Browsing by Author "Manoko, Mkabwa L. K."

Now showing 1 - 10 of 10
  • Thumbnail Image
    Item
    AFLP Markers Support Separation of Solanum Nodiflorum from Solanum Americanum Sensu Stricto (Solanaceae)
    (Springer Link, 2007) Manoko, Mkabwa L. K.; van den Berg, Ronald G.; Feron, Richard M. C.; van der Weerden, Gerard M.; Mariani, Celestina
    This study was aimed at examining the relationships between the African material of Solanum americanum (also designated as S. nodiflorum), accessions of this taxon from other geographical areas, and American S. americanum using AFLP markers. 96 individuals representing 39 accessions of S. americanum sensu lato and related diploid species from the widest possible geographical range, and one accession of S. dulcamara (as outgroup) were used. The AFLP results suggested that American S. americanum differs from S. nodiflorum and that the material investigated in this study can be assigned to three different species: S. americanum sensu stricto, S. nodiflorum and a Solanum species from Brazil. These species can be differentiated based on a combination of floral and fruit characteristics.
  • Thumbnail Image
    Item
    Genetic diversity between Cultivated and Non-cultivated Moringa Oleifera Lam. Provenances Assessed by RAPD markers
    (2010-11-08) Mgendi, Mariam G.; Manoko, Mkabwa L. K.; Nyomora, Agnes M. S.
    Knowledge of population genetic diversity is one of the prerequisites for development of plant species conservation strategies. In the case of wild species that represent genetic resources for cultivated plants, an understanding of their genetic diversity is essential as they are the source of genetic material that are used to improve elite varieties. A total of 12 RAPD primers were used to investigate the genetic diversity between and within cultivated and non-cultivated provenances of Moringa oleifera Lam. from costal regions of Tanzania. Cluster analysis using NTSYS-pc and UPGMA program produced five clusters with similarity ranging from 54% to 96%. Clustering pattern revealed a trend of genetic separation between cultivated and non-cultivated individuals which could be attributed to genetic changes taking place in escapees’ individuals as they adapt to the natural environment. Based on the results, selection of elite germplasm and conservation of M. oleifera genetic resources could be achieved by considering individuals both from wild and cultivated plants.
  • Thumbnail Image
    Item
    Genetic Diversity of the African hexaploid Species Solanum scabrum Mill. and Solanum nigrum L. (Solanaceae)
    (2008) Manoko, Mkabwa L. K.; van den Berg, Ronald G.; Feron, Richard M. C.; van der Weerden, Gerard M.; Mariani, Celestina
    Two hexaploid species of Solanum sect. Solanum are present in Africa: Solanum scabrum and S. nigrum. Solanum scabrum is a widely cultivated species and is used as a leafy vegetable, as a source of medicine and as a source of ink dye. In previous studies a wide range of morphological diversity has been reported in this species and in some studies subspecies have been proposed. Subspecies are also recognized in S. nigrum. However, it has not been established whether or not the morphological differences are reflected at the genomic level. The present study applies AFLPs to study the genetic diversity in S. scabrum and its relationship to geographical provenance, morphological differences and the possible existence of subspecies within S. scabrum and S. nigrum. The data obtained were analyzed with cluster analysis (using UPGMA and NJ). The results indicate that the genetic variation within S. scabrum was higher within accessions than between accessions. Accessions did not cluster according to their geographical provenance, indicating that accessions from different geographical areas were not significantly different genetically. The clustering reflected neither morphological differences nor domestication status (cultivated or wild). The morphological differences exhibited by S. scabrum could be due to selection by farmers for different plant types. The AFLP derived clustering pattern did not segregate the subspecies recognized in S. scabrum and S. nigrum into separate subclusters.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    A new Tetraploid Species of Solanum L. sect. Solanum (Solanaceae) from Tanzania
    (2012) Manoko, Mkabwa L. K.; van der Weerden, Gerard M.; van den Berg, Ronald G.; Mariani, Celestina
    Solanum umalilaense Manoko sp. nov. (Solanaceae) is described from the Umalila area, in the southern highlands of Tanzania. Its novelty is supported with both morphological and AFLP data. Phenetic and phylogenetic analyses place Solanum umalilaense as a unique and well-supported taxon among tetraploid species of Solanum sect. Solanum from Africa. It can be distinguished from other African species by its extremely developed branching, each branch producing many multi-flowered inflorescences, flowers with short calyx lobes and its persistent, small, light yellowish brown fruits.
  • Thumbnail Image
    Item
    Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods
    (Hindawi Publishing Corporation, 2015-11-12) Mabeyo, Petro E.; Manoko, Mkabwa L. K.; Gruhonjic, Amra; Fitzpatrick, Paul A.; Landberg, Göran; Erdélyi, Máté; Nyandoro, Stephen S.
    Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3′-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from to  μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from  μg/g in Amaranthus sp. to  μg/g DW in C. maxima and was hence significantly different (). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Taxonomic Characterization and Identification of African Nightshades (Solanum L. section Solanum).
    (2003) Mwai, G. N.; Tiomo, B.; Manoko, Mkabwa L. K.; Mariani, Celestina; van der Weerden, Gerard M.; Schippers, R. R.
  • Thumbnail Image
    Item
    Using Morphological Markers to Assess Variations between and within Cultivated and Non-cultivated Provenances of Moringa Oleifera Lam. in Tanzania
    (2011-05-30) Mgendi, Mariam G.; Nyomora, Agnes M. S.; Manoko, Mkabwa L. K.
    The use of morphological markers to assess variations between and within cultivated and non-cultivated provenances of Moringa oleifera Lam. from selected coastal regions of Tanzania was studied. A descriptors list of 15 selected morphological characters was used to generate a character state matrix. Cluster analysis using NTSYS-pc and UPGMA program produced six clusters with similarity ranging from 66% to 100%. The majority cultivated and non-cultivated clusters with similarity ranging from 86-100% and 97-100% respectively reflected a clustering pattern based on the status of individuals whether cultivated or non-cultivated. Most individuals from same population clustered differently indicating high morphological variations within populations than between populations. The present results suggest that selection and conservation of elite germplasm could be achieved by considering individuals from both cultivated and non-cultivated plants.