Unraveling the impact of salinity stress on gas exchange dynamics in barley

master's thesis

• Title (croatian): Istraživanje utjecaja solnog stresa na dinamiku izmjene plinova kod ječma
• Author: Danijela Školjarev
• Mentor: Boris Lazarević (mentor)
• Committee member: Boris Lazarević (predsjednik povjerenstva)
• Committee member: Toni Safner (član povjerenstva)
• Committee member: Gabrijel Ondrašek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Plant Nutrition); Zagreb
• Defense date and country: 2024-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

This study investigated the effects of salt stress on the physiological responses of barley
(Hordeum vulgare L.) by analyzing the transpiration rate (E), photosynthetic rate (A),
intercellular CO2 concentration (Ci), stomatal conductance (gsw), and A/Ci ratio under varying
NaCl concentrations (50, 100, 200 mM) over three measurement periods (24, 72 and 168 hours).
Results showed that by the final measurement time, salt stress reduced E, A, Ci and gsw,
particularly at 200 mM NaCl, where reductions of 34% in E, 27% in A, 35% in gsw, and 19%
in Ci were recorded compared to control. While severe salinity led to marked physiological
inhibition, plants subjected to moderate salt stress (50 and 100 mM NaCl) showed signs of
recovery in E, A, Ci and gsw measurements, suggesting potential acclimation mechanisms. The
findings contribute to a deeper understanding of barley's tolerance to salinity, offering insights
into developing salt-tolerant crops for saline-affected regions.

Abstract (croatian)

Ova studija istražuje fiziološke odgovore ječma (Hordeum vulgare L.) na solni stres, s
naglaskom na analizu stope transpiracije (E), fotosintetske stope (A), koncentracije
međustaničnog CO₂ (Ci), provodljivosti puči (gsw) te omjera A/Ci, pri različitim
koncentracijama NaCl (50, 100 i 200 mM) tijekom tri vremenska intervala mjerenja (24, 72 i
168 sati). Rezultati pokazuju da je do kraja eksperimentalnog perioda solni stres značajno
smanjio E, A, Ci i gsw, posebno pri koncentraciji od 200 mM NaCl. Zabilježen je pad od 34%
za E, 27% za A, 35% za gsw i 19% za Ci u odnosu na kontrolnu skupinu. Iako je visok stupanj
saliniteta rezultirao izraženom fiziološkom inhibicijom, biljke izložene umjerenom stresu (50 i
100 mM NaCl) pokazale su znakove oporavka u parametrima E, A, Ci i gsw, što upućuje na
potencijalne mehanizme prilagodbe. Ovi rezultati pridonose boljem razumijevanju mehanizama
tolerancije ječma na stres izazvan salinitetom, pružajući vrijedne informacije za razvoj sorti
usjeva otpornijih na slane uvjete tla.

• Keywords: barley; salt stress; photosynthesis; stomatal conductance; gas exchange
• Keywords (english): ječam; solni stres; fotosinteza; provodljivost puči; izmjena plinova
• Language: english
• URN:NBN: urn:nbn:hr:204:940175
• Study programme: Title: Environment, Agriculture and Resource Management; Study programme type: university; Study level: graduate; Academic / professional title: Master of Engineering in Agriculture (Master of Engineering in Agriculture)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-07-25
• Created on: 2024-10-16 09:09:40