Search results for "A FLUORESCENCE"
showing 9 items of 19 documents
Leaf-Level Spectral Fluorescence Measurements : Comparing Methodologies for Broadleaves and Needles
2019
Successful measurements of chlorophyll fluorescence (ChlF) spectral properties (typically in the wavelength range of 650–850 nm) across plant species, environmental conditions, and stress levels are a first step towards establishing a quantitative link between solar-induced chlorophyll fluorescence (SIF), which can only be measured at discrete ChlF spectral bands, and photosynthetic functionality. Despite its importance and significance, the various methodologies for the estimation of leaf-level ChlF spectral properties have not yet been compared, especially when applied to leaves with complex morphology, such as needles. Here we present, to the best of our knowledge, a first comparison of …
Effect of nanoaquacitrates on physiological parameters of Fodder Galega infected with phytoplasma
2018
The laboratory experiments have been found that so aking seeds Galega orientalis L. (Fodder galega) in nanoaquacitrates solutions of Mn (10 and 20 mg/dm 3), Mo (4 mg/dm3) and Mg (2 and 4 mg/dm3), has been lead to germination energy rise, while Mn( 10 and 20 mg/dm3) and Mo (4 mg/dm3) concentrations has been influenced germinating ability. At the same time, the soaking seeds in solution of nanoaquacitrates Mn (20 mg/dm3) had the biggest stimulatory effect on the accumulation 7 daily sprouts mass (on 18%). It has been shown that s oaking seeds in nanoparticles Mn and Mo solutions leads to the increase of catalase activities (especially under the influence of manganese) and peroxidase activitie…
Modeļsistēmas izveide spilvainā ancīša (Agrimonia pilosa) pētījumiem kontrolētos apstākļos par vides faktoru ietekmi uz augu fizioloģisko stāvokli
2021
Darbā ir apkopota informācija par mitruma ietekmi uz augu fizioloģiskajiem parametriem. Darba mērķis bija izveidot spilvainā ancīša Agrimonia pilosa modeļsistēmu kontrolētos apstākļos pētījumiem par vides faktoru ietekmi uz augu fizioloģisko stāvokli. Fizioloģiskās atbildes uz mitruma ietekmi noteica ar hlorofila a fluorescences analīzes palīdzību. Darba rezultātā secināts, ka Agrimonia pilosa augšņu analīžu rezultāti kopumā atbilst vispārpieņemtajiem augiem nepieciešamajām minerālās barošanās prasībām. Eksperimenta laikā izdevās vienmērīgi nodrošināt augsnei nepieciešamo mitruma līmeni pa variantiem. Hlorofila a fluorescence parādīja, ka Agrimonia pilosa augiem vispiemērotākie ir vidēja mi…
In vivo photoprotection mechanisms observed from leaf spectral absorbance changes showing VIS–NIR slow-induced conformational pigment bed changes
2019
Abstract Regulated heat dissipation under excessive light comprises a complexity of mechanisms, whereby the supramolecular light-harvesting pigment–protein complex (LHC) shifts state from light harvesting towards heat dissipation, quenching the excess of photo-induced excitation energy in a non-photochemical way. Based on whole-leaf spectroscopy measuring upward and downward spectral radiance fluxes, we studied spectrally contiguous (hyperspectral) transient time series of absorbance A(λ,t) and passively induced chlorophyll fluorescence F(λ,t) dynamics of intact leaves in the visible and near-infrared wavelengths (VIS–NIR, 400–800 nm) after sudden strong natural-like illumination exposure. …
Species- and site-specific efficacy of commercial biocides and application solvents against lichens
2017
Abstract Control of lichens on stone cultural heritage is mostly achieved by a combination of mechanical removal with biocide applications. However, there is a lack of scientific evidence on the efficacy of different biocides on different species, and on the consistency of biocide effects on heritage sites in different environmental conditions. This results in some uncertainty when conservation interventions to control lichens are routinely defined on the basis of restoration tradition or empirical evaluation, without experimental measures of how lichens respond. In this work, we quantitatively evaluated (a) the efficacy of five commercially-available biocides, applied using a brush or with…
ENHANCEMENT OF WHEAT VIRUS-RESISTANCE AT APPLICATION OF THE SE NANOPARTICLES CITRATES AND CONSORTIUM OF SOIL MICROORGANISMS
2021
The influence of pre-sowing seed treatments of selenium nanocitrates (SeNPs) and application of soil formed microorganism consortium (biological preparation (BP) Extrakon) on wheat plants infected with wheat streak mosaic virus (WSMV) were investigated in greenhouse and fields conditions in 2018-2019 (on territories of Zabolotny Institute of Microbiology and Virology of NASU). The pre-sowing seed treatments of 1% selenium nanocitrates (SeNPs) with application of BP Extrakon initiating the growth of juvenile wheat in laboratory experiments were found. In the field experiment on variants of WSMV-infected plants, two weeks after inoculation (tillering stage), we observed the appearance of char…
3D digitization of transparent objects by polalization techniques in IR & by triangulation in UV
2011
Two non-conventional methods for the 3D digitization of transparent objects via non-contact measurement are reported in this thesis. 3D digitization is a well acknowledged technique for opaque objects and various commercial solutions based on different measurement approaches are available in the market offering different types of resolution at different prices. Since these techniques require a diffused or lambertian surface, their application to transparent surfaces fails. Indeed, rays reflected by the transparent surface are perturbed by diverse inter-reflections induced by the refractive properties of the object. Therefore, in industrial applications like quality control, the transparent …
Dažādu augu sugu formaldehīda attīrīšanas efektivitāte botāniskā gaisa filtra sistēmā un to fizioloģiskā stāvokļa novērtējums
2021
Botānisku gaisa biofiltrāciju var izmanot, lai attīrītu iekštelpu gaisu no gaistošajiem organiskajiem savienojumiem. Piecus biofiltra modeļu variantus pakļāva formaldehīda ietekmei sešas reizes ar četrām dienām starp ekspozīcijām. Noteica formaldehīda koncentrāciju pirms un pēc biofiltra un augu fizioloģisko stāvokli, mērot hlorofila fluorescenci. Augu biofiltri samazināja formaldehīda koncentrāciju vidēji par 33%. Mentha aquatica var. litoralis par 46%, Chlorophytum comosum par 31%, Epipremnum aureum par 31% un Anthurium sp. par 26%. Salīdzinājumam, biofiltra modelis bez augiem attīrīja 20% formaldehīda. Laika gaitā attīrīšanas efektivitāte pieauga, bet būtiska sakarība bija tikai C. comos…
Biotehnoloģisko metožu izmantošana vietējās selekcijas apšu hibrīdu pavairošanā audu kultūrā
2015
Pavairojot apšu hibrīdus audu kultūrā, nākas saskarties ar tādām problēmām kā kultivēšanas dārdzība, infekcijas un kultūras ilgtermiņa uzturēšanas izmaksas. Darba mērķis bija izstrādāt zinātnisko pamatu vietējās selekcijas apšu hibrīdu pavairošanas un uzglabāšanas efektivitātes paaugstināšanai. Darbā pārbaudīta HgCl2 virsmas sterilizācijas tehnika un tās ietekme uz mikrospraudeņu vitalitāti, kā reprezentatīvo rādītāju izmantojot hlorofila a fluorescences parametru vērtības; ex vitro pavairošanas pieeja; mikrospraudeņu uzglabāšanas iespējas +50C temperatūrā. Iegūtie rezultāti liecina, ka HgCl2 virsmas sterilizācija ir izmantojama mikrospraudeņu dezinfekcijai un augu vitalitāti būtiski neiete…