Cornelian cherry (Cornus mas) is a valuable food, medicinal and ornamental plant. It is rarely attacked by pests and diseases and can be grown with minimal use of chemicals. It is also resistant to frost and drought and does not require much care. Cornelian cherry fruits, due to their high nutritional value and health-promoting properties, can be widely used in the food, pharmaceutical and cosmetic industries. In addition to its importance as a fruit tree, cornelian cherry is also a valuable ecological tree. It provides early spring pasture for pollinators, is suitable for landscaping and for extensive and ecological management systems such as edible forests. Its longevity and resistance make it a promising tree species even in the context of climate change.
Gene pool
Cornelian cherry has only relatively recently attracted the attention of fruit tree breeders. Systematic programs for establishing a collection of genotypes, varietal selection and breeding of cornelian cherry have been introduced in several European countries. The largest collection of cornelian cherry genotypes is located in the National Botanical Garden named after Hryshko in Kiev, which is operated by the National Academy of Sciences of Ukraine. The collection includes officially registered cornelian cherry varieties, as well as numerous hybrids developed in the course of the breeding and selection program. The gene pool consists of more than a hundred wild and cultivated genotypes from Ukraine, Poland, Bulgaria, Slovakia, the United Kingdom, Austria and Georgia and represents a rich biological and economic potential, as well as a rich source of material for further breeding and varietal selection.
Interesting history
On the outskirts of Kiev and on the territory of the National Botanical Garden of Ukraine, there are 150-200-year-old cornelian cherry plants, which still bear abundant fruit today. These plants were brought to the territory of Crimea during the formation of Kievan Rus. A positive role in this process was played by monasteries, especially Vydubychi, Mezhyhirya and Kyiv-Pechersk Lavra, which were famous for their beautiful gardens and were located near Kiev on the Dnieper route from the Varangians to the Greeks. This medieval trade route connected Scandinavia, Kievan Rus and the Eastern Roman Empire. The princes were fascinated by the monastery gardens and began to grow cornelian cherries on their estates and near their palaces. Various drinks and delicacies were prepared from the fruits. The history of planting and growing cornelian cherry, brought to Crimea in 1905 from the Caucasus, is also documented. To this day, these plants bring a rich harvest of fruits. At the beginning of the twentieth century, Ukrainian pomologist Lev Simirenko reported that the shrub that gave rise to the current varieties with yellow fruits was discovered in the Crimean forest by the gardener Kefeli.
Varietal selection
The National Botanical Garden of the National Academy of Sciences of Ukraine (NBG) has been engaged in the selection of varieties, the study of cultural characteristics and methods of propagation of cornelian cherry in Ukraine for several decades. The cornelian cherry gene pool of the NBG is characterized by a wide range of biological and economic characteristics. The fruits of cornelian cherry can be dark red, cherry-red, pink or yellow. In nature, there are practically no cornelian cherries with yellow fruits. Therefore, varieties with yellow and very sweet fruits are very original. The yellow pear-shaped fruits of the Nezhny variety are especially elegant. In terms of shape, the fruits can be oval, pear-shaped or bottle-shaped. The average weight of the fruit ranges from 5.0 to 8.0 grams. Their maximum weight reaches 10.0 grams. In the best varieties, the stone makes up 7.5-10.0% of the total weight of the fruit. In wild forms it is up to 18-21%. The total sugar content ranges from 8.0 to 16.0%. The organic acid content ranges from 1.3 to 2.4%. The vitamin C content ranges from 101 to 193 mg%. The anthocyanin content ranges from 670 to 850 mg% in the peel and from 36 to 121 mg% in the pulp. In the wild, the yield ranges from 2.8 to 4.8 kg per bush. With an ideal amount of sunshine and rain, cornelian cherry regularly produces rich crops of large, juicy fruits. The yield per plant ranges from 30 to 80 kg.
Cultivation prospects and breeding resources
Varieties bred in the National Botanical Garden are the basis for creating productive, profitable cornelian cherry plantations and private cornelian cherry gardens.
Cornelian cherry genotypes were collected from virtually every region of Ukraine, from a variety of sources including experimental orchards, research institutions, arboretums, commercial farms, private gardens, abandoned house sites, and from the wild. The specimens in the collection were evaluated for productivity, fruit quality, and winter hardiness, and those varieties that best met the needs of commercial growers and amateur gardeners were selected. More than 350 different varieties were identified, of which more than 100 were selected for the collection and propagated for further study and breeding. The greatest diversity among cornelian cherry varieties was found in Crimea. The collection of cornelian cherry genotypes in the National Botanical Garden in Kiev represents a rich biological and economic potential, as well as a rich source of material for further breeding and varietal selection. The first step of the breeding program was to identify the most promising candidates for breeding. The second step was to develop hybrids with specific characteristics and traits.
Results of breeding work
At the end of the 20th century, much work was done in Europe to popularize cornelian cherry and develop new varieties. Intensive breeding work, especially in countries such as Ukraine (NBG Kiev under the leadership of Svetlana Valentinovna Klimenko), Poland (Arboretum Bolestraszyce), Slovakia (VÚOOD Bojnice), Bulgaria, and other European countries, led to the emergence of a wide range of varieties.
The Bolestraszyce Arboretum in Poland bred several interesting large-fruited varieties of cornelian cherry. The highly productive Bolestrazycki variety and the Szafer variety, characterized by high sugar content and a long harvest period, were obtained by selecting seedlings from a bush that was planted in the 19th century on the estate of the Polish Zamojsky family. The Dublany variety with pear-shaped fruits was named after the village. Juliusz is a very early variety ripening in early August. Kresowiak is a universal variety with pear-shaped fruits. Paczoski with characteristic bright red fruits was named after the botanist Józef Konrad Paczoski. The name of the Podolski variety with oval-shaped fruits refers to the Podolia region. The universal Raciborski variety is named after the botanist Marian Raciborski. The newest Polish variety is Marceli with dark leaves and high yield.
Three interesting cultivars have been registered in Bulgaria in the Scientific and Production Association "Varieties of Seeds and Planting Material". Kazanlak with pear-shaped fruits, Pancharevo with cylindrical fruits and the Shumen variety with oblong fruits.
In 1989, the Slovak Research Institute of Fruit and Ornamental Trees a.s. Bojnice registered two cultivars, Devín and Titus, bred by selection from natural material from the localities of Vihorlat, Strážovská hornatina and Moravian foothills. In 2001, the varieties Alex and Expres were registered, which were created by hybridization of selections of natural populations of the species from the localities of the municipalities of Dolné Vestenice and Horné Vestenice and subsequent selection in hybrid offspring. The fifth variety that comes from Slovak selection is Maxim, a highly productive cornelian cherry with large fruits introduced in 2009.
In 1991, the cultivar Joliko was registered, developed by Dr. Helmut Pirc from Austria. The Joliko variety, known for its rich harvests and large fruits, is grown mainly in Austria, Germany and Switzerland. In 1992, the cultivar Matador was registered in France. The Azerbaijan Institute of Genetics and Selection developed the cultivars Armudi-Zogal and Ak-Zogal. Extensive research into the natural gene pool, as well as the breeding of new cultivars, is underway at the Central Horticultural Institute in Yalovaya, Turkey, at the Horticultural Department of the Tbilisi Agricultural Institute in Georgia, and at the Moldovan Botanical Institute.
Cornelian cherry appeared in the Ukrainian State Register only in 1990. In Ukraine, the main characteristics selected during breeding were reliable fruiting, high productivity and frost resistance in the local forest-steppe climatic zone. Here is a brief description of the most promising Ukrainian varieties: Koralovy Marka (Кораловий Марка) has large coral-pink fruits. Korallovy (Коралловий) is a very unusual early cornelian cherry with pink-orange fruits of an original shape and excellent sweet taste. Semyon (Семён) is one of the most valuable cultivars in the collection. It has pear-shaped fruits that ripen in mid-September. Elegantny (Елегантний) is a dwarf shrub 1.5-1.8 m high with a compact crown, whose attractive bottle-shaped fruits weigh up to 9 grams, have a pronounced taste and can be stored for about a month after ripening. It is an early variety that ripens in early August. Bukovinsky (Буковинський) is an early variety with cylindrical fruits of bright yellow color and excellent sweet taste. It comes from Bukovina in the Chernivtsi region. Nezhny (Ніжний) and Yantarny (Янтарный) have yellow fruits and are particularly interesting. One of them has been included in the state program of cultivar testing. The fruits of the yellow cornelian cherry have the same shape and size as the red fruits. The differences are, of course, in the color, which is an attractive amber-yellow. The fruits are characterized by an excellent sweet taste. Varieties with yellow fruits probably no longer occur in the wild. The varieties Svetlyachok (Світлячок) and Exotichesky (Екзотичний) were developed as a result of somatic mutations. Cornelian cherry, like other fruit trees, has a high degree of somatic variability, which can provide new material for breeding and selection. Somatic variability and its potential role in breeding new clones of fruit species is a rapidly developing area of genetics. Breeding based on somatic variability promises to be as important as traditional breeding techniques. Starokievsky (Старокиївський) is a variety with round fruits. Originalny (Оригінальний) with dark red fruits and the lighter variety Olena (Олена) stand out for their taste. Pervenets (Первенець) is a medium-early cornelian cherry with oval fruits. Ugolok (Угольок) is a late variety with pear-shaped fruits ripening in mid-September. Radost (Радість) has oval fruits that remain on the bush even after ripening. Yevgeniya (Євгенія) has highly rated taste qualities. Vydubecky (Видубицький) was named after the Vydubychi Monastery in Kiev. It is one of the most productive Ukrainian varieties with very large fruits, excellent taste qualities and long shelf life. Lukyanovsky (Лук'янівський) is one of the best varieties for direct consumption, also excellent for all types of processing. Nikolka (Ніколка) is a very early variety ripening in early August. Vladimirsky (Володимирський) is one of the most productive varieties of large-fruited cornelian cherries with the largest fruits. It is characterized by excellent taste, good durability and long shelf life.
Effective propagation methods
The expansion of the cultivation area of this species depends on the availability of quality planting material. The investigation of the natural gene pool and the breeding of new cornelian cherry cultivars depend on effective propagation. Techniques for vegetative propagation of cornelian cherry have been developed. The main technique used is chip budding in early August, which has a success rate of 90 to 98%. Grafting by dormant scion wood in February to March has a success rate of 75 to 78%. Seedlings serve as rootstocks for grafting. Further breeding of cornelian cherry requires the preservation of its gene pool, which will always be essential for the development of reliably productive varieties suitable for the needs of commercial growers and gardeners.
The current range of varieties offers sufficient variability to satisfy the requirements of cornelian cherry growers, thus opening the way to wider commercial use of this unique fruit species.
