Phenotypic variations in fruits and selection potential in Sclerocarya birrea subsp. birrea

Abstract

The domestication of indigenous fruits through agroforestry is seen as one of the important issues in the transformation in the way in which land is used within rural areas. A study of the variation in fruit traits is also important as it is a prerequisite for cultivar development in the domestication process. Following an aridity gradient, phenotypic variation was assessed in fruits of Sclerocarya birrea subsp. birrea, native to West African semi-arid areas. Fruits were collected from 42 trees of various diameters in agroforestry parklands from the dry and semi-humid Sudanian zones. They were partitioned into peel, flesh and pit. Each fruit was labelled and its components were measured and weighted. The overall mean fruit mass was 18.58 ± 0.24. g (mean ± SE) but fruits from the population in the drier zone were significantly larger (19.90 ± 0.37. g vs 17.02 ± 0.24. g; P< 0.001). The results showed a strong correlation between fruits and their components (P< 0.05). Tree diameter was very weakly correlated with fruit traits. There was a high level of variation in fruit characteristics and components within and between populations. The within-population variation accounted for the greatest part (67-100%) of the total variation. Many trees, mainly from the drier zones, showed superior phenotypic traits. Five groups of trees which represented different fruit morphotypes were identified for various prospective exploitations. The results strongly support the implementation of preliminary practical conservation action and domestication of S. birrea in West Africa. © 2011 Elsevier B.V.