Comparison of BLUE and BLUP/REML in the selection of clones and families of potato (Solanum tuberosum)

The use of best linear unbiased prediction/restricted maximum likelihood (BLUP/REML) in perennial crops and animal breeding enhances selection gain. However, its advantage with respect to annual crops is not clear. We compared the BLUP and best linear unbiased estimator selection efficiency in the breeding of various potato generations. This was done by simulating various selection intensities on clonal families (full sibs), and clones. The characters evaluated were tuber yield and tuber specific gravity. Two criteria were adopted for comparison: a) incidence of families or clones and b) selection gain. For tuber yield, BLUP/REML method was slightly more efficient for selecting families in the first clonal generation, if it were above 50%. Below this value, both methods were equivalent. However, they both presented equal behavior for family selection of tuber specific gravity. For clonal selection, BLUP/REML showed robust superiority from 10 to 90% selection intensities in both characters. Therefore, the adequate use of BLUP/REML in potato breeding can enhance the selection gain on the yield and specific gravity of tubers. © FUNPEC-RP

Ciência e tecnologia aplicada aos agroecossistemas da Amazônia Central

Este livro, produzido no contexto do Projeto Implantação de Unidades Demonstrativas Agroflorestais na Amazônia, desenvolvido pelo Instituto Nacional de Pesquisas da Amazônia – Inpa, é uma apresentação de resultados científicos aplicados provenientes da colaboração interinstitucional que reúne parceiros de pesquisa, alguns já de longa data, que se debruçaram sobre as questões e desafios de produzir conhecimento agroecológico voltado ao bioma amazônico

Diversidade de feijão-macuco ( Pachyrhizus spp. Fabaceae) baseada em caracteres morfoagronômicos na amazônia brasileira

Yam bean is a non-conventional horticultural crop adapted to the Amazon region. It presents edible roots, yet, its seeds contain cytotoxic components such as rotenone and pachyrhizin. The Instituto Nacional de Pesquisas da Amazonia has 64 yam bean genotypes in its germplasm bank, however, their diversity is unknown. The aim of this study was to assess the diversity of these genotypes using 10 morphoagronomic traits, plant height, number of secondary branches, shoot biomass, stem diameter, root biomass, number, length, diameter, length/diameter ratio (L/D), and shape. The accessions were planted on non-flooded land, Manaus, Amazonas (02º 59'48.2''S and 60º 01' 22.4''W) in completely randomized design with three replicates and three plants per plot spaced 0.5 x 1 m. The results showed significant diversity for all characters except for stem diameter and visual assessment of root shape. Biplot graphic explained 60% of the total variation, which identified that genotypes P44, P22 and P18 have high values for root yield (80-108 t ha-1), number of secondary branches (15-31) and shoot biomass (0.5-0.8 kg plant-1). Cluster analysis, considering 50% of relative Euclidean distance, revealed 15 major groups. We conclude that the genotypes assessed have wide diversity and some of them high root yield potential. This suggests that a yam bean breeding program can be successful for the yield of roots and seeds in the Amazonian region.O feijão-macuco é uma hortaliça não convencional da Amazônia. Suas raízes são comestíveis e suas sementes tóxicas por conter rotenona e paquirizina. O Instituto Nacional de Pesquisas da Amazônia (INPA) tem conservado 64 genótipos de feijão-macuco em seu banco de germoplasma, mas a diversidade genética destes é desconhecida. O objetivo deste trabalho foi avaliar estes acessos utilizando 10 descritores morfoagronômicos tais como: altura de planta, número de ramas secundárias, massa da parte aérea, diâmetro de caule, massa, número, comprimento, diâmetro, relação comprimento/diâmetro e formato de raízes. O experimento foi conduzido em terra firme no município de Manaus (02º 59'48.2''LS e 60º 01' 22.4''LO), em delineamento de blocos ao acaso com três repetições e três plantas por parcela. Os resultados mostraram diversidade significativa para todos os caracteres, exceto para diâmetro do caule e avaliação visual do formato da raiz. O Biplot explicou 60% da variação total o qual mostrou que os genótipos P44, P22 e P18 tem elevada produtividade de raízes (80-108 t ha-1), número de ramificações secundarias (15-31) e massa da parte aérea (0.5-0.8 kg/planta). A análise de agrupamento considerando 50% da distancia euclidiana relativa mostrou 15 grupos principais. Por tanto, concluímos haver ampla diversidade nos genótipos especialmente para produtividade de raízes. Isto indica que o melhoramento de feijão-macuco, na região Amazônica, pode ter sucesso para aumentar a produtividade de raízes e sementes.", 'p

Seleção de progênies de tomate em Rondônia

This study aimed to select endogamic progenies of tomato cv. Yoshimatsu and to conduct a progeny test in the state of Rondônia. The experiment was carried out in a randomized block design with four replicates and eight plants per plot, spacing 1x0.5 m, with one stem. A significant variation was observed among the fifteen progenies for productivity (2.0-5.5 kg plant-1), seed mass with placenta (18-31.5 g fruit-1), number of fruits per plant (18.8-38.7) and soluble solids (3.4-4.2°Brix). No significant variation was noticed for fruit size, pericarp thickness, number of locules, pH, number of flowers and fruit set, though. P6 progeny showed to be the most productive one (110 t ha-1): average fruit mass was 142.5 g, salad type tomato, 7.5 locules, 3.5°Brix, pH 4.2, 60.9 flowers per plant and 64.2% fruit set. Thus, these data show genetic variability of cultivar Yoshimatsu, being possible to obtain lines and/or cultivars with medium to large fruits adapted to the state of Rondônia. © 2019, Sociedade de Olericultura do Brasil. All rights reserved

Caracteres morfoagronômicos revelam elevada diversidade genética das variedades crioulas de pimenta Murupi

Murupi chili pepper is a hot Amazonian pepper that has been used as flavoring in the region, yet its diversity is unknown. This paper aims to assess the diversity in 20 landraces from Peruvian, Colombian, and Brazilian Amazon. The experiment was installed in Manaus-AM, using a randomized complete block design with three replicates and five plants per plot. Analyses of variance showed significant differences for all nine descriptors. Fruit yield showed, in average, to be 208.08 fruits per plant, tantamount to 381.44 g per plant. Given 50% of relative distances estimated by generalized Mahalanobis distances and, nearest neighbor clustering, they displayed six groups. Cluster I comprised 50% of the landraces. Clusters IV, V and VI were represented by ‘8’ (Putumayo, Colombia), ‘27’ (Yurimaguas, Peru) and ‘24’ (Jutaí-AM, Brazil), respectively. The highest yielding landrace showed to be ‘17’ (Manicoré-AM, Brazil), bearing 685.5 fruits and 1.92 kg per plant. Our findings suggest Murupi pepper may possibly be improved by selection and/ or hybridization. © 2018, Sociedade de Olericultura do Brasil. All rights reserved

Heterosis and combining ability in bell pepper lines with resistance to multiple pathogens

The aim of this study was to develop bell pepper hybrids with resistance to multiple pathogens and make inferences in regard to components of heterosis in hybrids obtained from lines presumed to be resistant to Pepper yellow mosaic virus (PepYMV), Phytophthora capsici, or Meloidogyne incognita. The studies were carried out in a greenhouse. We used ten lines, thirty experimental hybrids, and seven controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata Super, and Criollo de Morelos-334). For all experiments, a randomized block design was used with three replications (with plots composed of 16 plants). For evaluation of the reactions to P. capsici and to PepYMV, the percentages of asymptomatic plants were considered. For evaluation of the reactions to M. incognita, the reproduction index and the reproduction factor of the nematode were calculated. The additive gene effects were important for all the traits evaluated, and for percentage of plants resistant to PepYMV and P. capsici, the non-additive effects were also important. The alleles that control resistance to PepYMV, to P. capsici, and to M. incognita have a degree of dominance near 1, in absolute value, which indicates a favorable situation for obtaining hybrids that accumulate multiple resistance to these pathogens

Inibição do crescimento de bactérias Gram-negativas em microdiluição por tratamento com Nisina e EDTA

The outer membrane composition of Gram-negative bacteria provides more resistance against the action of antimicrobial agents from the class of bacteriocins, in comparison to Gram-positive bacteria, naturally more susceptible. Aiming the control of proliferation Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhimurium, antimicrobial assays were performed with nisin as biocidal agent (concentrations 123 to 1,111 AU mL-1) and EDTA as chelating agent, compared to a Gram-positive (Staphylococcus aureus ATCC25923). The susceptibility evaluations were performed in broth microdilution with Mueller-Hinton medium and inoculum with 106 CFU mL-1 of indicator bacterium, and the results were obtained by optical density readings (630 nm) at regular intervals during the incubation period. It was observed that EDTA is capable of reducing cell viability of P. aeruginosa. The bacteriocin nisin demonstrated effective antimicrobial action to four indicator bacteria, under different concentrations. The combined treatments of nisin+EDTA obtained high inhibition rates, and the presence of EDTA was significant only to Gram-negative bacteria. Thus, treatments accounted effective strategies to promote inhibition of cell growth during microdilution broth assays.A composição da membrana externa das bactérias Gram-negativas fornece mais resistência à ação dos agentes antimicrobianos da classe das bacteriocinas, em comparação às bactérias Gram-positivas, naturalmente mais suscetíveis. Com o objetivo de controlar a proliferação de Escherichia coli, Pseudomonas aeruginosa e Salmonella Typhimurium, foram realizados ensaios antimicrobianos com nisina como agente biocida (concentrações 123 a 1.111 AU mL-1) e EDTA como agente quelante, comparado a um Gram-positivo (Staphylococcus aureus ATCC25923) . As avaliações de suscetibilidade foram realizadas em microdiluição em caldo com meio Mueller-Hinton e inóculo com 106 UFC-1 de bactéria indicadora, e os resultados foram obtidos por leituras de densidade óptica (630 nm) em intervalos regulares durante o período de incubação. Observou-se que o EDTA é capaz de reduzir a viabilidade celular de P. aeruginosa. A bacteriocina nisina demonstrou ação antimicrobiana eficaz para quatro bactérias indicadoras, sob diferentes concentrações. Os tratamentos combinados de nisina + EDTA obtiveram altas taxas de inibição e a presença de EDTA foi significativa apenas para bactérias Gram-negativas. Assim, os tratamentos representaram estratégias eficazes para promover a inibição do crescimento celular durante ensaios de caldo de microdiluição

Caracterização das resistências a múltiplos patógenos em híbridos experimentais de pimentão

The aim of this study was to assess resistance to some of the major sweet pepper pathogens [Phytophthora capsici, Pepper yellow mosaic virus (PepYMV) and Meloidogyne incognita] in a group of experimental hybrids and their respective parental lines, and to identify hybrids possibly resistant to all three pathogens. Ten parental breeding lines, thirty experimental hybrids and seven commercial controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata Super and Criollo de Morelos-334) were used. Each experiment was set up in a randomized complete block design with three replications and plots consisting of 16 plants. For assessment of resistance to P. capsici and PepYMV, the percent of asymptomatic plants was considered. In evaluating reactions to M. incognita, both the nematode reproduction index and the nematode reproduction factor were calculated. Five hybrids were found with resistance to all three pathogens. For all three pathogens, there was evidence that hybrids with two resistant parental lines showed slightly higher levels of pathogen resistance than those with only one resistant parental line. © 2017, Sociedade de Olericultura do Brasil. All rights reserved

Diversity of yam bean ( Pachyrhizus spp. Fabaceae) based on morphoagronomic traits in the Brazilian Amazon

ABSTRACT Yam bean is a non-conventional horticultural crop adapted to the Amazon region. It presents edible roots, yet, its seeds contain cytotoxic components such as rotenone and pachyrhizin. The Instituto Nacional de Pesquisas da Amazonia has 64 yam bean genotypes in its germplasm bank, however, their diversity is unknown. The aim of this study was to assess the diversity of these genotypes using 10 morphoagronomic traits, plant height, number of secondary branches, shoot biomass, stem diameter, root biomass, number, length, diameter, length/diameter ratio (L/D), and shape. The accessions were planted on non-flooded land, Manaus, Amazonas (02º 59'48.2''S and 60º 01' 22.4''W) in completely randomized design with three replicates and three plants per plot spaced 0.5 x 1 m. The results showed significant diversity for all characters except for stem diameter and visual assessment of root shape. Biplot graphic explained 60% of the total variation, which identified that genotypes P44, P22 and P18 have high values for root yield (80-108 t ha-1), number of secondary branches (15-31) and shoot biomass (0.5-0.8 kg plant-1). Cluster analysis, considering 50% of relative Euclidean distance, revealed 15 major groups. We conclude that the genotypes assessed have wide diversity and some of them high root yield potential. This suggests that a yam bean breeding program can be successful for the yield of roots and seeds in the Amazonian region

Selection intensities of families and clones in potato breeding

Families selection has not been recommended as a selection method for vegetative propagated species. To verify its utility for potato improvement a series of experiments were carried out under warm temperatures (rainy season). Thirty clonal families originated from heat tolerant parents were evaluated for tuber yield and specific gravity. After obtaining the seedling generation (SG) and the first clonal generation (FCG) individual clones from a further two generations were assessed. Simulations were conducted with different intensities of family selection in SG and FCG and intensities of clonal selection in subsequent generations. The results show that family selection intensities between 50% and 60% allowed the greatest gains. Estimates of h² at the families level were always higher than at the clones level and corroborate for the more effective selection of families in early generations. The selection of families for tuber specific gravity can be made in the early generations (SG and FCG) regardless of the temperature conditions where the individual clones will be selected. The sequential selection of families with intensities of 60% (SG) and 60% (FCG) would promote greater efficiency for the selection of clones in second or third clonal generation. In the case of applying stronger selection intensities for a higher efficiency with sequential selection (SG and FCG) weaker intensities should be applied in the SG and stronger intensity in FCG . Family selection for tuber yield could be practiced in the FCG as long as the selection of clones was not held in contrasting temperature conditions