Anatomic and Morphological Peculiarities of Fruits and Seeds of Sorbus L. (Rosaceae) Genus under Conditions of Introduction
The paper studies the anatomic and morphological peculiarities of fruits and seeds of 17 species of Sorbus introduced in the Saint Petersburg Botanical Garden, including one species of local flora, S. aucuparia L. f. rosea. The fruits and seed of Sorbus species are diverse, which can be used as taxonomy criteria in discussion of arguable issues arising during the systematization of the plant genus. The species differ in the external color of a fruit and morphology of seeds in them which can be dissimilar within one fruit or even one dissepiment. Seeds differ the most by shape and dimensions, structure and number of cell layers in the testa. In primitive and archaic species, the number of cell layers in the testa, especially parenchyma layers, is large (6–7 layers in S. cashmiriana and S. roopiana). The smallest number of parenchyma layers (2–4) is typical for more evolutionary advanced species S. sambucifolia, S. ‘Joseph Rock’, S. alnifolia, S. commixta and S. luristanica.
 Abdullina, R.G., Putenikhin, V.P. (2015). Quality of seeds of different Sorbus L. species on introduction in the Bashkir piedmont of the western Urals. Bulleting of Samara Scientific Center of RAS, vol. 17, no. 4, pp. 236–239.
 Asbaganov, S.V. (2014). Biological basics of introduction of Sorbus rowan in Western Siberia. PhD dissertation. Novosibirsk: Central Siberian Botanical Garden of SB RAS, pp. 170.
 Asbaganov, S.V., Gorbunov, A.B., Simagin, V.S. et al. (2013). ``Rowan'', Introduction of non-conventional fruit, berry and vegetable plants in Western Siberia. Novosibirsk: Geo, pp. 61–85.
 Berezhnaia, Z.G. (1985). Rowan. Moscow: Lesn. promyshlennost, 79 p.
 Gabrielyan, E.Ts. (1975). Anatomy of testa of Asian Sorbus species in terms of their systematization. Biological journal of Armenia, vol. XXVIII, no. 4, pp. 15–22.
 Gabrielyan, E.Ts. (1978). Rowans (Sorbus L.) of Western Asia and Hymalaya. Yerevan: Press of Academy of Sciences of Armenya SSR, 258 p.
 Zalibekov, M.D. (2008). Ecological dependence of population variability and introduction resources of Sorbus L. genus in Dagestan: externded abstract of dissertation of Cand. Sci. (Biology). Makhachkala, 22 p.
 Kazarova, S.Yu., Boyko, G.A. Collection of rowans in Botanical Garden of MSU. Proc. IV Intern. Conf. ``Biological diversity. Introduction of plants'', pp. 275–277. Saint Petersburg.
 Koltsova, M.A., Kozhevnikov, V.I. (1997). Rowans in Stavropol Krai. Stavropol, 119 p.
 Levina, R.E. (1987). Morphology and ecology of fruits. Leningrad: Nauka, 160 p.
 Maksimova, G.V. (1980). Biology and ecology of Sorbus L. genus species introduced by the botanical garden of AS UzSSR. PhD dissertation thesis. Tashkent, 20 p.
 Nikolaeva, M.G., Razumova, M.V., Gladkova, V.N. (1985). Reference book on germination of dormant seeds. Leningrad: Nauka, Leningrad branch, 506 p.
 Petrova, I.P., Borodina, N.A. (1992). Rowan. Introduction results in Moscow. Moscow: Nauka, 120 p.
 Razumova, M.V. (1987). Biology of seed germination of Sorbus genus species (Rosaceae). Bot. Journ, vol. 72, no. 1, pp. 77–83.
 Skupchenko, L.A., Mishurov, V.P., Volkova, G.A., Portnyagina, N.V. (2003). Introduction of useful plants in subzone of middle Taiga of Komi Republic (Results of operation of Botanical Garden over 50 years), vol. 3. St. Peterburg: Nauka, 214 p.
 Tumanyan, S.A. (1978). Morphological and anatomical characteristic of rowan seeds from the section of Dorbus (L.) Pers. (=Aucuparia K. Koch.). Bulletin of the Main Botanical Garden, no. 109, pp. 73–80.
 Firsov, G.A., Vasilyev, N.R. (2015). Rowan (Sorbus) genus in the collection of Saint Petersburg Botanical Garden. Plant kingdom of Asian Russia, no. 4, pp. 86–93.
 Firsov, G.A., Volchanskaya, A.V., Yandovka, L.F. (2019). Fruitless rowans (Sorbus) of Saint Petersburg Botanical Garden. Plant kingdom of Asian Russia, no. 1(33), pp. 101–107.
 Shvirst, E.P. (2016). Agroecological estimation of adaptive abilities of home rowan grades in Magadan region. Modern trends in devel. of sci. and techn., no. 1–4, pp. 138–141.
 Grimshaw, J., Bayton, R. (2009). New Trees: Recent Introductions to Cultivation. The Board of Trustees of the Royal Botanic Gardens, Kew and The International Dendrology Society, 976 p.
 Maciejewska-Rutkowska, I., Bednorz, L. (2004). Sem and stereoscope microscope observations on the seeds ofthe polish species of the genus Sorbus L. (Rosaceae). Acta societatis botanicorum poloniae, vol. 73, no. 4, pp. 293–300.
 McAllister, H. (2005). The genus Sorbus. Mountain ash and other rowans. Kiew: Published by The Royal Botanic Gardens, 252 p.
 Robertson, K.R., Phipps, J.B., Rohrer, J.R., Smith, P.G. (1991). A synopsis of genera of the Maloideae (Rosaceae). Syst. Bot., vol. 16. no. 2, pp. 376–394.
 Stein, W.I., Bonner, F.T., Karrfalt, R.P. (2008). Sorbus L. mountain-ash. Woody Plant Seed manual, USDA Forest Service Agriculture Handbook, pp. 1059–1064.