Initial and post-cryogenic assessment of viability of russian plum cultivars pollen (Prunus rossica Erem.) in the conditions of the North-West of RussiaO.E. Radchenko, M.V. Erastenkova, A.V. Pavlov and V.G. VerzhukE3S Web Conf., 254 (2021) 02002DOI: https://doi.org/10.1051/e3sconf/202125402002