African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12024

Full Length Research Paper

The genetic diversity and population structure of common bean (Phaseolus vulgaris L) germplasm in Uganda

Dennis Okii*
  • Dennis Okii*
  • Makerere University, College of Agricultural and Environmental Sciences, Department of Crop production. P.O Box 7062, Kampala, Uganda; National Crops Resources Research Institute-Namulonge, P.O. Box 7084, Kampala, Uganda.
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Phinehas Tukamuhabwa
  • Phinehas Tukamuhabwa
  • Makerere University, College of Agricultural and Environmental Sciences, Department of Crop production. P.O Box 7062, Kampala, Uganda.
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James Kami
  • James Kami
  • University of California, Department of Plant Sciences/MS1, Section of Crop and Ecosystem Sciences, 1 Shields Avenue, Davis, CA 95616-8780, USA.
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Annet Namayanja
  • Annet Namayanja
  • National Crops Resources Research Institute-Namulonge, P.O. Box 7084, Kampala, Uganda.
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Pamela Paparu
  • Pamela Paparu
  • National Crops Resources Research Institute-Namulonge, P.O. Box 7084, Kampala, Uganda.
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Michael Ugen
  • Michael Ugen
  • National Crops Resources Research Institute-Namulonge, P.O. Box 7084, Kampala, Uganda.
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Paul Gepts
  • Paul Gepts
  • University of California, Department of Plant Sciences/MS1, Section of Crop and Ecosystem Sciences, 1 Shields Avenue, Davis, CA 95616-8780, USA.
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  •  Received: 15 May 2014
  •  Accepted: 20 June 2014
  •  Published: 16 July 2014

Abstract

The knowledge and understanding of the genetic variability of common bean (Phaseolus vulgaris L.) germplasm is important for the implementation of measures addressed to their utilizations and conservation. The objective of this study was to characterize common bean in Uganda using polymorphic molecular markers for use in hybridization and variety development. Genomic DNA was extracted from plants at the first trifoliate leaf stage growing in pots using the modified cetyl-trimethylammonium bromide (CTAB) method. The gene pool membership (Andean vs. Mesoamerican) for each accession was established with the phaseolin marker. Simple sequence repeat (SSR) alleles were separated by capillary electrophoresis that provided further information on the organization of genetic diversity. The Andean and Mesoamerican genotypes were present in similar frequencies (51 vs. 49%, respectively). All SSR markers tested were polymorphic with mean polymorphism information content (PIC) of 0.8. The model-based cluster analysis of SSR diversity in the STRUCTURE software found three sub populations (K3.1, K3.2 and K3.3) genetically differentiated with moderate Wrights fixation indices (FST) values 0.14, 0.12 and 0.09, respectively and many cases of admixture. The STRUCTURE result was confirmed by Principal Coordinate analysis (PCoA) which also clustered beans in three groups. Most Andean genotypes were included in K3.1 and Mesoamerican genotypes belonged to the K3.2 and K3.3 subgroups. This study sets the stage for further analyses for agronomic traits such as yield, resistance to biotic and abiotic stresses and the need for germplasm conservation.

 

Key words: Phaseolin, Simple sequence repeat (SSR), hybridization, wrights fixation index (FST), structure.