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.

Key words: Gene pool, phaseolin protein, shatterproof, molecular markers, French beans.