bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Mapping of QTLs Underlying Partial Resistance to Sclerotinia sclerotiorum in Soybean PI 391589A and PI 391589B
Authors: Guo Xiaomei , Wang Dechun , Gordon Stuart G. , Helliwell Emily , Smith Trista , Berry Sue Ann , St. Martin Steven K. , Dorrance Anne E.
Published: May 2008

Soybean [Glycine max (L.) Merr.] PI 391589B, a selection from PI 391589A was recently identified as a new source of resistance to Sclerotinia sclerotiorum (Lib.) deBary, which causes Sclerotinia stem rot. The objective of this study was to identify the quantitative trait loci (QTLs) associated with resistance to S. sclerotiorum in PIs 391589A and 391589B. BC1F4:5 and BC1F4:6 populations from a cross of ‘Kottman’(2) × PI 391589A and a population of F2‐derived lines from a cross of PI 391589B × IA2053 were evaluated for resistance to S. sclerotiorum in the field and in the greenhouse from 2003 to 2005 and genotyped with simple sequence repeat markers. Single factor analysis identified 18 markers on nine linkage groups (LGs) significantly (P < 0.05) associated with resistance to S. sclerotiorum in the two populations. Four regions on LGs E, F, M, and O were significantly associated with the disease resistance in both populations. The four regions are between Satt411 (12.9 cM) and Satt369 (56.2 cM) on LG E, between Satt269 (11.4 cM) and AW186493 (21.0 cM) on LG F, between Satt463 (50.1 cM) and Satt323 (60.1 cM) on LG M, and between Satt581 (106.0 cM) and Satt153 (118.14 cM) on LG O on the soybean composite map developed by Song and others in 2004. Composite interval mapping identified seven QTLs (P < 0.10), each explaining 6.0 to 15.7% of the phenotypic variance. A QTL on LG M near marker Satt463 (50.1 cM) is unique to PI 391589A and B. Therefore, PIs 391589A and 391589B offer breeders a new allele for resistance to the disease.
Alternative Recurrent Selection Strategies Using Doubled Haploid Lines in Hybrid Maize Breeding
Authors: Gordillo G. Andres , Geiger Hartwig H.
Published: May 2008

Recurrent testcross selection based on doubled haploid lines can be highly effective in hybrid maize (Zea mays L.) breeding. As a consequence, however, the genetic variance of the breeding population is reduced more rapidly. To limit the reduction of variance, a minimum effective population size (Ne) has to be ensured. However, maintaining sufficient Ne restricts the achievable selection intensity, in particular when crosses are made every year to start a new selection program such that the hybrid breeding population representing one heterotic group is divided into multiple, timely staggered subpopulations. Intercrossing lines from different subpopulations, defined herein as interlinking, allows the breeder to alleviate this restriction. In this study, the formula for predicting the genetic gain from selection is extended to account for interlinking of subpopulations. The optimum allocation of test resources was determined for two interlinking strategies and a control mating scheme (without interlinking) under one‐, two‐, and three‐stage testcross selection. Our results show that optimum interlinking of staggered subpopulations provides faster breeding progress than advancing non‐interlinked subpopulations separately. Moreover, the manner in which subpopulations are interlinked and the proportion of intercrossed lines from different subpopulations is fundamental in the design of efficient recurrent selection plans.
Salinity Tolerance of 33 Greens‐TypePoa annuaExperimental Lines
Authors: Dai Jing , Schlossberg Maxim J. , Huff David R.
Published: May 2008

Current literature suggestsPoa annuaL. (annual bluegrass) is intolerant to salinity stress. Response of greens‐typePoa annuato chronic salinity stress (12 wk at 8.0 dS m−1) was evaluated over two greenhouse experiments. Vegetative samples of 33 greens‐typeP. annuaexperimental lines were maintained at a 6.4‐mm mowing height and irrigated daily with modified Hoagland's solutions possessing salinity levels of 0.7 dS m−1(nonsaline control) or 8.0 dS m−1(NaCl treatment, approaching 0.25 strength sea water, approx. 13.5 dS m−1). Clipping yield dry weight (CYD) and leaf water content (LWC) were measured weekly. Digital images were collected at the end of weeks 1, 4, 8, and 12 to determine percentage cover (PC) and dark green color index (DGCI). Across all lines, all sample dates, and both experiments, salinity stress significantly reduced PC (30.8%), DGCI (9.3%), CYD (33.9%), and LWC (3.3%) compared with nonsaline controls (α = 0.05), suggesting chronic salinity stress is detrimental to greens‐typeP. annuaquality. However, significant differences in relative PC and relative CYD were observed among lines, indicating that substantial variation in salinity tolerance exists in greens‐typeP. annua. Numerous greens‐typesP. annuaexperimental lines, such as PSU 99‐9‐21, PSU 01‐1‐46, and PSU 05‐1‐14, possess moderate‐to‐good salinity tolerance and are potentially suitable for use on golf courses with moderate salt problems.
New Plant Introductions with Resistance to the Soybean Aphid
Authors: Mian M. A. Rouf , Hammond Ronald B. , St. Martin Steven K.
Published: May 2008

The soybean aphid (SA; Aphis glycines Matsumura) was first found in the northern soybean [Glycine max (L.) Merr.] growing regions of the United States in 2000. By 2005, the aphids had spread to 23 soybean growing states reaching as far south as Mississippi and Georgia and also north into Ontario, Canada. The objective of this study was to identify new sources of resistance to the SA. Nearly 200 soybean genotypes (cultivars, breeding lines, and plant introductions [PIs]) were screened for resistance to SA in a greenhouse choice test using SA collected in Wooster, OH. Three PIs (PI 243540, PI 567301B, and PI 567324) were identified as resistant while six PIs were identified as moderately resistant. The findings on the three resistant and three of the six moderately resistant PIs were confirmed through further field and greenhouse tests. PI 243540 displayed strong antibiosis resistance such that SA was unable to survive on this PI in a no‐choice test. The other two resistant PIs possessed mainly antixenosis type resistance. PI 243540 and PI 567301B were also resistant to the SA collection from Illinois. The aphid resistant PIs identified in this study will be useful in efforts to develop aphid‐resistant soybean cultivars.
Soil Compaction, Corn Yield Response, and Soil Nutrient Pool Dynamics within an Integrated Crop‐Livestock System in Illinois
Authors: Tracy Benjamin F. , Zhang Yan
Published: May 2008

Integrated crop–livestock systems directly link crop and livestock production together to generate positive economic and environmental outcomes. Some methods used in integrated systems, like winter grazing on cropland, could negatively affect soil properties and crop productivity. We compared soil compaction, corn (Zea mays L.) yield, and soil nutrient pools between an integrated crop–livestock system and continuous corn system to address this issue. The study was conducted near Pana, IL, between 2002 and 2006. Soil compaction was evaluated indirectly by measuring soil penetration resistance (PR) and surface CO2 effluxes. Total soil C, N, and microbial biomass C, were measured from 2002 to 2005. Soil PR and CO2 effluxes showed inconsistent trends related to soil compaction and cattle presence. Corn yield from 2004 to 2006 was higher (P = 0.01) in the integrated system (11.6 Mg ha−1) compared with continuous corn (10.6 Mg ha−1). Total soil C concentration increased significantly from 2002 to 2005 within components of the integrated system but remained unchanged in continuous corn. Microbial biomass C was also higher in the integrated system but only in 2005. The study determined that integration of crops with livestock had generally positive effects on crop yield and soil organic matter despite the potential for livestock to compact soil during winter grazing.
Carbon Isotope Discrimination, Selection Response, and Forage Production of Tall Fescue in Contrasting Environments
Authors: Johnson R. C. , Hopkins A. A. , Evans M. A.
Published: May 2008

Carbon isotope discrimination (Δ) usually correlates with the dry matter to transpiration ratio (transpiration efficiency) in C3 species, but its heritability and relationship to forage production are less clear. In a 4‐yr study of tall fescue (Festuca arundinacea Schreb.) at Pullman, WA (relatively cool with low humidity), and Ardmore, OK (relatively hot with high humidity). we determined (i) if Δ differences in divergently selected populations made on single plants were maintained in solid seeded plots, and (ii) how Δ in selected populations and a set of four cultivars was related to forage production. Differences in Δ for low and high Δ populations selected on spaced plants were maintained in solid seeded plots at both Pullman and Ardmore. At Pullman, the low Δ selection had higher production than the high Δ selection with the base population intermediate. Partial correlations with all entries between Δ and forage production, controlling for harvest date effects, were not significant. However, partial correlation between Δ and forage production on the selected and base populations was significant (r = −0.59, P < 0.05, n = 12) at Pullman, although not at Ardmore. The data show selection for low Δ may improve forage production in some environments, although not consistently. For breeding tall fescue, one cycle of phenotypic selection for low Δ in advanced material is recommended.
Effect of Advanced Cycle Breeding on Genetic Diversity in Barley Breeding Germplasm
Authors: Condón Federico , Gustus Charles , Rasmusson Donald C. , Smith Kevin P.
Published: May 2008

Plant breeding that emphasizes crosses among elite parents in a closed population (advanced cycle breeding) is presumed to decrease genetic diversity. To assess the effect of plant breeding on allelic diversity, we evaluated regional ancestors, parental lines, and cultivar candidates from the University of Minnesota six‐rowed barley (Hordeum vulgare L.) breeding program between 1958 and 1998 using pedigree information, 70 simple sequence repeat (SSR) markers, and a gene specific marker. Pedigree and SSR allelic diversity indices revealed a decrease in genetic diversity, from an average of 5.89 alleles per locus in the ancestors group to 2.34 alleles per locus in the fourth decade of breeding. A correspondence analysis showed differentiation in the germplasm with time. At specific loci, we detected both reductions and no change in the number of alleles over time. Several marker loci that demonstrated a reduction in number of alleles were associated with major loci for disease resistance or malting quality and were presumably under selection during breeding. Assessment of locus‐specific allelic variation across the genome in breeding germplasm should identify both the regions of the genome that should be conserved and the regions of the genome where there are opportunities to introgress new allelic diversity without disrupting desirable gene complexes.
Patterns of Diversity in Populations of the Turfgrass Pathogen Colletotrichum cereale as Revealed by Transposon Fingerprint Profiles
Authors: Crouch Jo Anne , Glasheen Bernadette M. , Uddin Wakar , Clarke Bruce B. , Hillman Bradley I.
Published: May 2008

Anthracnose disease of cool‐season turfgrasses, caused by the fungus Colletotrichum cereale, has recently emerged as one of the most significant pathogens of Poa annua Here we investigated the utility of four repetitive transposable elements as molecular markers for the analysis of C. cereale populations. Southern blot hybridization analysis revealed lineage‐specific polymorphisms and distribution patterns for these transposons. Comparative phylogenetic analysis of three nonrepetitive protein coding DNA sequences against the transposon restriction fragment length polymorphisms indicated that the transposon sequences have similar evolutionary histories to those found in the sampled C. cereale population, despite the alteration of several transposon copies by repeat‐induced point mutation. The variability and ubiquity of the Ccret2A15 transposon in C. cereale genomes suggest that this element could be used as a reliable DNA marker to discriminate between lineages of the fungus, identify hybrid genotypes, and analyze genetic diversity in populations of this turfgrass pathogen.
Discovery of Soybean Aphid Biotypes
Authors: Kim Ki‐Seung , Hill Curtis B. , Hartman Glen L. , Mian M.A. Rouf , Diers Brian W.
Published: May 2008

The soybean aphid [Aphis glycines Matsumura (Hemiptera: Aphididae)] is an invasive insect pest of soybean [Glycine max (L.) Merr.] that was first reported in North America in 2000. There are currently no reports of soybean aphid biotype diversity and this information is needed before aphid resistance genes are deployed. The objective of this research was to test for aphid biotype variation. The response of two A. glycines isolates, one collected in Ohio and the other in Illinois, were compared by infesting eight soybean genotypes in nonchoice tests. The same genotypes also were tested with the Ohio isolate using a choice test. In the nonchoice test, there was a significant (P < 0.0001) effect of aphid isolate, genotype, and a significant aphid isolate by soybean genotype interaction for the number of aphids per plant 10 and 15 d after infestation. The responses of the eight genotypes to the Ohio isolate in the choice test were similar to their responses in nonchoice tests. PI 200538 and PI 567597C were resistant to both the Ohio and Illinois isolates and will be useful sources of resistance to both isolates. These tests confirm that there are at least two distinct biotypes of A. glycines in North America.
Inheritance of Resistance to Alfalfa Mosaic Virus in Soybean PI 153282
Authors: Kopisch‐Obuch F. J. , Koval N. C. , Mueller E. M. , Paine C. , Grau C.R. , Diers B. W.
Published: May 2008

Alfalfa mosaic virus (AMV) infects soybean [Glycine max (L.) Merr.] causing mosaic or mottle patterns on leaves. Resistance to AMV has been identified in soybean, but no AMV resistance genes have been mapped or assigned gene symbols. The objective of this research was to study the genetic basis of resistance to AMV from plant introduction (PI) 153282. This resistance was studied in a population of F4:7 lines developed from a cross between this PI and the susceptible cultivar Syngenta (NK) S19‐90. Results from the F4:7 population were confirmed in F2 and F2:3 populations developed by crossing the same parents. A major AMV resistance gene was mapped as a quantitative trait locus (QTL) near the simple sequence repeat marker Sat_226 in the F4:7 population. For this QTL, the resistance allele was from PI 153282, the LOD score was 45.5, and the QTL explained 79% of the genotypic variation for resistance in the population. The identification of an AMV resistance gene near Sat_228 was confirmed in the F2 and F2:3 populations and the resistance gene showed complete dominance in the F2 population. This AMV resistance gene identified from PI 153282 is named Rav1 and it should be useful in breeding for resistance to this virus.
Development and Characterization of Microsatellite Markers for the Grain Amaranths
Authors: Mallory Melanie A. , Hall Rozaura V. , McNabb Andrea R. , Pratt Donald B. , Jellen Eric N. , Maughan Peter J.
Published: May 2008

The grain amaranths (Amaranthus hypochondriacus L., A. cruentus L., and A. caudatus L.) are important pseudo‐cereals native to the Americas. The objective of this project was to produce and characterize a set of highly informative, reproducible microsatellite markers for the grain amaranths. A total of 1457 clones were sequenced from three microsatellite‐enriched libraries. Of these, 353 contained unique microsatellites. An additional 29 microsatellite loci were identified from 728 bacterial artificial chromosome–end sequences. A total of 179 microsatellites were polymorphic across accessions from the three grain amaranths. Among these polymorphic microsatellite loci, a total of 731 alleles were identified with an average of four alleles per locus. Heterozygosity values ranged from 0.14 to 0.83, with a mean value of 0.62. Thirty‐seven (21%) of the markers were polymorphic between the parents of a segregating population. Phylogenetic analysis using the marker data placed A. hybridus L. accessions into two of the three grain amaranth clades, suggesting the polyphyletic evolution of the three cultivated species from different A. hybridus ancestors. The transferability of these markers to A. hybridus, A. powellii S. Wats., and A. retroflexus L. is reported and suggests that these markers may be useful in studying other species within the genus Amaranthus, including several economically important weeds and ornamentals.
Divergent Selection for Vegetative Phase Change in Maize and Indirect Effects on Response to Puccinia sorghi
Authors: Basso C. F. , Hurkman M. M. , Riedeman E. S. , Tracy W. F.
Published: May 2008

In maize (Zea mays L.), some experiments have indicated that early vegetative phase transition is associated with increased resistance to disease, insects, and stalk lodging. The sweet corn population Minn11 was selected over three cycles of divergent recurrent selection for early‐phase transition and late‐phase transition. Objectives were to determine the effectiveness of divergent recurrent selection and if the divergent selection program was associated with resistance to common rust (Puccinia sorghi). Selection resulted in a significant linear response for last leaf with juvenile wax in both the early and late directions of selection. The third cycle in the late direction (C3L) had two more leaves with juvenile wax than cycle zero (C0). The third cycle in the early direction (C3E) had 1.5 fewer leaves with juvenile wax than C0. To determine the effects of divergent selection for vegetative phase change on response to common rust the populations were inoculated with rust at three developmental times, vegetative stage (v) 5, v10, and v15, and rust damage was rated on leaves 7 through 13 individually, resulting in 21 potential responses for each direction of selection. Among the 21 leaf by developmental stage combinations, there were 9 significant linear trends in the late direction of selection. Most of the linear trends were detected in leaves 7 through 9. Selection for early transition did not affect response to common rust. The amount of leaf area damaged by rust in C3E never differed from the amount in C0.
Genetic Mapping of the Wheat Leaf Rust Resistance Gene Lr60 (LrW2)
Authors: Hiebert Colin W. , Thomas Julian B. , McCallum Brent D. , Somers Daryl J.
Published: May 2008

Leaf rust (caused by Puccinia triticina Eriks.) is an important disease of wheat (Triticum aestivum L.) in North America. This study was conducted to assess the utility of the uncharacterized resistance gene Lr60 (formerly LrW2) for the development of resistant cultivars by demonstrating its novelty, genetic location, and the breadth of resistance that it confers. Haploids of a single gene line carrying Lr60 (RL6172) were pollinated with a susceptible cultivar to generate hybrids with random chromosome deficiencies arising from irregular meiosis of the haploid. Out of 488 hybrids, four were susceptible to leaf rust. All susceptible hybrids lacked several polymorphic microsatellite alleles from RL6172 that are specific to chromosome 1D. Analysis of an F2 population confirmed that Lr60 was located on the short arm of 1D, 8.4 cM distal to the microsatellite BARC149. Since Lr21 is also located on 1DS a cross was made between single gene lines of Lr21 and Lr60; five susceptible plants recovered in F2 out of 1141 individuals tested were confirmed with progeny tests. This ratio (5:1136) gives an estimated recombination frequency of 13% between Lr21 and Lr60 RL6172 was tested with 37 isolates of P. triticina, encompassing a diversity of virulence found in North America; one isolate was virulent. Lr60 is a novel resistance gene and represents a useful diversification of the genetic resources available in wheat for development of leaf rust resistant cultivars.
Weed Population Dynamics after Six Years under Glyphosate‐ and Conventional Herbicide‐based Weed Control Strategies
Authors: Westra Philip , Wilson Robert G. , Miller Stephen D. , Stahlman Phillip W. , Wicks Gail W. , Chapman Phillip L. , Withrow John , Legg David , Alford Craig , Gaines Todd A.
Published: May 2008

Field studies using glyphosate‐resistant corn (Zea mays L.), sugarbeet (Beta vulgaris L.), and spring wheat (Triticum aestivum L.) were conducted at Scottsbluff, NE, Torrington, WY, and Fort Collins, CO, over 6 yr to evaluate weed population dynamics under glyphosate‐ and conventional herbicide–based weed control strategies. We report the response of common lambsquarters (Chenopodium album L.), wild buckwheat (Polygonum convolvulus L.), and all grasses combined to four management strategies imbedded in two crop rotations. There were no consistent or highly significant benefits from a diverse crop rotation versus continuous corn when weed control was considered. Rotating herbicide mode of action for general weed control provided no benefit above that provided by glyphosate at 0.8 kg acid equivalent (ae) ha−1 applied twice each year. There was no evidence that any weed species developed resistance to glyphosate. The most striking finding of these studies was the buildup of common lambsquarters and wild buckwheat that occurs when glyphosate is applied at 0.4 kg ae ha−1 twice each year. Such a low‐use‐rate approach is to be completely discouraged since it appears to enrich the gene pool for individuals that survive low rates of glyphosate. The continuing decline in the real cost of glyphosate should eliminate any legitimate reason for growers to consider using less than the full labeled rate of glyphosate. All treatments that included glyphosate at all three locations over 6 yr provided significantly better grass control than the nonglyphosate conventional treatments.
Gene Flow and Genetic Structure of Wild Soybean (Glycine soja) in Japan
Authors: Kuroda Yosuke , Kaga Akito , Tomooka Norihiko , Vaughan Duncan A.
Published: May 2008

In many parts of Japan cultivated soybean and wild soybean are sympatric. The objective of this study was to measure gene movement from cultivated soybean to wild soybean and within wild soybean in natural populations in Japan. Seven microsatellite markers that were found to have particularly high ability to discriminate components of the soybean complex in Japan were used to measure the extent of pollen and seed dispersal within and between populations of G. soja at seven localities (14 populations) in northern, central, and southern regions of Japan (1334 seeds/168 individuals) were measured. Each G. soja site consisted of two neighboring populations (100 m–2 km apart), which were adjacent to ( <5 m), or isolated from ( >50 m), cultivated soybean fields. Gene flow from G. max to G. soja was not detected. However, in populations of G. soja, the outcrossing rate ranged from 0–6.3% (average 2.2%), and the dispersal distance of pollen ranged from 5–25 m (average 10.5 m). In addition, 13 individuals of G. soja (7.7%) collected in four populations were assigned to neighboring populations (100–400 m). The results suggest the occurrence of long‐distance seed dispersal in G. soja Spatial autocorrelation analysis revealed a clear isolation by distance model, and a strong positive genetic correlation among individuals was observed within a range of 400 m (r = 0.168–0.551). Gene flow by hybridization among G. soja individuals occurs more frequently than the rare hybridization events between G. max and G. soja in Japan.
Theoretical Expected Genetic Gains for Among‐and‐Within‐Family Selection Methods in Perennial Forage Crops
Authors: Casler Michael D. , Brummer E. Charles
Published: May 2008

Genetic gains in forage yield lag far behind the gains made in grain yield of cereal crops, partly because of the use of inefficient selection methods that make little use of additive genetic variance within half‐sib or full‐sib families. The objectives of this study were (i) to compute expected genetic gains for among‐and‐within‐family (AWF) selection methods, (ii) to compare these selection methods to standard family and progeny‐test selection methods, and (iii) to define the conditions under which AWF selection methods may be superior to progeny‐test selection. Among‐and‐within‐family selection is equal to or better than family selection under all circumstances provided the within‐family selection criterion (X or Y) is heritable and has a positive genetic correlation with the desired trait (Y). Among‐and‐within‐family selection is favored over progeny‐test selection by (i) high heritability on an individual‐plant basis (relative to heritability on a family‐mean basis), (ii) within‐family selection intensity ≥ among‐family selection intensity, and (iii) possibly a shorter cycle time (for some species and some breeding programs). These conditions are more frequently achieved for half‐sib mating systems due to the greater partitioning of additive genetic variance within families, but AWF selection can also be heavily favored in a full‐sib mating system under conditions that are a bit more restrictive.
Evaluation of Seedling Resistance to Tan Spot and Stagonospora nodorum Blotch in Tetraploid Wheat
Authors: Chu C. G. , Friesen T. L. , Faris J. D. , Xu S. S.
Published: May 2008

Tetraploid durum wheat (Triticum turgidum L. subsp. durum), an important cereal used for making pasta products, is more vulnerable to various wheat diseases than bread wheat (T. aestivum L.). To identify resistant sources useful for improving durum resistance to tan spot [caused by Pyrenophora tritici‐repentis (Died.) Drechs.] and Stagonospora nodorum blotch (SNB) [caused by Phaeosphaeria nodorum (E. Müller) Hedjaroude], we evaluated 688 accessions belonging to T. turgidum L. subspecies T. carthlicum, T. polonicum, T. turgidum, T. dicoccum, and T. turanicum for their seedling resistance to P. tritici‐repentis and P. nodorum Accessions were inoculated with a P. tritici‐repentis race 1 isolate (Pti2) and a mixture of three diverse isolates of P. nodorum (LDNSn4, BBCSn5, and Sn2000). Then 206 accessions with low and intermediate disease reaction to either of the inocula were further evaluated for reactions to P. tritici‐repentis and P. nodorum and for sensitivity to host‐selective toxins produced by the two pathogens. Data showed that 25 and 132 accessions had high levels of or partial resistance to tan spot and SNB, respectively, with 10 accessions, including T. dicoccum and T. turgidum, showing resistance to both diseases. The resistant accessions identified in this study would be particularly useful for developing durum wheat germplasm resistant to tan spot and SNB due to their semidomesticated characteristics and same genomic constitutions as durum wheat.
Determination of Mega‐Environments for Peanut Breeding Using the CSM‐CROPGRO‐Peanut Model
Authors: Putto W. , Patanothai A. , Jogloy S. , Hoogenboom G.
Published: May 2008

Breeding for locally adapted cultivars requires a subdivision of the target region into mega‐environments. Crop models could assist in generating the required data for mega‐environment determination. The objective of this study was to determine whether subdividing the peanut (Arachis hypogaea L.) production areas in Thailand into mega‐environments using a crop simulation model would be justified. The Cropping System Model (CSM) CROPGRO‐Peanut was used to simulate pod yield of 17 diverse peanut lines for 130 locations covering all peanut production areas in Thailand. The data were statistically analyzed, and the genotype and genotype × environment (GGE) biplot method was used to subdivide the peanut production areas into subregions. The results reveal that the genotype × location interaction accounted for only a small proportion of total yield variation for all years. The analyses of yearly data by the GGE biplot shows inconsistent results across years for location grouping as well as for the winning genotypes of the individual location‐groups. The GGE biplot analysis of the mean data over 30 yr also indicates a similarity in genotype discrimination for all the locations. The results from this study show that the subdivision of peanut production areas into mega‐environments is not justified for Thailand. Therefore, for peanut breeding, Thailand should be considered as one mega‐environment.
Western Corn Rootworm Damage Subtly Affects Corn Growth under Moderate Environmental Stress
Authors: Cox W. J. , Shields E. , Cherney D. J. R.
Published: May 2008

Western corn rootworm (Diabrotica virgifera virgifera Le Conte) is more prevalent because of its increased adaptation to crop rotation and increased continuous corn (Zea mays L.). A 2‐yr field study using seed and soil‐applied insecticide treatments evaluated growth responses of corn to rootworm damage. The control had moderately severe (1.40 on a 0–3 node‐injury scale), whereas the 1.25 mg kernel−1 clothianidin [(E)1‐(2‐chloro‐1, 3‐thiazol‐5‐ymethyl)‐3‐methyl‐2 nitroguanidine] treatment had minor (0.18) rootworm damage at silking (R1 stage). The control vs. clothianidin had a lower leaf area index at the 12th leaf (V12) stage (2.80 vs. 3.18) but similar values at R1 (4.59 vs. 4.76) and early grain‐fill (R3) stages (4.30 vs. 4.64 m2 m−2, respectively). The control vs. clothianidin had a lower mean crop growth rate from R1 to R3 (23.6 vs. 36.3) but similar rates from the V12 to R1 (34.9 vs. 36.4) and R3 to late grain‐fill (27.2 vs. 25.3 g m−2 d−1, respectively) stages. The control vs. clothianidin had less kernels per square meter (4423 vs. 4751) but similar kernel weight (257 vs. 248 mg) and harvest index values (0.48 vs. 0.49 kg kg−1, respectively). The control vs. clothianidin had lower yield (9.7 vs. 10.6 Mg ha−1, respectively), but root damage ratings did not correlate with yield (r = −0.19, n = 48). The relationship between corn rootworm damage and corn growth was subtle and inconsistent across growth stages, but the control consistently yielded 8 to 9% less than the clothianidin treatment.
Genetic Variation and Genotype × Environment Interactions of Phytosterol Content in Three Doubled Haploid Populations of Winter Rapeseed
Authors: Amar Samija , Becker Heiko C. , Möllers Christian
Published: May 2008

Phytosterols are natural constituents of vegetable oils and are known for their cholesterol‐lowering properties. The oil of rapeseed (Brassica napus L.) is one of the richest natural sources of phytosterols. Genetically enhancing the phytosterol content could give an added value to the rapeseed oil and derived products. Our objectives were to develop a gas‐liquid chromatographic method for the analysis of phytosterol content in seeds of oilseed rape, to determine the genetic variation and the genotype × environment interactions, and to estimate correlations between phytosterols and other important seed quality traits in three doubled haploid populations of winter rapeseed. The populations were tested during several years in three to four environments. Sitosterol and campesterol were detected as the two major phytosterols followed by brassicasterol, avenasterol, and stigmasterol. Large differences were found in total phytosterol content (2.57 to 4.15 g kg−1 seed), with predominant genetic variance components resulting in high heritabilities ranging from 0.84 to 0.91. Phytosterol content was not negatively correlated with oil content and there were no close correlations to protein and glucosinolate content. The large genetic variation along with high heritabilities indicate that an effective breeding for enhanced phytosterol content and modified composition should be possible without negative impacts on oil, protein, or glucosinolate content.
Cold Acclimation Threshold Induction Temperatures in Cereals
Authors: Fowler D. Brian
Published: May 2008

To acquire a competitive advantage and ensure survival when exposed to low‐temperature extremes, cool season plants must be programmed to respond to temperatures favorable for growth and environmental cues that signal seasonal changes. This project was initiated to determine (i) the cold acclimation threshold induction temperatures (ITs) in wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and rye (Secale cereale L.) and (ii) their relationship to plant freezing tolerance at full acclimation. A wide range of genotypic specific IT and initial rapid acclimation responses that were inversely related to decreases in temperatures below the threshold was observed both within and among species, indicating that cereals monitor temperature with a high level of precision. Hardy wheat cultivars had a 5.7°C warmer activation temperature than tender genotypes when the vernalization gene was neutralized in near‐isogenic lines, and a 12°C difference in IT of hardy rye compared with tender barley cultivars emphasized the high cold adaptation potential of rye. This early response to decreasing temperatures means that hardy rye had a longer time to prepare for the extremes of winter and was in a better position to cope with unexpected frosts during the growing season. Differences in IT were closely related to the differences in freezing tolerance at full acclimation. However, a longer vegetative stage also meant that winter habit genotypes were more responsive to extended periods at acclimation temperatures in the threshold range.
Calculation of Left Ventricular Relaxation Time Constant-Tau in Patients With Aortic Regurgitation by Continuous-Wave Doppler
Authors: Xufang Bai
Published: May 2008

Left ventricular relaxation time constant, Tau, is the best index to evaluate left ventricular diastolic function. The measurement is only available traditionally in catheter lab. In Echo lab, several methods of non-invasive measurement of Tau have been tried since 1992, however almost all the methods are still utilizing the same formula to calculate Tau as in catheter lab, which makes them inconvenient, time-consuming and sometimes not very accurate. A simple method to calculate Tau in patients with mitral regurgitation has been developed just based on Weiss’ formula and simplified Bernoulli’s equation. Similarly, formulas are developed here by pure mathematical derivative to calculate Tau by continuous-wave Doppler in patients with aortic regurgitation.
The Process of Finding a Shape: Stabilising New Research Structures in Swedish Teacher Education, 2000–2007
Authors: Arreman Inger Erixon
Published: May 2008

This article explores the development and effects of Swedish post-war policies on the emergence of a research base for teacher education. From 2001 onwards, it is possible to undertake research and postgraduate studies within teacher education in Sweden, which prior to the 2001 reform was not possible. The article draws on a variety of frameworks to explore relationships between various parts of teacher education and also more widely in the university. These include relations of power, discourse and gender based on the theoretical perspectives of Bourdieu, Foucault, Sarfatti Larson and Connell among others. Policy documents relating to teacher education and research into national, regional and local perspectives were used to explore institutional history, structures and research development in teacher education from 1946 to the present time. For a micro-level perspective, an interview study was also carried out between 2000 and 2002 with teacher educators and senior managers who from the late 1940s were responsible for teacher education programmes, in and around Umeå, in northern Sweden. A further complementary interview study was carried out with teacher educators and union representatives between 2005 and 2007. The extended study reveals the emergence of new research areas in teacher education as a multilayered process involving a variety of actors at different levels at Umeå University and elsewhere. The aim of the article is to explore the implications of the new research structures for teacher education in Sweden and also to contribute to current cross-national discourses on the need to establish a research base for teacher education.
Middle-Class Families and School Choice: Freedom versus Equity in the Context of a ‘local Education Market’
Authors: Reinoso Antonio Olmedo
Published: May 2008

This article analyses the impact of social class on the process of school choice in Spain from the viewpoint of middle-class families. This practice must be seen in the framework of the new social context generated by the information society. The article begins by briefly describing changes in school choice policies in Spain. For a wider understanding, these changes are related to the broader process of the marketisation of education, which has been taking place in this country for the last 20 years. In the second part of the article, qualitative data are presented on how middle-class parents understand and experience the process of choosing a particular school for their children. In this study, 24 interviews were carried out in the city of Granada (southern Spain). They were fully transcribed and analysed using the methodology suggested by ‘grounded theory’ and Bourdieu's concept of social class. Aspects related to social and cultural capital are added to the traditional social class indicators, which are usually expressed in economic terms. Attention centres on the creation of reconversion strategies for these different forms of capital used by families to obtain positional advantage for their children. This research thus revisits the principles of social reproduction theories from the viewpoint of the ‘winners’, i.e. middle-class families.
Age of Indicators: Changes in the Finnish Education Policy Agenda
Authors: Kauko Jaakko , Varjo Janne
Published: May 2008

Quality assurance and evaluation (QAE) have become a vital part of education governance, both globally and nationally. This article is an attempt to represent and analyse first, how the idea of education indicators has arrived, has been accepted and has been modified in Finland. Secondly, it describes what are the aims given and actions taken in developing national indicators by different actors. The article sketches the development of education indicators in Finland through two time periods of high adaptational pressure of Europeanisation. During the ‘short 1970s' ( c. 1970–76), the idea of social indicators was introduced for the very first time on the Finnish comprehensive education policy agenda. This first attempt faded away by the mid 1970s. However, the ‘long 1990s' reinvented the idea and it seems that this period, beginning from c. 1986, is still ongoing. Drawing on Börzel & Risse's thoughts, the authors explain the differences in these two decades mainly with the changes in ‘facilitating factors' and the duration of adaptational pressure.
Advancing the European Education Agenda: International Conference of the European Education Policy Network (EEPN) and the Centre for Educational Policy and Innovation, Katholieke Universiteit Leuven, Belgium
Authors:   Contributors to the report: Cynthia De Bruycker (Katholieke Universiteit Leuven), Avril Keating (EEPN), Ruth Keeling (EEPN), Geert Kelchtermans (Katholieke Universiteit Leuven), Maarten Simons (Katholieke Universiteit Leuven) and Isabel Snauwaert (Katholieke Universiteit Leuven)
Published: May 2008

An international conference on the theme ‘Advancing the European Education Agenda’ took place in Brussels and Leuven, Belgium from 30 November to 1 December 2007. This conference, part of a conference series organised by the European Education Policy Network, aimed to stimulate debate among policy researchers and policy makers who are interested in the rapid education policy developments taking place in the European arena. In this report the authors provide an overview of the key themes, challenges and tensions that were raised during this meeting. These discussions clustered around four themes: higher education, research and innovation; mobility, integration and inclusion; learning, languages and skills; and bridging the gap between education policy and research.
Altered Calcium Homeostasis Does Not Explain the Contractile Deficit of Diabetic Cardiomyopathy
Authors: Zhang Lin , Cannell Mark B. , Phillips Anthony R.J. , Cooper Garth J.S. , Ward Marie-Louise
Published: May 2008

OBJECTIVE—This study examines the extent to which the contractile deficit of diabetic cardiomyopathy is due to altered Ca2+ homeostasis.

RESEARCH DESIGN AND METHODS—Measurements of isometric force and intracellular calcium ([Ca2+]i, using fura-2/AM) were made in left ventricular (LV) trabeculae from rats with streptozotocin-induced diabetes and age-matched siblings.

RESULTS—At 1.5 mmol/l [Ca2+]o, 37°C, and 5-Hz stimulation frequency, peak stress was depressed in diabetic rats (10 ± 1 vs. 17 ± 2 mN/mm2 in controls; P < 0.05) with a slower time to peak stress (77 ± 3 vs. 67 ± 2 ms; P < 0.01) and time to 90% relaxation (76 ± 7 vs. 56 ± 3 ms; P < 0.05). No difference was found between groups for either resting or peak Ca2+, but the Ca2+ transient was slower in time to peak (39 ± 2 vs. 34 ± 1 ms) and decay (time constant, 61 ± 3 vs. 49 ± 3 ms). Diabetic rats had a longer LV action potential (APD50, 98 ± 5 vs. 62 ± 5 ms; P < 0.0001). Western blotting showed that diabetic rats had a reduced expression of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a, with no difference in expression of the Na+/Ca2+ exchanger. Immunohistochemistry of LV free wall showed that type I collagen was increased in diabetic rats (diabetic 7.1 ± 0.1%, control 12.7 ± 0.1%; P < 0.01), and F-actin content reduced (diabetic 56.9 ± 0.6%; control 61.7 ± 0.4%; P < 0.0001) with a disrupted structure.

CONCLUSIONS—We find no evidence to support the idea that altered Ca2+ homeostasis underlies the contractile deficit of diabetic cardiomyopathy. The slower action potential and reduced SERCA2a expression can explain the slower Ca2+ transient kinetics in diabetic rats but not the contractile deficit. Instead, we suggest that the observed LV remodeling may play a crucial role.
Blood Glucose Monitoring: A Practical Guide for Use in the Office and Clinic Setting
Authors: Odegard Peggy Soule , Beach Jennifer Rose
Published: May 2008

In Brief

Interpretation of self-monitoring of blood glucose (SMBG) results is not routinely practiced in the office and clinic setting. However, such interpretation in the presence of patients may facilitate improved patient-provider discussion, clinical decisions, and ability to manage glycemic patterns. This review outlines key steps in a systematic review of SMBG data, including 1) identifying the degree of blood glucose control using mean and standard deviation or variance, 2) identifying patient safety concerns with regard to hypoglycemia, and 3)understanding the factors influencing blood glucose control by noting trends and patterns. Case studies are provided to illustrate the process for using and interpreting electronic SMBG downloads.
“It Feels Like Home When You Eat Rice and Beans”:Perspectives of Urban Latinos Living With Diabetes
Authors: Caban Arlene , Walker Elizabeth A. , Sanchez Severa , Mera Maria S.
Published: May 2008

Background. Studies on Hispanics/Latinos with diabetes have largely focused on Mexican-American populations. This qualitative study explored psychosocial issues that affect diabetes self-management for Hispanic men and women of primarily Caribbean ancestry.

Methods. Thirty-seven adults with diabetes in Bronx, N.Y., were recruited to seven focus groups, which were conducted in Spanish and English,audiotaped, transcribed, and subjected to qualitative analysis.

Results. New themes emerged that are not well documented in the research literature for Hispanic/Latino populations with diabetes. These include the effect of diabetes on sexual health problems, perceptions about the link between depression and diabetes, intergenerational issues and their impact on participants' beliefs about diabetes, and perceptions of discrimination and discontinuity in health care.

Conclusions. Findings suggest that perspectives among Hispanic/Latino populations about living with diabetes are diverse, and more research is needed. Social-cognitive theory and socio-ecological models of health may be useful to diabetes health care professionals in understanding patients' experiences with diabetes and informing the development of psychosocial and educational interventions that consider individuals and their environment.
Early Patient and Clinician Experiences with Continuous Glucose Monitoring
Authors: Bloomgarden David K. , Freeman Janine , DeRobertis Elizabeth
Published: May 2008

Fifteen years after publication of landmark studies that clearly demonstrated the benefits of intensive diabetes management, patients continue to fall short of glycemic goals. The risk of hypoglycemia remains a major barrier to optimal glycemic control.

Continuous glucose monitoring (CGM) can assist in overcoming some of the limitations of self-monitoring of blood glucose by providing the ability to track glucose levels 24 hours a day, observe glucose trends and patterns, and receive alarms or alerts for actual and impending hypo- and hyperglycemia. In the brief time it has been available, studies have already demonstrated an association between the use of CGM and less time spent in hypo- and hyperglycemia, reduced glycemic variability, and reduced hemoglobin A1c levels.

Because little information exists in the literature regarding teaching and learning experiences to assist clinicians beginning to incorporate CGM into their practices, the training and user experience from a 12-week study of patients using the FreeStyle Navigator CGM system was evaluated. Through responses to questionnaires, clinicians indicated the ability to train easily on the CGM system, and both patients and clinicians felt that they were able to make more informed decisions on therapy adjustments based on information from the receiver and the data management reports.

It is important for clinicians and patients to understand the scope and limitations of this new technology to prevent unrealistic expectations. It is imperative to provide adequate training and education to effectively manage and use the large amount of data made available by CGM.
Use of Real-Time Continuous Glucose Monitoring Technology in Children and Adolescents
Authors: Block Jen M. , Buckingham Bruce
Published: May 2008

In Brief

This article combines research findings and clinical experience that are unique to the use of continuous glucose monitoring in children and adolescents. It stresses the importance of realistic expectations, describes consideratons related to wearability, and reviews the potential benefit of glucose alarm features for pediatric patients.
So Much More Than “Sex Ed”: Teen Sexuality as Vehicle for Improving Academic Success and Democratic Education for Diverse Youth
Authors: Ashcraft Catherine
Published: May 2008

Although sexuality saturates adolescent life, schools do little to address teen sexuality. As educators feel increasingly burdened by competing societal demands, caring for youth sexual health becomes a secondary goal at best. This article argues that the public health costs are only one reason for addressing sexuality in schools and suggests that academic and democratic reasons for addressing sexuality also exist. It illustrates how sexuality can be a potentially powerful resource for increasing the academic achievement and civic engagement of a diverse range of youth. As such, addressing sexuality serves not only public health goals but also academic and democratic goals—goals that have long been central for schools. To make this argument, the author draws from her ethnography of ESPERANZA, a community-based sex education program, illustrating how ESPERANZA used teen interest in sexuality to help youth become leaders, increase academic skills, expand career aspirations, and engage in democratic civic action.