Initial root length in wheat is highly correlated with acid soil tolerance in the field

In acid soils, toxic aluminum ions inhibit plant root growth. In order to discriminate aluminum (Al) tolerance, trustful screening techniques are required. In this study, 20 wheat cultivars, showing different levels of Al tolerance, were evaluated in a short-term soil experiment to access their relative root length (RRL). Moreover, the alleles of two important genes (TaALMT1 and TaMATE1B) for Al tolerance in wheat were discriminated. Both of these genes encode membrane transporters responsible for the efflux of organic acids by the root apices that are thought to confer tolerance by chelating Al. Genotypes showing TaALMT1 alleles V and VI and an insertion at the TaMATE1B promoter were among the ones showing greater RRL. Mechanisms of Al tolerance, which are not associated with organic acid efflux, can be potentially present in two cultivars showing greater RRL among the ones carrying inferior TaALMT1 and TaMATE1B alleles. The RRL data were highly correlated with wheat performance in acid soil at three developmental stages, tillering (r = 0.93, p 0.001), silking (r = 0.91, p 0.001) and maturation (r = 0.90, p 0.001), as well as with the classification index of aluminum toxicity in the field (r = 0.92, p 0.001). Since the RRL was obtained after only six days of growth and it is highly correlated with plant performance in acid soil under field conditions, the short-term experiment detailed here is an efficient and rapid method for reliable screening of wheat Al tolerance.(AU)

Initial root length in wheat is highly correlated with acid soil tolerance in the field

In acid soils, toxic aluminum ions inhibit plant root growth. In order to discriminate aluminum (Al) tolerance, trustful screening techniques are required. In this study, 20 wheat cultivars, showing different levels of Al tolerance, were evaluated in a short-term soil experiment to access their relative root length (RRL). Moreover, the alleles of two important genes (TaALMT1 and TaMATE1B) for Al tolerance in wheat were discriminated. Both of these genes encode membrane transporters responsible for the efflux of organic acids by the root apices that are thought to confer tolerance by chelating Al. Genotypes showing TaALMT1 alleles V and VI and an insertion at the TaMATE1B promoter were among the ones showing greater RRL. Mechanisms of Al tolerance, which are not associated with organic acid efflux, can be potentially present in two cultivars showing greater RRL among the ones carrying inferior TaALMT1 and TaMATE1B alleles. The RRL data were highly correlated with wheat performance in acid soil at three developmental stages, tillering (r = 0.93, p 0.001), silking (r = 0.91, p 0.001) and maturation (r = 0.90, p 0.001), as well as with the classification index of aluminum toxicity in the field (r = 0.92, p 0.001). Since the RRL was obtained after only six days of growth and it is highly correlated with plant performance in acid soil under field conditions, the short-term experiment detailed here is an efficient and rapid method for reliable screening of wheat Al tolerance.

Evaluation of tamoxifen citrate efficiency on sexual inversion of Nile tilapia (Oreochromis niloticus) / Avaliação da eficiência do citrato de tamoxifeno na inversão sexual de tilápia do Nilo (Oreochromis niloticus)

The experiment was conducted to evaluate the influence of tamoxifen on sexual inversion of Nile tilapia larvae from two days of life, the experimental desing was compounded of five treatments and three replicates, and fish were fed diets with different amounts of tamoxifen: 0, 25, 50, 75 and 100 mg kg-1 of feed. After 28 days of treatment, larvae were counted and transferred to water tanks of 500 liters and then which were fed with a diet containing 28% crude protein for more 60 days. After this period the fry were sexed by the squash. The survival 75.5 ± 5.74, 73 ± 4.76, 66 ± 11.19, 76.5 ± 4.12, 75 ± 3.46 and average percentage of male individuals 62.5 ± 5, 70 ± 8.1, 60 ± 8.2, 70 ± 0.0, 62.5 ± 9.5 for treatments 0, 25, 50, 75 and 100 mg of tamoxifenkg-1 diet, respectively, showed no statistically significant differences (p 0,05). The number of gonads in each fish experienced a significant reduction in the treatments with 75 and 100 mg of tamoxifen (89.3 and 79.3 ± 0.527 ± 0.378) when compared with treatments 0, 25 and 50 mg of tamoxifen (98, 9 ± 1.0, 97.6 ± 1.0 and 94.5 ± 1.0, respectively), the histological structure of female gonads did not differ and ovaries in all treatments showed well-defined and oocytes at several stages of maturation.(AU)

O experimento foi realizado com o objetivo de avaliar a influência do tamoxifeno na inversão sexual de larvas de tilápia a partir dos dois dias de vida. Os animais foram distribuídos em um delineamento experimental de cinco tratamentos e três repetições, recebendo dietas com diferentes quantidades de tamoxifeno: 0, 25, 50, 75 e 100 mg kg-1 de ração. Após 28 dias de tratamento, as larvas restantes em cada tratamento foram contadas e transferidas para caixas de água de 500 L onde receberam ração comercial com 28% de proteína bruta por 60 dias. Após este período, os alevinos foram sexados pelo método squash. A sobrevivência 75,5 ± 5,74; 73 ± 4,76; 66 ± 11,19; 76,5 ± 4,12; 75 ± 3,46% e a porcentagem média de indivíduos machos 62,5 ± 5; 70 ± 8,1; 60 ± 8,2; 70 ± 0,0; 62,5 ± 9,5% para os tratamentos 0, 25, 50, 75 e 100 mg de tamoxifeno kg-1 de ração, respectivamente, não apresentaram diferenças estatísticas significativas. O número de gônadas presentes em cada indivíduo apresentou redução significativa, nos tratamentos com 75 e 100 mg de tamoxifeno (89,3 ± 0,527 e 79,3 ± 0,378%) quando comparado com os tratamentos 0, 25 e 50 mg de tamoxifeno (98,9 ± 1,0; 97,6 ± 1,0 e 94,5 ± 1,0%, respectivamente), a estrutura histológica das gônadas femininas não apresentou diferenças e os ovários em todos os tratamentos apresentaram ovócitos bem definidos e em vários estádios de maturação.(AU)

Efeito do citrato e taurina em meio CR2aa no desenvolvimento de embriões bovinos fecundados in vitro / Effect of citrate and taurine added to CR2aa medium on the development of in vitro-fertilized bovine embryos

Avaliou-se o efeito do citrato em meio CR2aa suplementado com soro fetal bovino (SFB) ou livre de proteínas séricas e sua associação com taurina no desenvolvimento de embriões bovinos fecundados in vitro. Embriões foram cultivados em CR2aa contendo 0, 0,5, 1,0 e 3,0mM citrato, suplementado com 10 por cento SFB (experimento 1) ou com álcool polivinil (PVA; experimento 2). No terceiro experimento, embriões foram cultivados em meio com 0,5mM citrato, ou 7mM taurina, ou com a associação de ambos, suplementado com SFB. Os cultivos foram realizados com células do cumulus em ambiente a 38,8ºC com 5 por cento de CO2 em ar atmosférico. Melhora no desenvolvimento embrionário foi observado no cultivo de embriões em CR2aa com 0,5 e 1,0mM citrato na ausência de SFB (P<0,05), 8,6 por cento e 11,3 por cento de blastocistos, respectivamente, porém com valores mais baixos (P<0,05) que embriões cultivados em CR2aa com SFB (31,9 por cento). Associação de citrato com taurina em meio com SFB não influenciou (P>0,05) a produção de embriões ou o número de células. Citrato em meio CR2aa pode ser uma alternativa para cultivo embrionário em condições atmosféricas com 5 por cento de CO2 em ar na ausência de proteína sérica.(AU)

The effect of citrate added to CR2aa medium supplemented with fetal calf serum (FCS) or serum-proteinfree and its association with taurine on the development of in vitro-fertilized bovine embryos was evaluated. Embryos were cultured with 0, 0.5, 1.0, and 3.0mM citrate, in CR2aa supplemented with 10 percent FCS (experiment 1), or polyvinyl alcohol (PVA; experiment 2). In experiment 3, embryos were cultured with 0.5mM citrate, 7.0mM taurine or with association of both, in medium supplemented with FCS. Embryo culture was performed with cumulus cells at 38.8ºC in 5 percent CO2 under air for all experiments. Positive effect on embryo development was only observed with 0.5 and 1.0mM citrate in FCS-free CR2aa (P<0.05; 8.6 percent and 11.3 percent blastocyst, respectively), however with lower embryo rate than CR2aa with FCS (31.9 percent). Association between citrate and taurine in medium supplemented with FCS did not affect (P>0.05) embryo rate nor total cell number. Citrate in CR2aa medium can be an alternative for serumfree embryo culture under 5 percent CO2 in air, absence of serum protein.(AU)

Avaliação do comportamento anti-oxidante de sais orgânicos (acetato, citrato e lactato), em produtos cárneos frescais / Evaluation of the anti-oxidant of organic salts (acetate, citrate and lactate) in meat products

Os sais orgânicos vêm sendo investigados para uso em alimentos, devido à exigência dos consumidores por alimentos cada vez mais saudáveis, livres de substâncias que possam causar danos à saúde, a curto, a médio ou a longo prazo. Os ácidos orgânicos são considerados GRAS (Generally Recognized as Safe) para os alimentos, segundo a FDA (Food and Drug Administration) e têm sido indicados como aditivos naturais capazes de inibir ou retardar as alterações causadas por agentes físico-químicos ou microbiológicos. Este trabalho investigou o uso do acetato, do citrato e do lactato, nas concentrações de 1 por cento, 2 por cento e 3 por cento como agentes anti-oxidantes em lingüiças frescais de frango. A sua ação anti-oxidante foi medida através de análises de determinação do pH, determinação da acidez total e de índice de peróxido. Os dados foram avaliados através de análise de variância (ANOVA), tendo as suas médias agrupadas pelo teste de amplitude múltipla de Duncan, ao nível de 5 por cento. Foram considerados como fatores as concentrações do acetato, citrato e lactato (controle, 1 por cento, 2 por cento, 3 por cento). Os resultados indicaram que o citrato e o lactato de sódio apresentaram ação anti-oxidante mais pronunciada nas concentrações de 1 e 2 por cento.(AU)

Organic salts used in food have been investigated, due to consumers' demand for healthier food that is free of substances, which may cause damage to health in the short, medium or long term. Organic acids are considered GRAS (Generally Recognized as Safe) for food, according to FDA (Food and Drug Administration), and theyhave been indicated as natural additives, able to inhibit or even delay alterations caused by microbiological orphysiochemical agents. In this work, the use of acetate, citrate and lactase was investigated at concentrations of 1%, 2% and 3% as antioxidant agents in fresh chicken sausages. Its antioxidant action was measured through analysisof pH determination, total acidity, and peroxide index. Data were evaluated by variance analysis (ANOVA), andaverages were grouped by Duncan's multiple range test at 5% level. Concentrations of acetate, citrate, andlactase were considered as factors (control, 1%,2%,3%). Results indicated that citrate and sodium lactaseshowed more significant antioxidant action at concentrations of 1 and 2%. (AU)

Evaluation of tamoxifen citrate efficiency on sexual inversion of Nile tilapia (Oreochromis niloticus) / Avaliação da eficiência do citrato de tamoxifeno na inversão sexual de tilápia do Nilo (Oreochromis niloticus)

The experiment was conducted to evaluate the influence of tamoxifen on sexual inversion of Nile tilapia larvae from two days of life, the experimental desing was compounded of five treatments and three replicates, and fish were fed diets with different amounts of tamoxifen: 0, 25, 50, 75 and 100 mg kg-1 of feed. After 28 days of treatment, larvae were counted and transferred to water tanks of 500 liters and then which were fed with a diet containing 28% crude protein for more 60 days. After this period the fry were sexed by the squash. The survival 75.5 ± 5.74, 73 ± 4.76, 66 ± 11.19, 76.5 ± 4.12, 75 ± 3.46 and average percentage of male individuals 62.5 ± 5, 70 ± 8.1, 60 ± 8.2, 70 ± 0.0, 62.5 ± 9.5 for treatments 0, 25, 50, 75 and 100 mg of tamoxifenkg-1 diet, respectively, showed no statistically significant differences (p 0,05). The number of gonads in each fish experienced a significant reduction in the treatments with 75 and 100 mg of tamoxifen (89.3 and 79.3 ± 0.527 ± 0.378) when compared with treatments 0, 25 and 50 mg of tamoxifen (98, 9 ± 1.0, 97.6 ± 1.0 and 94.5 ± 1.0, respectively), the histological structure of female gonads did not differ and ovaries in all treatments showed well-defined and oocytes at several stages of maturation.

O experimento foi realizado com o objetivo de avaliar a influência do tamoxifeno na inversão sexual de larvas de tilápia a partir dos dois dias de vida. Os animais foram distribuídos em um delineamento experimental de cinco tratamentos e três repetições, recebendo dietas com diferentes quantidades de tamoxifeno: 0, 25, 50, 75 e 100 mg kg-1 de ração. Após 28 dias de tratamento, as larvas restantes em cada tratamento foram contadas e transferidas para caixas de água de 500 L onde receberam ração comercial com 28% de proteína bruta por 60 dias. Após este período, os alevinos foram sexados pelo método squash. A sobrevivência 75,5 ± 5,74; 73 ± 4,76; 66 ± 11,19; 76,5 ± 4,12; 75 ± 3,46% e a porcentagem média de indivíduos machos 62,5 ± 5; 70 ± 8,1; 60 ± 8,2; 70 ± 0,0; 62,5 ± 9,5% para os tratamentos 0, 25, 50, 75 e 100 mg de tamoxifeno kg-1 de ração, respectivamente, não apresentaram diferenças estatísticas significativas. O número de gônadas presentes em cada indivíduo apresentou redução significativa, nos tratamentos com 75 e 100 mg de tamoxifeno (89,3 ± 0,527 e 79,3 ± 0,378%) quando comparado com os tratamentos 0, 25 e 50 mg de tamoxifeno (98,9 ± 1,0; 97,6 ± 1,0 e 94,5 ± 1,0%, respectivamente), a estrutura histológica das gônadas femininas não apresentou diferenças e os ovários em todos os tratamentos apresentaram ovócitos bem definidos e em vários estádios de maturação.