Creation of new forms of Raphanus sativus L. with the predicted complex of economically valuable traits using the methodology of accelerated plant breeding

New highly productive forms of Raphanus sativus L. were obtained at the Agrophysical Research Institute (FSBSI ARI) agrophysical Research Institute), using the original methodology of accelerated breeding. They are intended for cultivation in the open ground of the Leningrad Region (daikon) and under conditions of intensive light culture (small radish lines and F1 hybrids of small radish and daikon). The aim of the research is to improve the methodology of accelerated selection developed by the authors for the creation of new highly productive forms of Raphanus sativus L. adapted to specific growing conditions. At first stage, the intraspecific diversity of root crops of the species Raphanus sativus L. (more than 60 cultivars of different groups and origin) was studied in intense light culture. Plants were grown under DNAT-400 and DRIKZ-400 lamps with irradiation intensity of 70–80 W/m2 of PAR. Root medium was the peat with mineral additives, moisturize daily with a Knop solution by alternating with water. The reactions of different varieties of the East Asian radishes (35 cultivars) on long day conditions (18-hour photoperiod) and low spring temperatures were evaluated. The most resistant to these stressors cultivars were identified, and hybridization of them produced transgressive forms of daikon with complex resistance. The revealing of these forms and the subsequent stabilizing selection were performed in the open ground in the Leningrad region at sowing in the first decade of may. As a result of the research, a highly productive variety of daikon Peterburgskyi, adapted to spring sowing in the open ground of the Leningrad region, was obtained. When breeding new forms of radish for light culture, the collection of cultivars of different origin was studied and varieties were identified with a yield of commercial root crops up to 3 kg/m2 for 25 days of vegetation, as well as varieties that are sources of economically valuable traits implemented in conditions of intensive light culture (the maximum length/diameter of the root crop, early maturity, resistance to bolting, compact rosette, glabrous leaf type and etc). Combinations of crosses were selected, in the progeny of which heterotic and transgressive hybrids are obtained, that are 160–230% higher than the parent varieties by weight of root crops. On their basis, highly productive early ripening lines of radish for light culture were created with a yield of 4.5–5 kg/m2 for 23–25 days from sowing. Moreover, the prospectivity of selection work with hybrid offspring in a crossbreeding combination of small radish and daikon in light culture is shown. Heterotic F1 hybrids with a root mass of 100–150 g (yield up to 7 kg/m2) formed 42 days after sowing, were obtained.

Keywords: new breeding technologies, regulated agroecosystem, biodiversity of Raphanus sativus L., small radish, daikon, intensive light culture, heterosis, transgression.