Search

Cultivation of Dacryodes edulis (G. Don) H. J. Lam commonly known as safou to improve the livelihood of the local population has been growing rapidly in the range of occurrence of safou and recent emergence of the market chain introduced by the World Agroforestry Center (ICRAF) experts has stimulated this further. Domestication through conventional genetic improvement (breeding) of safou has relied on phenotype selection and quantitative genetics through field trials breeding. Technologies to increase productivity, increase sustainable resource use, respond to climate change and enhance efficiency are required to meet demand. Biotechnology applications give a scope for rapid improvement and also facilitate the breeding program. Advantages of biotechnology application using molecular markers in breeding programs includes: study of genetic diversity, DNA fingerprinting of individuals, easy identification of specific traits or genes of interest, rapid propagation of improved genotypes and integration of gene(s) of interest into the species. It also provides genetic basis for selecting individuals and particular regions of the genome in a breeding program, reduce breeding population, can lead to early selection of traits and the development of a new variety with combination of characteristics. The complementary role of these techniques will be necessary for a successful genetic improvement program in the species. This review examines the achievements obtained using classical techniques, emphasizes missing gaps for the application of molecular techniques and discusses the complementary role of biotechnology techniques for a sustainable genetic improvement program in the species. Keywords: Dacryodes edulis, domestication, population, genetic diversity, multiplication, biotechnology and genetic improvement

Pentaclethra macrophylla Benth (Fabaceae) has emerged as one of the top underutilized agroforestry species with considerable economic and nutritional value in West and Central Africa where the species is endemic and exploited by farmers. However, the species suffers from a level of exploitation that is unsustainable. This dramatically decreases the natural resource base. Key information such as tree variation is needed to develop an efficient strategy for its domestication. This study therefore assesses the species phenotypic variation in two populations in the forest zone of Cameroon. Overall, 49 trees (19 in Lomie and 30 in Djoum) were sampled. Tree characteristics (diameter at breast height (DBH), height, crown diameter), pod (number of seeds per pod), seed (width, length, thickness, weight) and kernel traits (weight) were recorded. All these parameters were subjected to a combination of multivariate, PCA and cluster analyses. Results revealed four clusters of P. macrophylla trees with cluster IV considered as the best because it contains four elite trees (LOM/PM/09, LOM/PM/13, LOM/PM/15 and LOM/PM/16) with desirable tree characteristics. Clusters were further considered as different groups of trees, and seeds and kernel traits variation assessed using ANOVA analysis. Significant differences in mean kernel weight occured between groups. Cluster IV presented the highest mean kernel weight (19.25 ± 0.16 g), while cluster III had the lowest (13.28 ± 0.57 g). Within cluster IV, the highest kernel weight (25.83 ± 5.62 g) was found in tree number LOM/PM/09. Kernel weight was found to be positive and strongly correlated (r = 0.95) with seed weight. We can conclude that there is phenotypic variation between the trees of P. macrophylla in terms of DBH, height, crown diameter, number of seeds, seed width, seed length, seed thickness, seed and kernel weight. Results obtained in this study could serve as a useful guide for the selection of targeted P. macrophylla trees either for domestication or for conservation purposes.

Summary table of trust items. Elements of trusts Majority of producers trust traders on this item? Majority of traders trusts producers on this item Existence of mutual trusts Honesty information on quantity No No No Honesty information on quality No No No Reliability Yes No No Benevolence No No No Flexibility Yes Yes Yes Total number of yes 2/5 1/5 1/5 producers have less confidence that traders will change initially agreed buying terms when market conditions improve for the better. This interpretation follows producers’ narrative comments during data collection that traders often use fluctuating prices in urban markets to bargain for lower buying price, which according to the producers may not be true. This means that ignorant of reliable information on market prices, producers’ are forced to operate as price takers. In summary for all the five items used to measure trust, a majority of the producers interviewed do not trust traders on three out of the five items, while traders do not trust producers on four out of the five items (Table 2). Mutual trusts exist for one out of the five items. This means that, despite precautions taken at the beginning of the relationship, partners have not been able to build trust amongst them and may account for the low levels of partnership satisfaction.