Definition of morphofunctional groups in Panicum maximum accessions by canonical variables analysis

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.A avalia??o das caracter?sticas morfog?nicas em acesso de Panicum maximum apesenta grande potencial para permitir a identifica??o precoce de grupos de plantas com caracter?sticas morfofuncionais afins. O objetivo com o trabalho foi avaliar as caracter?sticas morfog?nicas de acessos de Panicum maximum e definir grupos morfog?nicos a fins por meio da an?lise de vari?veis can?nicas. Foram avaliados 17 acessos em delineamento em blocos ao acaso com tr?s repeti??es. Ap?s avalia??o da dispers?o dos escores relativos ?s vari?veis can?nicas, verificou-se a forma??o de sete grupos morfofuncionais. Maior destaque foi dado ?s plantas dos grupos 5, 6 e 7. O grupo 7 apresentou maior taxa de alongamento foliar, longa dura??o de vida da folha e o maior comprimento final da l?mina. No grupo 5, registrou-se alta taxa de alongamento e de aparecimento foliar associadas a baixa senesc?ncia. O grupo 6 reuniu maior alongamento de folhas a menor longevidade, indicando necessidade de manejo mais intensivo. Foi poss?vel formar grupos morfofuncionais com base nas caracter?sticas morfog?nicas de acessos de Panicum maximum. Destaca-se a identifica??o das plantas dos grupos 5 e 7 como plantas com grande potencial para produ??o de folhas e longa janela de corte, e das plantas do grupo 6 como plantas que demandar?o manejo mais frequente.ABSTRACT The evaluation of morphogenetic characteristics in Panicum maximum accessions has potential in the previous identification of groups of plants with related morphofunctional characteristics. The study was carried out to evaluate the morphogenetic characteristics of Panicum maximum accessions and to define related morphogenetic groups by analysis of canonical variables. Were evaluated 17 accessions in a complete randomized block design with three replicate. After the evaluation of the scores related to canonical variables, it verified the formation of seven morphofunctional groups. We emphasize the groups 5, 6 and 7. The group 7 had higher leaf elongation rate, leaf life spam and leaf length. In the group 5, was observed high leaf elongation and appearance rate associated with low senescence. The group six had high elongation and low leaf life spam, indicating these plants to a more intensive management. With the canonical variable analysis was possible the identification of morphofunctional groups based on the morphogenetic characteristics of Panicum maximum accessions. The identification of the groups 5 and 7 as high production plants and with a longer harvest period and the groups 6 with plants that needs more frequent defoliation

Genetic parameters of morphogenetic traits in Panicum maximum acessions

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.Objetivou-se com este trabalho estimar par?metros gen?ticos de caracter?sticas morfog?nicas em acessos de Panicum maximum. Foram avaliados 17 acessos (previamente selecionados pela Embrapa Gado de Corte) em delineamento em blocos ao acaso com tr?s repeti??es. Os acessos foram avaliados por meio de cortes a 25 cm do n?vel do solo em parcelas de 4,0 m2, com espa?amento de 1 m entre linhas. A partir das an?lises dos resultados, foi poss?vel notar que apenas as caracter?sticas taxa de alongamento de colmo, taxa de alongamento de folha e comprimento final da lamina foram estatisticamente diferentes entre os acessos avaliados. Para taxa de alongamento de colmo o coeficiente de varia??o do ambiente apresentou valor elevado. O coeficiente de varia??o genot?pico da taxa de alongamento de colmo foi o maior entre as vari?veis avaliadas, indicando o potencial de ganho na sele??o para o mesmo. Para o comprimento final da l?mina, foram observados coeficiente da varia??o do ambiente e coeficiente da varia??o genot?pica inferiores ? taxa de alongamento do colmo, contudo, foram obtidos herdabilidade e raz?o CVg/CVe semelhantes. Os coeficientes de varia??o residual e genot?pico da taxa de alongamento foliar foram intermedi?rios em rela??o ?s demais caracter?sticas e assumiram valores pr?ximos, que permitiram a estimativa de uma raz?o CVg/CVe pr?xima da unidade. O alongamento de folhas apresenta maior potencial para ser inserido no processo de avalia??o e sele??o de forrageiras devido a sua alta herdabilidade e raz?o entre os coeficientes de varia??o genot?pico e residual.The experiment was carried out to estimate the genetic parameters of morphogenetic characteristics in Panicum maximum accessions. Were evaluated 17 accessions in a complete block design with three replicate. The accessions were evaluated by cutting at 25 cm from de level soil in plots of 4 m?, with 1 m intercrop. It was possible to note only the stems elongation rate, leaf elongation rate and leaf length were statistically different between the accessions. To stems elongation rate we had high environmental coefficient of variation. In spite of this the genotypic coefficient of variation was also the higher between the characteristics evaluated, indicating potential to reduce this by selection. To leaf length, were observed genotypic and environmental coefficient of variation lower than the stems elongation rate, however were observed similar heritability and genotypic/environmental coefficient of variation rate. The genotypic and environmental coefficient of variation of leaf elongation rate were intermediated between the other characteristics and had next values, so the genotypic/environmental coefficient of variation rate was the higher in the experiment and next from one (0,93). The leaf elongation rate has potential to be included in the process of evaluation and selection of forage plants duly its high heritability and favorable environmental/genotypic coefficient of variation rate

Identification of stable reference genes for quantitative PCR in koalas

To better understand host and immune response to diseases, gene expression studies require identification of reference genes with stable expression for accurate normalisation. This study describes the identification and testing of reference genes with stable expression profiles in koala lymph node tissues across two genetically distinct koala populations. From the 25 most stable genes identified in transcriptome analysis, 11 genes were selected for verification using reverse transcription quantitative PCR, in addition to the commonly used ACTB and GAPDH genes. The expression data were analysed using stable genes statistical software - geNorm, BestKeeper, NormFinder, the comparative ΔCt method and RefFinder. All 13 genes showed relative stability in expression in koala lymph node tissues, however Tmem97 and Hmg20a were identified as the most stable genes across the two koala populations

Milk production systems retated momba?a grass

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.A produ??o animal em pastagens apresenta vantagens em rela??o aos outros sistemas de produ??o. Geralmente, o pasto ? o alimento mais vi?vel economicamente para a alimenta??o de ruminantes. O capim-momba?a ? uma cultivar de Panicum maximum nativa da ?frica, essa cultivar apresenta desenvolvimento satisfat?rio em sistemas de manejo mais intensivos e com altas taxas de lota??o. Por?m, para garantir a produtividade animal, a fisiologia da forrageira deve ser respeitada com auxilio das alturas de entrada de sa?da adequadas a cada esp?cie.Livestock production in pastures has advantages over other production systems. Generally, the grass is the most economically viable food for feeding to ruminants. The momba?a is a cultivar of Panicum maximum native to Africa, this cultivar has developed satisfactorily in more intensive management systems and high stocking rates. However, to ensure animal productivity, forage physiology must be respected with the aid of input output heights appropriate to each species

Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range