Produção de matéria seca, nodulação e absorção de nutrientes pela soja (Glycine max (L.) Merrill) em função de níveis de fósforo e zinco, em solos de Minas Gerais

The effects of levels of phosphorus and zinc on dry matter production, nodulation and nutrient uptake by soybean (Glycine max (L.) Merrill cv. 'UFV-l') were determined in greenhouse. Three levels of phosphorus, corresponding to 0, 200 or 400 kg P2O5/ha, and three of zinc, corresponding to 0, 15 or 30 kg of zinc sulfate/ha were tested in three soils. Plants were grown in clay pots containing 7 kg of either a Red-Yellow Latosol (LV), a Dark-Red Latosol, medium texture (LEm), or a Dark Red Latosol (LE. Seeds were inoculated with strains of Rhizobium japonicum during planting. Phosphate fertilization increased dry matter production and nodulation while zinc fertilization did not. Less dry matter was produced on LEm while most nodulation occured on this soil and the LV, The concentrations of N, Ca, Mg and Zn decreased with phosphate fertilizer suggesting a dilution effect as evident in plant growth intensity. The largest dose of phosphate decreased level of K in old leaves but increased K in young leaves and stems through translocation.O efeito de níveis de fósforo e zinco na produção de matéria seca, nodulação e absorção de nutrientes pela soja (Glycine max (L.) Merrill cv. 'UFV-1) foi estudado em condições de casa-de-vegetação. Foram testadas três doses de fósforo equivalentes a 0. 200 e 400 kg de P2O5/ha, e três de zinco equivalentes a 0, 15 e 30 kg de sulfato de zinco/ha, em três solos, em vasos contendo 7 kg de terra. Os solos estudados foram os seguintes: Latossolo Vermelho-Amarelo (LV), Latossolo Vermelho-Escuro, textura média (LEm), e Latossolo Vermelho-Escuro (LE). As sementes, no plantio, foram inoculadas com estirpes de Rhizobium japonicum. Foram observados aumentos da produção de materia seca das plantas e da nodulação, com a adubação fosfatada. A fertilização com zinco não alterou estes parâmetros. Produções menores de matéria seca das plantas foram verificadas no LEm, no entanto, este solo e o LV, foram os substratos que propiciaram as maiores nodulações. As concentrações de N, Ca, Mg e Zn decresceram com a adubação fosfatada, sugerindo-se um efeito de diluição, propiciado pelo intenso crescimento das plantas. A fertilização fosfatada, na maior dose, diminuiu o teor de K nas folhas velhas e aumentou-o nas novas e nas hastes, indicando ter havido translocação do referido nutriente

Influence of the ovine genital tract microbiota on the species artificial insemination outcome. A pilot study in commercial sheep farms

To date, there is a lack of research into the vaginal and sperm microbiome and its bearing on artificial insemination (AI) success in the ovine species. Using hypervariable regions V3–V4 of the 16S rRNA, we describe, for the first time, the combined effect of the ovine microbiome of both females (50 ewes belonging to five herds) and males (five AI rams from an AI center) on AI outcome. Differences in microbiota abundance between pregnant and non-pregnant ewes and between ewes carrying progesterone-releasing intravaginal devices (PRID) with or without antibiotic were tested at different taxonomic levels. The antibiotic treatment applied with the PRID only altered Streptobacillus genus abundance, which was significantly lower in ewes carrying PRID with antibiotic. Mageebacillus, Histophilus, Actinobacilllus and Sneathia genera were significantly less abundant in pregnant ewes. In addition, these genera were more abundant in two farms with higher AI failure. Species of these genera such as Actinobacillus seminis and Histophilus somni have been associated with reproductive disorders in the ovine species. These genera were not present in the sperm samples of AI rams, but were found in the foreskin samples of rams belonging to herd 2 (with high AI failure rate) indicating that their presence in ewes’ vagina could be due to prior transmission by natural mating with rams reared in the herd

Estudos sobre a nutrição mineral do sorgo granífero: VI. absorção de fosfato por raizes destacadas de plantas de três variedades comerciais

Experiments were carried out in order to study the effect of time external concentration, pH, temperature, aeration and inhibitors (KF, KCN and 2,4-DNP) on the phosphate absorption by the excised roots of grain Sorghum bicolor L. Moench var. Contibrasil 102, DeKalb and Tey-101, using 32P as tracer.Foi estudada a absorção de fosfato marcado com 32P por raizes destacadas de três variedades de sorgo granífero. A influência do tempo, concentração iônica externa, pH, aeração, venenos respiratórios e desacopladores de fosforilação oxidativa foi considerada; o estudo da cinéstica da absorção mostrou diferenças entre as variedades nos parâmetros michaelianos