scholarly journals Monitoring the Green Vegetation Period of Two Narcissus Taxa by Non-Destructive Analysis of Selected Physiological and Morphological Properties

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 585
Author(s):  
Katalin Jezdinská Slezák ◽  
Aleš Jezdinský ◽  
Miroslav Vachůn ◽  
Oldřiška Sotolářová ◽  
Robert Pokluda ◽  
...  

In a pot experiment, an early-flowering Narcissus pseudonarcissus cv. ‘Dutch Master’ (DM) and late-flowering N. poeticus cultural form (PO) were examined. The photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), photosynthetic water use efficiency (WUE), relative chlorophyll content (CCI) and chlorophyll fluorescence (F) were measured regularly. Leaf length, scape length and weight of the plant organs were also measured. The DM cultivar had higher gs and lower E values than the PO on most measuring dates (season average: gs: DM: 165.34, PO: 123.63; E: DM: 1.39, PO: 1.78 mmol H2O m−2s−1). The A curve was similar for the two taxa, except for the first measuring dates. The basic F values (F0, Fm, Fv) for DM were lower and CCI values were higher than for PO (season average of CCI: DM: 94.82, PO: 60.34). The Fm/F0, Fv/F0 and CCI curves were well described by a second order equation. The seasonal change of F and CCI values was the greatest for both taxa near the leaf tip. Bulb growth occurred in the two taxa in approximately the same calendar period, regardless of flowering time. A significant part of the leaf growth in DM occurred after flowering, while the leaves of PO reached their mature size by flowering.

2008 ◽  
Vol 35 (10) ◽  
pp. 885 ◽  
Author(s):  
Gaëtan Louarn ◽  
Karine Chenu ◽  
Christian Fournier ◽  
Bruno Andrieu ◽  
Catherine Giauffret

Maize (Zea mays L.) is a chill-susceptible crop cultivated in northern latitude environments. The detrimental effects of cold on growth and photosynthetic activity have long been established. However, a general overview of how important these processes are with respect to the reduction of productivity reported in the field is still lacking. In this study, a model-assisted approach was used to dissect variations in productivity under suboptimal temperatures and quantify the relative contributions of light interception (PARc) and radiation use efficiency (RUE) from emergence to flowering. A combination of architectural and light transfer models was used to calculate light interception in three field experiments with two cold-tolerant lines and at two sowing dates. Model assessment confirmed that the approach was suitable to infer light interception. Biomass production was strongly affected by early sowings. RUE was identified as the main cause of biomass reduction during cold events. Furthermore, PARc explained most of the variability observed at flowering, its relative contributions being more or less important according to the climate experienced. Cold temperatures resulted in lower PARc, mainly because final leaf length and width were significantly reduced for all leaves emerging after the first cold occurrence. These results confirm that virtual plants can be useful as fine phenotyping tools. A scheme of action of cold on leaf expansion, light interception and radiation use efficiency is discussed with a view towards helping breeders define relevant selection criteria.


2019 ◽  
Vol 16 (23) ◽  
pp. 4613-4625 ◽  
Author(s):  
Anne Alexandre ◽  
Elizabeth Webb ◽  
Amaelle Landais ◽  
Clément Piel ◽  
Sébastien Devidal ◽  
...  

Abstract. Continental relative humidity (RH) is a key climate parameter, but there is a lack of quantitative RH proxies suitable for climate model–data comparisons. Recently, a combination of climate chamber and natural transect calibrations have laid the groundwork for examining the robustness of the triple oxygen isotope composition (δ′18O and 17O-excess) of phytoliths, that can preserve in sediments, as a new proxy for past changes in RH. However, it was recommended that besides RH, additional factors that may impact δ′18O and 17O-excess of plant water and phytoliths be examined. Here, the effects of grass leaf length, leaf development stage and day–night alternations are addressed from growth chamber experiments. The triple oxygen isotope compositions of leaf water and phytoliths of the grass species F. arundinacea are analysed. Evolution of the leaf water δ′18O and 17O-excess along the leaf length can be modelled using a string-of-lakes approach to which an unevaporated–evaporated mixing equation must be added. We show that for phytoliths to record this evolution, a kinetic fractionation between leaf water and silica, increasing from the base to the apex, must be assumed. Despite the isotope heterogeneity of leaf water along the leaf length, the bulk leaf phytolith δ′18O and 17O-excess values can be estimated from the Craig and Gordon model and a mean leaf water–phytolith fractionation exponent (λPhyto-LW) of 0.521. In addition to not being leaf length dependent, δ′18O and 17O-excess of grass phytoliths are expected to be impacted only very slightly by the stem vs. leaf biomass ratio. Our experiment additionally shows that because a lot of silica polymerises in grasses when the leaf reaches senescence (58 % of leaf phytoliths in mass), RH prevailing during the start of senescence should be considered in addition to RH prevailing during leaf growth when interpreting the 17O-excess of grass bulk phytoliths. Although under the study conditions 17O-excessPhyto do not vary significantly from constant day to day–night conditions, additional monitoring at low RH conditions should be done before drawing any generalisable conclusions. Overall, this study strengthens the reliability of the 17O-excess of phytoliths to be used as a proxy of RH. If future studies show that the mean value of 0.521 used for the grass leaf water–phytolith fractionation exponent λPhyto-LW is not climate dependent, then grassland leaf water 17O-excess obtained from grassland phytolith 17O-excess would inform on isotope signals of several soil–plant-atmosphere processes.


2018 ◽  
Vol 40 (6) ◽  
Author(s):  
Marlúcia Pereira dos Santos ◽  
Victor Martins Maia ◽  
Fernanda Soares Oliveira ◽  
Rodinei Facco Pegoraro ◽  
Silvânio Rodrigues dos Santos ◽  
...  

Abstract The estimation of pineapple total leaf area by simple, fast and non-destructive methods allow inferences related to carbon fixation estimative, biotic and abiotic damages and correlating positively with yield. The objective was to estimate D leaf area and total leaf area and of ‘Pérola’ pineapple plants from biometric measurements. For this purpose, 125 slips were selected and standardized by weight for planting in pots. Nine months after planting in a greenhouse, the plants were harvested to evaluate the total leaf area of the plant, D leaf area and D leaf length and width using a portable leaf area meter. Pearson correlation analysis was made and it was observed significative positive and strong correlation among the studied variables. Then, regression models were adjusted. It was observed that the D leaf area of ‘Pérola’ pineapple can be estimated from the length and width of this same leaf and the total leaf area can be estimated from the D leaf area.


Author(s):  
Mohammad Mehdi Arab ◽  
Annarita Marrano ◽  
Rostam Abdollahi-Arpanahi ◽  
Charles A Leslie ◽  
Hao Cheng ◽  
...  

Abstract Walnut production is challenged by climate change and abiotic stresses. Elucidating the genomic basis of adaptation to climate is essential to breeding drought tolerant cultivars for enhanced productivity in arid and semi-arid regions. Here, we aimed to identify loci potentially involved in water use efficiency (WUE) and adaptation to drought in Persian walnut using a diverse panel of 95 walnut families (950 seedlings) from Iran, which show contrasting levels of water availability in their native habitats. We analyzed associations between phenotypic, genotypic, and environmental variables from datasets of 609 K high-quality single-nucleotide polymorphisms (SNPs), three categories of phenotypic traits (WUE related traits under drought, their drought stress index and principal components), and 21 climate variables and combination of them (first three PCs). Our genotype-phenotype analysis identified 22 significant and 266 suggestive associations, some of which were identified for multiple traits, suggesting their correlation and a possible common genetic control. Also, genotype-environment association analysis found 115 significant and 265 suggestive SNP loci that displayed potential signals of local adaptation. Several sets of stress-responsive genes were found in the genomic regions significantly associated with the aforementioned traits. Most of the candidate genes identified are involved in abscisic acid signaling, stomatal regulation, transduction of environmental signals, antioxidant defense system, osmotic adjustment, and leaf growth and development. Upon validation, the marker-trait associations identified for drought tolerance-related traits would allow the selection and development of new walnut rootstocks or scion cultivars with superior water use efficiency.


2016 ◽  
Vol 34 (3) ◽  
pp. 422-427 ◽  
Author(s):  
Wellington A Erlacher ◽  
Fábio L Oliveira ◽  
Gustavo S Fialho ◽  
Diego MN Silva ◽  
Arnaldo HO Carvalho

ABSTRACT The recent exploration of yacon demands scientific information for improving the crop production technology. This study aimed to set a leaf area estimate model for yacon plants, using non-destructive measurements of leaf length (L) and/or width (W). Sixty-four representative yacon plants were randomly selected in an experimental field during the full vegetative growth. One thousand leaves of various sizes were taken from those plants for setting and validating a model. The logarithmic model best fitted this purpose, the result of multiplying length by width being used as independent variable. Yacon leaf area can be determined with high precision and accuracy by LALW = (-27.7418 + (3.9812LW / ln LW ) , disregarding the leaf size.


2021 ◽  
Vol 49 (4) ◽  
pp. 12536
Author(s):  
Yu-Syuan LI ◽  
Kuan-Hung LIN ◽  
Chun-Wei WU ◽  
Yu-Sen CHANG

Houttuynia cordata Thunb. (HC) is a traditional medicinal plant with a variety of pharmaceutical activities. The objective of this study was to investigate the growth, photosynthetic parameters, and antioxidant properties of HC plants in response to various temperatures. Pots of HC plants were maintained in day/night temperatures of 15/10 °C, 20/15 °C, 25/20 °C (control), 30/25 °C, and 35/30 °C for two months in each of five growth chambers having a 13.5 h photoperiod at 396, 432, 474, 449, and 619 µmol·m-2·s-1 radiation, respectively. Eight plants for each temperature were randomly placed in a growth chamber. HC plants survived at 30/25 °C and 35/30 °C treatments and had significantly higher plant heights, leaf numbers, and soil-plant analysis development (SPAD) and normalized difference vegetation index (NDVI) values compared to other treatments. However, long-term 35/30 °C treatment caused reductions in leaf length and width, significantly decreasing shoot and leaf fresh weight (FW) and dry weight (DW) compared to 30/25 °C treatment and controls. These results indicate that HC leaf development was affected during the 35/30 °C treatment, and that both SPAD and NDVI can help in advancing our understanding of the photosynthesis process in HC. Moreover, all plants subjected to 15/10 °C suffered more severely in all traits and parameters than other treatments. Therefore, HC plants tended to be heat-tolerant and exhibited adaptive morphologic plasticity to 30/25 °C conditions. Positive and significant correlations were observed among temperatures and total phenolics (TP), total flavonoids (TF), chlorogenic acid (CGA), and hyperoside (HO) content, and all bioactive contents increased as temperature increased, except that both CGA and HO content were remarkably decreased after 30/25 °C treatment. Thus, 30/25 °C treatment would be more beneficial for high marketability resulting from increased leaf number, DW, and all secondary metabolites compared to other treatments, and for use as a health food and for medicinal purposes. In addition, leaf growth, physiological parameters, and secondary metabolite accumulations in HC plants can be optimized for commercial production via temperature control technologies. This approach may also be applicable to leafy vegetables to produce stable industrial supplies having high leaf yields and metabolite content.


2001 ◽  
Vol 28 (2) ◽  
pp. 165 ◽  
Author(s):  
Yuncai Hu ◽  
Urs Schmidhalter

Expansion and dry weight (DW) of wheat leaves are spatially distributed along the axis and affected by salinity. The objective of this study was to evaluate the effect of salinity on the spatial distribution of cellular cross-sectional area and DW in the elongating and mature leaf zones of leaf 4 of the main stem of spring wheat (Triticum aestivum L. cv. Lona) during its linear growth phase. Plants were grown in illitic–chloritic silt loam with 0 and 120 mM NaCl in a growth chamber. Cellular cross-sectional area and DW contents of leaves were determined on the 5–20-mm scale along the leaf axis. Spatial distribution of cellular cross-sectional area changed slightly with distance within the elongation zone in both treatments. The cellular cross-sectional area of the leaf at 120 mM NaCl was reduced by 32% at 5 mm, as compared with about 36% averaged from the region between 5 and 30 mm from the leaf base, indicating that the reduction in the cellular cross-sectional area by salinity occurred mainly at the leaf base when the leaf initiates. A slight decrease in the DW per leaf length at a given location in the elongation zone may be due to the strongly decreased cellular cross-sectional area by salinity. This suggests that the limitation of leaf growth by salinity may be due mainly to the effect of salinity on leaf expansion, but not due to the effect on the synthesis of dry matter.


2021 ◽  
Author(s):  
Timothy Anderson

Abstract Image-based characterization of rock fabric is critical for understanding recovery mechanisms in shale formations due to the significant multiscale nature of shale source rocks. Nanoscale imaging is particularly important for characterizing pore-scale structure of shales. Nanoimaging techniques, however, have a tradeoff between high-resolution/high-contrast sample-destructive imaging modalities and low-contrast/low-resolution sample-preserving modalities. Furthermore, acquisition of nanoscale images is often time-consuming, expensive, and requires signficant levels of expertise, resulting in small image datasets that do not allow for accurate quantification of petrophysical or morphological properties. In this work, we introduce methods for overcoming these challenges in image-based characterization of the fabric of shale source rocks using deep learning models. We present a multimodal/multiscale imaging and characterization workflow for enhancing non-destructive microscopy images of shale. We develop training methods for predicting 3D image volumes from 2D training data and simulate flow through the predicted shale volumes. We then present a novel method for synthesizing porous media images using generative flow models. We apply this method to several datasets, including grayscale and multimodal 3D image volume generation from 2D training images. Results from this work show that the proposed image reconstruction and generation approaches produce realistic pore-scale 3D volumes of shale source rocks even when only 2D image data is available. The models proposed here enable new capabilities for non-destructive imaging of source rocks and we hope will improve our ability to characterize pore-scale properties and phenomena in shales using image data.


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