Features of Begonia grandis adaptation in contrasting cultivation conditions

The possibilities of adaptation of Begonia grandis Dry., the most cold-resistant representative of the genus, to conditions of the forest-steppe zone of Western Siberia, more severe than in areas of natural growth in China, are studied. The experiment carried out outdoors in spring-summer-autumn period in comparison with a year-round greenhouse cultivation. It was established that the development of plants placed outside the greenhouses accelerates: the flowering time was reduced by 1.5 times and fruiting began two months earlier. The productivity indicators increased such as the number of simultaneously blooming inflorescences, the number of female flowers in separate inflorescence and the number of ripened fruits. The coefficient of vegetative propagation also increased. The number of bulbils was almost 2.5 times more, with significant increase in their size. It was shown that plants of B. grandis grown in the open air were adapted to the conditions of the forest-steppe of Western Siberia. By the time of autumn frosts, they are completing flowering, form ripen seeds and bulbils. Thus, reproduction is provided both by seed and vegetative means. However, to undergo the full life cycle of B. grandis it is necessary to keep dormant tubers in greenhouse or shelter during the frosty period.