Russian adaptive apple (Malus x domestica Borkh.) varieties of VNIISPK - continuity of goals and developed technologies (review)

Apple ( Malus × domestica Borkh.) is one of the most economically important fruit crops with a predicted increase in global production. Apples are valued by nutritionists as an important source of sugars, ascorbic acid, other vitamins, trace elements, pectins and biologically active substances. Appearance (size, color) and aroma are the main factors of apple fruit attractiveness for the consumer. From an economic point of view, the main attention in recent decades has been paid to technological features, adaptability, productivity, keeping quality of fruits and resistance to diseases. Breeding research carried out in 1956-2021 at the oldest pomological All-Russian Research Institute of Fruit Crop Breeding (VNIISPK) which celebrated its 175th anniversary in 2020, resulted in 56 new apple cultivars, including 38 cultivars on a fundamentally new genetic basis. By the beginning of these studies in the orchards of central Russia, the main apple cultivars were landraces (Antonovka, Korichnoye Polosatoye, Osennye Polosatoye, Grushovka Moskovskaya and Papirovka) and the Michurin’s cultivars Pepin Shafranny, Bellefleur Kitayka, Bessemyanka Michurinskaya, Doch Korichnogo and Kitayka Zolotaya Rannya. At the first stage of our breeding program, the main methods were re-hybridization and breeding based on geographically remote crosses and open pollination. Veteran, Orlik, Pamyat Voinu, Orlovskoye Polosatoye and a number of other cultivars were created and released. Apple breeding at the polyploid level has been carried out since 1970. Triploid cultivars are characterized by more regular fruiting over the years, large fruit size and high marketability of fruits, and increased self-fertility. We have developed a technique for creating triploid apple cultivars and obtained a series of triploid cultivars from intervalent crosses (2 n = 2×) × (2 n = 4×). To date, 18 triploid cultivars have been released of which six are immune to scab. The best are the triploid ciultivars Rozhdestvenskoye (immune to scab) and Sinap Orlovsky, derived from two diploid cultivars due to the absence of chromosome reduction in one of the parents. These cultivars have become widespread, and each of them is zoned in four regions of Russia. Breeding of cultivars immune to scab has been carried out since 1977. A technique for selecting scab-immune cultivars and seedlings under artificial infection background has been developed. Twenty-four scab-immune cultivars were created and released, including six immune and triploid cultivars and four scab immune and columnar cultivars. The best immune cultivars are Bolotovskoe, Venyaminovskoe, Imrus, and Svezhest; Alexander Boyko, Vavilovskoe, Rozhdestvenskoe, Maslovskoe and Yablochny Spas are scab immune and triploid cultivars. Breeding of columnar apple cultivars has been carried out since 1984 resulting in five columnar cultivars Vostorg, Girlanda, Priokskoye, Poeziya, and Orlovskaya Yesenia. All of them, except for Orlovskaya Yesenia, are immune to scab. Apple breeding to improve the biochemical composition of fruits has been carried out since 1970. According to long-term data, Vavilovskoye (13.0 %) and Ministr Kiselev (13.1 %) are the cultivars with a high content of sugars, Ivanovskoye (19.5 mg/100 g), Veteran (19.4 mg/100 g) and Pepin Orlovsky (15.3 mg/100 g) are enriched with vitamin C, and Kandil Orlovsky (558 mg/100 g), Orlovsky Pioner (514 mg/100 g), Pamyati Khitrovo (480 mg/100 g) and Radost’ Nadezhdy (474 mg/100 g) have high content of P-active substances. In the future, we are planning to release new columnar triploid cultivars and triploid cultivars combining columnar habit and scab immunity (elite seedlings with such qualities have already been produced). Such apple hybrids have not yet existed either among cultivars or among wild forms.