Characterization of east african accessions of Musa AAB 'Apple' and Musa AA 'Muraru' dessert bananas



  • Authors : Onyango, M.A.

  • Document type : Thesis

  • Diploma : Doctor of Philosophy (Tropical Plant and Soil Sciences)

  • Year of publication : 2007

  • Publisher(s) : University of Hawaii

  • Place of publication : Honolulu (USA)

  • Pages : 261

  • Language(s) : English

  • Abstract : One of the major hindrances to future improvements in bananas and plantains production in East Africa is the endless range of names and synonyms used to describe different cultivars and the lack of understanding of their true biological relationships. The East African AAB 'Sukari Ndizi' and AA 'Muraru' dessert bananas are prime examples of this confusion. To better understand these two groups of bananas and to evaluate them for economically important traits, vital information such as the identity and distinctness of cultivars needed to be developed. This study had the following general objectives: (1) to use molecular and morphological tools to analyze the variation that exists within the East African AAB 'Sukari Ndizi' and AA 'Muraru' dessert bananas, (2) to classify AAB 'Sukari Ndizi' and AA 'Muraru' dessert banana cultivars into distinguishable groups for ease of reference and communication, (3) to identify their key characters for development of a provisional identification system, and (4) to identify superior AAB 'Apple' and AA 'Muraru' cultivars for production purposes. In this study, the classification of the East African AAB 'Sukari Ndizi' and East African AA 'Muraru' bananas was achieved using molecular microsatellite markers, morphological markers, flow cytometry ploidy analysis and horticultural trait evaluation. Microsatellite markers from both nuclear and chloroplast DNAs were useful for distinguishing the various bananas groups, and to separate 4 taxa of AAB 'Apple' dessert banana accessions using both cluster and principal component analysis. Using cluster analysis, the 'Sukari Ndizi' were classified as distinct taxon within the AAB 'Apple' dessert bananas. Flow cytometry analysis also confirmed that 'Sukari Ndizi' is triploid AAB and 'Muraru' is a diploid AA. Cluster analysis based on microsatellite data showed 'Muraru' to be distinct taxon from other AA accessions, and very closely related to the commercial AAA dessert bananas. Morphological studies have also identified key characters exclusive to these two banana groups that can be used for development of provisional identification systems. Finally, horticultural analysis of several cultivars was carried out using various traits, and these cultivars can be recommended for further production in the region. This study demonstrated that microsatellite markers are useful and powerful tools for banana classification and for the analysis of biological relationships. Flow cytometry determined the ploidy levels of the banana accessions. Analysis of variance of replicated accession samples and the use of Pisum sativum as an internal standard with flow cytometry, made it possible to predict the actual genomic composition of various accessions. (Author's abstract).

  • Keywords : ALTITUDE; VARIETIES; PHYLOGENY; RAPD; GENETIC VARIABILITY; TAXONOMIC CLASSIFICATION; UGANDA

  • Open access : No

  • Musalit document ID : IN080466


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