Zdravko Zankov

Professor Zdravko Dachev Zankov, PhD, ScD, entered the history of European ampelography as one of the most prolific Bulgarian breeders of the 20th century. Working within the Department of Viticulture at the Agricultural University of Plovdiv, he established a unique scientific school. Zankov focused primarily on the intraspecific hybridization of the Vitis vinifera species, aiming to combine outstanding flavor profiles, early ripening periods, and high marketability within new grapevine genotypes.

Scientific Activity and Biological Research

Unlike many contemporary breeders of his era, Professor Zankov approached variety development through the profound exploration of the fundamental biology of grapevine seeds. In 1979, he defended his monumental doctoral dissertation titled "Studies on the Biology of Seeds and Seedlings of the Cultivated Grapevine (Vitis Vinifera L.)" (Izsledvania varhu biologiyata na semenata i semenachetata на kulturnata loza), which established his scientific priority in understanding trait inheritance mechanisms among hybrid offspring.

His academic and research endeavors included:

• Overcoming Reproductive Barriers: Zankov developed effective techniques for manipulating seedless grape varieties, utilizing them as paternal components to breed a new generation of large-fruited table grapes with rudimentary seeds.
• Inter-institutional Cooperation: The Professor did not limit his work to the Plovdiv research base. He actively collaborated with the prominent breeder Ivan Todorov and the viticultural team at the Institute of Agriculture and Seed Science "Obraztsov Chiflik" in Ruse, co-creating a widespread portfolio of highly successful varieties.
• Popularization of Ampelographic Knowledge: In 1977, he published a landmark monograph for the industry, "New Grapevine Varieties Developed in Bulgaria" (Novi sortove lozi, sazdadeni v Balgariya), setting rigorous standards for the agrobiological and pomological description of modern Bulgarian hybrids.

Breeding Milestones and Signature Varieties

Zdravko Zankov possessed a rare selection acumen for parental combinations. Most of the varieties he introduced became industry benchmarks due to their crisp flesh texture, distinct muscat aromas, and superior transportability.

Key varieties created by the professor independently and in co-authorship include:

• Ranno Bez Seme: Developed in 1965 in cooperation with I. Todorov and D. Mitev via the cross of Bolgar × Perlette, and officially recognized by the State Variety Commission in 1990. An ultra-early seedless variety ripening by August 10, it became an ideal raw material for premium raisin production via direct sun-drying.
• Rusensko Bez Seme: Bred in 1969 in collaboration with I. Todorov and K. Stoev by crossing Bolgar × Hybrid VI-4, and approved by the State Commission in 1981. This variety inherited a firm berry texture, an ability to withstand high transport stress, and advanced resistance to gray mold (Botrytis cinerea).
• Misket Rusenski: An early dark-skinned table variety obtained in 1973 alongside I. Todorov and D. Mitev from the parental line Muscat Hamburg × Cardinal, and officially released in 1986. The variety is highly valued for its intense, noble muscat flavor, very early maturity (late July to early August), and superior winter hardiness of the wood.
• Prista: A large-fruited table grape created in 1972 with I. Todorov and D. Mitev through the hybridization of Bolgar × Mimoza, and registered in 1988. It features yellow-green crisp berries with a well-defined, fine muscat profile and enhanced field tolerance to gray mold.
• Ryahovo: A high-performing table grape variety obtained in 1972 in cooperation with I. Todorov, S. Pirgozliev, and T. Nakova from the parental line Trakia × Black Rose, and officially recognized in 1997. The variety yields very large berries (up to 7.4 g) with a crisp texture, a delicate muscat taste, and an early ripening window around August 20.

Scientific Legacy

The lifetime work of Professor Zankov demonstrated that intraspecific selection within Vitis vinifera, when guided by precise parental matching, is capable of producing hybrids that significantly outperform their ancestors in terms of productivity, aesthetic market value, and environmental adaptability. The varieties he developed are still actively cultivated in both commercial vineyards across Bulgaria and private collections throughout Europe, remaining a classic benchmark of premium table grape breeding.