Propagation of Campanula bayerniana (Campanulaceae) by seeds as a reproduction model for the conservation of threatened small-seed plant species

Abstract

The in vitro seed propagation of small seeded Campanula species often incurs complications in the manual handling of the tiny seed material from seed sterilisation to seedling transplantation in soil. The lack of a simple and effective protocol which minimises manual operations makes the propagation of such species both challenging and inefficient. This study aimed to develop a protocol for the seed reproduction of threatened Campanula and other threatened small-seed plant species. The method was successfully tested on Campanula bayerniana subsp. bayerniana. The saplings were cultivated over a 5-month period through seed germination under in vitro conditions followed by their transfer to containers with a soil mix. The protocol employs small filter paper discs on which the seeds germinate and continue their development in soil substrate until the full biodegradation of the discs. The method involves surface treatment of the seeds with potassium permanganate solution, thus avoiding additional washing phases and direct contact with the seeds and seedlings, thereby preventing mechanical damage. This also facilitates the handling of each seed separately, minimising seed loss particularly when working with a small number of seeds. This study is also the first known example of the ex situ propagation of Campanula bayerniana.

Keywords

• campanula bayerniana
• ex situ conservation
• seed reproduction
• smallseeded plant species