Four PhD theses were maintained:
1. Audrius Skridaila ‘Introduction of woody plants to Vilnius University Botanical Garden 1781 - 2000’
2. Gitana Indrisiunaite ‘The investigation of Lithuanian gladioli (Gladiolus L.) at the Botanical Garden of Vilnius University and their evaluation’
3. Darius Ryliskis ‘Selection of vine (Vitis L.) varieties and clones having prospects in south-east Lithuania, their estimation, peculiarities of morphology and biology and biology and productivity’
4. Algis Aucina ‘Influence of climatic conditions and mycorrhiza on seedlings of different Scots Pine (Pinus sylvestris L.) populations’

The central Ribes/Rubus Europe database was established and managed (The IPGRI and ECP/GR request).

In 1998 - 2005, the scientific works were focussed on the national Genetic Resources program (Dr. A. Skridaila, Dr. S. Žilinskaitė, Dr. D. Ryliškis, Dr. R. Juodkaitė).

Solid-state Lighting Technology for Control of Photo Physiological Processes in Plants (HORTILED). Dr. S. Dapkūnienė. 2003–2006.
(together with Institute of Material Science and Applied Research, Institute of Botany, and Institute of Horticulture).

The processes of photosynthesis, photo morphogenesis were investigated in vitro under different LED illumination. Study of the influence of illumination spectrum (red, blue and far-red) on Chrysanthemum was continued. Morphological and biometric parameters and concentration of photosynthetic pigments in the plants were measured. Influence of different spectral components on photo physiological parameters of Chrysanthemum plants was determined. Scientific Research of the Plant Genetic Resource in Lithuania.

Investigations on Genetic Diversity and Conservation Problems of Wild and Underutilized Small Fruit. Dr. S. Žilinskaitė. 2004–2008.
(together with Botanical Garden of Kaunas Vytautas Magnus University and Institute of Botany).

Investigations have been carried out for species and cultivars of Chaenomeles Lindl. (39), Lonicera L. (38), Sorbus L. (36), Vaccinium L. (8), Rubus L. (2 species from 8 different places) and Fragaria vesca L. Micromycetes of the aboveground part of bushes were investigated. The disease-resistant cultivars and species were determined. The investigation of Lonicera L. polymorphism by RAPD method was started, first 20 plants were investigated. Research of stabilization of Vaccinium L. cultivars, Rubus L. species and Fragaria vesca L. in vitro culture were continued. The photosynthetic pigments of Vaccinium L. cultivars in conditions in vitro, in vivo, and in hortus were investigated.

Accumulation, Preservation and Investigation of Lithuanian Ornamental Plants. Dr. A. Skridaila, Dr. D. Ryliškis. 2004-2008.
(together with Botanical Garden of Kaunas Vytautas Magnus University, Institute of Botany, and Field Floriculture Research Station).

Investigation of bio-ecological, morphological and decorative features, phytopatological and entomological evaluation of 30 decorative plants genera, 4,010 taxa were carried out by 4 scientific Lithuanian institutions. Data analysis on Picea Dietr. A., Abies Mill. and Pinus L. genera was performed, and 20 most valuable taxa were selected. Proposal to add these species to the list of national plant genetic resources is under way. The list of plants in genera Dahlia Cav., Iris L., Paeonia L., Picea Dietr. A., Abies Mill., and Pinus L. was revised. 205 taxa (from 1,292) were selected for further research.

Polymorphism and Economical Value of the Natural and Induced Mutants and Establishment of Their Genetic Collections. Dr. L. Balčiūnienė. 2006.
(together with the Department of Botany and Genetics).

Correlations between phenotypic properties (height, first fruit ripe date and fruit yield) of wild Rubus idaeus L., collected from different parts of Lithuania and cultivated for several years, and soil chemical properties (contents of total nitrogen, available phosphorus, available potassium, humus and pH of the soil) were made also considering latitude and longitude of the collecting sites.

Polymorphism of Plants, Stability of Genome and Factors Changing It.
Prof. V. Rančelis, Dr. L. Balčiūnienė. 2001–2010.

Number of unstable barley mutants and lines based on reversions from the homeotic pleiotropic genetically unstable barley mutants was investigated. Two types of reversions denoted as N (normal) and as C (compact ear) were compared. The C type revertant was confirmed by flower structure analysis. The resistance to Erysiphe graminis, lodging of C type revertant, as well as protein content was investigated. Both N and C revertants from tw1 are interesting as a new source of genetic diversity.
Adaptation of Plants and Biotechnology of Cultivation and Reproduction.
Dr. S. Žilinskaitė, Dr. L. Balčiūnienė. 2006–2010.

At present there are over 9,500 taxa (species, subspecies, varieties and cultivars) of woody and herbaceous plants in the collections of the VU Botanical Garden. The adaptation of some genera (Lilium L., Pinus L., Vaccinium L.) in condition in hortus, in vitro, in vivo was investigated. The dependence of adaptation of different Lilium species and cultivars to ex vitro conditions after transplantation from micro-tubes for the duration of quiescence period was examined. The effect of different nursery substrata on the spread of mycorrhiza in symbiotic association with Scots Pine seedlings grown in bare-root nursery was investigated. The morphological classification of mycorrhiza morphotypes was accomplished by the traditional morphotyping and verified by the PCR-RELP molecular markers.

European Commission Community programme on the conservation, characterisation, collection and utilisation of genetic resources in agriculture
Core Collection of Northern European Gene Pool of Ribes L. (contract number AGRI-2006-0402). Dr. D. Ryliškis 2007-2011.

8 countries – Germany, Poland, Lithuania, Latvia, Estonia, Finland, Sweden and Denmark – are taking part in RIBESCO project. The European Commission-funded project is designed to improve the level of characterization and conservation of the northern pool of European Ribes (currants and gooseberries) germplasm by utilisation of coordinated, trans-national achievements. A decentralized core collection of the Northern EC Ribes germplasm has been established and preserved. A trans-national network has been created for the project. Easy-access documentation will be part of the activity, and the project promotes Ribes genetic material transfer and use between European partners. Firstly, the Ribes germplasm conserved in national ex-situ collection is subjected to phenotypic characterization using trans-nationally defined descriptors. Information obtained will be saved in a database and will be used to define the part of germplasm identified by using molecular markers and select material will be added to the Ribes core collection. Microsatellites are used, and the molecular data will be employed to provide a suggestion for an optimal size for core collection, in order to represent a maximum amount of genetic variation. The most valuable genotypes are selected to store in core collection. The selection is based on values defined by phenotypic characterization as well as agronomic, historical or other important cultural values. In addition, germplasm containing a high level of genetic variability as revealed by molecular identification is selected. The Ribes core collections are established to assure preservation, both in ex-situ collections and in vitro slow growth medium-term and cryopreservation long-term collections.

Solid-state lighting technology for plants in phytotrons and greenhouses. 2007-2009.
Institute of Material Science and Applied Research of Vilnius University, Botanical Garden of Vilnius University, and Institute of Horticulture. Head of Botanical Garden Group Dr. S. Dapkūnienė.

The plantlets of grape and potatoes were cultivated in vitro using an illumination system based on light – emitting diodes (LEDs). Morphological and biometric parameters and concentrations of photosynthetic pigments were measured after 28 - 30 days (grape) or 42 days (potato). We demonstrated that spectrally selective solid-state lighting is effective tool for cultivation in vitro and discussed the prospective of using this technology on a commercial scale.