A collection of blue (edible) honeysuckle suitable for use in genetic diversity research and breeding.

Honeysuckle (Lonicera L.) belongs to the family Caprifoliaceae Juss. The genus was named by the Swedish botanist Karl Linnaeus after the German botanist Adam Lonicero (1528-1586). They are shrubs and climbers common in the northern hemisphere, most of which are leaf-bearing, although there are some evergreens. The genus consists of over 180 species, with only one species growing naturally in Lithuania - the European fly honeysuckle (L. xylosteum L.), which produces red berries in autumn. The blue honeysuckle species belong to section Isika Rehd., subsection Caeruleae Rehd. The extent of the sub-section has been the subject of research and debate for many years: 12-13 species were formerly distinguished, but recently there has been a tendency to 'lump many together', i.e., to make L. caerulea L. a subspecies, or to remove it altogether. The generic or secondary terms altaica, baltica, cauriana, boczkarnikovae, edulis, emphyllocalyx, kamtschatica, pallasii, subarctica, stenantha, turczaninowii, venulosa, villosa, indicate that the plants bear blue fruit. The main species, the blue honeysuckle (Lonicera caerulea L.), is found in the mountains of central Europe and in the boreal (mid-latitude) forests of Eurasia and North America. It does not grow naturally in Lithuania, the nearest country to us is Latvia (where it is rare and protected). It grows in mountains, deciduous and mixed forests, undergrowth, on river and mountain slopes, in moist but well-aerated, neutral, or slightly acidic soils. It is a shrub up to 2m tall, with brown, flattened bark on the stems, which gives the plant its name, leaves up to 10cm long, usually elliptic, with double, yellow or greenish-yellow flowers, with 2 leaves in each axil. The fruit is a dark blue, rather variable-shaped multi-seeded berry.

Since the old times, breeders have tried to improve the flavor of the berries by reducing or eliminating bitterness, and by reducing crumbling. The berries are very valuable, rich in vitamins, biologically active polyphenols, and trace elements, and usually have a sweet or sweet-sour taste and a pleasant aroma due to the compound ethers of citric and malic acid. The difference between the earliest and the latest varieties is approximately 2-3 weeks. The main breeding centers are in Japan, Canada, and Russia. In recent years, breeding has been very intensive in Poland, where industrial plantations have already been established. In Lithuania, various varieties are cultivated by scientific institutions, arboretums, and private growers and the first industrial plantations have been established.

The aim of VU Botanical Garden Collection is to assemble a collection of blue honeysuckle suitable for use in genetic diversity research and breeding. The aim is to collect specimens of Lithuanian breeding, specimens of foreign origin reflecting genetic and morphological diversity of traits, and specimens from natural growing places.

The first mention of the blue honeysuckle in garden catalogues dates back to 1814.The accumulation, research and selection of the collection of honeysuckle as an edible fruit crop began after 1975 on the initiative of Dr Antanas Ryliškis, then Head of the Experimental Pomology Department. By the Catalogue of Life classification, the Garden's collection includes one species and five subspecies, as well as 36 varieties and 34 genetic lines selected in the Garden (a total of 101 specimens). Intensive research on the collection began in 1994 under the Lithuanian Plant Genetic Resources Programme, with the assessment of the fruit set and yield, the chemical composition of the fruit, resistance to fungal diseases, and molecular studies to assess the relatedness and diversity of the accessions. The molecular studies on the collection were summarized in Naugžemis' PhD thesis in 2011. The analysis of the collection has shown that most of the Russian varieties are based on honeysuckles from Kamchatka (16); the genetic lines in the collection are dominated (11 out of 34) by a single combination of traits (shrub of medium height, moderate fruiting, low berry drop, medium to large berries, elliptical); the planting material of the species comes either from the wild (3 samples) or from establishments (8).

IŠSAMUS KOLEKCIJOS PRISTATYMAS (ATSISIŲSTI)

		Lonicera caerulea subsp. pallasii Ledeb. The plants are widespread in northern and eastern Europe, as well as western and central Siberia. It does not grow in Lithuania, the closest to us is Latvia, from where this specimen was brought back during the 2012 expedition. Shrub up to 1,8 m tall, the berries are spherical, 0,5-0,8 g in weight, sour and bitter.
		Lonicera caerulea '96-2' This is a honeysuckle seedling from the Altai region of Russia, selected in Lithuania at VU Botanical Garden. Shrub up to 1.5 m tall, early fruiting. The berries are cylindrical, up to 1,5 cm long, weighing about 0,9 g, sweet and sour, with little crumbling. Yields up to 1,5 kg per bush.
		Lonicera caerulea  'Roksana' The variety was bred in Russia, based on a honeysuckle from Kamchatka. The shrub is not tall, up to 1,2 m, compact, with a spherical crown. The berries are cylindrical, up to 1,9 cm long, weighing 0,8-0,9 g, sweet and sour, and do not ripen. Yields up to 1,2 kg per bush.
		Lonicera caerulea  'Viola' The variety was developed in Russia as a hybrid of 'Sajanskaja-322' and 'Leningradskiy Velikan'. The shrub is not tall, up to 1,5 m, dense, with a spherical crown. The berries are cylindrical, large, up to 2,5 cm long, weighing 0,8-1,2 g, sweet and sour, and moderately crumbly. Yields 1,4-2,5 kg per bush.