Le phénotypage consiste à caractériser les plantes et leur comportement en vue de la sélection génétique. Cette étude a évalué le potentiel de l'imagerie hyperspectrale de proximité pour répondre à ces besoins. Elle s'appuie sur le lien existant entre la physiologie des plantes et leurs propriétés optiques. Cette étude a montré qu'il est possible de retrouver la réflectance des feuilles en dépit d'un éclairage naturel variable. La procédure de correction mise en place permet de retrouver la réflectance vraie de feuilles à plat et introduit un effet additif (dû à la réflexion spéculaire), un effet multiplicatif (dû au niveau d'éclairement) et un effet non linéaire (dû aux réflexions multiples) sur les feuilles inclinées des plantes au champ. Cependant, nous avons montré également que, grâce à des pré-traitements des spectres adéquats et à la PLS (Partial Least Square regression), la concentration en azote est accessible à partir de la réflectance (400-1000~nm) de feuilles fraîches sur pied. L'étude de spectres simulés a montré que la non prise en compte des réflexions multiples dans l'étalonnage d'un modèle conduisait à une surestimation de la concentration en azote des feuilles subissant des réflexions multiples. Enfin, cette étude a illustré l'intérêt de l'imagerie hyperspectrale de proximité par rapport à la spectrométrie ponctuelle. Le fait d'avoir une image, combiné à la haute résolution spatiale permet d'obtenir des données plus représentatives de la parcelle et de calculer une vitesse de fermeture de couvert. La réalisation de cartographies d'azote permet de suivre la concentration en azote dans différents étages foliaires ou parties d'une même feuille. / Henotyping consists in characterising plants and their behavior with the aim of the genetic selection. This study estimated the potential of the close-range hyperspectral imaging to meet these needs. It leans on the link existing between plant physiology and their optical properties. This study showed that it is possible to find leaf reflectance in spite of a variable natural lighting. The developed correction procedure allows finding the true reflectance of flat leaves and introduces an additive effect (due to specular reflection), a multiplicative effect (due to illumination level) and a not linear effect (due to the multiple reflections) on inclinated leaves of plants in the field. However, we also showed that, thanks to adequate preprocessing of the spectra and to PLS (Partial Least Square regression), the nitrogen concentration is accessible from the reflectance (400-1000~nm) of fresh leaves on standing plants. The study of simulated spectra showed that the not consideration of the multiple reflections in the calibration of a model lead to an overestimation of the nitrogen concentration leaves undergoing multiple reflections. Finally, this study illustrated the interest of close-range hyperspectral imaging with regard to the punctual spectrometry. The fact of having an image, combined with the high spatial resolution allows to obtain more representative data of the plot and to calculate a speed of cover closure. Nitrogen mappings allow following the nitrogen concentration in various leaf level or parts of the same leaf.

Wheat was grown hydroponically for 23 days ( early boot stage) in a controlled environment at NO3- concentrations of 100 and 1000 μ,M and CO2 levels of 360 and 1200 μ,mol mo1-1. Nitrogen consumption and transpiration were measured daily. Tissue nitrogen concentration, total biomass, and percent root mass were measured at harvest. Nitrogen recovery and nitrogen use efficiency were calculated. Elevated CO2 increased nitrogen consumption of the 100 μ,M NO3- treatment by 13.6% and the 1000 μ,M NO3- treatment by 21.3%. These increases were particularly evident during tillering and early grain fill. Whole plant nitrogen, shoot NO3-, and root NO3- concentrations were increased by elevated CO2. High CO2increased biomass by 15% and increased percent root mass by 11 %. Nitrogen recovery and nitrogen use efficiency were similar at both CO2 concentrations. Transpiration (L m-2ground d-1) decreased by 40% in elevated CO2. The 1000 μ,M NO3- treatment consumed more NO3- than did the 100 μ,M NO3- treatment (8.1% in ambient CO2, 15.5% in elevated CO2); this effect was most pronounced during the last 5 days of the experiment (flag leaf emergence and early grain fill). Percent root mass increased as N concentration decreased from 1000 to 100 μ,M. Nitrogen levels did not significantly affect tissue N concentration or biomass. Nitrogen losses increased as N supply increased; an average of 16% of the nitrogen added to the 100 μ,M NO3- treatment was lost, while the 1000 μ,M NO3- treatment lost 21%. Nitrogen use efficiency and transpiration were similar in both nitrogen treatments.

Magistro darbe tiriama paprastojo kiečio (Artemisia vulgaris L.) biologinių savybių priklausomybė nuo tyrimo vietos edafinių ir klimatinių ypatumų. Darbo objektas – paprastasis kietis (Artemisia vulgaris L.). Darbo tikslas – nustatyti įvairias paprastojo kiečio fiziologinias charakteristikas. Darbo metodai – Tyrimai atlikti LŽŪU aplinkotyros laboratorijoje. Azoto kiekis nustatytas Kjeldalio metodu. Dirvožemio sunkiųjų metalų analizė atlikta mėginius deginant „Multiwave 3000 Synthos 3000“ ir gauto ekstrakto elementų koncentracijos nustatytos pagal standartą LST ISO 11047 (Dirvožemio kokybė), naudojant liepsnos ir elektoterminės atominės absorbcijos spektrometrinius metodus. Flavonoidų kokybinė ir kiekybinė sudėtis nustatyta efektyviosios skysčių chromatografijos metodu. Epifitinių mikroorganizmų kiekis nustatytas naudojant sojos leptono ir Salsbūro agarą. Duomenys įvertinti, panaudojant Excel ir SPSS statistines programas. Darbo rezultatai. Atlikus tyrimus įvertintos paprastojo kiečio fiziologinės savybės ir gauti tokie rezultatai: dirvožemio geležies, cinko nikelio koncentracijos buvo didžiausios 2 km atstumu nuo AB “Achema” (prie geležinkelio), 0,5 km atstumu nuo AB „Achema“ – vidutinės, mažiausios – Kačerginės; dirvožemio ir paprastojo kiečio įvairių augalo dalių azoto koncentracija išsidėsto tokia tvarka: dirvožemio < šaknų < stiebų < žiedų < lapų; tarp visų tyrimo vietų reikšmingai skyrėsi paprastojo kiečio sausoji masė. Pagal stiebus ir žiedynus A. vulgaris L... [toliau žr. visą tekstą] / Topic of the diploma (Master degree in Ecology) was evaluation of Artemisia vulgaris L.) physiological-biochemical parameters depending on site edaphic and climatic factors. Research object - Artemisia vulgaris L. Purpose of the work – evaluation of various morphophysiological-biochemical parameters of Artemisia vulgaris L. in respect of the distance from the nitrogen fertilizer factory, ommiting ammonia also in respect of heavy metal concentrations in the soil. Methods. Analyses were performed at the laboratory of Environment of University of Agriculture of Lithuania. Concentration of nitrogen was determined by Kjeldal method. For the determination of the heavy metal concentration the samples of the soil were burned by „Multiwave 3000 Synthos 3000“ and obtained extracts were analysed following protocol for the soil quality (LST ISO 11047), using method of flame and electrothermal atomic absorbtion spectrometry. The amount of epiphytic microorganisms was determined bacteria on soya agar and fungi on Salsbur medium. Data were analysed using Excel and SPSS statistical packages. Results and discussion. Concentration of the nitrogen in the soil and leaves of Artemisia vulgaris, falls in the following order: site, located in 2 km distance from the factory < site located besides the factory < Kačerginė site located in 45 km distance from the factory (as a control, „relatively clean“ site). In the sampling sites of Artemisia vulgaris concentrations of heavy metal (Pb, Cr, Ni... [to full text]

Magistro darbe tiriama dirvinio ir karčiojo kiečių biologinės cherakteristikos nevienodos amoniakinės taršos vietose. Darbo tema: Dirvinio ir karčiojo (pelyno) kiečių biologinės charakteristikos nevienodos amoniakinės taršos vietose Darbo objektas - dirvinis kietis ir pelynas - paplitę Lietuvoje augalai, pasižymintys gausiomis vaistingomis medžiagomis - eteriniais aliejais ir flavonoidais. Darbo tikslas - nustatyti skirtingų (AB "Achema" atžvilgiu) vietų karčiojo kiečio, pelyno (Artemisia absinthum L.) ir dirvinio kiečio (Artemisia campestris L.) fiziologines-biochemines savybes. Darbo metodai - Kjeldalio metodas azoto nustatymui, atominės absorbcijos spektroskopija sunkiųjų metalų nustatymui. Salsburo ir sojos agaras mikroorganizmų auginimui. Darbo rezultatai - ištirtos tokios dviejų rūšių kiečių fiziologinės-biocheminės savybės: dirvožemio azoto ir sunkiųjų metalų koncentracija, kiečių įvairių organų masė, kiečių įvairių organų azoto koncentracija, kiečių antžeminių organų flavonoidų koncentracija, kiečių epifitinių mikroorganizmų skaičius, įvertinta kaip oro amoniakinė tarša ir dirvožemio tarša sunkiaisiais metalais reikšmingai įtakoja ištirtus kiečių fiziologinius rodiklius. Atlikti tyrimai parodė, kad dirvožemio ir abiejų rūšių augalų azoto koncentracija išsidėsto tokia tvarka: dirvožemio < stiebų < lapų < žiedų < skrotelių. Tirtos vietos pagal dirvožemio ar organų azoto koncentraciją nesiskyrė. Didžiausios dirvožemio sunkiųjų metalų koncentracijos nustatytos abiejų... [toliau žr. visą tekstą] / Topic of the master degree diploma: Various biological parameters of Artemisia absinthum L. and Artemisia campestris L. growing in the areas effected by different level pollution by ammonia. Artemisia absinthum L. and Artemisia campestris L. are common wild growing species in Lithuania. Despite these species are rich in flavonoids and essential oils till now in our country biology and biochemistry of these species have not received bigger attention. Present work aimed at evaluation of Artemisia absinthum L. and Artemisia campestris L. physiological-biochemical parameters depending on sampling site distance from the nitrogen fertilizer factory. Methods. Following physiological-biochemical parameters of these species were analysed: soil nitrogen and heavy metal concentrations, dry mass and nitrogen concentration of various organs of selected plant species, abundance of epiphytic microflora. Results. During vegetation period sampling was performed three times: in July, 2; July, 24, and September, 24. Obtained parameters were evaluated in respect of aerial ammonia pollution and heavy metal pollution of the soil. Present study showed that nitrogen concentration of the soil and various organs of both Artemisia species fell into following ascending order: soil < stems < leaves < inflorescences and fruits < rosettes. Between selected sites no differences were observed according to the soil and plant nitrogen concentration. The highest concentrations of heavy metals were observed... [to full text]

Soil samples from different locations with varied soybean cultivation histories were taken from arable fields in 2018 in East Germany and Poland (Lower Silesia) to evaluate the specific microsymbionts of the soybean, Bradyrhizobium japonicum, one to seven years after inoculation. Soybeans were grown in the selected farms between 2011 and 2017. The aim of the experiment was to investigate whether there is a difference in rhizobia contents in soils in which soybeans have been recultivated after one to seven years break, and whether this could lead to differences in soybean plant growth. The obtained soil samples were directly transferred into containers, then sterilized soybean seeds were sown into pots in the greenhouse. After 94 days of growth, the plants were harvested and various parameters such as the nodular mass, number of nodules, and dry matter in the individual plant parts were determined. In addition, the relative abundances of Bradyrhizobium sp. in soil samples were identified by sequencing. No major decline in Bradyrhizobium sp. concentration could be observed due to a longer interruption of soybean cultivation. Soil properties such as pH, P, and Mg contents did not show a significant influence on the nodule mass or number, but seem to have an influence on the relative abundance of Bradyrhizobium sp. The investigations have shown that Bradyrhizobium japonicum persists in arable soils even under Central European site conditions and enters into an effective symbiosis with soybeans for up to seven years.:Introduction Materials and Methods Results Discussion Supplementary Materials Author Contributions Funding Acknowledgments Conflicts of Interest References