Unveiling Balkans' Advances: In vitro Vitro Biotechnology of Woody Plants in the Early 21 st Century

Valbona Sota^1,2*Lilyana Nacheva³Dejan Bošnjak⁴Eleni Abraham⁵Sladjana Jevremović⁶Branislav Cvjetkovic⁷Vladislava Galović⁸Darko Jevremović⁹Zvjezdana Marković¹⁰Efigjeni Kongjika²Sanja Bogunović¹¹Svjetlana Zeljkovic¹²Vlatko Andonovski¹³Vanja Danicić⁷Tatjana Vujović^9*

• ¹Department of Biotechnology, Faculty of Natural Sciences, University of Tirana, Tirana, Tirana, Albania
• ²Research Center of Biotechnology and Genetics, Academy of Sciences of Albania, Tirana, Tirana, Albania
• ³Fruit Growing Institute, Agricultural Academy, Plovdiv, Plovdiv, Bulgaria
• ⁴Faculty of Agrobiotechnical Sciences, Josip Juraj Strossmayer University of Osijek, Osijek, Osijek, Croatia
• ⁵Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki, Greece
• ⁶Institute for Biological Research “Siniša Stanković” - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
• ⁷Faculty of Forestry, University of Banja Luka, Banja Luka, Bosnia and Herzegovina
• ⁸Institute of Lowland Forestry and Environment, University of Novi Sad, Novi Sad, Vojvodina, Serbia
• ⁹Fruit Research Institute, Čačak, Serbia
• ¹⁰Department of Viticulture and Enology, Faculty of Agriculture, University of Zagreb, Zagreb, Croatia
• ¹¹Department of Genetics, Forest Tree Breeding and Seed Science, Croatian Forest Research Institute, Jastrebarsko, Croatia
• ¹²Faculty of Agriculture, University of Banja Luka, Banja Luka, Bosnia and Herzegovina
• ¹³Faculty of Forestry Sciences, Landscape Architecture and Eco-Engineering 'Hans M', Saints Cyril and Methodius University of Skopje, Skopje, Skopje, North Macedonia

The Balkan Peninsula is a European biodiversity hotspot, home to 6,500 native vascular plant species, many of which are endemic. The region has various diverse range of climates and complex topography, creating conditions that suit many woody ornamental, fruit, and forest species. Nevertheless, climate change, habitat destruction, invasive species, plant diseases, and agricultural practices threaten natural ecosystems and cultivated species. Many Balkan countries have addressed these challenges using advanced biotechnological approaches, including micropropagation, in vitro conservation, and in vitro selection for stress-tolerant genotypes. This paper provides a comprehensive overview of in vitro plant biotechnology progress in the Balkan countries from the beginning of the 21st century until todayto the present, focusing with a focus on woody horticultural and forest species. The main directionsprimary objectives of scientific research include optimizing media composition for all components and micropropagation stages, as well as and effective initial explant selection. In addition, temporary immersion bioreactors, synthetic seed technology, and cryopreservation techniques have been explored to enhance plant production and and plant germplasm conservation. Scientific research for woody ornamentals and fruit tree species has progressed in Albania, Bulgaria, Croatia, Greece, and Serbia while remaining limited in other Balkan countries. Forest tree production research currently only occursis currently conducted in Bulgaria, Greece, and Serbia, with labs focusing on micropropagation and ex situ conservation. In addition to advances in scientific research, a certain number ofseveral commercial companies operate in the Balkans, with establishmentsestablished in Serbia, Greece, Bulgaria, and North Macedonia, which that produce in vitro-derived planting material for fruit trees and woody ornamental plants. Despite this progress, research in the Balkan countries remains fragmented, emphasizing the need to strengthen regional collaboration and knowledge exchange to promote agricultural development processes and biotechnological applications in this region. This review represents the first exploration of this topic in the Balkans and successfully unites researchers from several countries. This is the first review on this topic in the Balkans, and the process has brought together researchers from many countries. It highlights key scientific advances in in vitro biotechnology for woody plants, identifies challenges, and proposes solutions to solve them.