bluuebunny/crossref_metadata_2025 huggingface dataset:
Efeitos de diferentes níveis de cálcio dietético na cinética de cálcio e fósforo em eqüinos
Authors: Vitti Dorinha Miriam Silber Schmidt , Furtado Carlos Eduardo , Quadros João Batista da Silva , Lopes João Batista , Bueno Ives Cláudio da Silva , Nozella Eduardo Fernando , Godoy Patrícia Barboza de
Published: March 2008

Objetivou-se estudar o metabolismo de cálcio (Ca) e fósforo (P) nos eqüinos em crescimento que receberam diferentes níveis de suplementação de Ca: 0,15; 0,45 e 0,75% na dieta, utilizando-se o modelo determinístico e compartimental. Foram utilizadas informações sobre o estudo de metabolismo e cinética de Ca e P em tecidos, obtidas pela técnica da diluição isotópica. Constatou-se que os níveis dietéticos de Ca tiveram influência na absorção real do Ca, sendo menor para o nível 0,15% (4,97 g Ca/dia). As trocas de Ca entre o sangue e o trato digestivo foram menores para o nível 0,15%. A mobilização entre o sangue e os ossos e sangue e tecidos moles não foi influenciada pelos tratamentos, mas o balanço nos ossos e tecidos foi menor para o nível 0,15%. Os níveis de Ca dietéticos tiveram influência no P eliminado através da urina, sendo este valor maior para o tratamento 0,15% (2,49 g/animal/dia). A absorção real média do P foi de 83%, não havendo diferenças para os tratamentos. Verificou-se deposição óssea média de 9,69 g P/animal/dia, indicando que a quantidade de P fornecida foi adequada em relação à tolerância permissível à amplitude na relação Ca:P para a espécie na categoria animal estudada. Não houve diferenças significativas entre os fluxos de P nos diversos compartimentos, por intermédio do modelo de metabolismo. A ingestão de níveis crescentes de Ca afetou o metabolismo e a cinética deste elemento, entretanto, a proporção Ca:P é o fator predominante para determinar a excreção, retenção e absorção de Ca. A deposição de Ca no osso foi influenciada pela quantidade ingerida deste mineral. O metabolismo de P em eqüinos em crescimento não foi afetado pelos teores de Ca. O fornecimento de 13,4 g P/animal/dia foi suficiente para manter o metabolismo de P nos padrões considerados normais.
Degradação in vitro da fibra em detergente neutro de forragem tropical de baixa qualidade em função de suplementação com proteína e/ou carboidratos
Authors: Costa Viviane Aparecida Carli , Detmann Edenio , Valadares Filho Sebastião de Campos , Paulino Mário Fonseca , Henriques Lara Toledo , Mantovani Hilário Cuquetto
Published: March 2008

Objetivou-se avaliar o efeito da suplementação protéica e/ou com carboidratos sobre a degradação ruminal da fibra em detergente neutro (FDN) de forragem de baixa qualidade. Simulou-se a suplementação de bovinos em terminação, sob pastejo em Brachiaria decumbens de baixa qualidade, durante o período seco (70% de forragem e 30% de concentrado, com base na matéria seca). O concentrado referente ao tratamento base foi formulado de forma a apresentar 30% de proteína bruta, utilizando-se amido, como componente energético, e caseína, como componente protéico. Os tratamentos foram construídos a partir da omissão do fornecimento das fontes protéica e/ou energética do suplemento, associando-se, ainda, a substituição total do amido por pectina. Desta forma, seis foram os tratamentos avaliados: 1. forragem; 2. forragem + amido; 3. forragem + pectina; 4. forragem + caseína; 5. forragem + caseína + amido; e 6. forragem + caseína + pectina. Os tratamentos foram avaliados em ambiente ruminal simulado por incubação in vitro e submetidos a diferentes tempos de incubação: 0, 3, 6, 9, 12, 24, 36, 48, 72 e 96 horas. O procedimento de incubação foi repetido quatro vezes, perfazendo-se o total de quatro avaliações por tempo de incubação para cada tratamento. Os resíduos de incubação foram avaliados quanto ao teor de FDN e interpretados por intermédio de modelo não-linear logístico. Observou-se que a taxa de degradação da FDN potencialmente degradável (FDNpd) foi ampliada em cerca de 46% com a suplementação com caseína, resultando em incrementos de 14,6% sobre a fração efetivamente degradada. Observou-se efeito de menor amplitude com a inclusão ou alteração da fonte de carboidrato suplementar. A suplementação com amido causou redução na taxa de degradação da FDNpd, ao passo que a suplementação com pectina não afetou este parâmetro em comparação à ausência de carboidratos. Na presença de caseína, a suplementação com amido elevou o tempo de latência discreta para a degradação da FDN.
Técnicas para estimativa da digestibilidade e produção microbiana em bovinos
Authors: Dias Marcia , Leão Maria Ignez , Detmann Edenio , Valadares Filho Sebastião de Campos , Vasconcelos Angela Maria de , Souza Shirley Motta de , Paulino Mário Fonseca , Murça Tássio Bonomo
Published: March 2008

Objetivou-se avaliar estimativas de digestibilidade e de produção microbiana utilizando fibra em detergente neutro e ácido indigestível (FDNi e FDAi, respectivamente) e comparar a produção microbiana estimada pelos métodos das bases purinas e excreção urinária de derivados de purinas. Utilizaram-se quatro novilhas Holandês-Zebu com peso vivo médio inicial de 220 kg, fistuladas no rúmen e no íleo, mantidas em regime de confinamento com dieta à base de feno de capim-Tifton (Cynodon spp.), oferecido ad libitum, e 1 kg de concentrado (27% PB). O experimento durou 60 dias: sete de adaptação à dieta (antes do primeiro período), três períodos experimentais de 15 dias cada e quatro dias de intervalo entre os períodos. Foram realizadas coleta total de fezes, coleta de digesta omasal e ileal, coleta de conteúdo ruminal para isolamento bacteriano e coleta de amostra spot de urina. Para determinação dos fluxos de digesta omasal e ileal, foram utilizados como indicadores a FDNi e a FDAi. As condições do rúmen foram favoráveis à produção microbiana, com valores de pH e N-NH3 de 6,7 a 6,9 e de 10,3 a 14,1 mg/dL, respectivamente. A recuperação da FDAi não diferiu de 100% e produziu estimativas similares à excreção fecal e à digestibilidade total, quando comparada à coleta total de fezes, diferentemente de FDNi. As estimativas da produção microbiana via quantificação de derivados de purinas em amostras spot de urina não foram similares às obtidas por procedimentos invasivos via fluxo de matéria microbiana omasal. Assim, recomenda-se utilização de FDAi para estimativas de digestibilidade total e parcial e, para a produção microbiana, a excreção urinária dos derivados de purinas.
Níveis de uréia na ração de novilhos de quatro grupos genéticos: estimativa da produção de proteína microbiana por meio dos derivados de purinas na urina utilizando duas metodologias de coleta
Authors: Rennó Luciana Navajas , Valadares Filho Sebastião de Campos , Valadares Rilene Ferreira Diniz , Paulino Mário Fonseca , Rennó Francisco Palma , Silva Polyana Albino
Published: March 2008

Objetivou-se avaliar o efeito de quatro níveis de uréia na ração: 0; 0,65; 1,3 e 1,95% na matéria seca (MS), sobre a estimativa da produção de proteína microbiana por meio dos derivados de purinas na urina, em duas metodologias de coleta em novilhos de quatro grupos genéticos: Holandês, ½ sangue Holandês-Guzerá, ½ sangue Holandês-Gir e Zebu. Os animais foram alimentados com 50% de feno de capim tifton-85 e 50% de concentrado e distribuídos em quatro quadrados latinos (grupos genéticos) 4 ´ 4, sendo quatro animais, quatro períodos experimentais e quatro tratamentos (rações). As dietas continham aproximadamente 12% PB. As amostras de urina, em cada período experimental, foram obtidas a partir de coletas em 24 horas e por meio da coleta spot de urina, quando os animais urinaram espontaneamente. Na urina foram realizadas as análises dos derivados de purinas, alantoína e ácido úrico. Foram feitas comparações entre a produção microbiana usando as bases purinas no abomaso com os derivados de purinas na urina; entre as determinações da produção microbiana pelos derivados de purinas com duas equações distintas ou com as bases purinas no abomaso; e entre a estimativa da produção urinária, dos derivados de purinas e da produção microbiana através da coleta spot de urina com a coleta total de urina em 24 horas. A produção e as eficiências microbianas mostraram-se superiores para os animais holandeses, intermediárias para os mestiços e inferiores para os zebuínos. A estimativa da produção de compostos nitrogenados microbianos pode ser feita a partir da excreção dos derivados de purinas na urina. A coleta spot de urina consiste em metodologia rápida e eficaz na estimativa da excreção urinária dos derivados de purinas e da produção de compostos nitrogenados microbianos.
Níveis de uréia na ração de novilhos de quatro grupos genéticos: parâmetros ruminais, uréia plasmática e excreções de uréia e creatinina
Authors: Rennó Luciana Navajas , Valadares Filho Sebastião de Campos , Paulino Mário Fonseca , Leão Maria Ignez , Valadares Rilene Ferreira Diniz , Rennó Francisco Palma , Paixão Mônica Lopes
Published: March 2008

Objetivou-se avaliar o efeito de quatro níveis de uréia na ração (0; 0,65; 1,3 e 1,95% na matéria seca - MS) sobre pH e amônia ruminais, concentração plasmática de uréia, excreção fracional de uréia e excreções de uréia e creatinina, bem como avaliar as perdas urinárias endógenas por meio da excreção de creatinina em novilhos de quatro grupos genéticos (Holandês, ½ sangue Holandês-Guzerá, ½ sangue Holandês-Gir e Zebu). Os animais foram distribuídos em quatro quadrados latinos (grupos genéticos) 4 ´ 4, sendo quatro animais, quatro períodos experimentais de 14 dias cada um e quatro tratamentos (rações). As coletas de líquido ruminal, para determinação do pH e das concentrações de nitrogênio amoniacal (N-NH3), foram realizadas antes do fornecimento da dieta e 2, 4, 6 e 8 horas após. Durante a coleta de urina realizada em 24 horas, foi coletado o sangue aproximadamente 4 horas após a alimentação e, após centrifugação, obtido o plasma. Nas amostras de urina e plasma, foram determinadas as concentrações de uréia e creatinina. O pH ruminal apresentou comportamento semelhante para os grupos genéticos e foi influenciado positivamente pela inclusão de uréia na dieta. As concentrações de N-NH3 foram influenciadas positivamente pelos níveis de uréia na ração para os animais holandeses e mestiços. A concentração plasmática de N-uréico aumentou linearmente em função da adição de uréia na ração. A excreção fracional de uréia apresentou comportamento linear decrescente em função dos níveis de uréia na dieta. A excreção urinária de uréia não diferiu entre os animais holandeses e mestiços, mas foi superior em relação aos zebuínos. A excreção de creatinina não foi influenciada pelos grupos genéticos, nem pela inclusão de uréia na dieta, apresentando valor médio de 27,76 mg/kg PV. Sugere-se que as perdas urinárias endógenas de compostos nitrogenados sejam estimadas a partir da excreção de creatinina.
Melhoria organizacional na produção de bezerros de corte a partir dos centros de custos
Authors: Oaigen Ricardo Pedroso , Barcellos Júlio Otávio Jardim , Christofari Luciana Fagundes , Braccini Neto José , Oliveira Tamara Esteves de , Prates Ênio Rosa
Published: March 2008

O objetivo neste trabalho foi evidenciar a importância do custo de produção na pecuária de cria, descrevendo uma metodologia padronizada que consiga mensurar o custo de produção de bezerros de corte e, simultaneamente, validar o método em um sistema de produção. Dentro deste contexto, neste trabalho discute-se, inicialmente, a relevância da implantação da metodologia dos centros de custos como suporte à tomada de decisão, devido à necessidade de uma análise segmentada dos processos em sistemas de produção pecuários especializados na cria. As etapas para implantação deste método são descritas. Um sistema de produção, característico da Região Sul do Brasil, foi definido a partir de indicadores técnicos relatados em revisões bibliográficas. Foi simulada a aplicação desta metodologia no sistema em questão, no qual se visualizaram os custos de produção dos diferentes centros produtivos: touros, vacas de cria, recria das novilhas e desmame dos bezerros, possibilitando compreender o impacto de determinados processos e/ou tecnologias no sistema. Conseqüentemente, calcular o custo de produção de bezerros de corte a partir da utilização da metodologia dos centros de custos, mostrou-se factível de utilização em sistemas de produção baseados em pecuária de cria.
Effects of clove (Caryophyllus aromaticus L.) on the labeling of blood constituents with technetium-99m and on the morphology of red blood cells
Authors: Paoli Severo de , Giani Tania Santos , Presta Giuseppe Antonio , Pereira Marcia Oliveira , Fonseca Adenilson de Souza da , Brandão-Neto José , Medeiros Aldo da Cunha , Santos-Filho Sebastião David , Bernardo-Filho Mário
Published: March 2008

Clove (Caryophyllus aromaticus L.) has been used for clinical procedures. Blood constituents labeled with technetium-99m (99mTc) are used in nuclear medicine. The aim of this work was to evaluate the effects of clove extract on the labeling blood constituents with 99mTc and on the morphology of red blood cells. Blood samples were incubated with clove, stannous chloride and 99mTc. Plasma, blood cells, insoluble fractions of plasma and blood cells were separated. The radioactivity was counted and percentage of radioactivity (%ATI) to each blood fraction was calculated. The shape and morphometric parameter (perimeter/area ratio) were evaluated. Clove extract altered significantly (p<0.05) the %ATI of blood constituents and the shape of red blood cells without modifying the perimeter/area ratio. The results indicate that clove extract presents chemical compounds that interfere with the radiolabeling of blood constituents and alter the morphology of red blood cells by oxidative/chelating actions or interacting with the cellular membrane structure.
Biodistribution of the radiopharmaceutical sodium pertechnetate after biliopancreatic bypass with a duodenal switch
Authors: Araújo-Filho Irami , Rêgo Amália Cínthia Meneses , Brandão-Neto José , Villarim-Neto Arthur , Egito Eryvaldo Sócrates Tabosa , Azevedo Ítalo Medeiros , Medeiros Aldo Cunha
Published: March 2008

Study with the purpose to examine the effects of duodenal switch (DS), regularly performed in morbidly obese patients, on biodistribution of sodium pertechnetate in several organs of rats. There was no early or late mortality in either rats groups. The values of percent radioactivity per gram of tissue (%ATI/g), showed no significant difference in liver, stomach, small bowel, duodenum, kidney, heart, bladder, bone and brain, when compared the DS rats with sham and controls rats. A postoperative significant increase (p<0.05) in mean %ATI/g levels was observed in spleen, pancreas and muscle in group DS rats, as compared to group S and C rats. In the lung there was an increase and in thyroid a decrease in mean %ATI/g of DS rats, when compared to sham rats (p<0.05). In conclusion, the biliopancreatic diversion with duodenal switch in rats modified the biodistribution of sodium pertechnetate in thyroid, lung, pancreas, spleen and muscle.
Espiritualidade nas organizações e comprometimento organizacional
Authors: Regos Arménio , Cunha Miguel Pinha e , Souto Solange
Published: March 2008

A espiritualidade nas organizações está representada nas oportunidades para realizar trabalho com significado, no contexto de uma comunidade, com um sentido de alegria e de respeito pela vida interior. A literatura sobre o tópico é prolixa, mas a evidência empírica é ainda escassa. Neste artigo, procuramos contribuir para mitigar essa escassez. Mostramos como cinco dimensões de espiritualidade nas organizações (sentido de comunidade; alinhamento do indivíduo com os valores da organização; sentido de préstimo à comunidade; alegria no trabalho; oportunidades para a vida interior) explicam o comprometimento organizacional. A amostra abrange 361 indivíduos de 154 organizações. As dimensões de espiritualidade explicam 48%, 16% e 7% de variância, respectivamente, do comprometimento afetivo, do normativo e do instrumental. Os resultados sugerem que as pessoas denotam mais elevados laços afetivo e normativo, e mais fraco laço instrumental, quando experimentam mais forte sentido de espiritualidade no trabalho.
Soybean Sowing Date: The Vegetative, Reproductive, and Agronomic Impacts
Authors: Bastidas A. M. , Setiyono T. D. , Dobermann A. , Cassman K. G. , Elmore R. W. , Graef G. L. , Specht J. E.
Published: March 2008

The sensitivity of soybean [Glycine max (L.) Merr.] main stem node accrual to ambient temperature has been documented in greenhouse‐grown plants but not with field‐grown plants in the north‐central United States. Biweekly V‐node and R‐stage, stem node number, internode length, and other traits were quantified in an irrigated split‐plot, four‐replicate, randomized complete block experiment conducted in Lincoln, NE, in 2003–2004. Main plots were early‐, mid‐, late‐May, and mid‐June sowing dates. Subplots were 14 cultivars of maturity groups 3.0 to 3.9. Node appearance was surprisingly linear from V1 to R5, despite the large increase in daily temperature from early May (10–15°C) to July (20–25°C). The 2003 and 2004 May planting date regressions exhibited near‐identical slopes of 0.27 node d−1 (i.e., one node every 3.7 d). Cold‐induced delays in germination and emergence did delay the V1 date (relative to planting date), so the primary effect of temperature was the V1 start date of linearity in node appearance. With one exception, earlier sowings led to more nodes (earlier V1 start dates) but also resulted in shorter internodes at nodes 3 to 9 (cooler coincident temperatures), thereby generating a curved response of plant height to delayed plantings. Delaying planting after 1 May led to significant linear seed yield declines of 17 kg ha−1 d−1 in 2003 and 43 kg ha−1 d−1 in 2004, denoting the importance of early planting for capturing the yield potential available in soybean production, when moisture supply is not limiting.
Genetic Gain in Yield Potential of Upland Cotton under Varying Plant Densities
Authors: Schwartz Brian M. , Smith C.W.
Published: March 2008

Genetic gain studies have been used to evaluate the historical improvement of different traits, to provide insights into magnitudes of gain possible in future cultivars, and to defend the role of genetics during periods of stagnant or decreasing yield trends. This study was conducted over a 2‐yr period and included nine current or obsolete cotton (Gossypium hirsutum L.) cultivars grown in five plant densities to evaluate genetic gain with varying levels of interplant competition. The rates of genetic gain for lint yield were highest in the commercial, 1 by 0.3 m, and 1 by 1 m plant spacing treatments with slopes of 8.7, 8.2, and 7.1 kg ha−1 yr−1, respectively. Slopes were reduced in the 2 by 2 m and 3 by 3 m spacing treatments with gains of 3.6 and 1.5 kg ha−1 yr−1, respectively, implying that for lint yield, genetic gains have been made for tolerance to interplant competition and not only yield potential per se.
Genetic Diversity in CIMMYT Nontemperate Maize Germplasm: Landraces, Open Pollinated Varieties, and Inbred Lines
Authors: Warburton M. L. , Reif J. C. , Frisch M. , Bohn M. , Bedoya C. , Xia X. C. , Crossa J. , Franco J. , Hoisington D. , Pixley K. , Taba S. , Melchinger A. E.
Published: March 2008

CIMMYT is the source of improved maize (Zea mays L.) breeding material for a significant portion of the nontemperate maize growing world. Landraces which did not serve as sources for improved maize germplasm may contain untapped allelic variation useful for future breeding progress. Information regarding levels of diversity in different germplasm would help to identify sources for broadening improved breeding pools and in seeking genes and alleles that have not been tapped in modern maize breeding. The objectives of this study were to examine the diversity in maize landraces, modern open pollinated varieties (OPVs), and inbred lines adapted to nontemperate growing areas to find unique sources of allelic diversity that may be used in maize improvement. Twenty‐five simple sequence repeat markers were used to characterize 497 individuals from 24 landraces of maize from Mexico, 672 individuals from 23 CIMMYT improved breeding populations, and 261 CIMMYT inbred lines. Number of alleles, gene diversity per locus, unique alleles per locus, and population structure all differ between germplasm groups. The unique alleles found in each germplasm group represent a great reservoir of untapped genetic resources for maize improvement, and implications for hybrid breeding are discussed.
Postulation of Seedling Leaf Rust Resistance Genes in Selected Ethiopian and German Bread Wheat Cultivars
Authors: Mebrate Sewalem A. , Dehne Heinz‐W. , Pillen Klaus , Oerke Erich‐C.
Published: March 2008

Leaf rust caused by the fungus Puccinia triticina Eriks. is one of the most important foliar diseases of wheat (Triticum aestivum L.). Host resistance is the most economical and safest method of controlling the disease. Characterization of the host greatly facilitates the effective utilization of host resistance genes. Gene postulation helps to undertake a quick identification of the probable leaf rust resistance genes (Lr genes) present in a large number of wheat cultivars at a time. The objective of this study was to identify the race‐specific Lr‐genes present in 36 wheat cultivars from Ethiopia and Germany. Seventy‐six wheat genotypes, including 40 near‐isogenic lines (NILs), were tested against 31 isolates of P. triticina isolates collected from both countries. Lr‐genes Lr1, 2c, 3, 3ka, 9, 10, 14a, 14b, 13, 16, 18, 21, 23, 27+31, 30, 37, and 44 were postulated to be present in the Ethiopian wheat cultivars. Lr genes Lr9, 20, and 21 were present in the German wheat cultivars. The Lr‐genes present in some wheat cultivars could not be postulated because of non‐matching virulence combinations with any of the NILs. The results of this study show that most of the wheat cultivars tested do not have adequate resistance for leaf rust, indicating the need for incorporating more effective genes into the target wheat cultivars.
Marker‐Assisted Selection in Plant Breeding: From Publications to Practice
Authors: Xu Yunbi , Crouch Jonathan H.
Published: March 2008

The volume of publications on the development and to a lesser extent the application of molecular markers in plant breeding has increased dramatically during the last decade. However, most of the publications result from investments from donors with a strategic science quality or biotech advocacy mandate leading to insufficient emphasis on applied value in plant breeding. Converting promising publications into practical applications requires the resolution of many logistical and genetical constraints that are rarely addressed in journal publications. This results in a high proportion of published markers failing at one or more of the translation steps from research arena to application domain. The rate of success is likely to increase due to developments in gene‐based marker development, more efficient quantitative trait locus (QTL) mapping procedures, and lower cost genotyping systems. However, some fundamental issues remain to be resolved, particularly regarding complex traits, before marker‐assisted selection realizes its full potential in public sector breeding programs. These include the development of high throughput precision phenotyping systems for QTL mapping, improved understanding of genotype by environment interaction and epistasis, and development of publicly available computational tools tailored to the needs of molecular breeding programs.
Meloidogyne incognita Resistance in Soybean under Midwest Conditions
Authors: Kruger Greg R. , Xing Lijuan , LeRoy Allen R. , Westphal Andreas
Published: March 2008

Soybean cultivars of maturity groups II to IV were tested in the greenhouse for resistance to Meloidogyne incognita (Kofoid and White) Chitwood. Selected cultivars were tested in a field of sandy loam soil naturally infested with M. incognita and Heterodera glycines Ichinohe (2004) or in a silt loam soil artificially infested with M. incognita (2005). In 2004, H444NRR was resistant to M. incognita, but not to H. glycines; LS94‐3207 and LNX97164‐35‐5 were resistant to both nematodes; Gateway 427, H444NRR, LNX97164‐35‐5, and SB4399CT were moderately resistant to M. incognita in greenhouse tests; HF9665‐2‐15 was resistant to M. incognita but highly susceptible to H. glycines In 2005, LS94‐3207, H444NRR, LNX97164‐35‐5, and Manokin were resistant to M. incognita In microplots with two sandy loam soils, HF9665‐2‐15 exhibited tolerance to increasing inoculum levels of M. incognita High‐yielding soybean cultivars in maturity groups II to IV with resistance and tolerance to M. incognita were identified. Under field conditions, resistance to the more widespread nematode H. glycines, combined with resistance to M. incognita, is highly desirable to reduce the risk of yield reduction and to improve cropping sequences that include soybean.
Field‐based Selection Method Creates Alfalfa Populations That Differ in Nitrate Nitrogen Uptake
Authors: Lamb JoAnn F. S. , Russelle Michael P. , Fenton Diana M.
Published: March 2008

Sustainable agricultural systems could benefit from alfalfa (Medicago sativa L.) germplasm that reduce N losses to the ground water and decrease N fertilizer inputs. With the goal of producing alfalfa populations with altered nitrate N uptake, our objectives were to develop, assess, and refine an inexpensive selection method using Br− as an analog for nitrate under field conditions. Two selection schemes using divergent herbage Br− concentration and/or divergent herbage Br− uptake, both in combination with high herbage N content, produced two Cycle 1 and four Cycle 2 alfalfa populations. We evaluated these populations for both Br− uptake and nitrate N uptake (estimated by N derived from fertilizer, Ndff [15N‐labeled]) for one regrowth period in two locations in each of 2 yr. Weak associations between Br− uptake and Ndff were found during the establishment year, but strong correlations were found between Br− concentration and fraction of Ndff (fNdff) (r = 0.83) and between Br− uptake and Ndff (r = 0.85 to 0.90) when populations were evaluated during the first production year. Populations selected for high Br− concentration or uptake had greater Br− concentration and uptake, fNdff, and Ndff than populations selected for low Br− Our method of selecting alfalfa plants for differences in herbage Br− concentration or uptake in combination with high herbage N content is the first to successfully produce alfalfa populations that differ in nitrate N uptake in a field environment.
Clonal Selection for Lignin and Etherified Ferulates in Three Perennial Grasses
Authors: Casler M. D. , Jung H. G. , Coblentz W. K.
Published: March 2008

Decreased lignin concentration or decreased ferulate cross‐linking between arabinoxylans and lignin are two mechanisms to increase cell‐wall digestibility in plants. The objectives of this study were (i) to determine the consistency and clonal repeatability of lignin and etherified ferulates across multiple harvest dates and years, (ii) to determine if the genetic correlation between lignin and etherified ferulates can be altered by intensive selection, and (iii) to determine the effects of lignin and ferulates on digestibility of neutral detergent fiber (NDF). Thirty clones each of smooth bromegrass (Bromus inermis Leyss), orchardgrass (Dactylis glomerata L.), and reed canarygrass (Phalaris arundinacea L.) were evaluated in a replicated field study at four growth stages in 2004 and 2005 for NDF, lignin, esterified and etherified ferulates, and 24‐ and 96‐h in vitro NDF digestibility (IVNDFD). Clonal means were generally repeatable across years and harvest dates. Divergent selection created clonal groups with differential lignin and etherified ferulates, but the positive correlation between these two traits was reduced only in smooth bromegrass. Both lignin and etherified ferulates were negatively correlated with 96‐h IVNDFD and these relationships were maintained as all three grasses matured. Concentration of NDF was highly correlated with etherified ferulates, making it difficult to partition the impact of components of lignification on IVNDFD.
Genetic Diversity of Wild Soybean (Glycine soja Sieb. and Zucc.) Accessions from South Korea and Other Countries
Authors: Lee Jeong‐Dong , Yu Ju‐Kyung , Hwang Young‐Hyun , Blake Sean , So Yoon‐Sup , Lee Geung‐Joo , Nguyen H. T. , Shannon J. Grover
Published: March 2008

Wild soybean (Glycine soja Sieb. and Zucc.) is an important source of genetic variation for introducing useful traits into cultivated soybeans [Glycine max (L.) Merr.]. Little is known about genetic diversity within South Korean wild soybeans and how they differ genetically from other G. soja lines originating from other regions. Forty‐six simple sequence repeat markers covering the 20 soybean linkage groups were used to estimate genetic diversity among 274 wild soybean accessions from South Korea (210), China (34), Japan (25), and eastern Russia (5) and three cultivated checks. Glycine soja populations from South Korea, China, and Japan all had high genetic diversity with indexes of 0.849, 0.818, and 0.804, respectively. Cluster analyses grouped the 274 accessions into three genetic groups. Cluster I and II consisted of 85 accessions, with 79 of 85 from Korea, only one from China, and five from Japan. Cluster III contained 192 of the 274 G. soja accessions. Nearly all of the accessions from China and Japan, all from Russia, and 131 of 210 from South Korea were assigned to Group III. However, there was no difference between populations for genetic diversity for South Korea and China. Although it is a very small country, South Korea is a major center of diversity for wild soybeans and potentially a source of useful genes not found in other parts of the world.
Effectiveness of Early Generation Selection in Cowpea for Grain Yield and Agronomic Characteristics in Semiarid West Africa
Authors: Padi Francis K. , Ehlers Jeffrey D.
Published: March 2008

The effectiveness of early generation selection for grain yield in a cowpea [Vigna unguiculata (L.) Walp.] population was examined in the Guinea and Sudan savanna agroecologies of Ghana where genotype × location interaction is known to be large. A set of 131 F3:4 lines were developed from a cross between a local cultivar and an unadapted source of large grain size. Mild selection was practiced during line development at one location in the Guinea savanna zone to eliminate poorly adapted lines. Unreplicated F3 plant data were collected on all the lines at the one location during the development of the lines. Multilocation trials were conducted with lines formed by bulk harvest of F4 families to assess how effectively the early generation selection protocol was able to generate superior lines for the target agroecology. Genotypic correlation for grain yield between locations was high only between the two locations in the Guinea savanna zone. Narrow‐sense heritability estimates were low and not different from zero for grain yield, but heritability estimates for days to flowering and seed size were large. F4 lines derived from the highest 10% performing F3 individuals were no higher yielding than F4 lines derived from the remaining F3 individuals, indicating that early generation selection for yield was ineffective. Single‐seed descent (SSD) or bulk breeding methods will be more efficient than pedigree breeding for developing cowpea varieties with high yield potential for this agroecology.
Among‐and‐within‐Family Selection in Eight Forage Grass Populations
Authors: Casler M. D.
Published: March 2008

Forage yields increased little during the twentieth century, despite intensive breeding efforts in many species. Half‐sib family (HSF) and/or among‐and‐within‐family (AWF) selection methods may overcome this problem. The objective of this study was to compare HSF and AWF selection using forage yield of sward plots as the among‐family selection criterion and natural selection of survivors within swards as the within‐family selection criterion. Selection for increased forage yield was practiced in eight populations of orchardgrass (Dactylis glomerata L.), smooth bromegrass (Bromus inermis Leyss.), and hybrid wheatgrass [Elytrigia × muctonata (Opiz ex Bercht.) Prokud.]. Two methods of recombination were used: random plants from remnant seed (HSF) or sod cores from selected families four years after establishment (AWF). There were no consistent differences between HSF and AWF selection for orchardgrass, a bunch grass. For the other two species, both highly rhizomatous, AWF selection was two to four times more effective than HSF selection for increasing forage yield. Natural selection within families of the two rhizomatous grasses favored genotypes capable of filling in open spaces left by plant and/or tiller mortality. The consistent differences in selection responses between orchardgrass and the two rhizomatous species suggested that natural selection acted on some characteristic of the rhizomatous trait of these two grasses.
Weight per Grain, Oil Concentration, and Solar Radiation Intercepted during Grain Filling in Black Hull and Striped Hull Sunflower Hybrids
Authors: Izquierdo Natalia Gabriela , Dosio Guillermo Aníbal Adrián , Cantarero Marcelo , Luján Jorge , Aguirrezábal Luis Adolfo Nazareno
Published: March 2008

The effect of intercepted photosynthetically active radiation (PAR) on weight per grain and oil concentration and their dynamics was investigated in several sunflower (Helianthus annuus L.) striped and black hull hybrids grown in contrasting environments. The study included the previously investigated hybrids Dekalb G‐100 and NKT, and two near isohybrids, which differed in the character of the type of hull. The effect of intercepted PAR lower than those studied in previous works was also investigated. Oil concentration was affected by intercepted radiation but striped hull hybrids reached the maximum oil concentration at lower levels of intercepted PAR than black hull hybrids. A decrease in intercepted radiation decreased final oil concentration mainly due to a lower duration of the phase during which oil concentration linearly increases. Despite the hull type, changes in grain oil concentration that were originated by changes in intercepted radiation largely depended on kernel oil concentration. No differences were observed in the response of weight per grain to changes in intercepted radiation among black hull and striped hull hybrids. Low sensitivity of oil concentration to changes in intercepted PAR must be considered for modeling grain quality. Striped hull hybrids could perform as black hull hybrids in environments with low intercepted radiation during grain filling.
Soybean QTL for Yield and Yield Components Associated with Glycine soja Alleles
Authors: Li Dandan , Pfeiffer T. W. , Cornelius P. L.
Published: March 2008

U.S. soybean [Glycine max (L.) Merr.] germplasm has a narrow genetic base. The objective of this study was to identify G. soja Sieb. and Zucc. alleles for yield and yield component quantitative trait loci (QTL). Two populations of BC2F4 lines were generated from a mating between recurrent parent G. max ‘7499’ and donor parent G. soja PI 245331 with one line in each population tracing back to the same BC2 plant. Population A was used for the QTL identification analysis and Population B was used for the QTL verification test. The Population A lines were genotyped at 120 simple sequence repeat marker loci and one phenotypic marker locus. There were 11 putative QTL significantly associated with yield and yield component traits across three environments. One QTL for seed yield was found using the combined data. At this locus, the G. soja allele at Satt511 on LG A1 was associated with increased seed yield with an additive yield effect of 191 to 235 kg ha−1 depending on the QTL analysis method. Across environments in the validation population, lines that were homozygous for the G. soja allele at Satt511 demonstrated a 6.3% yield increase over lines that were homozygous for the G. max allele. One seed filling period QTL was identified on LG F with an additive effect of +1 d. This QTL also provided a +1 d additive effect on maturity. These results demonstrate the potential of identifying positive alleles in the exotic germplasm of soybean.
Heterotic Effects in Topcrosses of Modern and Obsolete Cotton Cultivars
Authors: Campbell B. T. , Bowman D. T. , Weaver D. B.
Published: March 2008

Historically, reselection, pedigree, and mass‐selection breeding methods have been used to develop open‐pollinated cultivars of upland cotton (Gossypium hirsutum L.). As a result, modern cotton cultivars should have accumulated additive genetic effects with time, while also possessing fewer nonadditive gene effects than obsolete cultivars. A topcross test was conducted to compare the heterotic effects of obsolete and modern cultivars for yield, yield components, and fiber quality. Significant differences were detected between heterosis values for the modern and obsolete cultivar groups for seed cotton yield, lint yield, lint percentage, and boll weight. No significant heterotic effects were detected for fiber quality. The obsolete group of cultivars showed average lint yield heterosis values of 34% compared with 23% for the modern cultivars. Both cultivar groups displayed significant, but similar heterosis values for the number of bolls per square meter (17 and 15%, respectively). The major yield component associated with lint yield heterosis for both groups was bolls per square meter, although boll weight heterosis also contributed to lint yield heterosis for the obsolete cultivars. Although modern cultivars produced considerable heterotic effects for yield, this study demonstrates that obsolete cultivars may provide an additional source of nonadditive genetic effects that can be exploited in a hybrid production system.
Genetic Determinants of Differential Resistance to Root‐Knot Nematode Reproduction and Galling in Lima Bean
Authors: Roberts P. A. , Matthews W. C. , Ehlers J. D. , Helms D.
Published: March 2008

Root‐knot nematodes (Meloidogyne spp.) are important root parasites that limit lima bean (Phaseolus lunatus L.) production, although genetic resistance is available. In accession L‐136, we investigated the apparent independence of genes controlling nematode reproduction and root galling. Segregation of nematode egg production and root‐galling phenotypes in F1, F2, F2:3, and F2:7‐9 populations from L‐136 × susceptible ‘Henderson Bush’ was determined in growth pouch, greenhouse pot, and field screenings. Three nuclear genes designated mir‐1 (recessive), Mig‐1 (dominant), and Mjg‐1 (dominant) were found to control M. incognita reproduction, M. incognita galling, and M. javanica galling, respectively. Contrast analysis indicated that gene combinations affected nematode egg production and gene combinations provided comprehensive resistance. This independent resistance to root‐knot galling and reproduction, reported for other leguminous crops and cotton (Gossypium spp.), has important implications for breeding broad‐based nematode resistance.
Selection for Drought Resistance in Common Bean Also Improves Yield in Phosphorus Limited and Favorable Environments
Authors: Beebe Stephen E. , Rao Idupulapati M. , Cajiao César , Grajales Miguel
Published: March 2008

An estimated 60% of common bean (Phaseolus vulgaris L.) production worldwide is at risk of drought. A breeding program was developed at the International Center of Tropical Agriculture (CIAT) to create drought resistant breeding lines with varietal potential in the small red, small black, cream (mulatinho) and cream‐striped (carioca) grain classes. Breeding populations were created from triple or double crosses. Field screening under terminal drought was performed at Palmira, Colombia in the dry season in F2, F3:5, and F6:8 generations over two cycles of recurrent selection in the small red and small black classes, and one cycle in the mulatinho and carioca classes. Drought resistant lines yielded significantly more than commercial check cultivars under drought in all color classes. Some outyielded the respective checks by 15 to 25% (depending on color class and trial) in one or more of three favorable environments, or in the combined analysis across favorable environments, and were also earlier to mature. Drought resistant lines presented up to 36% greater yield d−1 in favorable environments. Some also expressed superior yields in a phosphorus‐limited environment. Thus, selection for drought resistance has improved yield potential and plant efficiency across different environments. It is suggested that selection under drought stress reveals genes that correct inefficiencies inherited from the wild Phaseolus vulgaris, and are key to yield improvement of common bean.
Isoflavone Accumulation Kinetics in Soybean Seed Cotyledons and Hypocotyls: Distinct Pathways and Genetic Controls
Authors: Berger Monique , Rasolohery Claudine Aimée , Cazalis Roland , Daydé Jean
Published: March 2008

Seed isoflavone content is influenced by environment and genotype, but seed fractions such as hypocotyls and cotyledons display highly contrasted isoflavone contents and compositions. Moreover, the isoflavone content of hypocotyls appears less influenced by environment than that of cotyledons. The purpose of this study was to better understand isoflavone distribution between the two parts of the embryo during seed maturation. The accumulation kinetics of individual and total isoflavones in hypocotyls and cotyledons were recorded in three growth conditions (two years in greenhouse, and one year in the field) in four soybean [Glycine max (L.) Merr.] cultivars having contrasted isoflavone contents and compositions in their seed fractions, from 20 days after flowering (DAF, R5 stage) to seed maturity (R8 stage). As soon as 20 DAF, early isoflavone accumulation was observed in hypocotyls, whereas the isoflavone accumulation the in cotyledons began at R6 stage, after hypocotyl content had reached a plateau. Depending on the growth conditions, a continuous accumulation up to maturity was observed in cotyledons, resulting in a fourfold increase of the total isoflavone content. But whatever the growth conditions, isoflavone accumulation in hypocotyls was unchanged, suggesting that hypocotyl isoflavone content could mainly be under genotypic control. This study clearly shows that isoflavone synthesis and accumulation result from highly differenti ated pathways in hypocotyls and cotyledons.
Effect of Plant Density on Forage Yield and Quality of Intercropped Corn and Lablab Bean
Authors: Armstrong Kevin L. , Albrecht Kenneth A.
Published: March 2008

Low crude protein (CP) concentration in corn (Zea mays L.) silage is its major dietary limitation in dairy rations. In this experiment, four densities of corn (20,000, 40,000, 60,000, and 80,000 plants ha−1) and four densities of lablab bean [Lablab purpureus (L.) Sweet] (0, 40,000, 80,000, 120,000 plants ha−1) were intercropped to determine the optimal planting density in terms of forage yield, nutritive value, estimated milk production, and forage nutrient value. Experiments were conducted near Arlington and Lancaster, WI. Corn was sown in late April and lablab bean was sown in rows 8 cm beside corn rows 2 wk after corn planting. Averaged over locations, forage dry matter (DM) yield ranged from 11 Mg ha−1 to 20 Mg ha−1 as corn plant density increased from 20,000 to 80,000 plants ha−1 Lablab bean increased CP concentration by 22 g kg−1 DM between corn densities of 80,000 plants ha−1 and 20,000 plants ha−1 at a bean density of 120,000 plants ha−1 Calculated milk ha−1 values ranged from 17,500 kg ha−1 to 34,400 kg ha−1 as corn plant density increased from 20,000 to 80,000 plants ha−1 This experiment does not show benefit to addition of lablab bean into high producing corn stands. Corn sown at a density of 80,000 plants ha−1 and 0 bean plants ha−1 is recommended to maximize forage DM yield, milk ha−1, and crop value. Alternatively, addition of lablab bean into low density corn stands did increase CP concentration and feed nutrient value of the forage.
Population Ecology of the Eastern Box Turtle in a Fragmented Landscape
Authors: NAZDROWICZ NATHAN H. , BOWMAN JACOB L. , ROTH ROLAND R.
Published: March 2008

Abstract: In the mid‐Atlantic region, urban sprawl and development have resulted in habitat alterations and fragmentation; however, the effects on eastern box turtle (Terrapene carolina carolina) populations are unclear. To investigate the status of eastern box turtle populations in a fragmented landscape, we used mark—recapture and radiotelemetry to estimate population density, sex ratio, age structure, and survival on 4 study areas with differing degrees of isolation and human disturbance in northern New Castle County, Delaware, USA. We estimated adult population densities ranging from 0.81 turtles/ha to 3.62 turtles/ha among our 4 study areas. Sex ratios were male‐biased at 2 study areas and balanced at 2 study areas. Proportion of juveniles ranged from 0% to 31%. Estimated annual survival rate ranged from 0.813 to 0.977. Mortality of radiotagged and marked turtles was primarily due to natural causes, but mowing was the primary cause of human‐induced mortality. We found evidence of population decline at one study area due to low survival and recruitment. Human disturbances, isolation, and habitat composition appear to have the greatest influence on the box turtle populations we studied. To minimize mortality from human disturbance, we suggest planting crops adjacent to forest habitat that require no mowing or mowing at a height ≥15 cm. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):745–753; 2008)
Efficacy of Bear Deterrent Spray in Alaska
Authors: SMITH TOM S. , HERRERO STEPHEN , DEBRUYN TERRY D. , WILDER JAMES M.
Published: March 2008

Abstract: We present a comprehensive look at a sample of bear spray incidents that occurred in Alaska, USA, from 1985 to 2006. We analyzed 83 bear spray incidents involving brown bears (Ursus arctos; 61 cases, 74%), black bears (Ursus americanus; 20 cases, 24%), and polar bears (Ursus maritimus; 2 cases, 2%). Of the 72 cases where persons sprayed bears to defend themselves, 50 (69%) involved brown bears, 20 (28%) black bears, and 2 (3%) polar bears. Red pepper spray stopped bears' undesirable behavior 92% of the time when used on brown bears, 90% for black bears, and 100% for polar bears. Of all persons carrying sprays, 98% were uninjured by bears in close‐range encounters. All bear—inflicted injuries (n = 3) associated with defensive spraying involved brown bears and were relatively minor (i.e., no hospitalization required). In 7% (5 of 71) of bear spray incidents, wind was reported to have interfered with spray accuracy, although it reached the bear in all cases. In 14% (10 of 71) of bear spray incidents, users reported the spray having had negative side effects upon themselves, ranging from minor irritation (11%, 8 of 71) to near incapacitation (3%, 2 of 71). Bear spray represents an effective alternative to lethal force and should be considered as an option for personal safety for those recreating and working in bear country. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):640–645; 2008)