Abstract:
Soybean (Glycine max (L.) Merril) is one of the most popular pulses
because of its protein content and nodulating ability. However, most farmers and
researchers do not have sufficient genetic information of the genotypes that they grow.
This research aimed at determining the molecular characteristics of selected soybean
genotypes grown in different regions of East Africa and make recommendations to the
farmers and researchers. Genotypes were collected from Uyole, Ukiriguru, Kawanda,
Namulonge, Njoro and Embu Agricultural Institutes as well as from farmers. Molecular
analysis was done by DNA being extracted according to phenol chloroform method. This
was followed with PCR process using custom ordered pair of primers that corresponded
to the flanking ends of the targeted gene fragment (5S ribosomal genes). Restriction
fragment length polymorphism (RFLP) and gene clean were then performed on the
isolated PCR fragments. The elute was confirmed on agarose gel then sent for automated
sequencing ABI prism (Applied Biosystems) at ILRI. The resulting gene sequences were
compared with gene sequences of known Glycine species using various enzymes in
computer based simulations. The gene sequences were then subjected to gene blast using
MEGA 4 and resulted with a phylogenetic tree for the selected East African soybean. The
studied cultivars were found to be closely related to Glycine max species. Enzyme Sac11
was identified as a marker for the East African soybean genotypes. These results may
also assist plant breeders to produce hybrids with the best performing cultivars based on
their genetic diversity.
