Abstract

Botha Sharlto Thabo

Sclerocarya birrea (A. Rich.) Hochst. subsp. caffra (Sond.) Kokwaro (Marula) is one of the traditionally important indigenous multi-purpose fruits trees in Africa, which has been commercialized as its fruits and processed nuts/kennels have entered local, regional and international trade. This study was an analysis of the variation between and within provenances of S. birrea sub-species caffra with respect to seed mass of dried fresh seed, total soluble solids (total sugars) content of fresh fruits, and the vitamin C content of fresh fruits as well as family heritabilities of fruit parameters and seed mass. A nested sampling procedure was followed for where there were four areas (provenances), eight to ten families (parent trees) and fifty fruits per family. There were significant differences in provenance and family in seed mass (p=0.06 and p=0.0001) and vitamin C (p=0.001 and p=0.0001), total soluble solids lacked provenance variation (p=0.35) but had wide family variation (p=0.0001). There was no correlation between parameters except a significant correlation between rainfall intensity and total soluble solids content; lower the rainfall higher the sugar content and the higher the rainfall the lower the sugar content (p=0.06). The most variable parameter was vitamin C with the highest family heritability, however all traits had relatively high family heritabilities (above 0.5). It was concluded that the results of fruit composition and seed mass could be of remarkable importance in the identification of superior genotypes, making use of the wide family variation that exists. A study to capture a wider range of provenances and families including studying the environmental parameters of soils, rainfall and altitude for more precision.