Phenotypic Variation of Agromorphological Traits of the Shea Tree, Vitellaria paradoxa C.F. Gaertn., in Mali

Abstract

Forty-one shea tree populations were sampled, spanning the main climatic zones of Vitellaria paradoxa Gaertn. in Mali and 10-35 adult trees were chosen randomly in the agroforestry parklands of each area. A total of 12 morphological traits, related to tree morphology, fruit size and leaf form were measured. The variance components showed that variation among populations represented the smaller percentage of the total variation with most of the values varying between 15 and 30%. The repeatability coefficient was generally high for tree within populations with values ranging between 0.23 and 0.78. Although genetic correlations cannot be accurately estimated, due to difficulties in separation from environmental effects, the results indicate that there is a very low genetic relation between the three kinds of traits, i.e., between those related to tree, those related to leaf and those related to fruit. Leaf and fruit size traits were positively and significantly correlated with rainfall, although tree circumference was negatively correlated with rainfall and the significantly larger shea trees were noted in the drier areas -an observation thought linked to human management of the parklands. Soil drainage and parkland density, however, did not explain differences between populations for fruit traits. This study offers preliminary information for the development of a breeding population for a shea tree improvement programme. The value of repeatability, the low correlation between sets of traits and the distribution of variation, suggest that selection of many individual trees within a few populations, would allow capture of large genetic gain especially for fruit traits.

Exploring local knowledge and preferences for shea (Vitellaria paradoxa) ethnovarieties in Southwest Burkina Faso through a gender and ethnic lens

“…In this study, Bobo women explained that nuts from different shea ethnovarieties are mixed together at the time of butter processing, making it difficult to assign clear shea butter traits to individual trees or ethnovarieties. A similar observation has been made by Sanou et al (2006). nonetheless, Bobo and Mosse women in Bana-Bobo and Bana-lamogoya, respectively, claimed to have gained observational knowledge of the fat content of nuts from different ethnovarieties.…”

“…Shea trees are allogamous, and cross pollination between trees can result in large phenotypic differences that are accentuated by environmental factors (Gwali et al 2012). Differences in shea nut weight can be linked to soil fertility and variations in climate, particularly rainfall (lovett & Haq 2000b;Maranz & Wiesman 2003;Sanou et al 2006). Furthermore, the various traits examined have different patterns of variation (Sanou et al 2006).…”

“…Differences in shea nut weight can be linked to soil fertility and variations in climate, particularly rainfall (lovett & Haq 2000b;Maranz & Wiesman 2003;Sanou et al 2006). Furthermore, the various traits examined have different patterns of variation (Sanou et al 2006).…”

Variabilité morphologique du baobab (Adansonia digitataL.) au Mali

“…Selon Sanou et al, la sélection humaine chez Vitellaria paradoxa Gaertn. f. au Mali aurait favorisé la conservation et la multiplication des arbres possédant des fruits à forte quantité de pulpe [18]. D'autres études ont décelé une grande variabilité chez les espèces de savanes sèches.…”

The Evolution of Shea Butter's "Paradox of paradoxa" and the Potential Opportunity for Information and Communication Technology (ICT) to Improve Quality, Market Access and Women's Livelihoods across Rural Africa

“…The fruits are harvested around May until September, coinciding with the rainy season [5]. The genetic variability of shea is noted to be high [7,8,[11][12][13][14] and there is no tradition of planting trees, as shea is highly effective in propagating itself in this environment. Recent work, however, with micro-propagation, rooting cuttings and grafting may allow opportunities to formally domesticate and enrich parklands through selection and planting of more productive shea trees [15][16][17][18].…”