Creating Opportunities for Domesticating and Commercializing Miombo Indigenous Fruit Trees in Southern Africa - Indigenous Fruit Trees in the Tropics: Domestication, Utilization and Commercialization - page 151

Ensuring that adequate numbers of trees are selected can become a challenge in
small populations with desirable tree traits. (ii) Establishing a production
population by intensive selection within the selected population will also lead to
loss of genetic diversity, although it will not lead to long-term erosion. (iii) The
use of seed sources from commercial plantations or orchards (farmers in our
case) would lead in the short term to reduced diversity and inbreeding
depression. Ways in which recurrent selection can achieve genetic diversity are
well known, but arduous and long-term breeding investment is required.
Fortunately, most of the miombo indigenous fruit trees are amenable to
vegetative propagation, and efficient clonal propagation techniques that might
be used for accelerated impact have been described (Akinnifesi et al ., 2006;
Leakey and Akinnifesi, Chapter 2, this volume). Cornelius et al . (2006) has
outlined how the propagation of many selected clones within the network of the
farming community, using village cultivars and the propagation of only a few
selected clones (five to ten) from each village, can be used for the rapid
production of superior propagules. This participatory clonal propagation
approach has been used by ICRAF in West Africa (Tchoundjeu et al ., 2006) and
southern Africa for Uapaca kirkiana and Strychnos cocculoides (Akinnifesi et al .,
2006), and Latin America has applied clonal seed selection in the peach palm
(Cornelius et al ., 2006).
Participatory identification of elite trees for clonal selection
Tree domestication is a paradigm shift, from a focus on tree improvement
based on breeding and conventional forest tree selection to horticultural
approaches focused on quality germplasm production for wider cultivation to
serve the needs of smallholder farmers. It is an iterative process that includes a
wide range of activities. The processes involved include the exploration of wild
populations and the identification of superior tree species and provenances
from natural variability; the evaluation and selection of suitable trees and clonal
propagation to develop superior cultivars; macro- and micropropagation
techniques for multiplication; scaling up to the dissemination of germplasm;
and acquiring knowledge of tree management (Akinnifesi et al ., 2006). The
domestication approaches and strategies deployed for individual species vary
according to their functional use, ecology and biology, niches and biophysical
limits (Simons and Leakey, 2004; Akinnifesi et al ., 2006; Tchoundjeu et al .,
2006; Leakey and Akinnifesi, Chapter 2, this volume).
Tree domestication in ICRAF Southern Africa has evolved from multipurpose
tree screening in the 1980s to a more participatory domestication programme
involving pomological and market-led approaches, starting from 1996. The
concept of 'ideotype' is a first step towards developing an improved plant by
combining characters which provide a guide to the selection of potential breeding
stock in a wild population (Dickman, 1985). Its application to fruit trees, such as
mango ( Mangifera indica ) (Dickman et al ., 1994), and the domestication of
priority indigenous fruit trees, such as Irvingia gabonensis (bush mango) in
Nigeria, has been described by Leakey and Page (2006) as an aid to the
multiple-trait selection of superior trees for cultivar development, and offers an