Domestication, Utilization and Marketing of Indigenous Fruit Trees in West and Central Africa - Indigenous Fruit Trees in the Tropics: Domestication, Utilization and Commercialization - page 173

The participatory domestication project in the humid lowlands of West and
Central Africa, which started in 1998, was initially limited to Cameroon and
Nigeria with a focus on Irvingia gabonensis (Leakey et al ., 1998; Atangana et
al ., 2001, 2002; Tchoundjeu et al ., 2005), Dacryodes edulis (Leakey and
Ladipo, 1996; Leakey et al ., 2002; Mialoundama et al ., 2002; Wahuriu et al .,
2004; Anegbeh et al ., 2005), Ricinodendron heudelotii (Ngo Mpeck et al .,
2003), Pausinystalia johimbe (Tchoundjeu et al ., 2004) and Prunus africana
(Dawson and Powell, 1999; Tchoundjeu et al ., 1999, 2002; Simons et al .,
2000). The project expanded progressively into Equatorial Guinea and Gabon
(2002), the Democratic Republic of Congo and Ghana (2004), and the list of
priority species subsequently expanded, so that it now includes Gnetum
africanum (a leafy vegetable), Annickia chlorantha (medicinal tree) (Facheux et
al ., 2003), Vernonia , Alchornea , Dombeya , Myrianthus , Polyscias , Vitellaria
species and Lophira lanceolata (melliferous - or nectar-producing - species),
and Allanblackia species (an indigenous fruit nut tree).
In order to capture genetic variation and select the best trees, targeted
germplasm collection was organized in natural stands of priority species according
to the method described by Dawson and Were (1997). The first batch of marcotts
did not meet expectations when they started fruiting, as farmers did not fully
understand the needs and processes of germplasm collection, and indicated to the
domestication team the trees located near their homestead. Subsequently, more
time was spent with farmers explaining the objectives of participatory tree
domestication using training materials as visual aids, and arranging exchange visits
to other participating villages to enhance their understanding of this concept.
Assessment of phenotypic variation in fruit and nut traits was carried out
from 1998 to 2001 for Irvingia gabonensis (Leakey et al ., 2000, 2005; Atangana
et al ., 2001, 2002; Anegbeh et al ., 2005), Dacryodes edulis (Leakey et al ., 2002;
Kengni et al ., 2003; Wahuriu et al ., 2004; Anegbeh et al ., 2005) and
Ricinodendron heudelotii (Ngo Mpeck et al ., 2003). Quantitative descriptors for
variation in indigenous fruit and nut traits were identified (Leakey et al ., 2000),
and significant tree-to-tree variation was observed in measured traits (Atangana
et al ., 2001; Leakey et al ., 2002, 2005; Ngo Mpeck et al ., 2003; Wahuriu et al .,
2004; Anegbeh et al ., 2005). This allowed selection of superior trees for
vegetative propagation using the 'ideotype' concept (Atangana et al ., 2002;
Leakey et al ., 2005) for Irvingia gabonensis (Leakey et al ., 2002) and Dacryodes
edulis . The ideotype included traits of economic importance, such as the sizes of
different components of the fruit and/or kernel, visual traits such as colour of the
skin or flesh, organoleptic traits (Kengni et al ., 2001) and nutritional traits
(including protein, fatty acid and vitamin contents and food thickening properties
(Leakey et al ., 2005)). Genetic selection also required the identification of a
market-oriented ideotype, as it was based on seasonality of fruiting, yield or any
other relevant trait that may enhance the value or utility of a product.
The next phase was the development of appropriate protocols for the
vegetative propagation of identified superior trees to allow the multiplication of
selected genotypes. The idea behind participatory domestication is to provide
farmers with a package of techniques and help them adopt and use the
technologies that are most appropriate for their conditions. Vegetative propagation