diplomsko delo
Mateja Petavs Kristančič (Author), Polonca Trebše (Mentor)

Abstract

V okviru diplomskega dela sem opravila dva enaka 14-dnevna prehranjevalna poskusa, v katerih sem kopenske enakonožne rake Porcellio scaber, Latreille 1804 izpostavila acetamipridu, pesticidu, uporabnem v kmetijstvu, dodanem v hrano v koncentracijah 0, 10, 25 in 50 μg acetamiprida g-1 suhe mase lista. Spremljala sem preživetje živali in sem živali ter zaužite liste stehtala pred in na koncu poskusa. Ravno tako sem na koncu poskusa stehtala njihove iztrebke v petrijevkah. S pridobljenimi podatki sem izračunala učinkovitost asimilacije (AE). Po končanem poskusu sem živalim odstranila prebavne žleze (hepatopankreas), jih homogenizirala in dodala ustrezne reagente za spektofotometrično določanje malondialdehida (MDA), pokazatelja stresa. Vzorcem sem izmerila absorbance pri različnih valovnih dolžinah (280, 535 in 600 nm) ter po enačbi iz literature izračunala odstotek vsebnosti MDA. Vrednosti so predstavljene brez enot. Namen diplomske naloge je bil ugotoviti: kakšne učinke povzročajo različne koncentracije acetamiprida na smrtnost, spremembo telesne mase, količino zaužitih listov, količino iztrebkov ter ugotoviti povezavo med fiziološkimi parametri (prehranjevanje, iztrebljanje, asimilacijska učinkovitost) in lipidno peroksidacijo pri modelnem organizmu Porcellio scaber, Latreille 1804. Dobljeni rezultati v obeh 14-dnevnih prehranjevalnih poskusih so pokazali majhne razlike v umrljivosti, količini zaužite hrane, v spremembi telesne mase in učinkovitosti asimilacije. Med prvim poskusom je poginilo nekaj več osebkov kot med drugim poskusom. Živali so v prvem poskusu izgubile telesno maso, tako v kontrolni skupini, kot pri vseh izpostavljenih koncentracijah, več pri koncentraciji 10 µg acetamiprida g-1 suhe mase lista, malo manj pri višjih koncentracijah acetamiprida v hrani (25 in 50 µg acetamiprida g-1 suhe mase lista). Med drugim poskusom je živalim telesna masa naraščala, le živalim, izpostavljenim koncentraciji 50 µg acetamiprida g-1 suhe mase lista, je telesna masa padla. Ker sem pričakovala, da se bo z višanjem koncentracije acetamiprida v hrani zmanjševala telesna masa živali (manj zaužitih listov), sem pričakovala tudi premosorazmeren odnos med koncentracijo acetamiprida in vsebnostjo MDA v vzorcih. Torej naraščanje koncentracije MDA z naraščanjem koncentracije acetamiprida. Rezultati so pokazali drugače. Vsebnost MDA v prebavnih žlezah je bila v obeh poskusih nizka (0,3). Malce višja vsebnost MDA (0,6) se je pokazala le v prvem poskusu pri živalih, ki so bile izpostavljene 25 µg acetamiprida g-1 suhe mase lista. Iz rezultatov vsebnosti MDA v vzorcih je bilo ugotovljeno, da živali niso bile pod večjim stresom, torej lahko sklepamo, da izpostavljenost kopenskih enakonožnih rakov Porcellio scaber, Latreille 1804 acetamipridu v navedenih koncentracijah znotraj 14-dnevnega obdobja ni povzročala negativnih sprememb v življenjskem ciklusu živali.

Keywords

prehranjevalni poskus;Porcellio scaber;Latreille 1804;acetamiprid;lipidna peroksidacija;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UNG FZO - Faculty of Environmental Sciences
Publisher: [M. Petavs Kristančič]
UDC: 661
COBISS: 4520187 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Toxicity of acetamiprid to nontarget terrestrial isopods Porcellio Scaber (Isopods, Crustacea)
Secondary abstract: As part of the thesis I conducted two 14-day feeding experiments whith non-target terrestrial isopods Porcellio scaber, Latreille 1804. The isopods were exposed to acetamiprid trough food in concentrations of 0, 10, 25 and 50 µg of acetamiprid g-1 of dry mass of the leaf. At the end of the feeding experiment the results for mortality, weight change, consumption rate and defecation were obtained. With the acquired data, I calculated the assimilation efficiency (AE). At the end of the experiment I removed the digestive glands of the hepatopancreas from the animals, homogenized them and added relevant reagents for spectrophotometrically determining malondialdehyde (MDA), which indicates stres in the organisms. I measured the absorbance of the sample at three different wavelengths (280, 535 and 600 nm) and I determined the content of MDA. Lipid peroxidation (LP) was therefore calculated as a ratio between TBA-MDA product absorbance (535 nm) and protein absorbance (280 nm). Lipid peroxidation values are presented without units The purpose of this study was to determine: the impact caused by different concentrations of acetamiprid on mortality, body weight change and assimilation efficiency and to establish a link between physiological parameters (eating, defecation, assimilation efficiency) and lipid peroxidation in the model organism Porcellio scaber, Latreille 1804. The results obtained in both 14-day feeding experiments have shown little differences in the mortality rate, food intake or body weight changes and assimilation efficiency. In the first experiment some more individuals died than in the second one. The results of the first feeding experiment revealed that the animals lost weight in the control group, as well as at all exposed concentrations. The group exposed to 10 µg of acetamiprid g-1 of dry mass of the leaf lost more weight, followed by the group of 25 and 50 µg of acetamiprid g-1 of dry mass of the leaf. In the second experiment, the animals' body weight decreased only in the group exposed to a concentration of 50 µg of acetamiprid g-1 of dry mass of the leaf, in other groups the body weight increased. I expected that with the increased concentrations of acetamiprid in the food the body weight of the animals would decrease (less eaten leaves), that is why I also expected a directly proportional relationship between the concentration of acetamiprid and the content of MDA in the samples, which means increased concentration of MDA with increased concentration of acetamiprid. The results showed otherwise. The content of MDA in the digestive glands of the hepatopancreas in both experiments was low (0.3). Slightly higher content of MDA (0.6) was shown only in the first experiment where the animals were exposed to 25 µg of acetamiprid g-1 of dry mass of the leaf. From the results of MDA content in the samples it was foud that the animals were not under increased stress. Based on the results we can assume that the exposure of terrestrial isopods Porcellio scaber, Latreille 1804 to acetamiprid within the 14-day feeding experiment, does not have a negative effect in the lifecycle of the selected model organisms.
Secondary keywords: feeding experiment;Porcellio scaber;Latreille 1804;acetamiprid;lipid peroxidation;
URN: URN:SI:UNG
Type (COBISS): Undergraduate thesis
Thesis comment: Univ. v Novi Gorici, Fak. za znanosti o okolju
Pages: XII, 47 str., [20] str. pril.
ID: 9174933