bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen Removal and Nitrate Leaching for Two Perennial, Sod‐Based Forage Systems Receiving Dairy Effluent
Authors: Woodard Kenneth R. , French Edwin C. , Sweat Lewin A. , Graetz Donald A. , Sollenberger Lynn E. , Macoon Bisoondat , Portier Kenneth M. , Rymph Stuart J. , Wade Brett L. , Prine Gordon M. , Van Horn Harold H.
Published: August 2012

In northern Florida, year‐round forage systems are used in dairy effluent sprayfields to reduce nitrate leaching. Our purpose was to quantify forage N removal and monitor nitrate N NO−3–N concentration below the rooting zone for two perennial, sod‐based, triple‐cropping systems over four 12‐mo cycles (1996–2000). The soil is an excessively drained Kershaw sand (thermic, uncoated Typic Quartzipsamment). Effluent N rates were 500, 690, and 910 kg ha−1 per cycle. Differences in N removal between a corn (Zea mays L.)–bermudagrass (Cynodon spp.)–rye (Secale cereale L.) system (CBR) and corn–perennial peanut (Arachis glabrata Benth.)–rye system (CPR) were primarily related to the performance of the perennial forages. Nitrogen removal of corn (125–170 kg ha−1) and rye (62–90 kg ha−1) was relatively stable between systems and among cycles. The greatest N removal was measured for CBR in the first cycle (408 kg ha−1), with the bermudagrass removing an average of 191 kg N ha−1 In later cycles, N removal for bermudagrass declined because dry matter (DM) yield declined. Yield and N removal of perennial peanut increased over the four cycles. Nitrate N concentrations below the rooting zone were lower for CBR than CPR in the first two cycles, but differences were inconsistent in the latter two. The CBR system maintained low NO−3–N leaching in the first cycle when the bermudagrass was the most productive; however, it was not a sustainable system for long‐term prevention of NO−3–N leaching due to declining bermudagrass yield in subsequent cycles. For CPR, effluent N rates ≥ 500 kg ha−1 yr−1 have the potential to negatively affect ground water quality.
Increasing Hard Winter Wheat Yield Potential via Synthetic Wheat: I. Path‐Coefficient Analysis of Yield and Its Components
Authors: Cooper Jessica K. , Ibrahim A.M.H. , Rudd J. , Malla Subas , Hays Dirk B. , Baker Jason
Published: August 2012

Synthetic hexaploid wheat, created from a cross between durum [Triticum turgidumL. (syn.Triticum durumDesf.)] andAegilops tauschiiCoss., is a good source of new genes for bread wheat (Triticum aestivumL.) improvement. The purpose of this research was to evaluate the potential and performance of synthetic wheat in Texas. Ten elite primary synthetics from the International Maize and Wheat Improvement Center (CIMMYT) were backcrossed to two Texas cultivars, TAM 111 and TAM 112. Populations were bulked and “modified bulked” to advance generations. Yield‐related agronomic traits were measured on the BCF4and BCF5populations across five Texas locations. Improvement was observed in South Texas and the Blacklands, which had more disease pressure and fewer intermittent dry spells than locations in the Texas Rolling and High Plains. Selected bulks were not superior to nonselected bulks. Head number per unit area had the highest correlation with yield. Similar to crosses with spring wheat, synthetics contributed to yield through an increase in seed weight. Synthetic populations that produced higher grain yield than both TAM 111 and TAM 112 maintained their large seed size and weight but had increased number of heads and grains per head. Poorer performance in environments with harsh winters could be because of a lack of winter‐hardiness in the primary synthetics. Improved yield could result from selecting for increased number of heads per unit area and grains per head in lines derived from these populations.
Screening Method for Distinguishing Soybean Resistance to Fusarium virguliforme in Resistant × Resistant Crosses
Authors: Luckew Alexander S. , Cianzio Silvia R. , Leandro Leonor F.
Published: August 2012

Current greenhouse screening methods for soybean [Glycine max (L.) Merr.] sudden death syndrome (SDS) are not sensitive enough to evaluate progeny of resistant × resistant crosses, which can possess resistance alleles at up to 12 quantitative trait loci (QTL). The objective of the study was to modify the current greenhouse screening method, the layer method, to increase its sensitivity in distinguishing SDS‐resistant lines. Three experiments were conducted using infested sorghum [Sorghum bicolor (L.) Moench] as inoculum. In Exp. 1, five different inoculum densities (1:1, 1:5, 1:10, 1:15, and 1:20 inoculum:soil ratio) were compared, and the optimum density to distinguish genotypes was identified. In Exp. 2, the association between SDS field ratings and greenhouse severity scores was determined. In Exp. 3, the inoculum layer method was compared to the proposed modified mixed method. Inoculum ratios 1:15 and 1:20 showed the largest difference in SDS ratings between soybean genotypes. The best time to assess disease severity was 30 to 36 d after planting (DAP), with the highest correlation with field ratings at 36 DAP (r = 0.82, p < 0.05). The proposed modified method shifted the frequency distribution of SDS scores toward a normal curve. The findings indicate that the modified screening method using a 1:20 inoculum:soil ratio correlated well with field data and provided adequate screening of lines possessing up to 12 SDS resistant QTL without negatively impacting germination.
Association of Freezing Tolerance to LpCBFIIIb and LpCBFIIIc Gene Polymorphism in Perennial Ryegrass Accessions
Authors: Hulke Brent S. , Bushman Bradley S. , Watkins Eric , Ehlke Nancy J.
Published: August 2012

Perennial ryegrass (Lolium perenne L.) is considered a premier turfgrass and forage grass worldwide yet susceptibility to freezing damage limits its use. C‐repeat binding factor (CBF) dehydration‐responsive element‐binding protein (DREB) related genes are considered important for the regulation of abiotic stress in plants. In this study, CBF DREB‐related genes in perennial ryegrass, also known as LpCBF genes, were resequenced from cultivated and landrace plants from a worldwide collection. A total of 109 plants survived clonal propagation and were tested for freezing tolerance. The resulting data was subjected to mixed model analysis to determine whether the freezing tolerance is related to single nucleotide polymorphism (SNP) and indel markers within two genes, LpCBFIIIb and LpCBFIIIc. One major quantitative trait locus (QTL) was discovered in LpCBFIIIc for freezing tolerance, with the majority of the plants possessing the superior allele. Several minor loci were also discovered in this gene, but no significant loci were discovered in LpCBFIIIb.
Broadening Genetic Diversity in Canola Using the C‐Genome Species Brassica oleracea L.
Authors: Bennett Rick A. , Séguin‐Swartz Ginette , Rahman Habibur
Published: August 2012

Genetic diversity in spring type canola (Brassica napus L., AACC genome, 2n = 38) cultivars is narrow. Limited effort has been made to utilize genetic diversity from the diploid species Brassica oleracea L. (CC genome, 2n = 18) due to lack of canola quality traits in seeds of this species. The objectives of this study were to assess the feasibility of introgressing canola quality traits from B. napus into B. oleracea for the purpose of developing canola quality B. oleracea as well as development of B. napus with greater genetic diversity from B. oleracea while retaining canola quality traits. Two inbred (B. napus × B. oleracea) × B. oleracea populations were generated using B. napus ‘Hi‐Q’ and A01‐104NA and B. oleracea var. alboglabra (L. H. Bailey) Musil (Chinese kale). These populations were assessed for seed quality, effectiveness of selection based on morphological traits, genetic diversity using simple sequence repeat (SSR) markers, and ploidy levels using flow cytometry and cytological analysis of meiotic chromosomes. Zero‐erucic and low glucosinolate types were recovered from a relatively small segregating population. Morphological grouping could not reliably be used to select B. oleracea plants with 2n = 18; all BC1S6 families had nuclear DNA content similar to the B. napus parents. Marker analysis revealed a high level of B. oleracea alleles among backcross lines. These findings suggest that introgression of genetic diversity from the diploid B. oleracea C‐genome into stable, canola quality B. napus type lines is feasible and may have great potential in developing genetically diverse spring type varieties.
Germination Characteristics and Seedling Emergence of Switchgrass with Different Agricultural Practices under Arid Conditions in China
Authors: Fan Jing‐Wei , Du Yan‐Lei , Turner Neil C. , Li Feng‐Min , He Jin
Published: August 2012

Switchgrass (Panicum virgatum L.) is an important feedstock for bioenergy production, but establishment is difficult in cold arid areas. This study determined the conditions required to improve its germination and emergence in the field. Under controlled conditions, the effects of temperature, water status, and light on germination were studied by exposure to 12‐h alternating temperatures of 15/5, 20/5, 20/10, 25/10, 35/20, 40/20, and 45/20°C (day/night) and water potentials of 0, −0.2, −0.4, −0.6, −0.8, and −1.2 MPa in culture medium. Maximum percentage germination occurred at 35/20°C, 0 MPa water potential, and in continuous dark. In the field when planted in early spring (April), no emergence occurred when there was no surface cover or covered with straw mulch (SM) whereas using plastic film mulch (FM), emergence reached 383 seedlings m−2 with pre‐sowing irrigation but only 273 without irrigation. This was associated with higher soil temperatures and better soil moisture. However, in July seeding, SM lead to better water status and cooler soil conditions and thus better stand establishment. In contrast, FM treatment had poor establishment primarily due to the high temperatures. Our study indicates that emergence of switchgrass in an arid environment was (i) enhanced by pre‐sowing irrigation and shallow seeding, (ii) made possible in spring by the use of FM, and (iii) improved with SM for summer seeding.
QTLs for Energy‐related Traits in a Sweet × Grain Sorghum [Sorghum bicolor (L.) Moench] Mapping Population
Authors: Felderhoff T. J. , Murray S. C. , Klein P. E. , Sharma A. , Hamblin M. T. , Kresovich S. , Vermerris W. , Rooney W. L.
Published: August 2012

To meet anticipated markets for sweet sorghum [Sorghum bicolor (L.) Moench] production, the development of sweet sorghum hybrids is underway. As this development is in its infancy, genetic markers will be very useful to define the genetic basis of sugar yield components and reduce the time required to deliver new hybrids to market. The purpose of this research was to characterize genetic components that influence sweet sorghum productivity and agronomics. A grain × sweet sorghum mapping population was evaluated for 16 phenotypic traits across four environments. A population of 185 F3–derived F4 (F3:4) lines was derived from the parents ‘BTx3197’ and ‘Rio’, which are dry‐stalked grain and juicy‐stalked sweet sorghums, respectively. A genetic map was constructed with 381 single nucleotide polymorphisms, and quantitative trait locus (QTL) analysis was performed. A major and previously reported QTL for soluble solids was identified on chromosome 3, but in contrast to previous studies, this QTL colocalized with other QTLs that had negative influences on desirable traits. Therefore, selection for this QTL may not be advantageous. A limited number of QTLs for percent moisture were found, and results indicated that the dry‐stalk phenotype does not affect moisture content as measured in this study. Thus, breeding for moisture content will be more challenging than previously expected. The absence of dominance effects for the brix trait indicated that brix must be high in both parents to produce high brix in hybrids.
Identification of Soybean Genotypes Resistant to Fusarium graminearum and Genetic Mapping of Resistance Quantitative Trait Loci in the Cultivar Conrad
Authors: Ellis Margaret L. , Wang Hehe , Paul Pierce A. , St. Martin Steven K. , McHale Leah K. , Dorrance Anne E.
Published: August 2012

Fusarium graminearum, a necrotroph, has emerged as an important soybean [Glycine max (L.) Merr.] seedling pathogen in Ohio. An effective management strategy for seedling pathogens is host resistance; thus, the objectives of this research were to identify and characterize sources of resistance to F. graminearum. Twenty‐four soybean genotypes were screened for resistance using a rolled‐towel assay; seeds were inoculated with 2.5 × 104 macroconidia mL−1. A disease severity index (DSI) was calculated on the basis of the ratio of lesion length to total plant length at 7 days after inoculation. Five genotypes had high levels of resistance to F. graminearum, with DSIs ranging from 24 to 41.5%. These included the cultivar Conrad, which has high levels of partial resistance to the hemibiotroph, Phytophthora sojae. A population of 262 F6:8 recombinant inbred lines derived from a cross of Conrad × Sloan (susceptible) was then evaluated for resistance. The same rolled towel method was used, and resistance to F. graminearum segregated as a quantitative trait. The DSI ranged from 22 to 100% and the broad‐sense heritability estimate was 0.72. Four putative quantitative trait loci (QTLs) were identified from Conrad on chromosomes 8, 13, 15, and 16, and one putative QTL from Sloan mapped to chromosome 19. The putative QTLs identified in this population were not the same as those that confer resistance to P. sojae, which suggests that different loci are required for resistance to these two different types of seedling pathogens.
Assessment of Reliability of Secondary Traits in Selecting for Improved Grain Yield in Drought and Low‐Nitrogen Environments
Authors: Badu‐Apraku B. , Akinwale R.O. , Franco J. , Oyekunle M.
Published: August 2012

Grain yield of maize (Zea mays L.) has low heritability under low soil nitrogen (low N) and drought, necessitating the use of secondary traits with strong associations with yield for selection. A base index involving anthesis–silking interval, plant and ear aspects, ears per plant, and stay green characteristic is used for selection for yield under drought and low‐N stresses. Reports are contradictory on the reliability of stay green characteristic for selecting for yield under drought stress and of ears per plant and anthesis–silking interval in selecting for low‐N tolerance. Ninety extra‐early inbreds were evaluated for 2 yr at three locations in Nigeria under low N and drought to confirm reliability of stay green characteristic for selecting for drought tolerance and of ears per plant and anthesis–silking interval for low N. Plant aspect and plant and ear heights were identified as the most reliable traits for simultaneous selection for yield under low N and drought in the extra‐early inbreds. Stay green characteristic was unreliable for selecting drought tolerant genotypes while ears per plant and anthesis–silking interval were not among the reliable traits for selecting low‐N tolerant genotypes. Ear height, plant and ear aspects, and stay green characteristic were identified by both path–coefficient and genotype main effect plus genotype × environment interaction (GGE) biplot analyses as reliable for selecting for low N and ear aspect, plant height, and anthesis–silking interval for drought tolerance.
A Stable dw3 Allele in Sorghum and a Molecular Marker to Facilitate Selection
Authors: Barrero Farfan Ivan D. , Bergsma Benjamin R. , Johal Gurmukh , Tuinstra Mitchell R.
Published: August 2012

Dwarfism plays a key role in adapting crops to high‐input production systems by contributing to improved lodging resistance and fertilizer efficiency. In sorghum [Sorghum bicolor (L.) Moench], four dwarfing mutations have been found that profoundly reduce the stalk height. Notable among these mutations is dwarf‐3 (dw3), even though the phenotype it confers is unstable. The objectives of this research were to identify and characterize a stable mutant allele of the dw3 locus. Polymerase chain reaction (PCR) was used to amplify a region of dw3 containing the 882 bp tandem duplication that is diagnostic for the unstable allele. Analyses of PCR fragments from dwarf sorghum accessions that lacked the duplicated region led to the identification of Tx2737 as a possible carrier of a novel mutant dw3 allele. Sequence analysis confirmed and revealed the presence of a 6 bp deletion in exon 5 of dw3 that eliminates two highly conserved amino acids, Q1275 and R1276, from the enzyme. The frequency of this allele in sorghum germplasm appears to be very low with only 1% of the accessions in the diversity panel exhibiting this deletion. Field trials demonstrated that this allele of dw3 produces a stable dwarf phenotype with no height mutants found in Tx2737 and KS19. The new allele has been coined dw3‐sd2. The discovery of dw3‐sd2 and a DNA marker assay to facilitate selection will provide an opportunity to replace the unstable dw3 allele currently used in most commercial sorghum hybrids through introgression of dw3‐sd2 into elite parent lines.
Genetic Diversity and Host Specificity of Fungal Endophyte Taxa in Fescue Pasture Grasses
Authors: Ekanayake Piyumi N. , Hand Melanie L. , Spangenberg German C. , Forster John W. , Guthridge Kathryn M.
Published: August 2012

A number of pasture and turf grass species form mutually beneficial symbiotic associations with endophytic fungal species. Within the fescue grasses, diploid meadow fescue (Festuca pratensis Huds.) interacts with Neotyphodium uncinatum while allohexaploid tall fescue (Festuca arundinacea Schreb.) has been reported to associate with Neotyphodium coenophialum and two other morphologically distinct taxa (Festuca arundinacea taxonomic groups 2 and 3 [FaTG‐2 and FaTG‐3]). The evolutionary history of hexaploid tall fescue is complex, as part of a species group with varying ploidy levels and exhibiting distinct ecogeographical morphotypes. To evaluate both naturally occurring variation and host grass taxon specificity, diversity was determined in collections representing multiple meadow fescue and tall fescue accessions. Initial screening with a minimal set of endophyte‐specific simple sequence repeat (SSR) genetic markers detected endophyte incidence in 33% of 701 tested accessions. Subsequent analysis identified N. coenophialum genotypes within Continental and rhizomatous hexaploid and octoploid tall fescue [F. arundinacea subsp. atlantigena (St.‐Yves) Auquier] accessions. Festuca arundinacea taxonomic group 2 and FaTG‐3 endophytes appeared to be restricted to Mediterranean hexaploid and decaploid tall fescue [F. arundinacea cirtensis (St.‐Yves) Gamisans] hosts. Endophytes of meadow fescue were confirmed as belonging to N. uncinatum. This study has elucidated host specificity of fescue endophyte taxa and supported models for host–symbiont coevolution. A substantial number of candidate novel endophytes have been identified that are suitable for metabolic characterization and deployment by inoculation in fescue breeding programs.
Perspective on Forage Legume Systems for the Tallgrass and Mixed‐Grass Prairies of the Southern Great Plains of Texas and Oklahoma
Authors: Butler T. J. , Muir J. P.
Published: August 2012

Legumes have potential to transfer fixed N to nonlegume crops via grazing or decomposition as well as improve production, seasonal distribution, nutritive value, soil structure, and fertility in forage systems. This article summarizes the legume establishment, management, and grazing production experiments conducted in the southern Great Plains. It attempts to give perspective on the current state of producer adoption and the potential for future research to improve legume adoption. Several medics (Medicago spp.) and clovers (Trifolium spp.) are compatible and can be established with tall fescue [Schedonorus arundinaceus (Schreb.) Dumort]; however, due to limited precipitation, these have not reliably regenerated. Hairy vetch (Vicia villosa Roth) required annual establishment and was not as economical as N fertilizer in the perennial grass systems, but it was profitable and comparable to the annual system with 112 kg N ha−1 by conventional fertilizer. Alfalfa (Medicago sativa L.) may have the greatest potential in the southern Great Plains with cool‐season perennial grass systems like tall fescue when planted in a checkerboard orientation. An alternative approach for utilizing legumes may be to limit grazing access in pure stands similar to a supplementation program during periods of limited forage production or quality. There is a need for greater research including germplasm and rhizobia evaluations, improved seed production, weed control, and grazing before producer adoption becomes widespread. Future research should address constraints including legume establishment, management practices that extend the life of legumes in forage systems, and appropriate economic analysis of proposed novel systems.
Quantitative Trait Loci for Waterlogging Tolerance in a Barley Cross of Franklin × YuYaoXiangTian Erleng and the Relationship Between Waterlogging and Salinity Tolerance
Authors: Zhou Meixue , Johnson Peter , Zhou Gaofeng , Li Chengdao , Lance Reg
Published: August 2012

Breeding for waterlogging tolerance is an important and challenging objective in high rainfall areas across many countries in the world, as evaluation of the tolerance in the field is difficult and not reliable. Molecular markers can be effectively used in a breeding program to indirectly select waterlogging tolerance. In this study, 172 doubled haploid (DH) lines originating from a cross of YuYaoXiangTian Erleng (YYXT) and ‘Franklin’ were used to identify the quantitative trait loci (QTL) controlling waterlogging tolerance. For the purpose of comparing QTL from different DH populations, a consensus map was constructed using six different populations. A total of four QTL were identified, which controlled 6.2 to 30.1% of the phenotypic variation. Among these QTL, one located on chromosome 6H was not identified in previous studies. Two of the QTL were located at similar positions to QTL for salinity tolerance that had been reported earlier. Further analysis showed some relationships between waterlogging and salinity tolerance. Therefore, waterlogging and salinity tolerance can be improved simultaneously by marker‐assisted selection.
Extra Long Staple Upland Cotton for the Production of Superior Yarns
Authors: Joy Kolbyn , Smith C. Wayne , Hequet Eric , Ed Hughs S. , Hague Steve
Published: August 2012

Cotton (Gossypium spp.) fibers are produced primarily by G. hirsutum L., upland, and G. barbadense L., pima, or Extra Long Staple (ELS). Two ELS upland lines, developed by Texas AgriLife Research, along with ‘FiberMax 832LL’ (FM 832) and ‘DPL Pima HTO’ (Pima HTO), were grown in a randomized complete block design at College Station, TX, during 2007 and 2008. Subplots of spindle‐harvested seedcotton were ginned on a saw gin or roller gin with appropriate lint cleaning. High‐volume instrument (HVI) and Advanced Fiber Information System (AFIS) fiber parameters were determined. Combed 50‐Ne (English yarn count) and 80‐Ne yarns were produced. Upland ELS lines exhibited longer (p < 0.01) fibers than FM 832, but only TAM B182‐33 ELS produced fibers longer or equal (p < 0.01) to Pima HTO. Upland ELS lines produced stronger 50‐Ne ring‐spun yarns than FM 832 but not Pima HTO, which also produced stronger 80‐Ne ring‐spun yarn than the upland ELS lines. While roller ginning resulted in significantly higher micronaire, longer upper half mean length, more uniform fiber lengths, and longer upper‐quartile length than saw ginning among these genotypes, yarn parameters reported were not affected. All genotypes responded the same to ginning platform, suggesting that further development of the upland ELS trait will not dictate a change in ginning equipment for upland cotton. The upland ELS trait contributes to significantly improved upland yarn quality.
Grazing Management of Flaccidgrass Pastures in Autumn
Authors: Burns J.C. , Fisher D.S.
Published: August 2012

‘Carostan’ flaccidgrass (Pennisetum flaccidum Griseb.) is a perennial warm‐season grass with potential for pasture, but appropriate autumn (September to November) management is needed to maintain forage mass (FM) production and prevent declines in plant density. We evaluated 10 treatments over 3 yr consisting of an ungrazed control, four treatments with multiple grazing events (MG), four treatments with a single grazing event (SG), and one treatment grazed after frost. The winter residues after the treatments were greatest (P < 0.01) when ungrazed compared with the grazed treatments (3347 vs. 2265 kg ha−1) and differed (P ≤ 0.01) among and between (P < 0.01) the MG and SG treatments. Plant density decreased from 13 to 27% with 8 to 10 wk of regrowth before frost. Greater plant density decline (60%) occurred when plots were grazed three times and only allowed 4 wk of regrowth before frost. Total nonstructural carbohydrates (TNC) of ungrazed basal stems, crowns, and roots sampled in December were 158, 193, and 250 g kg−1, respectively, and when grazed were 124, 183, and 253 g kg−1, respectively. By April TNC had declined 56, 35, and 25%, respectively. Plant density was not related to autumn total FM, FM regrowth, or overwintering residue but was related (P ≤ 0.02) to TNC of December roots (r = 0.59) and TNC of April basal stems (r = 0.42), crowns (r = 0.61), and roots (r = 0.66). Allowing 6 wk of regrowth before frost minimized plant density losses for flaccidgrass.
Harvest Impacts on Alfalfa Stem Neutral Detergent Fiber Concentration and Digestibility and Cell Wall Concentration and Composition
Authors: Lamb JoAnn F. S. , Hans‐Joachim G. Jung , Riday Heathcliffe
Published: August 2012

Alfalfa (Medicago sativa L.) stem fiber concentration and digestibility, lignin, and polysaccharide composition impact energy availability for livestock and biofuel conversion. We evaluated stem neutral detergent fiber (NDF) concentration, 16‐ and 96‐h in vitro neutral detergent fiber digestibility (IVNDFD), total cell wall (CW) concentration, and proportions of Klason lignin (KL), cellulose (CEL), pectin (PEC), and hemicellulose (HC) in the cell wall for eight germplasms at two plant densities at two locations harvested at early bud (four cuts) and late flower (three cuts) for 2 yr. Growth environment influences at each harvest had the greatest impact on stem quality traits while plant density had no effect. Stem NDF, CW, and CEL were greater at late flower while 16‐ and 96‐h IVNDFD and PEC were greater at early bud. Stem KL and HC were variable but comparable at the two maturity stages. Correlations indicated that as NDF or CW increased, CEL increased, KL remained relatively constant, and 16‐ and 96‐h IVNDFD and PEC decreased. The large variability in response for stem quality traits suggested that to modify stem fiber and cell wall composition, alfalfa will need to be screened over several harvests to identify plants with consistent differences in stem quality.
Inheritance and Molecular Mapping of an Allele Providing Resistance to a Cowpea Mild Mottle‐Like Virus in Soybean
Authors: Brace Ryan C. , Fehr Walter R. , Graham Michelle A.
Published: August 2012

Damage to soybean [Glycine max (L.) Merr.] from a Cowpea mild mottle‐like virus (CPMMLV) (family Betaflexiviridae and genus Carlavirus) has been of increasing concern in Argentina, Brazil, Mexico, and Puerto Rico. Soybean cultivars and lines differing in their reaction to the virus have been identified. The first objective of our study was to determine the genetic basis of resistance and susceptibility of F1 plants and 100 F2–derived lines from the cross of ‘IA3023’ (resistant) × ‘IA3024’ (susceptible) using natural field infection in Puerto Rico and Mexico during 2011. All of the F1 plants were susceptible, and the segregation of F2–derived lines satisfactorily fit a ratio of 3 susceptible:1 resistant, which indicated that resistance was controlled by a recessive allele at a single locus. The second objective of our study was to determine the genetic location of the locus by genotyping 93 of the F2–derived lines. The molecular analysis identified a locus on chromosome 18 (linkage group G) at the same estimated genetic position as the marker BARCSOYSSR_18_0443 (89.8 cM). The locus was flanked by BARCSOYSSR_18_0456 (88.6 cM) and BARCSOYSSR_18_0458 (91.0 cM). The locus was designated Rbc1 and the resistance allele in IA3023 was identified as rbc1. Markers tightly linked to the Rbc1 locus can be used to select resistant progeny in segregating populations from crosses between resistant and susceptible parents.
Growth Regulators Improve the Intercrossing Rate of Cucumber Families for Recurrent Selection
Authors: Kumar Rakesh , Wehner Todd C.
Published: August 2012

Cucumber (Cucumis sativus L.) populations for recurrent selection often are intercrossed after each cycle using bees (Apis mellifera) in isolation blocks to save the expense of hand labor. This experiment was conducted to determine whether the rate of natural outcrossing could be increased using growth regulators, plot size management, and node of fruit position for seed harvest. The experiment was a factorial in a randomized complete block design with 2 yr (1997 and 1998), two growth regulators (treated and none), two plot sizes (single plant hills and small plots), two nodes of harvest (crown and top), and four replications (six in 1998). Plots or hills were planted to white‐spined ‘Sumter’ and were surrounded by rows of black‐spined ‘Wisconsin SMR 18’ pollenizer. Plots or hills of Sumter were treated with ethrel to induce gynoecy, and pollenizer rows were treated with silver nitrate to induce androecy. Untreated isolation blocks remained monoecious. Progeny of the harvested white‐spined plants were planted the following year to evaluate spine color, with black‐spined plants indicating an outcross. Results showed that node of harvest had no effect on outcrossing rate. However, growth regulators and plot size had a significant effect. Treated small plots, treated hills, and untreated hills had high outcrossing rates (54%) relative to untreated plots (30%). Therefore, if families are to be intercrossed in isolation blocks, they should be treated with growth regulators for maximum outcrossing.
Diversity and Genetic Structure of a Collection of Spanish Durum Wheat Landraces
Authors: Ruiz Magdalena , Giraldo Patricia , Royo Conxita , Villegas Dolors , Aranzana M. Jose , Carrillo Jose M.
Published: August 2012

Knowledge of the genetic structure of germplasm collections is crucial for conservation and efficient use of genetic resources. This study assessed the diversity and genetic structure of a collection of landraces of Spanish durum wheat (Triticum turgidum L.) using several marker systems and correlated the diversity and agromorphological traits with geographic and climatic features. Analyzed genotypes were separated into nine populations, with moderate to great genetic divergence among them. The three subspecies dicoccon, turgidum, and durum present in the collection largely determined the clustering of the populations. Genotype variation was lower in dicoccon and turgidum than in durum. Genetic differentiation by the agroecological zone of origin was greater in dicoccon and turgidum than in durum. Diversity arrays technology markers revealed two geographic substructures, east–west for dicoccon and northeast–southwest for turgidum. The ssp. durum had a more complex structure, consisting of seven populations with high intrapopulation variation. Diversity arrays technology markers allowed the detection of subgroups within some populations, with agromorphological and gliadin differences, and distinct agroecological zones of origin. Two different phylogenetic groups were detected, revealing that some durum accessions were more related to ssp. turgidum from northern Spain while others seem to be more related to durum wheats from North Africa.
Computing Integrated Ratings from Heterogeneous Phenotypic Assessments: A Case Study of Lettuce Postharvest Quality and Downy Mildew Resistance
Authors: Simko Ivan , Hayes Ryan J. , Kramer Matthew
Published: August 2012

Comparing performance of a large number of accessions simultaneously is not always possible. Frequently, only subsets of all accessions are tested in separate trials with only some (or none) of the accessions overlapping between subsets. Using standard statistical approaches to combine data from such a sparsely populated accession × trial matrix is precluded if different rating scales are used to evaluate accessions in those trials. Here we compare two approaches that can compute an overall linear rating for the performance of all accessions across a set of trials, even for accessions that were never tested together and were rated on dissimilar scales. We use data from lettuce (Lactuca sativa L.) postharvest quality collected on 178 accessions in 18 trials and assessment of lettuce resistance to downy mildew (Bremia lactucae Regel) performed on 583 accessions in 53 trials. The projected values (PV) approach uses a combination of principal component analysis and resampling to merge trial results and calculates an overall rating from real values. In contrast, the rank‐aggregation (RA) approach uses an extension of the Rasch model to combine rank‐ordered data from individual trials. We found high correlation between ratings produced by the two approaches for the postharvest quality (r= 0.803) and the resistance to downy mildew (r = 0.748). Combining data from multiple experiments identified lettuce accessions with a high level of resistance to the disease and a slow rate of deterioration when processed for salad. The PV and RA approaches also allow combining data from different laboratories or databases.
Genetic Variation for Morphology and Maturity Among the Half‐Sib Progeny of Nine Orchardgrass Germplasm Populations
Authors: Robins Joseph G. , Shaun Bushman B. , Jensen Kevin B. , Blaser Greg
Published: August 2012

Orchardgrass (Dactylis glomerata L.) acreage has declined compared to perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.). With the intent of developing new sources of orchardgrass germplasm, 162 half‐sib families from six orchardgrass germplasm populations and three orchardgrass cultivars were evaluated during 2008 for maturity and plant morphology at locations in Idaho and Utah. Genetic similarity of the populations was also characterized using simple sequence repeat markers. Genetic variation between families differed from zero for seven of the nine traits evaluated, with broad‐sense heritability estimates ranging from 0.26 (flag leaf width) to 0.74 (maturity). For each trait that exhibited genetic variation, half‐sib families were identified that possessed trait values similar to or more extreme than the values corresponding to the included commercial orchardgrass cultivars. Through principle component analysis, potential groupings of half‐sib families with similar phenotypic characteristics were identified; for example, taller plants with earlier maturity. Therefore, germplasm could be targeted for development of improved orchardgrass with maturity and morphology suitable to specific management practices, such as short stature, narrow leaves, and late maturity for mixture with legumes.
Strategies to Subdivide a Target Population of Environments: Results from the CIMMYT‐Led Maize Hybrid Testing Programs in Africa
Authors: Windhausen Vanessa S. , Wagener Silke , Magorokosho Cosmos , Makumbi Dan , Vivek Bindiganavile , Piepho Hans‐Peter , Melchinger Albrecht E. , Atlin Gary N.
Published: August 2012

To develop stable and high‐yielding maize (Zea mays L.) hybrids for a diverse target population of environments (TPE), breeders have to decide whether greater gains result from selection across the undivided TPE or within more homogeneous subregions. Currently, CIMMYT subdivides the TPE in eastern and southern Africa into climatic and geographic subregions. To study the extent of specific adaptation to these subregions and to determine whether selection within subregions results in greater gains than selection across the undivided TPE, yield data of 448 maize hybrids evaluated in 513 trials across 17 countries from 2001 to 2009 were used. The trials were grouped according to five subdivision systems into climate, altitude, geographic, country, and yield‐level subregions. For the first four subdivision systems, genotype × subregion interaction was low, suggesting broad adaptation of maize hybrids across eastern and southern Africa. In contrast, genotype × yield‐level interactions and moderate genotypic correlations between low‐ and high‐yielding subregions were observed. Therefore, hybrid means should be estimated by stratifying the TPE considering the yield‐level effect as fixed and appropriately weighting information from both subregions. This strategy was at least 10% better in terms of predicted gains than direct selection using only data from the low‐ or high‐yielding subregion and should facilitate the identification of hybrids that perform well in both subregions.
Molecular Characterization of Resistance to Fusarium Head Blight in U.S. Soft Red Winter Wheat Breeding Line VA00W‐38
Authors: Liu Shuyu , Christopher Mark D. , Griffey Carl A. , Hall Marla D. , Gundrum Patty G. , Brooks Wynse S.
Published: August 2012

Many quantitative trait loci (QTL) in wheat (Triticum aestivum L.) conferring resistance to Fusarium head blight (FHB), caused by the Fusarium graminearium, have been mapped in diverse genetic sources. Use of nonadapted FHB resistant sources by breeding programs in the soft red winter (SRW) wheat region of the United States has not been very successful. Therefore, native sources of FHB resistance identified or validated in SRW wheat cultivars predominantly have been used. The breeding line VA00W‐38 has moderate FHB resistance and does not possess any previously identified exotic sources of resistance in its parentage. A set of 182 recombinant inbred lines (RILs) were developed from the cross VA00W‐38 × Pioneer brand ‘26R46’ and tested in field scab nurseries and natural conditions in two environments for each of 2 yr. Eight consistent QTL were identified on chromosomes 1BL, 2A, 2DL, 5B, 6A, and 7A and explained 6.5 to 21.3% of phenotypic variation of traits associated with FHB resistance. Their logarithm of odds (LOD) scores ranged from 2.5 to 6.7. Favorable alleles to decrease FHB are from VA00W‐38 except one QTL on chromosome 7A. Major QTL on chromosomes 2DL, 6A, and 5B decreased FHB index (IND), Fusarium damaged kernels (FDK), and deoxynivalenol (DON), respectively. Tightly linked markers identified for these consistent QTL can be used to select for favorable alleles associated with FHB resistance in breeding populations after validation in diverse genetic backgrounds.
Diallel Analysis of Resistance to Fusarium Ear Rot and Fumonisin Contamination in Maize
Authors: Hung Hsiao‐Yi , Holland James B.
Published: August 2012

The fungus Fusarium verticillioides infects maize (Zea mays L.) ears and kernels, resulting in Fusarium ear rot disease, reduced grain yields, and contamination of grain with the mycotoxin fumonisin. Hybrid maize breeding programs involve selection for both inbred and hybrid performance; the emphasis placed on inbred versus hybrid selection depends on heritability of and the genetic correlation between resistance in the different generations. The objectives of this study were to assess the importance of general combing ability (GCA) and specific combining ability (SCA) for resistance to Fusarium ear rot and fumonisin contamination and to estimate the correlation between resistance measured in inbred and hybrid generations. We evaluated a diallel mating of 18 inbred lines from different heterotic groups with different levels of resistance. Hybrids had 27% less ear rot and 30% less fumonisin content than their inbred parents, demonstrating the importance of hybrid vigor to disease resistance. Both GCA and SCA were significant for yield and disease resistance, and inbred performance per se and corresponding GCA in hybrids were significantly correlated (r ≥ 0.78). Genetic variation for resistance was greater in inbred lines than among hybrids, however. These results suggest that the most efficient way to improve Fusarium ear rot and fumonisin contamination resistances in hybrids is to evaluate and select among inbred lines before using resources to create and evaluate hybrids.
Decentralized management of building indoors through embedded software agents
Authors: Fortino Giancarlo , Guerrieri Antonio
Published: August 2012

In order to support personalized people comfort and building energy
efficiency as well as safety, emergency, and context-aware information
exchange scenarios, next-generation buildings will be smart. In this paper we
propose an agent-oriented decentralized and embedded architecture based on
wireless sensor and actuator networks (WSANs) for enabling efficient and
effective management of buildings. The main objective of the proposed
architecture is to fully support distributed and coordinated sensing and
actuation operations. The building management architecture is implemented at
the WSAN side through MAPS (Mobile Agent Platform for Sun SPOTs), an
agent-based framework for programming WSN applications based on the Sun SPOT
sensor platform, and at the base station side through an OSGi-based
application. The proposed agent-oriented architecture is demonstrated in a
simple yet effective operating scenario related to monitoring workstation
usage in computer laboratories/offices. The high modularity of the proposed
architecture allows for easy adaptation of higher-level application-specific
agents that can therefore exploit the architecture to implement intelligent
building management policies.
Language engineering for syntactic knowledge transfer
Authors: Colhon Mihaela
Published: August 2012

In this paper we present a method for an English-Romanian treebank
construction, together with the obtained evaluation results. The treebank is
built upon a parallel English-Romanian corpus word-aligned and annotated at
the morphological and syntactic level. The syntactic trees of the Romanian
texts are generated by considering the syntactic phrases of the English
parallel texts automatically resulted from syntactic parsing. The method
reuses and adjusts existing tools and algorithms for cross-lingual transfer
of syntactic constituents and syntactic trees alignment.
Visuomotor Performance in KCNJ11-Related Neonatal Diabetes Is Impaired in Children With DEND-Associated Mutations and May Be Improved by Early Treatment With Sulfonylureas
Authors: Shah Reshma P. , Spruyt Karen , Kragie Brigette C. , Greeley Siri Atma W. , Msall Michael E.
Published: August 2012

OBJECTIVE

To assess performance on an age-standardized neuromotor coordination task among sulfonylurea-treated KCNJ11-related neonatal diabetic patients.

RESEARCH DESIGN AND METHODS

Nineteen children carrying KCNJ11 mutations associated with isolated diabetes (R201H; n = 8), diabetes with neurodevelopmental impairment (V59M or V59A [V59M/A]; n = 8), or diabetes not consistently associated with neurodevelopmental disability (Y330C, E322K, or R201C; n = 3) were studied using the age-standardized Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI).

RESULTS

Although R201H subjects tested in the normal range (median standard score = 107), children with V59M/A mutations had significantly lower than expected VMI standard scores (median = 49). The scores for all three groups were significantly different from each other (P = 0.0017). The age of sulfonylurea initiation was inversely correlated with VMI scores in the V59M/A group (P < 0.05).

CONCLUSIONS

Neurodevelopmental disability in KCNJ11-related diabetes includes visuomotor problems that may be ameliorated by early sulfonylurea treatment. Comprehensive longitudinal assessment on larger samples will be imperative.
Low Hemoglobin A1c in Nondiabetic Adults
Authors: Aggarwal Vikas , Schneider Andrea L.C. , Selvin Elizabeth
Published: August 2012

OBJECTIVE

To identify predictors of low hemoglobin A1c (HbA1c) (<5.0%) and to investigate the association of low HbA1c with cause-specific mortality and risk of liver disease hospitalization.

RESEARCH DESIGN AND METHODS

Prospective cohort study of 13,288 participants in the Atherosclerosis Risk in Communities Study. Logistic regression was used to identify cross-sectional correlates of low HbA1c, and Cox proportional hazards models were used to estimate the association of low HbA1c with cause-specific mortality.

RESULTS

Compared with participants with HbA1c in the normal range (5.0 to <5.7%), participants with low HbA1c were younger, less likely to smoke, had lower BMI, lower white cell count and fibrinogen levels, and lower prevalence of hypercholesterolemia and history of coronary heart disease. However, this group was more likely to have anemia and had a higher mean corpuscular volume. In adjusted Cox models with HbA1c of 5.0 to <5.7% as the reference group, HbA1c <5.0% was associated with a significantly increased risk of all-cause mortality (hazard ratio [HR]: 1.32, 95% CI: 1.13–1.55) and of cancer death (1.47, 95% CI: 1.16–1.84). We also noted nonsignificant trends toward increased risk of death from cardiovascular causes (1.27, 95% CI: 0.93–1.75) and respiratory causes (1.42, 95% CI: 0.78–2.56). There was a J-shaped association between HbA1c and risk of liver disease hospitalization.

CONCLUSIONS

No single cause of death appeared to drive the association between low HbA1c and total mortality. These results add to evidence that low HbA1c values may be a generalized marker of mortality risk in the general population.
Cardiovascular Events After Bariatric Surgery in Obese Subjects With Type 2 Diabetes
Authors: Romeo Stefano , Maglio Cristina , Burza Maria Antonella , Pirazzi Carlo , Sjöholm Kajsa , Jacobson Peter , Svensson Per-Arne , Peltonen Markku , Sjöström Lars , Carlsson Lena M.S.
Published: August 2012

OBJECTIVE

Obese individuals with type 2 diabetes have an increased risk of cardiovascular disease. The effect of bariatric surgery on cardiovascular events in obese individuals with type 2 diabetes remains to be determined. The Swedish Obese Subjects (SOS) study is a prospective, controlled intervention study that examines the effects of bariatric surgery on hard end points. The aim of the present study was to examine the effect of bariatric surgery on cardiovascular events in the SOS study participants with type 2 diabetes.

RESEARCH DESIGN AND METHODS

All SOS study participants with type 2 diabetes at baseline were included in the analyses (n = 345 in the surgery group and n = 262 in the control group). Mean follow-up was 13.3 years (interquartile range 10.2–16.4) for all cardiovascular events.

RESULTS

Bariatric surgery was associated with a reduced myocardial infarction incidence (38 events among the 345 subjects in the surgery group vs. 43 events among the 262 subjects in the control group; log-rank P = 0.017; adjusted hazard ratio [HR] 0.56 [95% CI 0.34–0.93]; P = 0.025). No effect of bariatric surgery was observed on stroke incidence (34 events among the 345 subjects in the surgery group vs. 24 events among the 262 subjects in the control group; log-rank P = 0.852; adjusted HR 0.73 [0.41–1.30]; P = 0.29). The effect of surgery in reducing myocardial infarction incidence was stronger in individuals with higher serum total cholesterol and triglycerides at baseline (interaction P value = 0.02 for both traits). BMI (interaction P value = 0.12) was not related to the surgery outcome.

CONCLUSIONS

Bariatric surgery reduces the incidence of myocardial infarction in obese individuals with type 2 diabetes. Preoperative BMI should be integrated with metabolic parameters to maximize the benefits of bariatric surgery.