Plant breeding reduces the genetic diversity of plants and could influence the composition, structure, and diversity of the rhizosphere microbiome, selecting more homogeneous and specialized ...microbes. In this study, we used 16S rRNA sequencing to assess the bacterial community in the rhizosphere of different lines and modern cowpea cultivars, to investigate the effect of cowpea breeding on bacterial community assembly. Thus, two African lines (IT85F-2687 and IT82D-60) and two Brazilian cultivars (BRS-Guariba and BRS-Tumucumaque) of cowpea were assessed to verify if the generation advance and genetic breeding influence the bacterial community in the rhizosphere. No significant differences were found in the structure, richness, and diversity of bacterial community structure between the rhizosphere of the different cowpea genotypes, and only slight differences were found at the OTU level. The complexity of the co-occurrence network decreased from African lines to Brazilian cultivars. Regarding functional prediction, the core functions were significantly altered according to the genotypes. In general, African lines presented a more abundance of groups related to chemoheterotrophy, while the rhizosphere of the modern cultivars decreased functions related to cellulolysis. This study showed that the genetic breeding process affects the dynamics of the rhizosphere community, decreasing the complexity of interaction in one cultivar. As these cowpea genotypes are genetically related, it could suggest a new hypothesis of how genetic breeding of similar genotypes could influence the rhizosphere microbiome.
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Our working hypothesis was that magnesium (Mg) supplementation modulates plant performance under low water availability and improves drought tolerance in soybean genotypes. Plants of Bônus 8579, ...M8808 and TMG1180 genotypes were grown under field conditions and subjected to three water stress treatments (control, moderate and severe stress) and three Mg levels 0.9 (low), 1.3 (adequate) and 1.7 cmolc dm-³ (supplementation). After 28 days of drought imposition, the growth parameters, osmotic potential, relative water content, leaf succulence, Mg content and photosynthetic pigments were assessed. In general, drought drastically decreased the growth in all genotypes, and the reductions were intensified from moderate to severe stress. Under adequate Mg supply, TMG1180 was the most drought-tolerant genotype among the soybean plants, but Mg supplementation did not improve its tolerance. Conversely, although the M8808 genotype displayed inexpressive responses to drought under adequate Mg, the Mg-supplemented plants were found to have surprisingly better growth performance under stress compared to Bônus 8579 and TMG1180, irrespective of drought regime. The improved growth of high Mg-treated M8808-stressed plants correlated with low osmotic potential and increased relative water content, as well as shoot Mg accumulation, resulting in increased photosynthetic pigments and culminating in the highest drought tolerance. The results clearly indicate that Mg supplementation is a potential tool for alleviating water stress in M8808 soybean plants. Our findings suggest that the enhanced Mg-induced plant acclimation resulted from increased water content in plant tissues and strategic regulation of Mg content and photosynthetic pigments.
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The present paper aims to compute climatological zones apt for the cultivation of pitaya based on trends in the occurrence of climate change events from the IPCC (Intergovernmental Panels on Climate ...Change) in Brazil. We used temperature and precipitation data from 4942 cities collected on the NASA/POWER platform (National Aeronautics and Space Administration/Prediction of Worldwide Energy Resources) from 1990 to 2020 to elaborate on the current scenario. The climate change scenarios were obtained using the CHELSA platform (Climatologies at high resolution for the earth’s land surface areas) and corresponded to the periods 2041–2060 and 2061–2080 associated with four IPCC climate change scenarios. The spatialization of the data occurred according to the bioclimatic classes designed to meet the thermal and water needs of the crop. In the current scenario, class B5 has a predominance of 37.07% of the country, characterizing the Midwest, Southeast, and Northeast regions, as well as the state of Paraná, as suitable for the cultivation of pitaya. Projections of temperature increase and reduction of accumulated rainfall were found throughout Brazil, but with greater impact in the North and Northeast regions, which had the greatest reduction of areas suitable for the cultivation of pitaya with a greater predominance of classes B8 and B9. In the South and Southeast regions, class B5 makes up a large part of the areas that remained suitable for the production of this fruit until 2080. The results suggest that climate change does not benefit the cultivation of pitaya in some regions of Brazil because the dimensions of the areas suitable for economic production are restricted.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Genotype × environment (G×E) interaction is an important source of variation in soybean yield, which can significantly influence selection in breeding programs. This study aimed to select superior ...soybean genotypes for performance and yield stability, from data from multi-environment trials (METs), through GGE biplot analysis that combines the main effects of the genotype (G) plus the genotype-by-environment (G×E) interaction. As well as, through path analysis, determine the direct and indirect influences of yield components on soybean grain yield, as a genotype selection strategy. Eight soybean genotypes from the breeding program of Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) were evaluated in field trials using a randomized block experimental design, in an 8 x 8 factorial scheme with four replications in eight different environments of the Cerrado of Northeastern Brazil during two crop seasons. Phenotypic performance data were measured for the number of days to flowering (NDF), height of first pod insertion (HPI), final plant height (FPH), number of days to maturity (NDM), mass of 100 grains (M100) and grain yield (GY). The results revealed that the variance due to genotype, environment, and G×E interaction was highly significant (P < 0.001) for all traits. The ST820RR, BRS 333RR, BRS SambaíbaRR, M9144RR and M9056RR genotypes exhibited the greatest GY stability in the environments studied. However, only the BRS 333RR genotype, followed by the M9144RR, was able to combine good productive performance with high yield stability. The study also revealed that the HPI and the NDM are traits that should be prioritized in the selection of soybean genotypes due to the direct and indirect effects on the GY.
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Land degradation by deforestation adversely impacts soil properties, and long-term restoration practices have been reported to potentially reverse these effects, particularly on soil microorganisms. ...However, there is limited knowledge regarding the short-term effects of restoration on the soil bacterial community in semiarid areas. This study evaluates the bacterial community in soils experiencing degradation (due to slash-and-burn deforestation) and restoration (utilizing stone cordons and revegetation), in comparison to a native soil in the Brazilian semiarid region. Three areas were selected: (a) under degradation; (b) undergoing short-term restoration; and (c) a native area, and the bacterial community was assessed using 16S rRNA sequencing on soil samples collected during both dry and rainy seasons. The dry and rainy seasons exhibited distinct bacterial patterns, and native sites differed from degraded and restoration sites. Chloroflexi and Proteobacteria phyla exhibited higher prevalence in degraded and restoration sites, respectively, while Acidobacteria and Actinobacteria were more abundant in sites undergoing restoration compared to degraded sites. Microbial connections varied across sites and seasons, with an increase in nodes observed in the native site during the dry season, more edges and positive connections in the restoration site, and a higher occurrence of negative connections in the degradation site during the rainy season. Niche occupancy analysis revealed that degradation favored specialists over generalists, whereas restoration exhibited a higher prevalence of generalists compared to native sites. Specifically, degraded sites showed a higher abundance of specialists in contrast to restoration sites. This study reveals that land degradation impacts the soil bacterial community, leading to differences between native and degraded sites. Restoring the soil over a short period alters the status of the bacterial community in degraded soil, fostering an increase in generalist microbes that contribute to enhanced soil stability.
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Identifying the climatic characterization of a region and its spatial and temporal variation, as well as its changes in the face of climate change events, is essential for agrometeorological studies ...because they can assist in the planning of strategies that reduce the negative impacts generated in the cultures exposed to critical climatic conditions. Thus, this study aimed to characterize the climatic conditions of the MATOPIBA region and its changes in scenarios of climate change using the classification index of Thornthwaite. Daily time series of rainfall and temperature data in the 1950–1990 period were used, covering 467 points over the studied region. The data set was used to estimate climatological water balance and climate index Thornthwaite (1948), and obtain the trends climatological according to IPCC (
2014
) climate change projections, with changes in the average air temperature (+ 1.5 °C and − 1.5 °C) and precipitation (+ 30% and − 30%). The MATOPIBA region is characterized by its humid, dry subhumid, and moist subhumid climate, with the rainy seasons, between October and April, and drought, from May to September, well defined. In MATOPIBA climate change scenarios, climatic extreme indices tend to alter the pattern, frequency, and distribution of climate class, which can increase climate risk and impact crop production. Therefore, the results obtained can be used to develop strategies to mitigate the vulnerability of crops to climate change conditions.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Water deficits have been considered the most restrictive environmental constraint on agricultural production worldwide. The current study aimed to investigate the role of silicon nutrition ...(Si) in activating defence mechanisms against drought damage in cowpea cultivars. The experiments were carried out in a randomized block design in a 2 × 2 × 4 factorial scheme, corresponding to two cowpea cultivars (BRS Novaera and BRS Tumucumaque), two water regimes (control well‐irrigated and water deficit) and four Si levels (0, 1.0, 2.0 and 4.0 mM). Plant growth and physiological and biochemical indicators were evaluated 28 days after drought imposition. Drought significantly reduced the photosynthetic pigments (Chl
b
and Chl
total
), gas exchanges (net photosynthesis, transpiration and stomatal conductance) and, consequently, all growth parameters of cowpea plants compared with well‐irrigated plants. However, Si at 2.0 mM activated critical responses in the BRS Novaera cultivar under drought, almost recovering plant performance and increasing drought tolerance. The beneficial Si‐induced effects were closely related to increased accumulation of Si, carbohydrates and free amino acids that likely promoted osmoregulation and were associated with an improved antioxidant system composed of proline and the activity of SOD, CAT and APX. These metabolic alterations were sufficient to enable enhanced net photosynthesis and plant growth. In conclusion, Si counteracts the deleterious effects of water deficit by efficiently inducing antioxidant defence and photosynthetic performance in Novaera plants. Si nutrition may constitute a potential strategy to cultivate cowpea plants in water‐scarce areas from arid and semiarid regions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Cowpea bean is a common crop quite appreciated in Brazil. However, it is known that its low yield depending on soil and climatic conditions. The aim of this research is the selection of ...high-performance black-eyed cowpea through GYT biplot analysis. Twelve (12) cowpea bean strains were assessed between 2016 and. The study followed a randomized complete block design, with four repetitions; two commercial cultivars were used ascheck. The following variables were assessed: number of days required for flowering, final stand, value for cultivation, pod yield, pod length, mean number of grains per pod and grain weight. The analysis of variance showed genetic variability between strains, differences between the assessed years and different strain-performance in each growing year. Based on the GYT biplot graph, cultivar BRS Itaim, and strains L9 and L7 recorded the best performance for the set of yield characteristics. Variable 'pod length' had positive correlation to bedding, number of days required for flowering and number of grains per pod. Variable '100-grain weight' had positive correlation to final stand, pod yield and mean grain weight per pod. Strains L9, L7 and cultivar BRS Itaim recorded the best yield regarding the assessed variables.
Extreme weather events, such as severe droughts, pose a threat to the sustainability of beef cattle by limiting the growth and development of forage plants and reducing the available pasture for ...animals. Thus, the search for forage species that are more tolerant and adapted to soil water deficit conditions is an important strategy to improve food supply. In this study, we propose utilizing the mathematical concept of the Manhattan distance to assess the variations in the morphological variables of tropical forage grasses under water-limited conditions. This study aimed to select genotypes of tropical forage grasses under different water stress levels (moderate or severe) at this distance and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Nine varieties from five species were examined. Forage grasses were grown in 12-L pots under three soil irrigation regimes 100% pot capacity-PC (well-irrigated control), 60% PC (moderate drought stress), and 25% PC (severe drought stress) with four replicates. Drought stress treatments were applied for 25 days during the forage grass tillering and stalk elongation phases. After exposure to drought stress, the growth and morphological traits of forage plants were evaluated. The results show that the use of the Manhattan distance combined with TOPSIS helps in the genotypic selection of more stable tropical forage grass varieties when comparing plants exposed to moderate and severe drought conditions in relation to the nonstressful environment (control). The 'ADR 300', 'Pojuca', 'Marandu', and 'Xaraés' varieties show greater stability when grown in a greenhouse and subjected to water stress environments. The selected forage varieties can be used as parents in plant breeding programs, allowing us to obtain new drought-resistant genotypes.
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10.
Rhizospheric microbial community in plant species from the Phaseolus genus Lopes, Angela Celis de Almeida; Mendes, Lucas William; Brito, Karla Annielle da Silva Bernardo ...
Applied soil ecology : a section of Agriculture, ecosystems & environment,
February 2023, 2023-02-00, Volume:
182
Journal Article
Peer reviewed
The rhizospheric microbial community is affected by plant genera and genotypes. However, the rhizospheric effect on the microbial community from distinct plant species belonging to the same genus is ...poorly understood. This study hypothesized that the rhizospheric microbial community differs between plant species from the Phaseolus genus (i.e. P. acutifolius A. Gray, P. lunatus L., P. vulgaris L., P. microcarpus Mart., and P. filiformis Benth.) and that these differences could be related to phylogenetic differences found in these plant species. The redundancy analysis showed a distinct microbial community mainly when comparing P. lunatus and P. microcarpus. The microbial richness and diversity varied among plants, where P. lunatus showed the highest richness and diversity and P. microcarpus the lowest. The abundances of specific microbial phyla varied between the rhizosphere of Phaseolus species. Actinobacteria was abundant in the rhizosphere of P. acutifolius, P. vulgaris, and P. filiformis, while Acidobacteria was abundant in the rhizosphere of P. lunatus. This study revealed that each Phaseolus species recruits a distinct microbial community in the rhizosphere, with the rhizosphere community of the domesticated species P. lunatus being the most distinct.
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•Rhizospheric microbial community differs according to phylogenetic distance of plants.•Phaseolus lunatus recruits distinct microbial community in the rhizosphere.•Microbial community from Phaseolus lunatus is more efficient in processing nitrogen.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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