Title Fiziološke reakcije kukuruza na vodni stres Author Valentina Zmeškal Mentor Milan Poljak (mentor)Committee member Milan Poljak (predsjednik povjerenstva)Committee member Ana Pospišil (član povjerenstva)Committee member Hrvoje Šarčević (član povjerenstva)Committee member Boris Lazarević (član povjerenstva)Granter University of Zagreb Defense date and country 2016-09-28, Croatia Scientific / art field, BIOTECHNICAL SCIENCES Abstract Kukuruz (Zea Mays L.) je jedna od najvažnijih kultura u svijetu uz pšenicu i rižu.
Kao tropska biljka, kukuruz je osjetljiv na mraz i nedostatak vode, a prema potrebi za vodom
ubraja se u biljke koje ekonomično troše vodu.
Gubici uzrokovanim vodnim stresom u ukupnoj biljnoj proizvodnji na Zemlji
(poljoprivreda, šumarstvo) veći su od gubitaka uzrokovanih svim drugim biotskim i abiotskim
čimbenicima zajedno.
Cilj ovoga diplomskog rada je utvrditi učinak vodnog stresa na fotosintetsku aktivnost
i oksidativni stres kukuruza.
U pokusu je korišten jedan od komercijalno najzastupljenijih hibrida u poljoprivrednoj
proizvodnji u Hrvatskoj, hibrid Pajdaš. Pokus je postavljen u komorama rasta Agronomskog
fakulteta u Zagrebu, po shemi slučajnog bloknog rasporeda u tri ponavljanja. Tretmani suše su
primijenjeni u fazi tri razvijena lista, navodnjavanjem biljaka otopinama polietilen glikola (u
koncentracijama koje su izazvale osmotski potencijal medija od -5 MPa i -1 MPa (kontrola).
Svaki tretman je primjenjivan tijekom tri tjedna, a mjerenja indeksa sadržaja klorofila i
paametara fotosinteze (intenzitet fotosinteze (A), provodljivost puči (gs), intenzitet
transpiracije (E), intercelularna koncentracije CO2 (ci)) su obavljana 24 h nakon primjene
tretmana. Na kraju pokusa određena je koncentracija prolina, stupanj oksidacije lipida i
istjecanje iona.
Stres suše nije uzrokovao pad sadržaja klorofila, ali je izazvao značajnu redukciju
fotosintetskih parametara (A, E, gs, ci) te možemo pretpostaviti da pad intenziteta fotosinteze
nije uzrokovan smanjenom sposobnošću fotosintetskog aparata za apsorpciju svjetlosti.
Glavni razlog smanjenja intenziteta fotosinteze jest redukcija provodljivosti puči. Redukcijom
provodljivosti puči, istovremeno je došlo i do smanjenja intercelularne koncentracije CO2, što
je uzrokovalo pad intenziteta fotosinteze. Koncentracije prolina, istjecanje iona i
koncentracije malondialdehida (MDA) bile su veće kod tretmana suše (-5 MPa), u odnosu na
kontrolu. Povećana peroksidacija lipida izazvala je narušavanje strukture biomembrana zbog
čega je došlo i do povećanja istjecanja iona iz stanica, što je također mogući uzrok pada
intenziteta fotosinteze pri duljem izlaganju biljaka stresu suše.
Abstract (english) Maize (Zea Mays L.) is one of the most important cultures in the world along wheat
and rice. As a tropical plant, maize is sensitive on frost and water deficiency, and according to
needs for water, it is one of plants that economical spents water.
Losses caused by the water deficit stress in total crop production on the Earth
(agriculture, forestry) are greater than losses caused by all other biotic and abiotic factors
together.
The objective of this master thesis is to determine the effect of water deficit stress on
the photosynthetic activity and oxidative stress of maize.
In the experiment was used hybrid Pajdaš, that is one of the most usually commercial
hybrids in agricultural production in Croatia. Experiment was set in growth chambers in
Faculty of Agriculture in Zagreb, on scheme of random blocked schedule in three repetition.
Treatments of drought was applied in stage of three developed leaves,and plants were
irrigated with polyethylene glycol dilutions (in concentrations that caused osmotic potential of
the media from -5 and -1 MPa (control). Each treatment was applied in a period of three
weeks, but measurements of chlorophyll concentration index (CCI), and parameters of
photosynthesis (photosynthesis intensity (A), stomatal cunductance (gs), transpiration
intensity (E) and intercelular concentration od CO2 (ci), were practised 24 hours after
treatment application. In the end of the experiment is determined concentration of proline, the
degree of oxidation of lipid and leakage of ions.
Drought stress was not caused falling in chlorophyll content, but has caused
significant reduction of parameters of photosynthesis (A, E, gs, ci) and we can assume that
falling of photosynthetic intensity isn't caused with reduce capability of the photosynthetic
apparatus for absorption of light. The main reason of reducing photosynthesis intensity is
reduction of stomatal conductance. By reduction of stomatal conductance, at the same time it
is come to the reduction of intercelular concentration of CO₂, which caused falling of
photosynthesis intensity. Concentration of proline, leakage ions and concentration of
malondialdehyde (MDA) was bigger in the treatment of drought (-5 MPa), compared to
control. Increased lipid peroxidation caused distortion of the structure of biomembranes
which has caused increased leakage of ions from cells, which is possible cause of falling of
the photosynthesis intensity at prolonged exposure of plants to drought stress.
Keywords
kukuruz
vodni stres
suša
fotosintetska aktivnost
Keywords (english)
maize
water deficit stress
drought
photosynthetic activity
Language croatian URN:NBN urn:nbn:hr:204:593925 Study programme Title: Agroecology Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2016-12-01 11:34:40
