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1.
Solomon Benor Frank R. Blattner Sebsebe Demissew Karl Hammer 《Genetic Resources and Crop Evolution》2010,57(2):293-306
Little information is available regarding the biodiversity and potential use of jute (Corchorus species) in Ethiopian agriculture. The present study summarizes species’ occurrence, use, geographical distribution, ecology,
and ethnobotany of Corchorus species in Ethiopia. An ecogeographical study, conducted in the Amhara, Oromia and Gambella Regional States in 2005 and 2008
resulted in the collection of seven different species with more than 100 accessions. The study revealed low similarity in
species composition between the Regional States, indicating that each region has its own unique set of species. Species numbers
are higher in the north-eastern and south-western than the central part of the country. C. aestuans L. and C. tridens L. are restricted to humid lowlands of south-western part of Ethiopia, growing at elevations up to 490 m, whereas, C. urticifolius Wight et Arn., C. trilocularis L. and C. schimperi Cufod. were collected only in the north-eastern part of the country with elevation ranges of 1,380–2,130 m. The only species
collected at a higher elevation (>2,100 m) was C. schimperi Cufod. Farmers’ perception, indigenous knowledge and folk taxonomy of jute species are better in Gambella than the other
studied regions. Although several Corchorus species are reported from Ethiopia, these species are neither cultivated nor popularly used as leafy vegetables. This is
mainly due to lack of awareness or knowledge about the species use, and abundant distribution of the species that allows gathering
of edible leaves with little expenditure of time, labour and other resources. Our results revealed that some species are threatened,
which necessitates highest priority for jute germplasm conservation in the country. In addition, creating public awareness
about the use of jute species as a cheap source of leafy vegetable will play an important role to diversify food sources,
reduce malnutrition, and contribute to household income generation of the farming community. 相似文献
2.
Wendawek Abebe Mengesha Sebsebe Demissew M. F. Fay R. J. Smith I. Nordal P. Wilkin 《Genetic Resources and Crop Evolution》2013,60(4):1365-1375
Yams (Dioscorea spp.) rank as the fourth most important root and tuber crop after potatoes, cassava and sweet potatoes. They are an economic crop in most of the tropics especially in West Africa, which produces over 95 % of the world output. Despite their cultural and economic importance there is taxonomic confusion regarding Guinea yams. The currently used classification scheme, which relies on vegetative and inflorescence characters, does not consistently delimit species boundaries between members of Guinea yams (D. cayenensis Lam.–D. rotundata Poir. complex), their wild relatives (D. abyssinica Kunth and D. praehensilis Benth.,) and D. sagittifolia Pax. Establishing the taxonomic identity of the germplasm and understanding the systematic relationships among crops is vital to the management of genetic resources and the utilization of accessions. In this study, amplified fragment length polymorphism (AFLP) genetic fingerprinting was used to evaluate and characterize 43 individual plants, belonging to different populations of wild and cultivated Guinea yams. The three primer combinations used in the AFLP analyses generated 158 scorable bands, with an overall polymorphism of 78 %. Ordination and cluster analyses of AFLP data failed to produce any clear species boundary between either the Guinea yam accessions or between them and their wild relatives. The average genetic similarity between the study individuals of Guinea yams and their wild relatives ranged from 60 to 100 %. The first, second and third principal coordinates axes cumulatively account for 77.45 % of the total variation. AFLP analyses also revealed a higher genetic divergence among cultivated Guinea yam accessions of the Sheko cultivars. Ordination and cluster analysis using UPGMA revealed no clear species boundaries between members of the complex. Thus, the taxonomy of these “species” needs to be revisited using other markers. 相似文献
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Wendawek Abebe Mengesha Sebsebe Demissew M. F. Fay R. J. Smith I. Nordal P. Wilkin 《Genetic Resources and Crop Evolution》2013,60(2):529-541
Genetic diversity and population structure of Guinea yams and their wild relatives collected from south and south west Ethiopia were assessed using microsatellite markers. The total number of alleles amplified for the 7 loci studied was found to be 60, with an average of 8.6 alleles per locus. The average expected heterozygosity for the entire population was found to be 64 % indicating that Guinea yams and their wild relatives in the study area display a high level of genetic diversity. Using allelic richness as a measure of genetic diversity the wild forms exhibited greater allelic diversity than the cultigens. Contrary to what is expected in vegetatively propagated crops, none of the seven loci studied showed a significant excess of heterozygotes. In all the comparisons made, a low mean FST (but significant) has been observed, indicating that the majority of microsatellite diversity in the populations under study was found within rather than between populations. 相似文献
5.
Solomon Benor Sebsebe Demissew Karl Hammer Frank R. Blattner 《Genetic Resources and Crop Evolution》2012,59(6):1125-1146
In this study, we investigated the genetic diversity and relationships in C. olitorius by analysing populations representing different distribution areas, and developed a hypothesis on the origin and spread of the species in the pantropics. We employed amplified fragment lengths polymorphism (AFLP) and morphometric analyses in a total of 101 C. olitorius accessions. Results of both data sets are mostly congruent. The molecular analysis indicated generally low genetic diversity within populations and the Nei’s gene diversity (He) ranged from 0.0457 to 0.0955 with a mean of 0.0763. Qualitative traits, especially related to leaf morphology, branching habit and stipule color were the taxonomically most informative characters. The highest morphological variability occurred within African accessions, indicating that this species originally evolved in Africa. In both analyses, the Asian materials were nested within African populations, especially with those from North and East Africa. This indicates an African origin of the species and we hypothesise that dispersal occurred via the Mediterranean–Indian trade routes instead of natural migration along the coasts from western Africa to the Indian subcontinent. Both analyses revealed materials from Ethiopia to be quite distinct. The highest number of private bands (N?=?35), percent polymorphism (29.29%), and gene diversity (0.0955) were also detected in wild accessions collected from Ethiopia, suggesting a long-term spatial isolation of C. olitorius populations in the country. Germplasm samples from this region could therefore be a useful source of genetic variation in jute breeding programs. 相似文献
6.
Demissew Sertse Oliver Gailing Nicolas-George Eliades Reiner Finkeldey 《Genetic Resources and Crop Evolution》2011,58(6):849-859
Juniperus procera is economically highly important but threatened tree species. It is the only species among 67 taxa in the genus Juniperus that naturally grows in Africa and south of the equator extending up to 18°S in Zimbabwe. Ethiopia is assumed to host the
largest J. procera populations, which are also believed to have high genetic variation owing to their wide ecological amplitude. This study
assessed genetic variation at AFLPs of J. procera populations in the Ethiopian highlands. In the study six populations, namely Chilimo, Goba, Menagesha-Suba, Wef-Washa, Yabelo
and Ziquala were included. A total of 20–24 trees from each population were investigated based on 128 AFLP band positions.
AMOVA revealed that most of the variation (94%) resided within populations of J. procera suggesting extensive gene flow among populations which is attributable to the outcrossing mating system and effective gene
transport mechanisms of the species. However, genetic differentiation among populations was still significant (P < 0.05), and the differentiation was significantly (P < 0.05) correlated with geographic distance. All population pairs were significantly (P < 0.05) differentiated except for Menagesha-Suba and Wef-Washa. These two populations also showed the highest gene diversity
(H
j = 0.301 and H
j = 0.297, respectively). These results are in accordance with historical records that claim the establishment of the Menagesha-Suba
juniper population as plantation of seedlings from Wef-Washa back in fifteenth century. 相似文献
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To investigate the woody species composition,diversity and structure of Kuandisha Afromontane forest,vegetation and environmental data were collected from 53 plots of 10 m 9 50 m for trees and shrubs and 265 subplots of 2 m 9 4 m for seedlings were laid along eight transect lines. The local name, scientific name, abundance,DBH, height and percentage foliage cover of species were recorded. Environmental variables, namely altitude, latitude and longitude as well as disturbance levels were also recorded in each plot. Structure, basal area, importance value index(IVI) and species prioritization were analyzed using spreadsheet programs. Correlation coefficients, frequency, relative frequency, Shannon diversity index,Shannon evenness and vegetation classification were analyzed using an R package. Sixty-six species belonging to40 families were recorded. Fabaceae was the most diverse family consisting of seven species, followed by Euphorbiaceae and Asteraceae. In terms of habit, 29 species were trees, 28 were shrubs, and 9 were lianas. The overall Shannon diversity index was 2.5. The frequency and relative frequency of woody species with DBH C2.5 cm ranged from 1.9 to 92.5 and 0.1 to 5, respectively. Seedling density varied among species ranging from five to 9938 individuals ha-1. The total basal area of woody species having DBH C2.5 cm is 15.3 m2ha-1. The IVI of species ranged from 0.13 for Solanum giganteum Jacq. to 28.4 for Croton macrostachyus Del. The woody vegetation was classified into five community types. Species richness,diversity and evenness of communities were strongly positively correlated. On the other hand, the correlation between disturbance and seedling density, and species richness was strongly negative. Thus, among the recorded woody species, a significant portion was either lacking regeneration or selectively removed for various purposes.The lack of seedlings of those species is mainly attributed to anthropogenic disturbances particularly free grazing. As a result, 14 tree, seven shrub and one liana species were prioritized for conservation and management interventions. 相似文献
9.
Plant species distributions show patterns along elevation gradients. Regardless of the diverse Afromontane vegetation in Ethiopia(AFE), studies of elevation patterns of woody plants are limited and they are restricted to small areas or single/few Mountains. Moreover, there is no general consensus on the patterns of woody taxa distribution by elevation. The objectives of this study were to examine the elevation patterns of woody taxa richness and their relationship with elevation in the AFE. Data were collected and compiled from the Flora of Ethiopia and Eritrea(Vols. 1–7). About 5918 plant species of 243 families were examined and their elevational distributions were recorded. The distributional ranges of woody taxa were aggregated at 19 points(sites) at 100 m intervals starting from 1500 to 3400 m a.s.l. Single-factor analysis of variance(one-way ANOVA) was used to test the hypothesis that mean species richness of woody taxa decreases from the lower to the upper limit of AFE. Simple linear correlation and regression were used to show the relationships of woody taxa richness with elevation. We documented the presence of 505 woody taxa(441 species,31 subspecies and 33 varieties) representing 267 genera and 90 families in the AFE. In terms of habit, 279 taxa are shrubs, 178 are trees and 48 are lianas. The distribution of woody taxa(trees, shrubs and lianas) showed a slight increase at the lower portion and a monotonic decline with increasing elevation. Species richness of trees, shrubs and lianas was negatively and significantly correlated with elevation(r =-0.985,-0.984,-0.981, respectively; all p 0.001). Our hypothesis was accepted because mean richness significantly decreased from the lower to the upper limit of AFE(p 0.001). Generally, monotonic patterns of decline in richness were observed for trees, shrubs and lianas. The contribution of shrubs to total richness increased with increasing elevation whereas that of trees and lianas decreased. 相似文献
10.
We undertook ethnobotanical study of forage/fodder plant species used by the Afar and Oromo （Kereyu and lttu） Nations in and around the semi=arid Awash National Park （ANP）, Ethiopia. The study aimed at investigating and documenting indigenous knowledge （IK） on forage/fodder plant species and threats to their survival. Ninety-six in= formants between 20 and 80 years old were selected using prior informa- tion. Data were collected using semi-structured interview, guided field wail discussion and field observation. Preference ranking, Jaccard＇s coefficient of similarity and priority ranking were used for data analysis. One hundred twenty-six forage/fodder species of 90 genera and 43 fami- lies were collected in the study area. More than 88% of the species were reported with their vernacular names, where 68% were reported by the Afar Nation and 70% by the Oromo Nation. Family Poaceae was repre- sented by 25 species （20%）, followed by Fabaceae 18 （14%）. Preference ranking for the most preferred forage grasses as perceived by key informants revealed that Chrysopogon plumulosus was the most important forage/fodder species. Overgrazing was the major threat in the study area, scoring 22%. 相似文献