Results of a study of self-pollination in two of Ukrainian flora's threatened species, Gladiolus imbricatus and Iris sibirica (Iridaceae), are presented. To confirm or refute the occurrence of self-pollination in G. imbricatus and I. sibirica, an experiment was conducted on pollen germination on their stigmas. It has been found that in G. imbricatus pollination with autogenous pollen grains on the last day of flowering leads to the growth of pollen tubes in the cases of both hand and natural pollination. However, pollen grains on the stigma of an isolated I. sibirica flower were not detected on the first or last day of flowering, which means the absence of a mechanism of autonomous pollen transfer within the meranthium. Ungerminated pollen grains were also found on the stigma after autogenous hand pollination. It has been experimentally confirmed that in the absence of pollinators at the end of the flowering phase in G. imbricatus, as well as in some other members of the genus, self-pollination and self-fertilization are possible, which contribute to the wellbeing of populations and species. With regard to I. sibirica, it has been found that the autogamous self-incompatibility inherent in this species prevents inbreeding, maintaining heterozygosity in plant populations, allowing plants' better adaptation to different environmental conditions.

Keywords: Gladiolus imbricatus, Iris sibirica, pollen grains, pollen tubes, pollination, self-incompatibility, selfpollination, threatened species

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1. Arafeh R.M.H., Sapir Y., Shmida A., Iraki N., Fragman O., Comes H.P. 2002. Patterns of genetic and phenotypic variation in Iris haynei and I. atrofusca (Iris sect. Onocyclus = the royal Irises) along an ecogeographical gradient in Israel and the West Bank. Molecular Ecology, 11: 39–53. https://doi.org/10.1046/j.0962-1083.2001.01417.x
2. Burova E.A. 1970. Autogamy in Irises. Botanicheskiy Zhurnal, 55(9): 1344–1348.
3. Doronkin V.M. 1987. Family Iridaceae. In: Flora of Siberia. Vol. 4. Araceae–Orchidaceae. Novosibirsk: Nauka, pp. 114–124.
4. Goldblatt P., Manning J. 1998. Gladiolus in Southern Africa. Cape Town: Fernwood Press, 320 pp.
5. Goldblatt P., Manning J. 2006. Radiation of pollination systems in the Iridaceae of sub-Saharan Africa. Annals of Botany, 97(3): 317–344. https://doi.org/10.1093/aob/mcj040
6. Goldblatt P., Manning J. 2021. Iridaceae of Southern Africa [Strelitzia, vol. 42]. Pretoria: South African National Biodiversity Institute (SANBI Publishing), 1159 pp. Available at: http://opus.sanbi.org/bitstream/20.500.12143/7671/1/2020_Strelitzia42_SANBI.pdf
7. Goldblatt P., Manning J.C., Bernhardt P. 2001. Radiation of pollination systems in Gladiolus (Iridaceae: Crocoideae) in southern Africa. Annals of the Missouri Botanical Garden, 88: 713–734. https://doi.org/10.2307/3298641
8. Hannan G.L., Orick M.W. 2000. Isozyme diversity in Iris cristata and the threatened glacial endemic I. lacustris (Iridaceae). American Journal of Botany, 87: 293–301. https://doi.org/10.2307/2656625
9. Imbert E., Wang H., Anderson B., Hervouet B., Talavera M., Schatz B. 2014. Reproductive biology and colour polymorphism in the food-deceptive Iris lutescens (Iridaceae). Acta Botanica Gallica: Botany Letters, 161(2): 117–127. https://doi.org/10.1080/12538078.2014.895419
10. Khela S. 2013. Iris sibirica. In: The IUCN Red List of Threatened Species 2013. Available at: https://www.iucnredlist.org/species/203236/2762502 (Accessed 15 November 2021).
11. Komarnicki L. 2016. Piękno irysów (Beauty of irises). Rzeszów: Bolestraszyce, 256 pp.
12. Kose M., Liira J., Tali K. 2019. Long-term effect of different management regimes on the survival and population structure of Gladiolus imbricatus in Estonian coastal meadows. Global Ecology and Conservation, 20: e00761. https://doi.org/10.1016/j.gecco.2019.e00761
13. Kostrakiewicz-Gierałt K., Palici C.C., Stachurska-Swakoń A., Nedeff V., Sandu I. 2018. The causes of disappearance of sword lily Gladiolus imbricatus L. from natural stands – synthesis of current state of knowledge. International Journal of Conservation Science, 9(4): 821–834.
14. Kron P., Stewart S.C., Back A. 1993. Self-compatibility, autonomous self-pollination, and insect-mediated pollination in the clonal species Iris versicolor. Canadian Journal of Botany, 71: 1503–1509. https://doi.org/10.1139/b93-182
15. Meusel H., Jäger E., Weinert E. 1965. Vergleichende Chorologie der Zentraleuropäischen Flora. Vol. 1. Jena: Gustav Fischer Verlag, 583 pp.
16. Mitka J., Oklejewicz K., Szewczyk M., Pawelec J. 2008. Kosaciec syberyjski Iris sibirica. In: Czerwona Księga Karpat Polskich (The Red Book of the Polish Carpathians). Ed. Z. Mirek, H. Piękoś-Mirkowa. Kraków: Rośliny naczyniowe. Instytut Botaniki im. W. Szafera PAN, pp. 436–438.
17. Morozova T.K. 2005. Iris sibirica. In: Red Book of the Republic of Belarus: Rare and endangered species of wild plants. Ed. G.P. Pashkov. Minsk: BelEn, pp. 222–224.
18. Moser D., Gygax A., Bäumler B., Wyler N., Palese R. 2002. Liste rouge des fougères et plantes à fleurs menacées de Suisse. Berne: Office fédéral de l'environnement, des forêts et du paysage, Chambésy: Centre du réseau suisse de floristique, and the Conservatoire et Jardin botaniques de la Ville de Genève, pp. 118.
19. Mosyakin S.L., Fedoronchuk M.M. 1999. Vascular plants of Ukraine. A nomenclatural checklist. Kiev, xxiii + 345 pp. https://doi.org/10.13140/2.1.2985.0409
20. Nikolić T., Topić J. 2005. Iris sibirica. In: Crvena knjiga vaskularne flore Hrvatske (Red Book of Vascular Flora of Croatia). Eds. T. Nikolić, J. Topić. Republika Hrvatska: Ministarstvo kulture, Drzavni zavod za zastitu prirode, pp. 458–459.
21. Odintsova A., Skrypec Ch. 2014. New data on pollinaton of Iris sibirica L. (Iridaceae). Studia Biologica, 8(3–4): 197–208. https://doi.org/10.30970/sbi.0803.383
22. Patalauskaitė D. 2021. Sibirinis vilkdalgis. Iris sibirica. In: Lietuvos raudonoji knyga. Gyvūnai. Augalai. Grybai (Red Data Book of Lithuania. Animals. Plants. Fungi). Ed. V. Rasomavicius. Vilnius: Leidykla "Lututė", p. 419.
23. Pellegrino G. 2015. Pollinator limitation on reproductive success in Iris tuberosa. AoB Plants, 7: plu089. https://doi.org/10.1093/aobpla/plu089
24. Pladias – Database of the Czech Flora and Vegetation. 2014–onward. Available at: https://www.pladias.cz/en/taxon/overview/Gladiolus%20imbricatus (Accessed 15 July 2021).
25. Planisek S.L. 1983. The breeding system, fecundity, and dispersal of Iris lacustris. The Michigan Botanist, 22: 93–101.
26. POWO. 2022–onward. Plants Of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Available at: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:437527-1 (Accessed 10 July 2022).
27. Postolache Gh. 2015. Sabiuta. Gladiolus imbricatus. In: Cartea roşie a Republicii Moldova (The Red book of the Republic of Moldova). Ed. M. Belencius. Republic Moldova: Stiinta, pp. 142.
28. Red Data Book of the Baltic region. Part 1. Lists of threatened vascular plants and vertebrates. 1995. Ed. T. Ingelög, R. Andersson, M. Tjernberg. Riga: Swedish Threatened Species Unit, Uppsala in cooperation with Institute of Biology, 95 pp.
29. Red Data Book of Ukraine. Plant Kingdom. 2009. Ed. Ya.P. Didukh. Kyiv: Globalkonsalting, 912 pp.
30. Sapir Y., Shmida A., Ne'eman G. 2006. Morning floral heat as a reward to the pollinators of the Oncocyclus irises. Oecologia, 147(1): 53–59. https://doi.org/10.1007/s00442-005-0246-6
31. Scrypec K., Tasenkevich L., Seniv M. 2020. Iris sibirica L. (Iridaceae) on the territory of Western Ukraine. Biosystems Diversity, 28(3): 211–215. https://doi.org/10.15421/012027
32. Semerenko L.V., Morozova T.K. 2005. Gladiolus imbricatus. In: Red Book of the Republic of Belarus: Rare and endangered species of wild plants. Ed. G.P. Pashkov. Minsk: BelEn, pp. 222–224.
33. Skrypec Ch., Odintsova A. 2014. Flowering and pollination traits in Gladiolus imbricatus L. Proceedings of Ternopil Volodymyr Hnatiuk National Pedagogical University. Series Biology, 4(61): 37–43.
34. Skrypec K. 2020. Reproductive biology of Gladiolus imbricatus L. and Iris sibirica L. (Iridaceae Juss.). Cand. Sci. Diss. Kyiv, M.G. Kholodny Institute of Botany NAS of Ukraine, 227 pp. (manuscript).
35. Szőllősi R., Medvegy A., Benyes E., Nemeth A., Mihalik E. 2011. Flowering phenology, floral display and reproductive success of Iris sibirica L. Acta Botanica Hungarica, 53(3–4): 409–422. https://doi.org/10.1556/ABot.53.2011.3-4.20
36. Takács A., Nagy T., Salamon-Albert É., Molnár V. A. 2015. The wildflower of the year 2014 in Hungary: Siberian flag (Iris sibirica L.). Kitaibelia, 20(2): 268–285. https://doi.org/10.17542/kit.20.268
37. Troitsky N.A. 1948. Some data on the biology of the flower Iris sibirica L. Botanical Journal, 33(3): 375–376.
38. Tucić B., Milojković S., Tarasjev A., Vujčić S. 1989. The influence of climatic factors on clonal diversity in a population of Iris pumila. Oikos, 56: 115–120. https://doi.org/10.2307/3566094
39. Turis P., Kliment J., Feráková V., Dítě D., Eliáš P., Hrivnák R., Košťál J., Šuvada R., Mráz P., Bernátová D. 2014. Red List of vascular plants of the Carpathian part of Slovakia. Thaiszia – Journal of Botany, 24(1): 35–87.
40. Tzvelev N.N. 1979. Iridaceae. In: Flora Partis Europaeae URSS. Vol. Ed. An.A. Fedorov. Leningrad: Nauka, pp. 292–311.
41. Uno G.E. 1979. The influence of pollinators on the breeding system of Iris douglasiana. The American Midland Naturalist, 108: 149–158. https://doi.org/10.2307/2425304
42. Webb D.A. 1980. Iris. In: Flora Europaea. Vol. 5. Eds T.G. Tutin, V.H. Heywood, N.A. Burges, D.M. Moore, D.H. Valentine, S.M. Walters. Cambridge: Cambridge Univ. Press, pp. 87–92.
43. Williams J.H. 2009. Amborella trichopoda (Amborellaceae) and the evolutionary developmental origins of the angiosperm progamic phase. American Journal of Botany, 96(1): 144–165. https://doi.org/10.3732/ajb.0800070
44. Wragg P.D., Johnson S.D. 2009. Breeding system and pollination of the narrowly endemic South African wildflower Gladiolus inandensis. In: The 94th ESA Annual Meeting, pp. 37–159:
45. Zink R.A., Wheelwright N.T. 1997. Facultative selfpollination in Island Irises. The American Midland Naturalist, 137(1): 72–78. https://doi.org/10.2307/2426756