Vpliv sezone na spreminjanje optičnih lastnosti velikega zimzelena : diplomsko delo

Novak, Anja (author), Gaberščik, Alenka (mentor)

Rastline so izpostavljene različnim stresnim dejavnikom, ki se spreminjajo tekom rastne sezone. Odziv rastline na stres se lahko odrazi v spremembi anatomskih in biokemijskih lastnosti, kar pa posledično vpliva tudi na njene optične lastnosti. V diplomskem delu smo preučevali, kako sprememba sezone vpliva na optične lastnosti listov velikega zimzelena (Vinca major). V okviru raziskave smo pregledali literaturo na temo svetlobnih razmer v okolju in specifično v podrasti. Podrobneje smo se posvetili optičnim lastnostim in odzivu rastline na spremembe v okolju ter njihove anatomske, morfološke ter biokemijske prilagoditve. Opisali smo tudi značilnosti območja, kjer so bile preučevane rastline nabrane. Izmerili smo odbojne in presevne spektre listov velikega zimzelena v novembru, aprilu in avgustu ter grafično predstavili njihovo relativno odbojnost in presevnost v območju od 280 do 887 nm. Meritve smo primerjali in jih kritično ovrednotili. Naredili smo DCA analizo in ugotavljali podobnosti med spektri na podlagi povprečnih vrednosti posameznih barvnih pasov. Pri DCA analizi smo ugotovili, da so si odbojnosti in presevnosti novembrskih in aprilskih listov dokaj podobne, medtem ko meritve avgustovskih listov izstopajo. Statistične analize razlik med barvnimi pasovi izmerjenimi v različnih delih sezone so pokazale, da je odboj sevanja največji v območju zelene in rumene svetlobe, z največjo relativno odbojnostjo novembrskih listov v tem območju. Velik del sevanja so listi odbijali v območju NIR, med vsemi listi pa je bil odboj največji pri vzorcih nabranih v mesecu aprilu. Večja relativna presevnost je bila izmerjena v podobnih območjih spektra kot relativna odbojnost. Pri novembrskih listih smo opazili večjo presevnost sevanja v območju zelenega in rumenega dela spektra, medtem ko je bila presevnost aprilskih in avgustovskih listov zelo majhna. V območju NIR smo izmerili največje vrednosti relativne presevnosti, ki je bila zlasti velika pri novembrskih in aprilskih listih. Pri avgustovskih listih je bila relativna presevnost v NIR izrazito manjša, kar bi lahko pripisali debelini listov. Na podlagi dobljenih rezultatov in razlik med spektri smo ugotovili, da sezona značilno vpliva na odbojnost in presevnost listne površine za svetlobo. Natančnejše zaključke bi nam omogočile anatomske in biokemijske analize, s katerimi bi lahko ugotovili povezave med spremembami anatomskih in biokemijski značilnosti in optičnih lastnosti listov velikega zimzelena.

• Language: Slovenian
• Keywords: optika, listi
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: PEF - Faculty of Education
• Publisher: [A. Novak]
• Year: 2015
• Number of pages: 26 str.
• PID: 20.500.12556/RUL-72603
• UDC: 58(043.2)
• COBISS.SI-ID: 10695497
• Publication date in RUL: 29.09.2015

Secondary language

• Language: English
• Title: The effect of season on the optical properties of Vinca major leaves

Abstract

Plants are exposed to various stressful factors which vary throughout the growing season. The stressful factors the plants are exposed to affect their anatomical and biochemical properties and therefore their optical properties. In this thesis, we studied the effect of season on the optical properties of Vinca major's leaves. Our research contained study of literature on the subject of light conditions in the environment and specifically in the undergrowth. We focused on the optical properties and plant response on the environmental changes and their anatomical, morphological as well as biochemical adaptations. We also paid special attention to the description of the area where the studied plants were picked. We measured the reflectance and transmittance of the Vinca major’s leaves in November, April and August and graphically presented their relative reflectance and transmittance in the range of 280 to 887 nm. We compared the measurements and evaluated them. The DCA analysis helped us define the similarities between the spectra based on the average values of the spectral bands. The DCA analysis showed that the leaves picked in November and April have similar spectral reflectance and transmittance, whereas the results acquired from the August leaves stand out. The statistical analysis of the acquired spectral bands has shown a maximum relative difference in reflectance in the case of Vinca major’s leaves picked in November, which was seen in the green and yellow spectra. Leaves reflected a large part of the radiation in the NIR range. The examples of the April leaves had the biggest reflection. Bigger relative transmittance was measured in the similar ranges of the spectra than it was the case in the relative reflectance. The November leaves had bigger transmittance in the green and yellow range, while the transmittance of the April and August leaves were very small. All of the studied leaves had big transmittance in the NIR range. The leaves gathered in November and April transmitted a lot of light in NIR range, whereas the leaves collected in August transmitted very few. This was due to the thickness of leaves. Based on the results gathered and differences between spectra we can determine that season typically affects the light reflectance and transmittance of the leaves. However, a more detailed analysis would give us a better understanding of connection between the anatomical and biochemical properties and Vinca major’s optical properties.

• Keywords: large periwinkle (Vinca major)