Performance of grain sorghum hybrids in soils with low and high aluminum saturation

The presence of aluminum (Al3+) in acidic soils is one of the main causes of low crop yield, since it inhibits the root growth, thus affecting the nutrients and water uptake by plants. An approach to grow crops in areas with high Al3+ saturation is the use of tolerant cultivars. This study aimed to evaluate commercial sorghum hybrids in soils with low and high aluminum saturation, in order to select cultivars with high grain yield, even when exposed to abiotic stress. Twenty hybrids were evaluated for characteristics such as plant flowering, plant height and grain yield. All three traits were significantly affected by Al3+, being grain yield the most affected one. Despite the significant genotypes x environments interaction for grain yield, it was possible to select hybrids with yield above the national average in both environments. The hybrids BRS373, 50A50, AS4639, DKB540, AS4625, A9721R, 1167092, DKB550, 1G282 and AG1040 showed a high yield under low and high Al-saturation conditions

Avaliação multiambiental de híbridos de sorgo durante a entressafra no Brasil

The objective of this work was to simultaneously select pre-commercial grain sorghum hybrids with high adaptability and yield stability, through mixed modeling, in 20 environments, during six years. The evaluated plant material consisted of 57 commercial grain sorghum hybrids. In all experiments, hybrids were arranged in a triple lattice design; some experiments used a 6x6 lattice, and others, a 5x5 lattice. Adaptability and stability parameters were obtained based on the prediction by harmonic mean of the relative performance of genotypic values (HMRPGV). The mixed models proved to be adequate to analyze the genotype x environment (GxE) interaction and the genotypic adaptability and stability studies on grain sorghum. The hybrids that stand out, considering all environments are 1G282, A9904, 50A50, A9902, and XB6022. The A9904 hybrid stands out in favorable environments, with a grain yield above average. Only 1G282 is among the five best hybrids for each group of environments, and it is the best grain sorghum hybrid for yield performance, adaptability, and stability. The predicted genotypic values based on genotypic means can be used in the environments with the same GxE interaction pattern because they are free of the GxE interaction.O objetivo deste trabalho foi selecionar, simultaneamente, híbridos pré-comerciais de sorgo granífero com alta adaptabilidade e estabilidade da produção de grãos, por meio de modelagem mista, em 20 ambientes, por seis anos. O material vegetal avaliado consistia de 57 híbridos comerciais de sorgo granífero. Em todos os experimentos, os híbridos foram arranjados em delineamento fatorial triplo; alguns experimentos utilizaram um fatorial 6x6, e outros, um fatorial 5x5. Os parâmetros de adaptabilidade e estabilidade foram obtidos com base na predição por média harmônica da performance relativa dos valores genéticos (MHPRVG). Os modelos mistos mostraram-se adequados para analisar a interação genótipo x ambiente (GxE) e os estudos de adaptabilidade e estabilidade genotípica do sorgo granífero. Os híbridos que se destacam, considerando-se todos os ambientes, são 1G282, A9904, 50A50, A9902 e XB6022. O híbrido A9904 destaca-se em ambientes favoráveis, com rendimento de grãos acima da média. Apenas 1G282 está entre os cinco melhores híbridos para cada grupo de ambientes e é o melhor híbrido de sorgo granífero quanto ao rendimento, à adaptabilidade e à estabilidade. Os valores genotípicos preditos com base em médias genotípicas podem ser usados em relação aos ambientes com o mesmo padrão de interação GxE por estarem livres da interação GxE

Pressure-support ventilation or T-piece spontaneous breathing trials for patients with chronic obstructive pulmonary disease : a randomized controlled trial

Background Little is known about the best strategy for weaning patients with chronic obstructive pulmonary disease (COPD) from mechanical ventilation. Spontaneous breathing trials (SBT) using a T-piece or pressure-support ventilation (PSV) have a central role in this process. Our aim was to compare T-piece and PSV SBTs according to the duration of mechanical ventilation (MV) in patients with COPD. Methods Patients with COPD who had at least 48 hours of invasive MV support were randomized to 30 minutes of T-piece or PSV at 10 cm H2O after being considered able to undergo a SBT. All patients were preemptively connected to non-invasive ventilation after extubation. Tracheostomized patients were excluded. The primary outcome was total invasive MV duration. Time to liberation from MV was assessed as secondary outcome. Results Between 2012 and 2016, 190 patients were randomized to T-piece (99) or PSV (91) groups. Extubation at first SBT was achieved in 78% of patients. The mean total MV duration was 10.82 ± 9.1 days for the T-piece group and 7.31 ± 4.9 days for the PSV group (p < 0.001); however, the pre-SBT duration also differed (7.35 ± 3.9 and 5.84 ± 3.3, respectively; p = 0.002). The time to liberation was 8.36 ± 11.04 days for the T-piece group and 4.06 ± 4.94 for the PSV group (univariate mean ratio = 2.06 [1.29±3.27], p = 0.003) for the subgroup of patients with difficult or prolonged weaning. The study group was independently associated with the time to liberation in this subgroup.Conclusions The SBT technique did not influence MV duration for patients with COPD. For the difficult/ prolonged weaning subgroup, the T-piece may be associated with a longer time to liberation, although this should be clarified by further studies

Patologias atuais: a compulsão e a sociedade dos excessos: Current pathologies: compulsion and the society of excesses

O artigo em tela tem por objetivo analisar os aspectos biopsicossociais da conduta compulsiva de consumo. Propõe-se a apresentar os elementos psicológicos contidos nesse comportamento, além de verificar quais são os resultados decorrentes dessa compulsão. O consumo compulsivo, também chamado de oniomania, é um transtorno causado pela ansiedade despertada pela necessidade de comprar e saciada, somente, quando é materializada a aquisição daquilo que se deseja comprar. O estudo em questão pode ser classificado como sendo de cunho bibliográfico, a partir da análise de documentos publicados em forma de artigos científicos e livros em formato digital

Heterosis and inbreeding depression in grain sorghum hybrids

Os programas de melhoramento de sorgo têm buscado cultivares que resultem em combinações híbridas de alto rendimento de grãos, altura de plantas ideal para colheita mecanizada, e precocidade. Para tal, é importante conhecer a diversidade, o comportamento per se das linhagens e o desempenho dos híbridos resultantes dos seus cruzamentos, para a escolha de melhores genitores. Diante do exposto, o presente trabalho teve por objetivo estimar a heterose e heterobeltiose de híbridos F 1 e a depressão endogâmica de híbridos F 2, para identificação daqueles que apresentem resultados promissores para lançamento. Os experimentos foram conduzidos nas safras de 2014/2015 e 2015/2016 na estação experimental da Embrapa Milho e Sorgo, em Sete Lagoas - MG. Foram utilizados 25 híbridos de sorgo granífero, sendo 11 em fase experimental e quatro comerciais (BRS330, BRS332, BRS373 e BRS380), desenvolvidos pela Embrapa Milho e Sorgo, além de outros dez híbridos comerciais de outras empresas, que foram utilizados como testemunhas. Como genitores dos híbridos da Embrapa foram utilizadas 17 linhagens, sendo dez linhagens A (macho estéril) e sete linhagens R (restauradoras). As parcelas experimentais foram compostas por quatro linhas de cinco metros, com espaçamento de 0,5m entre linhas, em que as duas fileiras centrais foram consideradas como área útil. Foram avaliadas as características: florescimento (FLOR), altura de plantas (AP), produtividade de grãos (PROD) e massa de mil grãos (M1000). A análise de variância conjunta foi procedida no programa Genes, e decomposta nos contrastes: Híbridos F 1 vs Testemunhas, Híbridos F 1 vs Pais e Híbridos F 1 vs Híbridos F 2 . Foram gerados boxplots para observação da amplitude das características, gráfico para estudo de correlações, cálculos de heterose, heterobeltiose e depressão endogâmica, e dendrograma para estudo da diversidade genética entre as linhagens com o programa R 3.6.2. Os híbridos 1167048, 1099044, 1170017 e 1169054 se destacaram para heterose em FLOR, com redução de até cinco dias no ciclo, em relação aos seus pais. O híbrido 1170017 apresentou a maior produtividade de grãos (6,23 t.ha -1 ), 50,42% de heterose e 43,55% de heterobeltiose. O híbrido 1167048 também se destacou com heterose acima de 60% para PROD, o que significou 2 t.ha -1 a mais do que a média de seus genitores. De maneira geral, foi notada baixa diversidade entre as linhagens. No entanto, os híbridos com melhores produtividades e alta heterose foram aqueles de maiores distâncias entre genitorese com melhores desempenhos per se. As linhagens L-01, L-06 e L-07 resultaram nos híbridos com as maiores produtividades de grãos. Com isso foi possível concluir que, o uso de sementes de híbridos F 1 é muito mais atrativo para o produtor, visto a acentuada depressão endogâmica que ocorre nos híbridos F 2, com redução de até 40% na produtividade de grãos. Além disso, exploração da variabilidade genética e manifestação da heterose e heterobeltiose nos híbridos F 1 torna seu uso mais vantajoso do que somente o das linhagens, mesmo aquelas com bom desempenho per se. Palavras-chave: Heterobeltiose. Sorghum bicolor. Melhoramento genético.Sorghum breeding programs aim to improve cultivars with high grain yield, ideal plant height for mechanical harvesting, and earliness. The study of the germplasm diversity, the performance per se of the lines and its hybrid combinations are important to select the best parents, and to achieve genetic gains. The present study aimed to estimate heterosis and heterobeltiosis of F 1 and F 2 sorghum hybrids. Twenty-five grain sorghum hybrids were grown, being 11 in the experimental phase and four commercial (BRS330, BRS332, BRS373 and BRS380), developed by Embrapa Maize and Sorghum, in addition to ten commercial hybrids from other private companies, which were used as checks cultivars. As parental of the Embrapa hybrids 17 lines were used, being ten A lines (male sterile) and seven R lines (restorer). The experimental plots were four rows, 5 m long, with 0.5 m row spacing, in which the two central rows were considered as useful area. The evaluated traits were: flowering (FLOR), plant height (AP), grain yield (PROD) and thousand grain weight (M1000). The joint variance analysis was carried out using Genes program, which was decomposed into contrasts: F 1 hybrids vs check cultivars, F 1 hybrids vs parental lines and F 1 hybrids vs F 2 hybrids. Boxplots were generated to observe the amplitude of the characteristics, graph to study correlations, calculations of heterosis, heterobeltiosis and inbreeding depression, and dendrogram to study genetic diversity between lines with the R 3.6.2 program. The hybrids 1167048, 1099044, 1170017 and 1169054 were the ones that stood out for heterosis in FLOR, with a reduction of up to five days in their cycles, in relation to their parents. The hybrid 1170017 showed the highest grain yield (6.23 t.ha -1 ), 50.42% heterosis and 43.55% heterobeltiosis. The hybrid 1167048 also stood out with heterosis above 60% for PROD, which meant 2 t.ha -1 more than the average of its parents. In general, low diversity between lines was noted in the dendrogram, even some lines A and R, which tend to be more genetically distant, presented themselves within the same group. However, it was noted that the hybrids with the best yield and high heterosis were those in which the parents showed the best performances per se. The lines L-01, L-06 and L-07 resulted in hybrids with the highest grain yields. The use of F 1 hybrid seeds is much more interesting for growers, considering the significant inbreeding depression that occurs in the F 2 hybrids, with a reduction of up to 40% in their grain productivity. In addition, exploration of genetic variability and heterosis and heterobeltiosis in hybrids makes its use more advantageous than only that of lines, even those with good performance per se. Keywords: Heterobeltiosis. Sorghum bicolor. Genetic Breeding

Performance of grain sorghum hybrids in soils with low and high aluminum saturation

<div><p>ABSTRACT The presence of aluminum (Al3+) in acidic soils is one of the main causes of low crop yield, since it inhibits the root growth, thus affecting the nutrients and water uptake by plants. An approach to grow crops in areas with high Al3+ saturation is the use of tolerant cultivars. This study aimed to evaluate commercial sorghum hybrids in soils with low and high aluminum saturation, in order to select cultivars with high grain yield, even when exposed to abiotic stress. Twenty hybrids were evaluated for characteristics such as plant flowering, plant height and grain yield. All three traits were significantly affected by Al3+, being grain yield the most affected one. Despite the significant genotypes x environments interaction for grain yield, it was possible to select hybrids with yield above the national average in both environments. The hybrids BRS373, 50A50, AS4639, DKB540, AS4625, A9721R, 1167092, DKB550, 1G282 and AG1040 showed a high yield under low and high Al-saturation conditions.</p></div

Evaluation of grain sorghum hybrids for aluminum tolerance in nutrient solution

 Sorghum (Sorghum bicolor L. Moench) is one of the most important cereal crops in the world. In Brazil, the acreage of grain sorghum during off-season is quite expansive. Most of this area is the Cerrado, a Brazilian biome that is similar to a Savannah and is characterized by high acidity and soluble aluminum at toxic levels for plants. The aluminum acts as a limiting factor in achieving high yields. The purpose of this work was to phenotype sorghum hybrids for aluminum tolerance. Eighteen hybrids were evaluated in a nutrient solution containing {0} or {27} µM Al3+. The work was carried out in a growth chamber at the Embrapa Maize and Sorghum, from April 4 to May 30, 2014. The lines ATF 13B (susceptible) and ATF 14B (tolerant) were used as check cultivars. Based on the Net Root Growth after 120 hours (NRG120), Net Root Growth (NRG168) after 168 hours and Relative Net Root Growth after 168 hours (RNRG168), it was possible to distinguish tolerant hybrids from susceptible ones.  The high aluminum saturation reduced root growth by 70%. The hybrids BRS 310 and BRS 373 were tolerant to aluminum stress under nutrient solution. The hybrid BRS 330 was clustered in an intermediate group, with an approximately 50% root growth reduction. The other hybrids were susceptible with significant root reduction.

Evaluation of grain sorghum hybrids for aluminum tolerance in nutrient solution

<div><p>ABSTRACT. Sorghum (Sorghum bicolor L. Moench) is one of the most important cereal crops in the world. In Brazil, the acreage of grain sorghum during off-season is quite expansive. Most of this area is the Cerrado, a Brazilian biome that is similar to a Savannah and is characterized by high acidity and soluble aluminum at toxic levels for plants. The aluminum acts as a limiting factor in achieving high yields. The purpose of this work was to phenotype sorghum hybrids for aluminum tolerance. Eighteen hybrids were evaluated in a nutrient solution containing {0} or {27} µM Al3+. The work was carried out in a growth chamber at the Embrapa Maize and Sorghum, from April 4 to May 30, 2014. The lines ATF 13B (susceptible) and ATF 14B (tolerant) were used as check cultivars. Based on the Net Root Growth after 120 hours (NRG120), Net Root Growth (NRG168) after 168 hours and Relative Net Root Growth after 168 hours (RNRG168), it was possible to distinguish tolerant hybrids from susceptible ones. The high aluminum saturation reduced root growth by 70%. The hybrids BRS 310 and BRS 373 were tolerant to aluminum stress under nutrient solution. The hybrid BRS 330 was clustered in an intermediate group, with an approximately 50% root growth reduction. The other hybrids were susceptible with significant root reduction.</p></div

Pressure-support ventilation or T-piece spontaneous breathing trials for patients with chronic obstructive pulmonary disease - A randomized controlled trial.

BACKGROUND:Little is known about the best strategy for weaning patients with chronic obstructive pulmonary disease (COPD) from mechanical ventilation. Spontaneous breathing trials (SBT) using a T-piece or pressure-support ventilation (PSV) have a central role in this process. Our aim was to compare T-piece and PSV SBTs according to the duration of mechanical ventilation (MV) in patients with COPD. METHODS:Patients with COPD who had at least 48 hours of invasive MV support were randomized to 30 minutes of T-piece or PSV at 10 cm H2O after being considered able to undergo a SBT. All patients were preemptively connected to non-invasive ventilation after extubation. Tracheostomized patients were excluded. The primary outcome was total invasive MV duration. Time to liberation from MV was assessed as secondary outcome. RESULTS:Between 2012 and 2016, 190 patients were randomized to T-piece (99) or PSV (91) groups. Extubation at first SBT was achieved in 78% of patients. The mean total MV duration was 10.82 ± 9.1 days for the T-piece group and 7.31 ± 4.9 days for the PSV group (p < 0.001); however, the pre-SBT duration also differed (7.35 ± 3.9 and 5.84 ± 3.3, respectively; p = 0.002). The time to liberation was 8.36 ± 11.04 days for the T-piece group and 4.06 ± 4.94 for the PSV group (univariate mean ratio = 2.06 [1.29-3.27], p = 0.003) for the subgroup of patients with difficult or prolonged weaning. The study group was independently associated with the time to liberation in this subgroup. CONCLUSIONS:The SBT technique did not influence MV duration for patients with COPD. For the difficult/prolonged weaning subgroup, the T-piece may be associated with a longer time to liberation, although this should be clarified by further studies. TRIAL REGISTRATION:ClinicalTrials.gov NCT01464567, at November 3, 2011