Germination techniques for seedling regeneration of the threatened Anogeissus leiocarpa (african birch)

Abstract

Plants are of great importance providing a wide range of essential ecosystem services through production of timber, fibers, food, forage and natural medicines. Anogeissus leiocarpa (Combretaceae) is one of the indigenous deciduous plants reported to have a medicinal property of treating cough, malaria, trypanasomiasis etc. Although the plant is categorized as Least Concern (LC) by the
International Union for Conservation of Nature (IUCN), but it is locally considered endangered facing serious overexploitation. This study was carried out to successfully germinate A. leiocarpa seeds using suitable seed scarifications. In achieving this, thirty different pretreatments from three major scarifications chemical, physical and mechanical were applied to soften hard seed coat while keeping the seeds viable, permeable to water and air so as to aid germination. At the end of the research (13 weeks) conducted within the screen house, nine out of the thirty pretreatments gave positive results with treatment (15mins H2SO4 + 96hrs Water at Room Temperature WRT) having the highest mean value of 2.051 in terms of number of seeds germinated (8seeds) and other growth parameters analyzed, followed by 800C for 10mins with 1.538 mean value having 6seeds germinated at P<0.05. However, six
of the nine pretreatments have significantly higher mean value than the control with 0.282 mean value. Out of two thousand two hundred and fifty (2250) seeds planted, twenty-eight (28) seeds were successfully germinated. Other pretreatment methods and biotechnological methods like plant tissue culture can be used to generate large number of seedlings for use in afforestation programs and conservation of the tree.