Ovisnost rasta i fotosinteze vodene leće (Lemna minor L.) o osmotskoj vrijednosti podloge i osvjetljenju

master's thesis

• Title (english): Effect of osmotic values of nutrient medium and illumination conditions on growth and photosynthesis in duckweed (Lemna minor L.)
• Author: Sonja Sorić
• Mentor: Željka Vidaković Cifrek (mentor)
• Committee member: Mirjana Kalafatić (član povjerenstva)
• Committee member: Ana Galov (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2011, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Vodena leća je mala brzorastuća jednosupnica koja se zbog visoke osjetljivosti i jednostavnog uzgoja u laboratorijskim uvjetima koristi za istraživanje učinka različitih tvari i okolišnih uvjeta. U ovom radu vodene leće su u kulturi in vitro uzgajane na hranjivoj podlozi po Pirsonu i Seidelu uz dodatak različitih koncentracija saharoze (5,0; 7,5 i 10,0 g/L) i izložene različitim izvorima osvjetljenja („Cool White“, 38-40 μmol m-2 s-1 te „GroLux“, 55 μmol m-2 s-1 s većim udjelom plavog i crvenog dijela spektra). Praćenjem rasta biljaka utvrđeno je da sve kulture imaju eksponencijalni rast u trajanju 16 dana pa je to vrijeme određeno kao vrijeme trajanja pokusa. Stopa rasta biljaka bila je proporcionalna povećanju koncentracije saharoze u hranjivoj podlozi neovisno o vrsti izvora svjetlosti. Najviša vrijednost stope rasta biljaka zabilježena je u vodenih leća izloženih izvoru svjetlosti „GroLux” na podlozi s 7,5 i 10,0 g/L saharoze. Mjerenjem učinkovitosti fotosistema II metodom saturacijskog pulsa, utvrđeno je da je fotokemijsko gašenje jedini parametar koji je ukazao na značajniju razliku u biljaka izloženih različitim koncentracijama saharoze i izvoru svjetlosti „Cool White“. Dobiveni rezultati pokazuju da više koncentracije saharoze (7,5 i 10,0 g/L) i izvor svjetlosti s većim udjelom plavog i crvenog dijela spektra („GroLux“) uzrokuju bolju stopu rasta biljaka dok učinkovitost fotosinteze nije bila ovisna o vrsti izvora svjetlosti.

Abstract (english)

Duckweed is a small, fast growing monocotyledon, commonly used in investigations of effects of various substances and environmental conditions due to high sensitivity and simple cultivation in laboratory conditions. In our experiment duckweeds were grown in vitro on Pirson – Seidel's nutrient medium supplemented with sucrose in concentrations 5.0, 7.5 i 10.0 g/L and exposed to different light conditions (Cool White, 38-40 μmol m-2 s-1 and GroLux, 55 μmol m-2 s-1 which has a higher proportion of blue and red part of the spectrum). It was found that all cultures kept exponential growth over period of 16 days, therefore it was defined as duration of the experiment. Under the both illumination conditions, growth rate of duckweeds followed the increase of sucrose concentrations in nutrient solution. The highest value of growth rate was noticed in plants exposed to GroLux light, especially on solution containing 7.5 and 10.0 g/L of sucrose. The only parameter of chlorophyll a fluorescence measurement which showed significant influence of osmotic conditions was photochemical quenching in plants exposed to Cool White light. Obtained results show that higher sucrose concentrations (7.5 i 10.0 g/L) and light containing higher proportion of blue and red part of the spectrum (GroLux) caused higher growth rate while efficiency of photosynthesis was not influenced by either of light conditions in duckweed.

• Keywords: svjetlost; osmotska vrijednost; rast; fotosinteza; vodena leća (Lemna minor L.)
• Keywords (english): light; osmotic values; growth; photosynthesis; duckweed (Lemna minor L.)
• Language: croatian
• URN:NBN: urn:nbn:hr:217:110469
• Study programme: Title: Biology; specializations in: Ecology; Course: Ecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra biologije (magistar/magistra biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-04-11 08:40:50