Phenotypic variation of baobab (Adansonia digitata L.) fruit traits in Mali

Abstract

We analyzed the phenotypic variation of baobab (Adansonia digitata L.) fruits from Mali to define the domestication potential of this species. 269 trees, selected from 10 provenances distributed along a rainfall gradient, were characterized. Five fruits were sampled from each tree. Total individual fruit weight was partitioned into shell, pulp, and seed weight. Ratios were calculated between pulp ? seed and total weight, and between pulp and seed weight. For all the measured fruit traits, we detected significant differences between provenances, as well as between trees from the same provenance. Assuming that the measured traits are under genetic control, the latter facts indicate that there are considerable opportunities for tree selection on a local scale. However, candidate plus trees with specific properties, e.g., extremely high pulp or seed weight, were found only in some locations. Mean pulp yield per fruit might be considerably increased by selecting the 5% trees with the highest pulp weight (mean: 45 ± 1 g, best 5%: [100 g). The same might be true for seed production (mean: 71 ± 2 g, best 5%: [150 g). Also the ratio between pulp and seed weight can be an important fruit characteristic for selection: in fruits with a low ratio, relatively more pulp sticks to the seeds when separating the two fruit parts by grinding, and thus more pulp will be lost for further processing. We identified several trees with a high pulp weight combined with a high ratio between pulp and seed weight. It is concluded that there is considerable phenotypic variability in traits of baobab fruit in Mali, offering opportunities for cultivar selection.

Phenotypic variation in fruit and seed morphology of Adansonia digitata L. (baobab) in five selected wild populations in Malawi

“…Our results compare favourably with several published literature on baobab phenotypic variations: (Barwick 2004;Carr 1958;De Smedt, et al 2011;FAO, 1982;Gebauer et al 2002;Gruenwald and Galiza 2005;Nour et al 1980). Gruenwald and Galiza (2005) reported that the percentage of fruit pulp varies according to the origin.…”

“…FAO (1982) have also reported baobab fruit size of up to 35 cm length by 8 to 15 cm width. De Smedt et al (2011) have reported mean pulp yield per fruit of 45 ± 1g and seed production of 71 ± 2g. Our results on pulp weight was higher because it included moisture content of fresh pulp (sun dried) which ranges from 10 to 12% compared with oven dried values (Gruenwald and Galiza 2005).…”

“…In addition, baobab is currently a crop of high economic value internationally (De Smedt et al 2011;Gruenwald and Galiza 2005). Baobab oil, extracted from the seed, is used in the cosmetics industry and is also sold internationally (Gruenwald and Galiza 2005).…”

“…Baobab fruit pulp has been approved for sale in the EU (2008/575/EC) and USA (GRAS Notice No. GRN 000273) (De Smedt et al 2011). With a wide range of geographical distribution, certain plant characteristics represent morphotypes (Sidibe and Williams 2002).…”

“…Zobel and Tarbert (1984) have attributed phenotypic variations in forest trees to three factors: the differing environments in which the trees are growing, the genetic differences among trees and interaction between the tree genotypes and environments where they grow. Across geographical range of baobab, the major phenotypic variation reported include leaf taste, size, form and colour of fruits, seed colour, pulp taste and colour, bark colour, height and width of trees (Sidibe and Williams 2002;Assogbadjo et al 2006) and fruit traits (Smedt et al 2011). Presently, domestication of baobab in southern Africa has begun with selection of clonal propagation, especially in Zambia and Malawi (Akinnifesi et al 2008b).…”