Comparative analysis of three vegetative propagation techniques of Rhizophora racemosa G.F.W. Meyer for ex-situ conservation

Context: Mangroves are threatened by human activities and climate change which affect their biotopes. For the sake of their preservation, this prospective study of the adaptation of Rhizophora racemosa from the Marine Park of Mangroves (PMM) in the Democratic Republic of Congo was conducted on the sandy soils of Kinshasa, more than 400 km from its natural site.

Methods: Three vegetative propagation techniques, including transplanting wildlings, germinating propagules and sowing propagule cuttings, were tested in pots. The experimental trial lasted six months.

Results: The transplanted wildlings barely survived the end of the trial (20%). The immature and mature propagules recorded the germination rates of 99.5% and 100% respectively. The seedlings resulting from this vegetative propagation experienced good growth and development after 6 months of cultivation. The use of propagules and their cuttings is thus the most recommended technique for transplanting R. racemosa G.F.W. Meyer into the soil of Kinshasa.

Conclusion: The domestication of R. racemosa G.F.W. Meyer ex situ based on propagule cuttings offers the possibility of ecologically relocating this plant species potentially threatened with extinction and thus ensuring its conservation.