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Jean-marc Bouvet - One of the best experts on this subject based on the ideXlab platform.
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near infrared spectroscopy for high throughput characterization of shea tree Vitellaria paradoxa nut fat profiles
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Fabrice Davrieux, Bokary Allaye Kelly, Francois Allal, Georges Piombo, John B Okulo, Massamba Thiam, Ousmane Diallo, Jean-marc BouvetAbstract:The Shea tree (Vitellaria paradoxa) is a major tree species in African agroforestry systems. Butter extracted from its nuts offers an opportunity for sustainable development in Sudanian countries a...
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Characterization of microsatellite markers in the shea tree (Vitellaria paradoxa C. F Gaertn) in Mali
Molecular Ecology Notes, 2005Co-Authors: Céline Cardi, Bokary Allaye Kelly, Haby Sanou, Alexandre Vaillant, Jean-marc BouvetAbstract:In order to study the genetic diversity and structure in the population of Vitellaria paradoxo, we characterized eight polymorphic microsatellite loci. Primers to amplify these loci were tested on 169 individual trees representing a sample of the population of shea tree in Mali. The loci were all polymorphic with a number of alleles between three to nine and with observed level of heterozygosity ranging from 0.035 to 0.507. These markers will be useful for genetic and ecological studies of this species. (Resume d'auteur)
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Size class distribution and spatial pattern of Vitellaria paradoxa in relation to farmers' practices in Mali
Agroforestry Systems, 2004Co-Authors: Bokary Allaye Kelly, Jean-marc Bouvet, Nicolas PicardAbstract:The impact of human activities on size class distribution and spatial distribution of Vitellaria paradoxa (karité or shea butter tree) in the parklands of sub-Saharan Africa has not been reported in the literature. Two sites (Koumantou and Mperesso) in southern Mali and three treatments (cultivated field, fallow and forest) per site were involved in the present study. Results of a statistical test for random distribution showed that the spatial pattern of Vitellaria paradoxa became progressively aggregated from cultivated field to fallow and then to forest. A permanent aggregated pattern found at Koumantou was not found at Mperesso. A test of the independence of larger and smaller tree locations shows that size classes clump together at Koumantou but not at Mperesso. Results of the third test showed that in the cultivated field, auto-correlation was only observed at large scale. In the fallow the trend was towards negative correlation for both sites. In the forest, negative correlation was observed up to 20 m at Koumantou whereas at Mperesso, positive correlation was observed around 35 m and above 50 m. Site differences may be explained by the intensity of fruit production and recruitment, bound to rainfall and land use pressure. Greater regularity of the spatial pattern in cultivated field, then fallow, may be the result of human intervention.
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An analysis of the pattern of genetic variation in Vitellaria paradoxa using RAPD markers
Agroforestry Systems, 2004Co-Authors: Jean-marc Bouvet, Christelle Fontaine, Haby Sanou, Céline CardiAbstract:Vitellaria paradoxa C.F.Gaertn. is one of the most economically and socially important tree species in the Sudano-Sahelian region. Little is known of the pattern of variation within its natural range. Eight populations covering most of the natural range from Senegal to Uganda were sampled and leaves of 118 individual trees were collected. An analysis of molecular diversity was carried out using random amplified polymorphic DNA (RAPD) markers. Fifteen random primers generated 67 polymorphic and 15 monomorphic RAPD loci ranging from size 1670 bp to 280 bp. Shannon's diversity index varied from Central Africa/Ndele (0.374) to Uganda/Amoya (0.350) but the differences between populations were smaller than the population standard errors. Correspondence analysis of unrooted neighbour-joining trees suggested that genetic distances between populations were correlated with geographic distances. This trend was confirmed by a Mantel test giving a coefficient of correlation between genetic and geographic distances of R = 0.88 (P = 0.0001). Result of AMOVA (analyses of molecular variance) showed that 14.8% (P = 0.002) of the RAPD variation was distributed among populations. Nested analysis of variance indicated that variance between the western and eastern groups of population represented 8.7% (P = 0.001) of the total variation and the variation amongst populations within group was 9.5% (P = 0.001). Eighty two percent of the variation was explained by variation amongst individuals within populations. The origin of genetic structure and level of diversity may be explained by the glacial refugia, the biological traits of Vitellaria paradoxa and by the impact of semi-domestication. Based on these results, sampling options of the natural populations are suggested for in or ex situ conservation. For the development of Vitellaria paradoxa breeding population, the sampling should consist of many individual trees selected within a few populations to capture a large proportion of variation.
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Size class distribution and spatial pattern of Vitellaria paradoxa in relation to farmers' practices in Mali
Agroforestry Systems, 2004Co-Authors: Bokary Allaye Kelly, Jean-marc Bouvet, Nicolas PicardAbstract:The impact of human activities on size class distribution and spatial distribution of Vitellaria paradoxa (karite or shea butter tree) in the parklands of sub-Saharan Africa has not been reported in the literature. Two sites (Koumantou and Mperesso) in southern Mali and three treatments (cultivated field, fallow and forest) per site were involved in the present study. Results of a statistical test for random distribution showed that the spatial pattern of Vitellaria paradoxa became progressively aggregated from cultivated field to fallow and then to forest. A permanent aggregated pattern found at Koumantou was not found at Mperesso. A test of the independence of larger and smaller tree locations shows that size classes clump together at Koumantou but not at Mperesso. Results of the third test showed that in the cultivated field, auto-correlation was only observed at large scale. In the fallow the trend was towards negative correlation for both sites. In the forest, negative correlation was observed up to 20 m at Koumantou whereas at Mperesso, positive correlation was observed around 35 m and above 50 m. Site differences may be explained by the intensity of fruit production and recruitment, bound to rainfall and land use pressure. Greater regularity of the spatial pattern in cultivated field, then fallow, may be the result of human intervention.
Julia R. Hindle - One of the best experts on this subject based on the ideXlab platform.
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Epitypification of Vitellaria paradoxa C.F. Gaertn. (Sapotaceae).
TAXON, 1995Co-Authors: John B. Hall, Julia R. HindleAbstract:From 1962 to 1970 a vigorous debate was carried out in connection with a proposal to conserve Butyrospermum Kotschy against Vitellaria C. F. Gaertn. (Hepper, 1962; Baehni, 1965; Aubreville, 1966; McVaugh, 1967: 229; 1970: 290). The proposal failed narrowly but this failure, while resolving arguments over the genus and species names, has not fully clarified the situation at subspecific level. The complication arises because the type specimen of V. paradoxa C. F. Gaertn., at Paris, consists only of a seed and lacks supporting information indicating its origin. Only material with foliage or inflorescences, or properly localized, can be readily referred to the glabrous or non-ferruginously hairy western (Senegal to Central African Republic) or the ferruginously hairy eastern (Ethiopia, Zaire, Uganda, Sudan) subspecies. Addressing this difficulty Hepper (1962) and Hemsley (1968) regarded Butyrospermum paradoxum (C. F. Gaertn.) Hepper subsp. paradoxum as a taxon restricted to the type specimen of its name while better material was referred to subsp. parkii (G. Don) Hepper (western) or subsp. niloticum (Kotschy) Hepper (eastern). This has the effect of artificially increasing the number of subspecies. Henry & al. (1983) later reviewed the nomenclature of the subspecies under Vitellaria, and they published the combination V. paradoxa subsp. nilotica (Kotschy) A. N. Henry & al. They chose to treat all names with the specific or subspecific epithet parkii (i.e. names based on material known to be from the western part of the range) as synonyms under V. paradoxa subsp. paradoxa. Hepper had presented reasons why assuming the Paris seed is of western origin is unjustified and Henry & al. offered no rejection of his arguments. A recent change in the Code now allows designation of an epitype of Vitellaria paradoxa which can be referred with confidence to a subspecies. It is proposed that the specimen labelled "Interior of Africa", Mungo Park (BM), be designated as the epitype of Vitellaria paradoxa so as to fix the application of the autonym, subsp. paradoxa. This specimen is simultaneously the type of Bassia parkii G. Don (1837: 35), better known as Butyrospermum parkii (G. Don) Kotschy, under which name the shea butter tree was generally known prior to Hepper's (1962) publication. Whilst the specimen lacks inflorescences, foliage is present and fruit is stored in the carpological collection. The herbarium label gives no information beyond the collector's name and general collecting area. However, the collecting date (26 May 1797) and locality (Tambacunda, West Africa, c. 13? N, 11?30' W) can be gleaned from the
Zeev Wiesman - One of the best experts on this subject based on the ideXlab platform.
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Influence of Climate on the Tocopherol Content of Shea Butter
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Steven Maranz, Zeev WiesmanAbstract:The shea tree, Vitellaria paradoxa Gaertner, is the source of a commercial seed fat known as shea butter. High-performance liquid chromatography (HPLC) analysis of the tocopherol content of shea butters from different regions of Africa showed high variability between provenances and a significant effect of climate on alpha-tocopherol levels. The total tocopherol content (alpha, beta, gamma, and delta) in 102 shea butter samples from 11 countries ranged from 29 to 805 microg/g of shea butter, with a mean of 220 microg/g. alpha-Tocopherol, the principal form detected, averaged 64% of the total tocopherol content. Shea butters from Vitellaria populations situated in hot, dry climates had the highest levels of alpha-tocopherol (for example, a mean of 414 microg/g in samples from N'Djamena, Chad). The lowest concentrations of alpha-tocopherol were found in samples from cool highland areas, especially in northern Uganda (a mean of 29 microg/g).
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Phenolic constituents of shea (Vitellaria paradoxa) kernels
Journal of agricultural and food chemistry, 2003Co-Authors: Steven Maranz, Zeev Wiesman, Nissim GartiAbstract:Analysis of the phenolic constituents of shea (Vitellaria paradoxa) kernels by LC-MS revealed eight catechin compounds-gallic acid, catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate-as well as quercetin and trans-cinnamic acid. The mean kernel content of the eight catechin compounds was 4000 ppm (0.4% of kernel dry weight), with a 2100-9500 ppm range. Comparison of the profiles of the six major catechins from 40 Vitellaria provenances from 10 African countries showed that the relative proportions of these compounds varied from region to region. Gallic acid was the major phenolic compound, comprising an average of 27% of the measured total phenols and exceeding 70% in some populations. Colorimetric analysis (101 samples) of total polyphenols extracted from shea butter into hexane gave an average of 97 ppm, with the values for different provenances varying between 62 and 135 ppm of total polyphenols.
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evidence for indigenous selection and distribution of the shea tree Vitellaria paradoxa and its potential significance to prevailing parkland savanna tree patterns in sub saharan africa north of the equator
Journal of Biogeography, 2003Co-Authors: Steven Maranz, Zeev WiesmanAbstract:Aim Woody vegetation patterns in African savannas north of the equator are closely connected to human presence, but the distinctions between natural and anthropogenic landscapes have not been clear to many observers. Criteria for identifying savanna landscapes on a continuum of intensity of anthropic impact are explored. Methods A key savanna tree species, Vitellaria paradoxa (Sapotaceae), was used as model for evaluating anthropic impact. Fruits harvested from tree populations across the species range were analysed for variation in traits valued by indigenous peoples. A simple selection index was used to scale tree populations from a hypothetical wild state to a hypothetical domesticated state. Index values were compared with trait values along climate zone gradients and evaluated in the context of indigenous savanna management practices and historical species distribution reports. Results Trait values such as fruit size and shape, pulp sweetness, and kernel fat content show a significant influence of temperature and rainfall. At the same time, the mean values of groups of traits vary perpendicular to the general climatic zone gradient. Selection index values between Vitellaria populations vary up to sixfold, with highest values in central Burkina Faso. Comparison of present day Vitellaria distribution with historical range limits show range expansion by human migration. Main conclusions The prevalence of major economic tree species in the savannas of Africa north of the equator is a strong indicator of human involvement in tree dispersal. This conclusion is supported by paleobotanical evidence and by recent Vitellaria range expansion as a result of human migration. The presence of high mean values of several Vitellaria fruit traits in central Burkina Faso suggests that selection for desired characteristics has occurred. The impact of indigenous savanna peoples on woody species composition and spatial distribution is probably much greater than usually thought and is the result of a deliberate strategy of altering the landscape to provide needed human resources.
John B. Hall - One of the best experts on this subject based on the ideXlab platform.
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Epitypification of Vitellaria paradoxa C.F. Gaertn. (Sapotaceae).
TAXON, 1995Co-Authors: John B. Hall, Julia R. HindleAbstract:From 1962 to 1970 a vigorous debate was carried out in connection with a proposal to conserve Butyrospermum Kotschy against Vitellaria C. F. Gaertn. (Hepper, 1962; Baehni, 1965; Aubreville, 1966; McVaugh, 1967: 229; 1970: 290). The proposal failed narrowly but this failure, while resolving arguments over the genus and species names, has not fully clarified the situation at subspecific level. The complication arises because the type specimen of V. paradoxa C. F. Gaertn., at Paris, consists only of a seed and lacks supporting information indicating its origin. Only material with foliage or inflorescences, or properly localized, can be readily referred to the glabrous or non-ferruginously hairy western (Senegal to Central African Republic) or the ferruginously hairy eastern (Ethiopia, Zaire, Uganda, Sudan) subspecies. Addressing this difficulty Hepper (1962) and Hemsley (1968) regarded Butyrospermum paradoxum (C. F. Gaertn.) Hepper subsp. paradoxum as a taxon restricted to the type specimen of its name while better material was referred to subsp. parkii (G. Don) Hepper (western) or subsp. niloticum (Kotschy) Hepper (eastern). This has the effect of artificially increasing the number of subspecies. Henry & al. (1983) later reviewed the nomenclature of the subspecies under Vitellaria, and they published the combination V. paradoxa subsp. nilotica (Kotschy) A. N. Henry & al. They chose to treat all names with the specific or subspecific epithet parkii (i.e. names based on material known to be from the western part of the range) as synonyms under V. paradoxa subsp. paradoxa. Hepper had presented reasons why assuming the Paris seed is of western origin is unjustified and Henry & al. offered no rejection of his arguments. A recent change in the Code now allows designation of an epitype of Vitellaria paradoxa which can be referred with confidence to a subspecies. It is proposed that the specimen labelled "Interior of Africa", Mungo Park (BM), be designated as the epitype of Vitellaria paradoxa so as to fix the application of the autonym, subsp. paradoxa. This specimen is simultaneously the type of Bassia parkii G. Don (1837: 35), better known as Butyrospermum parkii (G. Don) Kotschy, under which name the shea butter tree was generally known prior to Hepper's (1962) publication. Whilst the specimen lacks inflorescences, foliage is present and fruit is stored in the carpological collection. The herbarium label gives no information beyond the collector's name and general collecting area. However, the collecting date (26 May 1797) and locality (Tambacunda, West Africa, c. 13? N, 11?30' W) can be gleaned from the
Steven Maranz - One of the best experts on this subject based on the ideXlab platform.
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Influence of Climate on the Tocopherol Content of Shea Butter
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Steven Maranz, Zeev WiesmanAbstract:The shea tree, Vitellaria paradoxa Gaertner, is the source of a commercial seed fat known as shea butter. High-performance liquid chromatography (HPLC) analysis of the tocopherol content of shea butters from different regions of Africa showed high variability between provenances and a significant effect of climate on alpha-tocopherol levels. The total tocopherol content (alpha, beta, gamma, and delta) in 102 shea butter samples from 11 countries ranged from 29 to 805 microg/g of shea butter, with a mean of 220 microg/g. alpha-Tocopherol, the principal form detected, averaged 64% of the total tocopherol content. Shea butters from Vitellaria populations situated in hot, dry climates had the highest levels of alpha-tocopherol (for example, a mean of 414 microg/g in samples from N'Djamena, Chad). The lowest concentrations of alpha-tocopherol were found in samples from cool highland areas, especially in northern Uganda (a mean of 29 microg/g).
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Phenolic constituents of shea (Vitellaria paradoxa) kernels
Journal of agricultural and food chemistry, 2003Co-Authors: Steven Maranz, Zeev Wiesman, Nissim GartiAbstract:Analysis of the phenolic constituents of shea (Vitellaria paradoxa) kernels by LC-MS revealed eight catechin compounds-gallic acid, catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate-as well as quercetin and trans-cinnamic acid. The mean kernel content of the eight catechin compounds was 4000 ppm (0.4% of kernel dry weight), with a 2100-9500 ppm range. Comparison of the profiles of the six major catechins from 40 Vitellaria provenances from 10 African countries showed that the relative proportions of these compounds varied from region to region. Gallic acid was the major phenolic compound, comprising an average of 27% of the measured total phenols and exceeding 70% in some populations. Colorimetric analysis (101 samples) of total polyphenols extracted from shea butter into hexane gave an average of 97 ppm, with the values for different provenances varying between 62 and 135 ppm of total polyphenols.
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evidence for indigenous selection and distribution of the shea tree Vitellaria paradoxa and its potential significance to prevailing parkland savanna tree patterns in sub saharan africa north of the equator
Journal of Biogeography, 2003Co-Authors: Steven Maranz, Zeev WiesmanAbstract:Aim Woody vegetation patterns in African savannas north of the equator are closely connected to human presence, but the distinctions between natural and anthropogenic landscapes have not been clear to many observers. Criteria for identifying savanna landscapes on a continuum of intensity of anthropic impact are explored. Methods A key savanna tree species, Vitellaria paradoxa (Sapotaceae), was used as model for evaluating anthropic impact. Fruits harvested from tree populations across the species range were analysed for variation in traits valued by indigenous peoples. A simple selection index was used to scale tree populations from a hypothetical wild state to a hypothetical domesticated state. Index values were compared with trait values along climate zone gradients and evaluated in the context of indigenous savanna management practices and historical species distribution reports. Results Trait values such as fruit size and shape, pulp sweetness, and kernel fat content show a significant influence of temperature and rainfall. At the same time, the mean values of groups of traits vary perpendicular to the general climatic zone gradient. Selection index values between Vitellaria populations vary up to sixfold, with highest values in central Burkina Faso. Comparison of present day Vitellaria distribution with historical range limits show range expansion by human migration. Main conclusions The prevalence of major economic tree species in the savannas of Africa north of the equator is a strong indicator of human involvement in tree dispersal. This conclusion is supported by paleobotanical evidence and by recent Vitellaria range expansion as a result of human migration. The presence of high mean values of several Vitellaria fruit traits in central Burkina Faso suggests that selection for desired characteristics has occurred. The impact of indigenous savanna peoples on woody species composition and spatial distribution is probably much greater than usually thought and is the result of a deliberate strategy of altering the landscape to provide needed human resources.
