Genetska raznolikost hrvatskih provenijencija obične bukve (Fagus sylvatica L.) u odgovoru na sušni stres

doctoral thesis

• Title (english): Genetic variability of Croatian provenances of European beech (Fagus sylvatica L.) in response to drought stress
• Author: Sanja Bogunović
• Mentor: Renata Pernar (mentor)
• Committee member: Željko Škvorc (predsjednik povjerenstva)
• Committee member: Saša Bogdan (član povjerenstva)
• Granter: University of Zagreb; Faculty of Forestry and Wood Technology; (Institute of Forest Inventory and Management); Zagreb
• Defense date and country: 2022-12-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Forestry
• Universal decimal classification (UDC): 630 - Silviculture. Afforestation. Felling. Logging

Abstract

Prirodne šume obične bukve predstavljaju značajne šumske ekosustave Republike Hrvatske, s obzirom da je ona naša najučestalija vrsta šumskog drveća. S porastom svijesti o klimatskim promjenama, posebice s naglaskom na sušu u vegetacijskom periodu, raste i potreba za istraživanjima i pronalascima rješenja koja bi pridonijela očuvanju genetske

AB (sažetak)

raznolikosti obične bukve. Očuvanje genetske raznolikosti ove dominantne vrste pretpostavka je i za očuvanje ukupne biološke
raznolikosti njenih šumskih ekosustava. Jedan od ciljeva ovog

istraživanja je bio utvrditi razinu unutarpopulacijske i

međupopulacijske genetske raznolikosti hrvatskih provenijencija obične bukve kako bi dobili uvid u potencijal ove vrste za opstanak u predviđenim promijenjenim uvjetima okoline. Suša se navodi kao jedna od glavnih posljedica klimatskih promjena koja bi mogla dovesti do postupnog izumiranja obične bukve. Drugi cilj istraživanja je bila identifikacija provenijencija otpornijih na

I

stres uzrokovan sušom te utvrđivanje da li su razlike u otpornosti povezane s prevladavajućim klimatskim uvjetima u različitim područjima podrijetla. Istraživanje je provedeno na pomlatku 10 hrvatskih provenijencija obične bukve različitog geografskog porijekla. Tijekom prve godine trajanja pokusa procijenjivala su se kvantitativna fenotipska svojstava (visine, fenologija listanja te stupanj oštećenja biljaka kasnim proljetnim mrazem). Biljke su podijeljne u dva tretmana, prvi je predstavljao sušni stres, a drugi kontrolu. Biljni materijal (listovi, stabljike, korijenje) su uzorkovani u određenim vremenskim intervalima te je izmjerena biomasa, a nakon toga su izmjereni fiziološki parametri (količina δ13C izotopa, omjer i ukupna količina ugljika i dušika, količina askorbinske kiseline te količina fosfora u listovima i korijenju biljaka). Rezultati istraživanja ukazuju na statistički značajnu unutarpopulacijsku genetsku raznolikost s obzirom na analizirana kvantitativna fenotipska svojstva te na značajnu razinu genetske diferencijacije. Najbitniji klimatski parametri utvrđene genetske diferencijacije bili su oni koji ukazuju na surovost staništa, a zatim parametri koji opisuju toplinu i vlažnost staništa. Provenijencije su pokazale dvije različite strategije ublažavanja posljedica stresa uzrokovanog sušom: 1) povećanje mase korijena, te povećanje količina dušika i askorbinske kiseline u redoks stanju, 2) učinkovitije korištenje fosfora iz tla. U konačnici, provenijencije obične bukve koje rastu na višim nadmorskim visinama su pokazale širi raspon odgovora na sušni stres, te se može reći da su se u ovom istraživanju takve provenijencije istaknule kao vrlo vrijedan šumski genetski resurs u svjetlu klimatskih promjena.

Abstract (english)

Natural forests of European beech represent important forest ecosystems in Croatia, considering it is our most widespread forest tree species. Growing awareness of climate change, especially of predicted drought events during vegetation AB (Abstract) period, increases the need for research and finding solutions that would contribute to conservation of genetic resources of the species in Croatia. Conservation of genetic resources of this dominant tree species is the prerequisite for conservation of overall biodiversity of its forest ecosystems. One of the research goals was to determine the level of intrapopulation and interpopulation genetic variability of Croatian beech provenances in order to gain insight into the potential of this species for survival in the predicted climate changes. Drought is cited as one of the main consequences of climate changes that could lead to the gradual extinction of European beech. The second goal of the study was to identify provenances III more resistant to drought stress and to determine whether differences in resilience are related to prevailing climatic conditions in different areas of origin. The research was conducted on the offspring of 10 Croatian beech provenances of different geographical origin. During the first year of the experiment, quantitative phenotypic traits (heights, leaf phenology, and the degree of plant damage by late spring frost) were assessed. The plants were divided into two treatments, one represented drought stress and the second control. Plant material (leaves, stems, roots) was sampled at certain time intervals and biomass was measured, followed by physiological parameters (amount of δ13C isotope, ratio and the total amount of carbon and nitrogen, amount of ascorbic acid and amount of phosphorus in leaves and roots). The results of the research indicate a statistically significant intrapopulation genetic variability concerning the analyzed quantitative phenotypic traits and also a significant level of genetic differentiation of the provenances. The most important climatic parameters of the determined genetic differentiation were those that indicate the harshness of the habitat, followed by the parameters that describe the heat and humidity of the habitat. Provenances have shown two different strategies for mitigating the effects of drought stress: 1) increasing root mass, and increasing the amount of nitrogen and ascorbic acid in the redox state, 2) more efficient use of phosphorus from the soil. Finally, beech provenances growing at higher altitudes have shown a wider range of responses to drought stress, and it can be said that in this study such provenances have emerged as a very valuable forest genetic resource in light of climate change.

• Keywords: genetska raznolikost; obična bukva; sušni stres
• Keywords (english): Genetic variability; European beech; drought stress
• Language: croatian
• URN:NBN: urn:nbn:hr:108:403793
• Promotion: 2022
• Study programme: Title: POSTGRADUATE UNIVERSITY DOCTORAL STUDY PROGRAMME OF FORESTRY; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje biotehničkih znanosti, polje šumarstvo (doktor/doktorica znanosti, područje biotehničkih znanosti, polje šumarstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to authenticated users
• Created on: 2022-11-30 12:22:35