34 research outputs found

    Biosensor-based spatial and developmental mapping of maize leaf glutamine at vein-level resolution in response to different nitrogen rates and uptake/assimilation durations

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    Replicate versus treatment variability of the GlnLux in situ imaging protocol. Three replicates of raw GlnLux agar plate images (Fig. 3) were analysed for each N treatment (+/-) and leaf (1-3) combination (6 plates total per leaf). A 1 x 10-2 M Gln agar disk was also included on each plate for standardization. The ratios of luminescence produced by each standard disk against the GlnLux agar background were pooled to generate SEM and an estimate of plate-to-plate variability. The luminescence output of all three replicates for each N treatment was pooled to generate SEM, and an estimate of the comparative variability due to N uptake/assimilation. Values represent the SEM of 6 plates each. Significant difference at P<0.05 between the variance of the standardization ratio and leaf luminescence is indicated with an asterisk, as determined with F tests. Quantification of luminescence was performed using WinView software (version 2.5.16.5, Princeton Instruments, Trenton, USA). (DOCX 43 kb

    Calcium ion currents mediating oocyte maturation events

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    During maturation, the last phase of oogenesis, the oocyte undergoes several changes which prepare it to be ovulated and fertilized. Immature oocytes are arrested in the first meiotic process prophase, that is morphologically identified by a germinal vesicle. The removal of the first meiotic block marks the initiation of maturation. Although a large number of molecules are involved in complex sequences of events, there is evidence that a calcium increase plays a pivotal role in meiosis re-initiation. It is well established that, during this process, calcium is released from the intracellular stores, whereas less is known on the role of external calcium entering the cell through the plasma membrane ion channels. This review is focused on the functional role of calcium currents during oocyte maturation in all the species, from invertebrates to mammals. The emerging role of specific L-type calcium channels will be discussed

    Variability and trait‐specific accessions for grain yield and nutritional traits in germplasm of little millet ( Panicum sumatrense Roth. Ex. Roem. & Schult.)

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    Little millet (Panicum sumatrense Roth. Ex. Roem. & Schult.), a member of the grass family Poaceae, is native to India. It is nutritionally superior to major cereals, grows well on marginal lands, and can withstand drought and waterlogging conditions. Two-hundred diverse little millet landraces were characterized to assess variability for agronomic and nutritional traits and identify promising accessions. Highly significant variabilitywas found for all the agronomic and grain nutrient traits. Accessions of robusta were high yielding whereas those of nana were rich in grain nutrients. About 80% of the accessions showed consistent protein and zinc (Zn) contents whereas iron (Fe) and calcium (Ca) contents were less consistent (29.5 and 63.5%, respectively) over 2 yr. Promising trait-specific accessions were identified for greater seed weight (10 accessions), high grain yield (15), high biomass yield (15), and consistently high grain nutrients (30) over 2 yr (R2 = .69–.74, P ≤ .0001). A few accessions showed consistently high for two or more nutrients (IPmr 449 for Fe, Zn, Ca, and protein; IPmr 981 for Zn and protein). Five accessions (IPmr 855, 974, 877, 897, 767) were high yielding and also rich in Ca. Consumption of 100 g of little millet grains can potentially contribute to the recommended dietary allowance of up to 28% Fe, 37% Zn, and 27% protein. Multilocation evaluation of the promising accessions across different soil types, fertility levels, and climatic conditions would help to identify valuable accessions for direct release as a cultivar or use in little millet improvement

    Genetic diversity and genomic resources available for the small millet crops to accelerate a New Green Revolution - final

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    TG received partial scholarship support from the Queen Elizabeth II Graduate Scholarship in Science and Technology and additional support from a grant to MR from the International Development Research Centre (IDRC) and the Canadian Department of Foreign Affairs, Trade and Development (DFATD) as part of the CIFSRF program.Small millets are nutrient-rich food sources traditionally grown and consumed by subsistence farmers in Asia and Africa. They include finger millet (Eleusine coracana), foxtail millet (Setaria italica), kodo millet (Paspalum scrobiculatum), proso millet (Panicum miliaceum), barnyard millet (Echinochloa spp.), and little millet (Panicum sumatrense). Local farmers value the small millets for their nutritional and health benefits, tolerance to extreme stress including drought, and ability to grow under low nutrient input conditions, ideal in an era of climate change and steadily depleting natural resources. Little scientific attention has been paid to these crops, hence they have been termed “orphan cereals.” Despite this challenge, an advantageous quality of the small millets is that they continue to be grown in remote regions of the world which has preserved their biodiversity, providing breeders with unique alleles for crop improvement. The purpose of this review, first, is to highlight the diverse traits of each small millet species that are valued by farmers and consumers which hold potential for selection, improvement or mechanistic study. For each species, the germplasm, genetic and genomic resources available will then be described as potential tools to exploit this biodiversity. The review will conclude with noting current trends and gaps in the literature and make recommendations on how to better preserve and utilize diversity within these species to accelerate a New Green Revolution for subsistence farmers in Asia and Afric

    Whole plant acclimation responses by finger millet to low nitrogen stress final Tech Annex 8

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    This research was supported by CIFSRF grants to MNR from the Canadian International Development Research Centre (IDRC) and the Canadian Department of Foreign Affairs, Trade and Development (DFATD).The objective of this study was to survey shoot and root morphometric acclimation responses of FM to very low background N. To ensure minimal levels of N, plants were grown in pails containing an inert clay substrate called Turface in a semi-hydroponic system without added N (Tollenaar and Migus, 1984; Figures 1B,C). This system permitted a more detailed analysis of fine root traits including root hairs, as shown by our group with maize (Gaudin et al., 2011 a,b) and recently in FM (Goron et al., 2015), compared to excavation from soil. At the beginning of the study, it was unclear whether FM plants would reach maturity in the absence of added N

    Part-based geometric categorization and object reconstruction in cluttered table-top scenes

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    This paper presents an approach for 3D geometry-based object categorization in cluttered table-top scenes. In our method, objects are decomposed into different geometric parts whose spatial arrangement is represented by a graph. The matching and searching of graphs representing the objects is sped up by using a hash table which contains possible spatial configurations of the different parts that constitute the objects. Additive feature descriptors are used to label partially or completely visible object parts. In this work we categorize objects into five geometric shapes: sphere, box, flat, cylindrical, and disk/plate, as these shapes represent the majority of objects found on tables in typical households. Moreover, we reconstruct complete 3D models that include the invisible back-sides of objects as well, in order to facilitate manipulation by domestic service robots. Finally, we present an extensive set of experiments on point clouds of objects using an RGBD camera, and our results highlight the improvements over previous methods. © 2014 Springer Science+Business Media Dordrecht

    Application of biostimulant products and biological control agents in sustainable viticulture : A review

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    Current and continuing climate change in the Anthropocene epoch requires sustainable agricultural practices. Additionally, due to changing consumer preferences, organic approaches to cultivation are gaining popularity. The global market for organic grapes, grape products, and wine is growing. Biostimulant and biocontrol products are often applied in organic vineyards and can reduce the synthetic fertilizer, pesticide, and fungicide requirements of a vineyard. Plant growth promotion following application is also observed under a variety of challenging conditions associated with global warming. This paper reviews different groups of biostimulants and their effects on viticulture, including microorganisms, protein hydrolysates, humic acids, pyrogenic materials, and seaweed extracts. Of special interest are biostimulants with utility in protecting plants against the effects of climate change, including drought and heat stress. While many beneficial effects have been reported following the application of these materials, most studies lack a mechanistic explanation, and important parameters are often undefined (e.g., soil characteristics and nutrient availability). We recommend an increased study of the underlying mechanisms of these products to enable the selection of proper biostimulants, application methods, and dosage in viticulture. A detailed understanding of processes dictating beneficial effects in vineyards following application may allow for biostimulants with increased efficacy, uptake, and sustainability
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