Development of triploid apple cultivars as a priority in selection

Abstract

We carried out a detailed examination of the preliminary breeding (prebreeding) techniques during the development of triploid apple cultivars. The characteristics of diploid gamete donors are summarized. It should be noted that at times donors of diploid gametes with the necessary important traits must not only be selected among the existing tetraploid cultivars but also need to be specially bred, in particular, in cases when there are no cultivars and genotypes (donors of diploid gametes) with the given traits in nature. We developed the 30-47-88 apple form (Liberty × 13-6-106) by selection breeding. The 30-47-88 form is at once a donor of diploid gametes and of scab immunity (V f ). During 1970–2015, the following work was carried out on apple breeding using polyploidy: 455 crossing combinations were performed; 660000 flowers were artificially pollinated; 124700 hybrid seeds were obtained; and 47900 one-year-old seedlings were grown, from which, after multiple rejections, 13200 seedlings were planted in breeding orchards. For the first time in Russia, ten apple cultivars (Avgusta, Aleksandr Boiko, Bezhin Lug, Vavilovskoye, Dariona, Maslovskoye, Orlovsky Partizan, Osipovskoye, Patriot, and Yablochny Spas) are developed from intervalence crossings and regionalized. It is stated that apple cultivars developed at the All-Russian Research Institute of Fruit Crop Breeding (VNIISPK) are characterized as a rule by a high level of productivity, better fruit marketability, greater resistance to scab, and higher autogamy. Apple cultivars combining triploidy and scab immunity are developed. Promising breeding work is being performed for apple cultivars combining triploidy, scab immunity, and columnar habit (Co). Brief characteristics are provided for the obtained triploid and scab immune cultivars, Vavilovskoye and Yablochny Spas, developed from intervalence crossings, as well as three triploid cultivars obtained from crossing diploid cultivars. It is noted that triploid apple cultivars developed at VNIISPK are inferior to none of the foreign cultivars, based on a complex of commercial traits, and they significantly excel foreign cultivars in adaptability. Our apple cultivars may contribute to the import substitution of fruit production in Russia.