M. B. Kwapata

Phenotypic variation in fruit, seed and seedling traits of nine Uapaca kirkiana provenances found in Malawi

Uapaca kirkiana is one of the priority indigenous fruit tree species for domestication in southern Africa. Natural populations of U. kirkiana are declining due to deforestation, forest fragmentation and wildfires. Knowledge of genetic variation is prerequisite for development of conservation strategies. A provenance evaluation study was conducted at Bunda College of Agriculture in Lilongwe, central Malawi to determine the variability in fruit, seed and seedling characteristics of nine populations found in the southern, central and northern regions of Malawi. Results showed significant differences (P≤0.05) between provenances in fruit weight, seed weight, seed length and seed width. The central Malawi provenances of Dzalanyama and Chimaliro had the heaviest mean weight of fruits of 23.9g and 23.8 g respectively, the lightest fruits (14.6g) were found in Namoni Katengeza provenance. There were no significant differences (P≤0.05) in number of seeds per fruit within and between provenances. The provenances differed significantly in cumulative germination percentage, ranging from 26% for Tsamba provenance in southern Malawi to 87% for Dzalanyama provenance in central Malawi. There was a consistent regional variation in stem collar diameter and height growth with central Malawi (Dzalanyama and Chimaliro) and northern Malawi provenances having taller seedlings ranging from 5.2 to 9.0 cm, with the exception of Namoni Katengeza provenance in central Malawi. The root collar diameters were significantly higher for Dzalanyama and Chimaliro (2.5 to 3.9 cm) than southern Malawi provenances whose seedling collar diameter averaged 2.3 centimetres. The nursery provenance trial has shown existence of considerable variation in seed germination, fruit and seed traits in U. kirkiana. Seed and seedling growth traits may prove to be important criteria for selection of provenances for domestication to provide farmers with sustained fruit production for consumption and economic benefits.

Growth Performance of Uapaca kirkiana Müell. ArgProvenances in a Breeding Seedling Orchard in Malawi

Growth Performance of Uapaca kirkiana Muell. Arg Provenances in a Breeding Seedling Orchard in Malawi The population of Uapaca kirkiana Muell. Arg an indigenous fruit tree in southern and eastern Africa continues to decline due to deforestation, forest fragmentation and wildfires. Domestication of the fruit tree has been a priority to increase its genetic diversity and improve livelihoods of small scale farmers. The process of domestication of trees requires knowledge of ecological adaptive traits and intra-specific variation. A breeding seedling orchard comprising seven provenances was established at Bunda in Lilongwe the capital of Malawi in 2006. Growth performance was assessed through measurements in tree height, diameter at breast height (dbh), root collar diameter, number of branches and number of flowers for eight years. Results show that there are statistical significant differences (P ≤ 0.05) in height, diameter at breast height, root collar diameter among the seven provenances. Dzalanyama had the highest mean value for height and diameter at breast height ranging from 1.8 to 3.9 metres and 3.0 to 8.9 centimetres respectively, however a local provenance collected from within 5 kilometre radius of the test site showed the least growth performance suggesting that use of a local provenance does not always guarantee the best performance. Height was found to have high heritability values ranging from 0.31 to 0.43 while number of branches and number of flowers didnot appear to be under strong genetic control with heritability values of 0.12 and 0.08 respectively. The values for growth and genetic traits are from one site that could overestimate heritability values. Selection of provenances for tree improvement should be based on a combination of factors including seed quality and performance of provenances in multi-location trials.