable small maize breeding programs in developing countries to adopt the DH technology for line development.
Genetic Structure in a Core Subset of Cultivated Barley Germplasm
Authors: Fu Yong‐Bi
Published: April 2012

Cultivated barley (Hordeum vulgare L. subsp. vulgare) is one of the economically most important cereals with a large number of germplasm accessions conserved worldwide. A core subset of 571barley accessions representing 94 countries was developed, genotyped using 30 informative simple sequence repeat (SSR) markers, and analyzed with several common approaches. The distance‐based analysis of the 230 SSR allele profile revealed a major division of the barley accessions that explained 6 to 8% SSR variation. The model‐based Bayesian analyses revealed six optimal clusters that captured 17.5% SSR variation. The clusters varied in size from 34 to 160, consisted of accessions from many countries and regions, and were well represented by accessions with various important agronomic traits such as kernel row number and growth habit. Such germplasm partitions were further supported from principal component and neighbor‐joining analyses. A mini core subset of 219 accessions from 94 countries was thus developed for future structural inferences. Interestingly, the revealed genetic structure is consistent with the known barley domestication history. Therefore, the inferred optimal clusters may provide the best possible structural description of the current global cultivated barley gene pool and also are useful for future barley research in association mapping, adaptation, and domestication.
Sources of Resistance to Stem Rust (Ug99) in Bread Wheat and Durum Wheat Identified Using Focused Identification of Germplasm Strategy
Authors: Endresen Dag Terje Filip , Street Kenneth , Mackay Michael , Bari Abdallah , Amri Ahmed , De Pauw Eddy , Nazari Kumarse , Yahyaoui Amor
Published: April 2012

The focused identification of germplasm strategy (FIGS) has been validated using predictive computer models in simulation studies to predict a priori known trait scores. This study was designed as a “blind” study where the person calculating the computer model did not know the actual trait scores. This study design provides a more realistic test of the predictive capacity of the FIGS approach compared to previous studies. Furthermore this study also explored the suitability of FIGS for the identification of resistance in bread wheat (Triticum aestivum L. subsp. aestivum) and durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] to Ug99—a strain of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) and typified to race TTKSK. The predictions were validated against a dataset with the screening of wheat accessions conducted in Yemen in 2008. Only a small training set representing 20% of the trait screening results was disclosed to the person conducting the data analysis for the calibration of the prediction model. The hit rate for identification of Ug99‐resistant accessions was more than two times higher when using the FIGS approach compared to a random selection of accessions. These results suggested that FIGS was well suited for the identification of samples with resistance to fungal pathogens. It is therefore recommended that FIGS approach be used as a complement to expert knowledge and experience when selecting accessions for plant breeding and crop research activities.
Genotypic and Phenotypic Variability in Three Prairie Acacia Accessions
Authors: Noah Ray L. , Muir James P. , Brady Jeffrey A. , Wittie Roger D. , Kattes David H. , Pitman William D. , Rea Gary L. , Brakie Melinda R.
Published: April 2012

This study examined three prairie acacia [Acacia angustissima var. hirta (Mill.) Kuntze var. hirta (Nutt.) B.L. Rob.] accessions from Texas for genetic overlap, adaptation to a wide range of latitudes, as well as seed and herbage yield, nutritive values, and effect of forage harvest on seed production at Stephenville, TX. The southernmost accession (Kingsville prairie acacia; KPA) yielded >400% more (P ≤ 0.05) herbage (3483 kg dry matter ha−1 yr−1) at Stephenville, TX, than the other entries the third year after establishment. Herbage removal negatively (P ≤ 0.05) affected seed yield, which was as much as 2590 kg ha−1 yr−1 for unharvested Plains germplasm prairie acacia (PPA) the second year after establishment. Final percent plot cover differed (P ≤ 0.05) among locations (Knox City, TX, 50%; Stephenville, TX, 100%; Nacogdoches, TX, 99%; Homer, LA, 61%). Differences (P ≤ 0.05) in leaf:stem ratios, some nutritive values, and crude protein yields were measured among accessions, with KPA showing the most promise where there were differences. Genetic analysis of inter–simple sequence repeat markers indicated the least within accession difference between two north Texas accessions (91 and 92% similarity) and the most difference between these two and KPA (79% similarity), which also presented a taller, woodier growth habit. Genetic variation within prairie acacia germplasm collected in Texas is expressed primarily in herbage production.
Analysis of U.S. Genetically Engineered Crop Regulation and Litigation
Authors: McGinnis Esther E. , Meyer Mary H. , Smith Alan G.
Published: April 2012

The commercial potential of genetically engineered (GE) crops has not been fully realized in the United States. Over the past decade, environmental litigation dramatically affected the pace of GE crop development, testing, and deregulation. The U.S. Animal and Plant Health Inspection Service (APHIS) regulates GE organisms that may pose a risk to plant or animal health. However, recent litigation initiated by nongovernmental organizations such as the Center for Food Safety and the International Center for Technology Assessment has exposed APHIS's vulnerability to lawsuits under the National Environmental Policy Act (NEPA) for failing to assess the environmental risks of novel GE crops. In these cases, APHIS committed two types of mistakes. First, APHIS did not differentiate between traditional GE crops whose risks are well characterized and novel GE crops that may raise unique environmental risks and societal issues based on their distinctive biology. Consequently, it did not adequately evaluate the legally defined environmental risks of these novel crops. Second, APHIS did not fully appreciate NEPA's sweeping scope and focus on procedural compliance to ensure transparent and thorough environmental decision making. As a result, APHIS impeded the development and commercialization of GE crops and must take a more defensive posture in the future to deter costly and lengthy NEPA litigation in the case of novel GE crops.
Fiber and Yarn Performance of Upland Cotton with Improved Fiber Bundle Strength
Authors: Gregory K. , Ng E. H. , Smith W. , Hequet E. , Hague S.
Published: April 2012

The U.S. cotton (Gossypium spp.) industry has shifted focus in recent years to an export market, necessitating further development of upland cotton (G. hirsutum L.) cultivars with superior fiber properties to maintain competitiveness. This study was conducted to compare both fiber and yarn performance of upland cotton genotypes with similar average fiber length but enhanced fiber bundle strength (Str) with two high quality commercial controls, ‘FM 832LL’ and ‘DP 491’. The high Str strains and commercial upland controls were grown in Weslaco, TX, during the summers of 2009 and 2010 with standard agronomic practices for south Texas, including furrow irrigation. Plots were spindle‐machine harvested, seedcotton ginned on a research gin without a lint cleaner, and lint and yarn tested at the Fiber and Biopolymer Research Institute (FBRI) in Lubbock, TX. Lint and yarn data collected included high volume instrument (HVI) and advanced fiber information system (AFIS) derived data and ring spun yarn data (mini‐spinning protocol). Years were different for almost every fiber and yarn property except Str, immature fiber content (IFC), yarn tenacity (Ten), work required for yarn breakage (Work to Break) and the number of thin places per kilometer that are at least 50% smaller in diameter than adjacent portions of yarn (Thin). All of the high Str strains had higher Ten in 2009 than the controls and 9 of the 11 had higher Ten in 2010. The high Str genotypes resulted in more even yarns (as determined with the Uster Tester 3 [Uster Technologies]).
Geostatistical Analysis of Quality Protein Maize Outcrossing with Pollen from Adjacent Normal Endosperm Maize Varieties
Authors: Machida Lewis , Derera John , Tongoona Pangirayi , Mutanga Onisimo , MacRobert John
Published: April 2012

Nutritional advantages of quality protein maize (QPM) (Zea mays L.) over normal endosperm maize (NM) were previously demonstrated by several researchers. However, QPM grain quality loss occurs when a QPM crop receives pollen from NM. This is because the opaque‐2 gene allele that confers the QPM trait is recessive. The objective was to estimate outcrossing levels and patterns in QPM growing adjacent to NM. White grain QPM crops were grown on nine blocks of 0.21 ha each surrounded by at least a 10‐m band of yellow NM at two sites in Zimbabwe. At maturity 160 samples of five QPM ears each were randomly selected to determine outcrossing. Outcrossing was estimated as percentage of yellow kernels on each ear. Ordinary kriging was used to estimate outcrossing levels in areas that were not sampled. Both prediction and error surfaces were produced for each block using the best ordinary kriging model out of the available 11 in ArcMAP 9.2 computer package. Results indicated that five models (exponential, stable, pentaspherical, rational quadratic, and J‐Bessel) predicted outcrossing patterns of the nine experiments. Outcrossing levels were high (63 to 83%) in the peripheral areas of the QPM crops, but less than 20% outcrossing was observed on at least 60% of each of the crop areas with no significant compromise of QPM quality based on a QPM quality index of 0.8. In conclusion, QPM and NM can coexist, and ordinary kriging could be used in visualizing spatial distribution of outcrossing in a QPM crop.
Production and Economics of Grazing Alfalfa in the Southern Great Plains
Authors: Butler Twain J. , Biermacher Jon T. , Interrante Sindy M. , Sledge Mary K. , Hopkins Andrew A. , Bouton Joseph H.
Published: April 2012

Alfalfa (Medicago sativa L.) is a high‐quality forage legume that may have potential to improve net returns to stocker cattle producers in the southern Great Plains. The objective of this 3‐yr field study was to compare the agronomic and economic performance of alfalfa grazing systems under two management strategies. Treatments were (i) continuous stocking for the entire growing season, referred to as full‐season grazing; and (ii) a late‐season rest, which was continuous stocking of alfalfa until 1 August. Steers (250 ± 25 kg initial body weight) were weighed every 28 d during each grazing season, and stocking rates were adjusted with put‐and‐take steers based on forage mass. In each 28‐d grazing period, forage mass and total gain (TG) were measured, allowing calculation of average daily gain (ADG). Animals had ADG of 0.93 and 1.05 kg d−1 and TG of 449 and 379 kg ha−1 on alfalfa for the full‐season grazing treatment and the late‐season rest (August termination), respectively. The 3‐yr average production cost ($278 ha−1) did not differ between the two management treatments; however, expected net return was greater (P < 0.01) for the full‐season alfalfa grazing treatment ($314 ha−1) compared to the 1 August termination date ($145 ha−1). Therefore, a late‐season rest from grazing was not economically beneficial to grazing alfalfa in this 3‐yr experiment, and grazing alfalfa with summer stockers may be a viable option for producers in the southern Great Plains.
Characterization and Effectiveness of Co‐inoculation of Sinorhizobium Strains on Annual Medics
Authors: Singh Ruchi , Interrante Sindy M. , Butler Twain J. , Young Carolyn A.
Published: April 2012

Selection and identification of better‐adapted annual medics with an appropriate rhizobia inoculum is crucial for improved forage quality and yield. The objectives of this study were to characterize 11 rhizobial strains used for an effectiveness study on annual medics and generate an inoculum blend suitable for annual medic species adapted to the southern Great Plains. Each strain was compared to reference rhizobia strains by polymerase chain reaction (PCR) based on repetitive sequences (rep‐PCR) and ribosomal gene sequences and analyzed for plant growth promoting (PGP) activities. Genetic characterization separated the strains into two groups belonging to Sinorhizobium medicae (seven isolates) and Sinorhizobium meliloti (four isolates). Three of the 11 strains tested positive for the PGP activities of indole acetic acid production and phosphate solubilization. A blend of three strains (NFmix3, consisting of WSM1115, 102F85, and M49), of which two were positive for PGP activities, was used in an effectiveness study for the annual medics Medicago minima (L.) Bartal., Medicago orbicularis (L.) Bartal., Medicago rigidula (L.) All., and Medicago rigiduloides E. Small. The NFmix3 association with three of the four annual medic species resulted in equivalent biomass production as that of the single specific strain. The NFmix3 blend would be suitable and more economic for use with a mixture of medic species that may provide expansion of the grazing season.
Signal Grass Litter Decomposition Rate Increases with Inclusion of Calopo
Authors: Siqueira da Silva Hiran Marcelo , Batista Dubeux José Carlos , Ferreira dos Santos Mércia Virginia , de Andrade Lira Mário , de Andrade Lira Mário , Muir James P.
Published: April 2012

Low N availability is a major limitation in tropical and subtropical pasture systems and one of the main causes for system degradation. Including legumes in forage mixes may enhance soil‐N presence and cycling, therefore mitigating the problem. To test this theory, signal grass [Brachiaria decumbens (Stapf) R. D. Webster] litter chemical composition and decomposition after inclusion of calopo (Calopogonium mucunoides Desv.) at 0, 50, or 100% of litter mass was evaluated. Litter samples were collected from both species and incubated by litter bag technique for 0, 4, 8, 16, 32, 64, 128, or 256 d in 2007 and 2008. Biomass decomposition was described by a simple exponential organic matter (OM) decay model (p < 0.0001; Y predicted [the remaining biomass at a given time of decomposition, predicted by the single exponential model] = 91.11–0.00451t and 94.16–0.00217t for year 1 and 2, respectively). Remaining biomass was lower (p < 0.05) in 2007 (28%) than 2008 (54%) following 256 d incubation at least in part because of greater lignin concentrations in 2008 litter. Pure signal grass litter C:N values were 74 to 76% greater (p < 0.05) than pure legume while the inclusion of 50% calopo reduced (p < 0.05) grass ratios by 62 to 64%. Net annual N mineralization increased (p < 0.05) from 27% without legume to 38% with legume inclusion at 50% of the grass litter, a nutrient cycling acceleration of 16% (p < 0.05). This research indicated that the inclusion of calopo will ameliorate N deficiency in soils of a signal grass pasture.
Screening Method and Response Surface Design for Drying Hybrid Maize to Maintain Seed Quality
Authors: Arisnabarreta Sebastián , Eslava Ezequiel T. , Cannon Paul
Published: April 2012

Hybrid maize (Zea mays L.) ear drying is an expensive process and considered a bottleneck in seed production. The seed industry does not have an effective procedure to screen germplasm for drying temperature sensitivity and optimum drying conditions. The aims of this paper were (i) to develop a simple, rapid, and reliable technique to screen drying temperature tolerances and (ii) to exploit the response surface design (i.e., predictive model of the relationship between factors and the response) to identify optimum drying temperatures. Trials consisted of screening experiments, in which ears were constantly dried at 35 and 45°C, and response surface experiments, in which samples were subjected to different drying temperatures in two phases (30, 35, and 40°C for the first and 35, 40, and 45°C for the second drying phase). Standard germination, cold, and accelerated aging tests were conducted to measure the effect of drying regimes on seed quality. Drying hours and rates were determined. Drying hours and rate were reduced 36 and increased 44% in the stress treatment relative to the control, respectively. Genotypes differed in drying temperature tolerances only when the cold test was used in the analyses. The response surface design allowed identifying specific temperature combinations for the first and the second drying phases that optimized quality parameters. The results of this study can be useful tool for seed industries to optimize their drying process and seed quality.