Fruit Growing Institute in Plovdiv

The Fruit Growing Institute in Plovdiv (Bulgarian: Институт по овощарство — Пловдив) was originally established for the breeding and study of fruit crops. However, in the second half of the 20th century, it became a major center for breeding table and seedless grapevine varieties. The work of the institute's viticulture branch was aimed at creating commercially successful, large-berried forms with very early and early ripening periods for the domestic market and fresh export.

History of the Breeding School and Methods

The main development phase of viticultural breeding at the institute is associated with the name of Professor Mincho Kondarev and his research group. The scientists applied the method of complex stepwise hybridization of European grapevine varieties (Vitis vinifera), combining selection for berry quality with selection for seedlessness.

The institute's experimental plantations and laboratories were used to evaluate berry attachment strength, transportability of bunches, and their shelf life during storage, as well as to study the effect of growth regulators (specifically, gibberellin) on seedless forms. This allowed the introduction of varieties that became the foundation of commercial table viticulture in Bulgaria.

Breeding Achievements of the Institute

The seedless and early table hybrids developed by the institute's staff gained the highest recognition in ampelography:

• Super Ran Bolgar: A white table grape variety obtained by Mincho Kondarev from a cross of the parental pair Bolgar × Alphonse Lavallée. The variety is characterized by a very early ripening period, large oblong berries, and crisp flesh, becoming a benchmark for early market produce in Southern Bulgaria.
• Rusalka 3: A seedless grape variety created by crossing the varieties Mirny × May 5 (V-6) and officially recognized in 1981. It features firm berry flesh, high sugar content, and early ripening, making it suitable for both fresh consumption and raisin production.
• Kondarev 6: A white seedless grape variety obtained from a cross of the varieties Italia × Hybrid VI-4. The variety is valued for its high yield, marketable appearance of bunches, and good flavor qualities.
• Kondarev 10: A large-berried table grape variety with dark purple skin, bred by crossing the parental pair Chaush × Alphonse Lavallée to extend the ripening sequence of table produce.

Current State of Research and Biotechnological Methods

At the current stage, the institute has ceased breeding new grapevine hybrids, completely shifting its material and technical base toward the preservation, sanitization, and reproduction of the existing gene pool. The main focus of work has become the production of certified virus-free planting material using in vitro culture of isolated apical meristems.

In the institute's biotechnology laboratory, explants of varieties bred by Mincho Kondarev (including the Rusalka series) and other valuable Bulgarian clones are introduced into sterile culture for rapid micropropagation. The meristem regeneration method combined with thermotherapy allows the elimination of systemic viral pathogens and the causative agent of grapevine crown gall (Agrobacterium vitis). The resulting super-elite plants serve as the foundation for establishing mother plantations. In addition, the institute conducts work on the cryopreservation of meristems for the long-term preservation of rare Balkan grapevine genotypes.