Browsing by Author "Nyomora, Agnes M."

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    Effect of Timing of Seed Collection and Provenance on Seed Viability and Germination of Dalbergia melanoxylon
    (Scientific Research, 2008) Amri, E.; Lyaruu, H. M. V.; Nyomora, Agnes M.; Kanyeka, Z. L.
    Dalbergia melanoxylon is one of the most expensive timbers in the world used for the manufacturing of musical instruments and decorative objects such as carvings. The effect of timing of seed collection and provenance on seed viability and germination were investigated. Percentages of germination capacity and germination energy were significantly higher for seeds collected 12 and 16 weeks after maturity. Seed viability was highest 59.8% at fruit maturity stage and significantly decreased to 25.7% for seeds collected 24 weeks after maturity. Significantly highest germination capacity 25.8% was obtained for seeds collected from Ubena provenance followed 20.5% for seeds collected from Mkundi provenance. Percentage of seed viability collected from Ubena was superior 57.56% to other provenances followed Mkundi provenance, which had 49.42%. Seed collection in D. melanoxylon should be done between 8-16 weeks after maturity from superior provenances to obtain seeds with high germination energy and germination capacity.
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    Two New Pro-Apoptotic Glucopyranosides from Tulbaghia Violacea Genetic Diversity between Cultivated and Non-Cultivated Moringa Oleifera Lam. Provenances Assessed By RAPD Markers
    (2010) Mgendi, Mariam G.; Manoko, Mkabwa K.; Nyomora, Agnes M.
    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.
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    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.; Manoko, Mkabwa 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.