Domestication of Xylopia parviflora (A. Rich.) Benth: testing different pre-treatment protocols and substrates for inducing seeds germination

Abstract

Xylopia parviflora, one of the most highly valued indigenous fruit tree species in sub-Saharan Africa, is still exploited in the wild because it has not been domesticated yet. As a contribution to its domestication process, investigations were undertaken on germination requirements and desiccation tolerance of its seeds. Three substrates, three accessions, 13 pre-germination treatments and different levels of seed dehydration were tested for their effect on seed germination. Results showed that mean germination percentages were significantly higher both on river sand (37.95 ± 1.8%) and on mixture of forest top soil + river sand (40 ± 1.8%) than on forest top soil alone (31.03 ± 1.8%). Bangoua had the highest germination percentage (41.3 ± 1.8%), followed by Bayangam 2 (38.2 ± 1.8%) and Bayangam 1 (27.18 ± 1.8%). Untreated control seeds exhibited coat-imposed dormancy which was expressed by overall 5.5 ± 3.7% germination. The most effective treatment to overcome dormancy was hydrochloric acid treatment for 10 min, followed by sulfuric acid treatment for 5 min and mechanical scarification with respective germination percentages of 80.0 ± 3.7, 63.3 ± 3.7, and 56.6 ± 3.7%. The desiccation tolerance test showed that X. parviflora seeds are desiccation-tolerant and that their storage behaviour is orthodox.