Seed quality of Aristolochia macrophylla Lam. and A. manshuriensis Kom. in St. Petersburg

Abstract

Background. The study and mobilization of natural flora species in botanical gardens allow the curators to save biological resources of useful plant species, and recommend them for urban landscaping. In the flora of Russia, one species of a woody vine from the genus Aristolochia L. is A. manshuriensis Kom.; it is included in the Red Data Book of Russia.Methods The material for the study was A. macrophylla Lam. and A. manshuriensis from the collection of the Peter the Great Botanical Garden maintained by the Komarov Botanical Institute of the RAS. Winter hardiness was assessed; plant height, stem diameter, and crown diameter were measured. The sizes and age are given according to the state of the plants in the fall of 2017. Seed quality was assessed with due regard to the approved guidelines. X-ray analysis of fruits and seeds was carried out using the methods developed for the use of microfocus radiography for seeds and fruits.Results. A. manshuriensis has been grown in the Peter the Great Botanical Garden since 1909. The first flowering was observed in 1918 and 1919, the first fruiting in 1924. Currently, plants of the third or fourth generation are present in the collection. A. macrophylla has been known in St. Petersburg since 1816. Over a 200-year period of introduction, only flowering was observed. For the first time, fruiting in this species was registered in 2007; since 2014, second-generation plants have been grown. Analysis of the seeds collected in 2016 and 2017 showed that they are viable and of high quality in both species of Aristolochia. These species are winter-hardy, demonstrate rapid growth, and may somewhat vary in the timeframe of the passage of main phenological phases in their seasonal rhythm of development.Conclusion. For laying out plantations, it is better to use seeds. A. macrophylla and A. manshuriensis are promising for wider cultivation and use in vertical landscaping.