Genetic divergence toward the selection of promising bean progenitors via mixed multivariate models

Abstract The genetic variability present in the bean (Phaseolus vulgaris L.) germplasm that is currently used as an agricultural crop has been shown to be stable in production and is acceptable for human sustenance. Accordingly, to maintain as much of the available variability as possible, this study aimed to examine the genetic divergence in the bean using multivariate analysis to identify the sources of genetic variability and enable breeders to recognize genetic combinations that have a greater chances of success before crossings are performed. This study was conducted in a randomized block design with three replications in the agricultural year 2015. The agronomic traits evaluated were the stem diameter (DIAM) in millimeters, plant height (PH) in centimeters, number of seedsper plant (NS), protein percentage (PROT), height of the first pod (HFP) in centimeters, pod number (PN), grain mass per plant (GM) in g plant−1, grain yield (GY) in kg ha−1, and straw yield (SY) in kg ha−1. To enable selection of the most divergent genotypes, twenty different genotypes were analyzed via clustering according to the average linkage criterion (UPGMA) using a matrix of the mean standardized Euclidean distances and principal component analysis based on the values predicted via a multivariate mixed model. The results obtained in this study revealed a high degree of genetic divergence and allowed the progenies to be allocated into different groups, as well as recommended crossings for future bean breeding programs.Resumen La variabilidad genética presente en el germoplasma de frijol (Phaseolus vulgaris L.) actualmente utilizada en la agricultura es la garantía más pronunciada de estabilidad de la producción y sustento humano en relación con este cultivo. En consecuencia, para mantener la mayor variabilidad disponible posible, este estudio tuvo como objetivo examinar la divergencia genética mediante análisis multivariante para identificar fuentes de variabilidad genética y permitir a los mejoradores reconocer las combinaciones genéticas con mayores posibilidades de éxito antes de que se realicen los cruces. El experimento se realizó en diseño de bloques al azar con tres repeticiones en el año agrícola 2015. Los caracteres agronómicos evaluados fueron: diámetro del tallo (DIAM) en mm; altura (ALT) en cm; cantidad de semillas (CS); porcentaje de proteína (PROT); altura de la primera vaina (APV) en cm; número de pod (NP); masa de grano por planta (MG) en g planta−1; rendimiento de grano (RG) en kg ha−1; y rendimiento de paja (RP) en kg ha−1. Para seleccionar los genotipos más divergentes, se analizaron 20 diferentes agrupando según el criterio de ligamiento promedio (UPGMA) usando la matriz de distancias euclidianas estandarizadas medias, y el análisis de componentes principales en base a los valores predichos mediante el modelo mixto multivariante. Los resultados obtenidos en este estudio revelaron un alto grado de divergencia genética y permitieron la asignación de las progenies en diferentes grupos, así como recomendaciones para cruces en futuros programas de mejoramiento de frijol

Genetic insights into elephantgrass persistence for bioenergy purpose.

Abstract Persistence may be defined as high sustained yield over multi-harvest. Genetic insights about persistence are essential to ensure the success of breeding programs and any biomass-based project. This paper focuses on assessing the biomass yield persistence for bioenergy purpose of 100 elephantgrass clones measured in six growth seasons in Brazil. To assess the clones' persistence, an index based on random regression models and genotype-ideotype distance was proposed. Results suggested the existence of wide genetic variability between elephantgrass clones, and that the yield trajectories along the harvests generate genetic insights into elephantgrass clones' persistence and G x E interaction. A gene pool that acts over the biomass yield (regardless of the harvest) was detected, as well as other gene pools, which show differences on genes expression (these genes are the major responsible for clones' persistence). The lower and higher clones' persistence was discussed based on genome dosage effect and natural biological nitrogen fixation ability applied to bioenergy industry. The huge potential of energy crops necessarily is associated with genetic insights into persistence, so just this way, breeding programs could breed a new cultivar that fulfills the bioenergy industries

Seedling emergence of five varieties of citric rootstocks grown in environments with different levels of shading

The emergence of citrus seedlings is influenced by several factors. One is the degree of brightness. The objective of the experiment was to evaluate the influence of four environments in the emergence of seedlings of five citrus varieties rootstocks. The work was carried out on private property located in the city of Alegre-ES, located at 20° 49’ south latitude and 41° 32’ west longitude and 322 m altitude. The experimental design was completely randomized in a split plot, with four rooms consisting of 0, 30, 50 and 80% shading in the plot and five varieties of rootstocks subplots, with four repetitions and twenty-five seeds per replicate. The rootstocks used were the Rangpur lime, lemon Volkameriano, Poncirus trifoliata, ‘Swingle’ citrumelo and Flying Dragon. After 60 days of sowing, emergence rate index, emergence percentage, leaf number and height were evaluated. At 124 days, leaf area, total chlorophyll (a + b), root dry mass and shoot were evaluated. The citric rootstocks tested responded differently when subjected to shading, and can use physiological and morphological mechanisms to maintain or even improve the emergence and seedling vigor. It was observed that the P. trifoliata rootstock obtained better performance when compared to others and that 50% shading can be adopted in this stage of citrus seedling production since it reduces seedling time in the tubes and does not affect the seedling quality

POBREZA RURAL E DESIGUALDADE DE RENDA NA AMAZÔNIA: UM ESTUDO DA PRODUÇÃO FAMILIAR RURAL DO ESTADO DO ACRE

No Brasil, a pobreza e a insegurança alimentar concentrada no meio rural tem chamado bastante atenção por sua amplitude, principalmente no âmbito da agricultura familiar, onde a produção para o autoconsumo está no centro da reprodução familiar. Dessa forma, o presente trabalho objetiva identificar a relação entre a segurança alimentar, o autoconsumo e a pobreza da produção familiar rural do Estado do Acre. Especificamente, busca-se verificar os indicadores socioeconômicos, bem como os níveis de autoconsumo da produção familiar rural acreana. Para tanto, são utilizados indicadores econômicos adequados e específicos para estes estudos a partir dos estratos sociais identificados pela linha de pobreza no Estado. Os resultados demonstram um crescente número de famílias nas linhas de pobreza e extrema pobreza, elevando o número de pessoas em situação de insegurança alimentar, ocasionados, sobretudo pelo baixo autoconsumo

POBREZA RURAL E DESIGUALDADE DE RENDA NA AMAZÔNIA: UM ESTUDO DA PRODUÇÃO FAMILIAR RURAL DO ESTADO DO ACRE

No Brasil, a pobreza e a insegurança alimentar concentrada no meio rural tem chamado bastante atenção por sua amplitude, principalmente no âmbito da agricultura familiar, onde a produção para o autoconsumo está no centro da reprodução familiar. Dessa forma, o presente trabalho objetiva identificar a relação entre a segurança alimentar, o autoconsumo e a pobreza da produção familiar rural do Estado do Acre. Especificamente, busca-se verificar os indicadores socioeconômicos, bem como os níveis de autoconsumo da produção familiar rural acreana. Para tanto, são utilizados indicadores econômicos adequados e específicos para estes estudos a partir dos estratos sociais identificados pela linha de pobreza no Estado. Os resultados demonstram um crescente número de famílias nas linhas de pobreza e extrema pobreza, elevando o número de pessoas em situação de insegurança alimentar, ocasionados, sobretudo pelo baixo autoconsumo

Repeatability analysis of guava fruit and leaf characteristics

Psidium guajava L. (guava) is an important species that presents high genetic variability due to its mixed reproductive system, which is desired in breeding programs. Repeatability is an important tool for the selection of genotypes in pre-breeding studies. When genetic variability is present, the knowledge regarding the number of samples to be used in repeatability studies is indispensable. This study aims to determine the number of necessary measures while optimizing resources and maintaining the reliability of the results for the variables evaluated in P. guajava. The experiment was carried out with genotypes from three Brazilian States: Espírito Santo, São Paulo, and Minas Gerais, and a total of 79 P. guajava genotypes were collected. The following characteristics were evaluated: young leaf length and width; developed leaf length and width; fruit length; fruit diameter and fruit cavity diameter; and fruit weight and pulp weight. For the evaluated characteristics, deviance, permanent phenotypic and temporary environment variance, coefficients of repeatability and determination, accuracy and the number of estimated measurements required were determined. We established that the number of measurements required in repeatability analysis for a coefficient of repeatability with a reliability of 80% is four, for the measurements of developed leaf width, pulp weight, fruit diameter, and fruit cavity diameter

Acretismo placentário – sinais de suspeição na avaliação ecográfica pré-natal de rotina / Placental accretism - signals of suspection in prenatal echographic evaluation of routine

O acretismo placentário é caracterizado por uma invasão anormal do tecido placentário além da camada decídua, fator que corrobora para uma invasão intensa, podendo alcançar a serosa uterina. Sua classificação pode ser compreendida de acordo com a profundidade de penetração – acreta, increta, percreta. Seu diagnóstico complementar envolve os achados ultrassonográficos. Os principais sinais de suspeição que se pode destacar na avaliação ecográfica pré-natal de rotina são a perda do espaço hipoecoico retroplacentário, múltiplas lacunas irregulares na espessura placentária, irregularidade da interface entre o útero e a bexiga, adelgaçamento do miométrio subjacente, protuberância da placenta, massa exofítica focal, hipervascularização uterovesical intraplacentária e retroplacentária. Entretanto, a ausência de sinais ultrassonográficos não descarta o diagnóstico de acretismo placentário, especialmente na presença de fatores de risco preditores