magistrsko delo
Tjaša Štruc (Author), Nina Šajna (Mentor)

Abstract

V okviru magistrskega dela smo uporabili in predstavili metode, ki se uporabljajo na področju ekologije rastlin. Na izbrani lokaciji v Laškem, smo štiri leta zapored zgodaj spomladi izvajali meritve v populaciji čemaža Allium ursinum in spremljali okuženost čemaževih listov z ličinkami vrste Cheilosia fasciata, ki predrejo listni epidermis, živijo v listu in se prehranjujejo z listnim mezofilom. Namen naloge je bil preučiti ali imajo okuženi listi slabšo fotosintetsko učinkovitost ter slabšo alelopatsko delovanje kot zdravi listi. Poleg tega pa smo s simulacijo okužbe listov želeli preveriti ali se bodo ti listi v fotosintetski učinkovitosti in alelopatskem delovanju odzvali podobno kot okuženi listi. Z metodo merjenja fluorescence klorofila in merjenjem vrednosti količine klorofila (SPAD) smo ugotavljali razlike v fotosintetskem učinkovanju in vsebnosti klorofila med zdravimi in okuženimi listi. Dobljene podatke smo statistično obdelali in rezultate primerjali znotraj posameznih sezon merjenja ter sezone med sabo. Ugotovili smo, da imajo okuženi listi slabšo fotosintetsko učinkovitost kot zdravi listi. Manjše so bile tudi vrednosti SPAD. V vseh sezonah se je pokazal trend drastičnega manjšanja učinovitosti fotosinteze s trajanjem okužbe. Ugotovili smo, da se vpliv okoljskih dejavnikov na fotosintetsko delovanje rastline zelo zmanjša, ko pride do okužbe listov. Sklepamo, da je tako pospešeno propadanje listov obrambni odziv rastline na okužbo z ličinkami. Tako tudi larva ne doseže zrelega stanja žerke pred zabubljenjem. Simulacijo okuženosti listov smo naredili z luknjanjem listov v času prvega pojava naravne okuženosti listov čemaža. Na listih s simulirano herbivorijo smo opravljali enake meritve ter ob enakem času, kot pri zdravih in naravno okuženih listih. Prvo simulacijo smo izvedli v letu 2013. Listi s simulirano okužbo so pokazali večjo podobnost z zdravimi listi, kot z okuženimi listi, kar ne potrjuje naše hipoteze. Ta trend je bil prisoten v vseh treh sezonah simuliranja. Sama tehnika izvedbe simuliranja ni dobro posnemala postopnega miniranja listov, kar je najverjetnejši razlog za dobljene rezultate. Nasplošno je naravno miniranje listov zelo težko posnemati. Za dokazovaje alelopatskega delovanja čemaža smo leta 2015 v laboratoriju opravili t.i. metodo Lepidium test, s katero smo ugotavljali učinke vodnih ekstraktov rastlinskih tkiv (listov čemaža) in prsti (iz sestoja čemaža) na uspešnost in potek kalitve semen vrtne kreše (Lepidium sativum). Rezultati so pokazali, da čemaž ima potencialni alelopatski vpliv. Zdravi listi so imeli večjo alelopatsko učinkovanje kot okuženi listi, saj so bile povprečne dolžine kalic vrtne kreše krajše. V tleh ni bilo prisotnih zaviralnih snovi.

Keywords

čemaž;Allium ursinum;herbivorija;Cheilosia fascinata;listni miner;fluorescenca klorofila;SPAD;simulacija herbivorije;alelopatija;Lepidium test;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FNM - Faculty of Natural Sciences and Mathematics
Publisher: [T. Štruc]
UDC: 581.524.13:582.584.1(043.2)
COBISS: 21689352 Link will open in a new window
Views: 1395
Downloads: 149
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Other data

Secondary language: English
Secondary title: Effect of Cheilosia fascinata larvae on the photosynthetic activity of wild garlic (Allium ursinum) and its allelopathic potential
Secondary abstract: In this dissertation, we employed methods that are applied in the field of plant ecology. Four years in a row, we carried out measurements on the population of wild garlic Allium ursinum at the selected location in Laško and observed infection of wild garlic leaves with the larvae Cheilosia fasciata, living in the leaf and feeding on the leaf mesophyll. Our intention was to examine whether the infected leaves have lower photosynthetic efficiency and lower allelopathic activity than the healthy leaves. We have been analyzing this using the method of measuring chlorophyll fluorescence and the method of measuring the amount of chlorophyll in leaf tissue (SPAD). We have determined that the infected leaves are photosynthetically less efficient than the healthy leaves. The results showed the trend of drastic reduction in photosynthetic efficiency with duration of infection as well as faster leaf decay. We can conclude this is the plant's defensive response to infection with the larvae. By simulating the infection of the leaves, we wanted to check whether their photosynthetic efficiency and allelopathic activity would be the same as those of the infected leaves. We simulated leaf infection by piercing the leaves during the first occurrence of natural infestation of wild garlic leaves. The leaves with simulated infection proved more similar to the healthy leaves than to the infected leaves. The simulation technique itself did not imitate the process of gradual leaf mining very well, which is the most probable reason for the obtained results. To prove the potential allelopathic activity of wild garlic, we performed the so called Lepidium test method, which we used in order to determine the effects of aqueous extracts of wild garlic leaves and soil from wild garlic strand on the successfulness and progress of germination of garden cress seeds (Lepidium sativum). The results showed that wild garlic has potential allelopathic influence, wherein the healthy leaves had greater allelopathic effect than the infected ones. The soil contained no inhibitory substances.
Secondary keywords: wild garlic;Allium ursinum;herbivory;Cheilosia fascinata;leaf miner;chlorophyll;fluorescence;SPAD;artificial herbivory;allelopathy;Lepidium test;master theses;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za naravoslovje in matematiko, Oddelek za biologijo
Pages: VII, 36 f.
ID: 8890177