Reproductive biology of a rare species Begonia ludwigii in greenhouse conditions of the Siberian Botanical Garden of Tomsk State University

The paper presents the results of a reproductive biology study and the Begonia ludwigii seasonal development rhythm - a species classified by the International Union for Conservation of Nature as a rarity category EN (endangered species). The studies have shown that when cultivated in the Tomsk State University Siberian Botanical Garden greenhouse conditions, this species has high potential seed productivity (about 75,000 ovules per inflorescence), high fertility and pollen viability, but at the same time low true seed productivity (seed rate not more than 27%). It was established that the Begonia ludwigii seeds, in the greenhouse conditions, are tied to heterogamous pollination due to the absence of pollinating insects. The use of xenogamous artificial pollination increased the coefficient of seed productivity by almost 3 times. The paper also describes the full seasonal development rhythm, flowering biology, biomorphological features of pollen and seeds