Abstract:
French bean (Phaseolus vulgaris L.) is a major export crop in Kenya where it serves as a cash crop for
smallholder farmers and a source of employment. However, there is limited information on
characterization of available germplasm which is essential in genetic improvement of this crop. The
present study was therefore aimed to identify the gene pool affiliations of Kenyan French bean
germplasm using specific molecular markers in order to understand the available germplasm for future
use in breeding programs. The germplasm panel consisted of 46 accessions, comprising 40 French
bean and six dry bean genotypes. The accessions were characterized using four gel-based molecular
markers: SHP1-A, SHP1-B, SHP1-C and phaseolin protein marker. The most informative marker was the
phaseolin protein marker which indicated that 82% of the French bean genotypes are of Andean origin,
while 18% are of the Mesoamerican origin. Low polymorphism was observed for the SHP1 markers and
the data from the three SHP1 markers did not correspond to the phaseolin protein marker for the French
bean germplasm although SHP1-A and SHP1-B were able to differentiate the Andean from the
Mesoamerican differential cultivars. The information on the gene pool affiliations of Kenyan French
bean accessions is important for breeders to harness the divergence between the two gene pools in
order to broaden the genetic base of the crop.
