Produtividade e concentração de amido em batata-doce em função da aplicação de potássio

O trabalho teve como objetivo avaliar as características agronômicas da batata-doce, a concentração de amido e o potencial de rendimento de álcool em função da aplicação de doses de potássio via solo. O experimento foi conduzido em casa de vegetação em delineamento experimental inteiramente casualizado, sendo cinco doses de K2O (0, 100, 200, 300 e 400 kg ha-1). Avaliou-se o teor de potássio na parte aérea, a produção de parte aérea, a concentração de amido, a produtividade de raiz e rendimento potencial de álcool. Mediante os resultados, foi encontrada maior produtividade de raízes de batata-doce, 21,2 t ha-1, quando aplicado 294 kg de K2O ha-1. A máxima concentração de amido na raiz foi obtida na dose de 267 kg de K2O ha-1. Entretanto, o máximo rendimento potencial de etanol foi obtido na dose de 270 kg de K2O ha-1, demonstrando, assim, que a adubação com potássio promoveu melhor desenvolvimento vegetativo e produtivo de plantas de batata-doce. Além disso, promoveu a melhora da qualidade industrial pela elevação na concentração de amido nas raízes e rendimento potencial de etanol, concluindo-se que o fornecimento do íon potássio contribuiu para o rendimento de componentes biométricos e produtivos na cultura da batata-doce

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Gene action and reciprocal effects for root traits in tropical maize under contrasting nitrogen conditions

Em milho, a eficiência no uso do nitrogênio (N) não ultrapassa 50% e uma forma de contornar esse problema é a melhoria da eficiência do uso e absorção de N (EUN) por meio do melhoramento genético de caracteres de morfologia e arquitetura de raízes. Embora o número de trabalhos com caracterização de genótipos para morfologia de raiz tem aumentado na última década, esses trabalhos tem focado na avaliação per se de linhagens e híbridos. Assim, pouco se sabe sobre a relação entre os parentais e seus cruzamentos em relação à morfologia de raiz, principalmente sobre condições contrastantes de N. Assim, neste trabalho, objetivou-se estimar a capacidade de combinação efeito recíproco entre linhagens de milho tropical eficientes no uso de N para caracteres de morfologia de raiz em condições contrastantes de N. Para isso, 10 linhagens de milho e os 90 híbridos (45 F 1 e 45 recíprocos) foram avaliados para caracteres de raiz em condições contrastantes de N em casa de vegetação. Houve baixa significância para a interação dos caracteres com o nível de N. A seleção em ambiente com diferentes níveis de N só seria recomendada para os caracteres AP, MPAS e DTR em linhagens e MPAS e RSR em híbridos. Efeitos aditivos tem papel importante na EUN, entretanto, para caracteres como RSR, MRS, CRA e VOL os efeitos não aditivos foram importantes. Para CGC houve significância para a maioria dos caracteres em ambos os níveis, exceto para RSR e CRA. O caractere que apresenta maior influência de efeito não aditivo é RSR. As linhagens que apresentaram efeito de CGC positivo para todos os caracteres, nos dois níveis de N, foram VML022 e VML016. A linhagem VML028 apresentou valores negativos para efeito de CGC em ambos os níveis de N. Para o efeito de RCGC positivo as linhagens que se destacaram foram VML004, VML017, VML020 e VML028. A CGC foi o parâmetro em que o nível de N apresentou maior influência. Correlações de média a baixa magnitude foram observadas para efeito de F 1 com recíproco e RCGC com F 1 em baixo N. Foi constatada alta correlação para efeito de RCGC e heterose dos recíprocos. Conclui-se que o efeito recíproco desempenha função importante, quando em baixo N, para promover EUN e influencia na manifestação da heterose. Os efeitos de CGC apresentam maior contribuição na expressão da maioria caracteres de raiz para EUN. Palavras-chave: Estresse abiótico. Eficiência no uso de N. Dialelo completo.In maize, the efficiency in the use of nitrogen (N) does not exceed 50% and one way to get around this problem is to improve the efficiency of the use and absorption of N (EUN) through the genetic improvement of characters of root morphology and architecture. Although the number of studies with genotype characterization for root morphology has increased in the last decade, these studies have focused on the per se evaluation of lines and hybrids. Thus, little is known about the relationship between parents and their crosses in relation to root morphology, mainly about contrasting conditions of N. So, this study aimed to estimate the ability to combine the reciprocal effect between efficient tropical corn lines. use of N for root morphology characters under contrasting N conditions. For this, 10 strains of corn and 90 hybrids (45 F 1 and 45 reciprocal) were evaluated for root characters under contrasting conditions of N in a greenhouse. There was a low significance for the interaction of the characters with the level of N. Selection in an environment with different levels of N would only be recommended for the characters AP, MPAS, and DTR in strains and MPAS and RSR in hybrids. Additive effects play an important role in EUN, however, for characters such as RSR, MRS, CRA, and VOL the non-additive effects were important. For CGC there was the significance for most characters at both levels, except for RSR and CRA. The lines that showed a positive CGC effect for all characters, at both levels of N, were VML022 and VML016. The line VML028 showed negative values for the CGC effect at both levels of N. For the effect of positive RCGC the strains that stood out were VML004, VML017, VML020, and VML028. CGC was the parameter on which the N level had the greatest influence. Correlations of medium to low magnitude were observed for the effect of F 1 with reciprocal and RCGC with F 1 in low N. A high correlation was found for the effect of RCGC and heterosis of the reciprocal. It is concluded that the reciprocal effect plays an important role when in low N, to promote EUN and influences the manifestation of heterosis. The effects of CGC make a major contribution to the expression of most root characters for EUN. Keywords: Abiotic stress. Efficient use of N. Complete diallel.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Post-harvest characterization of strawberry hybrids obtained from the crossing between commercial cultivars

Abstract The lack of programs to improve the strawberry crop in Brazil has led to a growing increase in the use of seedlings imported from Chile, which leads to a certain dependence of imported material on the part of the producers and increases the production even more, since the producers have. This proves even more the need for the development of cultivars adapted to the local conditions of cultivation. In this sense, the aim was to evaluate the post-harvest of fruits of 15 hybrids of strawberry obtained from the cross between commercial cultivars, in order to select the materials with chemical quality superior to the cultivars most planted in Brazil. The contents of soluble solids, titratable acidity, ratio, vitamin C, anthocyanins and phenol were evaluated. The characterization of strawberry hybrids indicated that the RVFS 13-07, RVFS 13-24, RVCS 13-07, RVCS 13-10 and RVCA 13-08 materials stood out in post-harvest evaluations, with higher levels of functional compounds (vitamin C, anthocyanins and phenolics) and higher values of quality parameters (soluble solids, titratable acidity and ratio), important characteristics for the in natura consumption or for use by the industry. These hybrids were shown to be promising to continue the crop breeding program by demonstrating that they carried characteristics of interest for intraspecific crosses. The values obtained for the analyzed characteristics were higher than the values found in the literature for the cultivars most planted and consumed in Brazil and in the World, which demonstrates the efficiency in the selection process

Genetic divergence among processing tomato hybrids and formation of new segregating populations

ABSTRACT Tomato is the most important vegetable species and has a strong bottleneck effect in its domestication and evolution. In exploring the existing genetic variability in commercial germplasm, germplasm has been proven to be an excellent alternative to obtain inbred lines in order to provide superior new hybrids in the future. In this sense, the objective of this study was to estimate the genetic distance among commercial processing tomato hybrids via agronomical and quality postharvest fruit traits with the aim of suggesting promising crosses for the formation of base populations for tomato breeding. Ten hybrids of processing tomato were evaluated in a complete randomized block design with three replicates. In total, eleven agronomic and postharvest fruit quality traits were evaluated. The genetic distances were estimated between the hybrids using the generalized Mahalanobis () and Gower () distances. The genetic distance among tomato hybrids was determined using a graphic projection of the first two canonical variables. The presence of significant genetic variability among the hybrids (P <0.05) was demonstrated and was sufficient for the selection of the best hybrids before the breeding process. The hybrid Laura stood out for its postharvest characteristics and was the most divergent genotype compared to the others evaluated. The most promising crossings for the formation of segregating populations with superior genetic merit are Kátia x Laura, Vênus x Laura, Fascínio x Laura, AP-533 x Laura, Tinto x Laura, AP-529 x Laura, Supera x Laura, Granadero x Laura, Granadero x AP533, Granadero x Ap529 and Granadero x Kátia