Nursery results on genetic variation, vegetative propagation and other growth factors of importance for domestication of Pterocarpus Angolensis DC.

[摘要] ENGLISH SUMMARY: Pterocarpus angolensis is an important indigenous timber tree species occurring in warm andsummer rainfall areas of southern and central Africa. It belongs to the family Fabaceae, asubfamily of Leguminosae. Phenotypically superior trees are exploited by subsistence andcommercial timber using industries. Local people found in areas where P. angolensis grows,use it for medicinal and boat, mortar and pestle manufacture. Exploitation of the species is ata high rate, however, not much research on its silviculture, tree improvement anddomestication has been done. Some problems associated with the species are: slow naturalregeneration, difficulty in rooting cuttings and requirement of seed treatment prior togerminating it in order to break the dormancy.Four Provenances from Chimanimani (Zimbabwe), Masese, Mufumbwe and Solwezi(Zambia) and eleven families from Masese provenance were investigated for their existingvariations in terms of seedling growth rates. The trials were conducted at the Faculty ofForestry nursery, University of Stellenbosch. The objectives were to study (i) the response ofthe four provenances to soil sterilisation and inoculation (ii) existing seedling growthvariations (iii) the shooting and rooting ability of cuttings.There were significant differences in seed germination rates, mean seedling height, root collardiameter and total above and below ground biomass between provenances, families, soilsterilisation and inoculation treatments. Mufumbwe provenance had a significantly highermean height from time of planting to 217 days of seedling growth. Chimanimani provenancehad higher above and below ground biomass than other provenances but had the lowestseedling mean height.Seedling growth variations were observed in the eleven families from one provenance. Soilinoculation, unlike sterilisation, was found to be more beneficial to seedling growth. Almostall cuttings produced shoots easily but with no root development. Shoots were not maintainedfor a long period. Only diameter class 3 - 4.9 cm had surviving shoots by day 104 of theexperiment. There is need to continue with research work on P. angolensis otherwise it isunder extinction threat and industries relying on the species would suffer.

[发布机构] Stellenbosch University