Browsing by Author "Mariani, Celestina"

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    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.
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    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.
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    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.
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    Semi-viviparous Embryo Development and Dehydrin Expression in the Mangrove Rhizophora Mucronata Lam.
    (2010) Tibazarwa, Flora I.; Nitsch, L. M. C.; Wolters-Arts, M. M. C.; Mariani, Celestina; Derksen, J. W. M.
    Rhizophora mucronata Lam. is a tropical mangrove with semi-viviparous (cotyledon body protrusion before shedding), non-quiescent and non-desiccating (recalcitrant) seeds. As recalcitrance has been thought to relate to the absence of desiccation-related proteins such as dehydrins, we for the first time systematically described and classified embryogenesis in R. mucronata and assessed the presence of dehydrin-like proteins. Embryogenesis largely follows the classic pattern till stage eight, the torpedo stage, with the formation of a cotyledonary body. Ovule and embryo express radical adaptations to semi-vivipary in the saline environment: (1) A large, highly vacuolated and persistent endosperm without noticeable food reserves that envelopes the developing embryo. (2) Absence of vascular tissue connections between embryo and maternal tissue, but, instead, transfer layers in between endosperm and integument and endosperm and embryo. Dehydrin-like proteins (55–65 kDa) were detected by the Western analysis, in the ovules till stage 10 when the integuments are dehisced. An additional 50 kDa band was detected at stages 6–8. Together these results suggest a continuous flow of water with nutrients from the integument via the endosperm to the embryo, circumventing the vascular route and probably suppressing the initially induced dehydrin expression.
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    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.