Application of DNA fingerprint is the method which permits documentation of genetic material with high accuracy and permanency as it is not predisposed by environment, epistatic interactions and other factors. Seed quality and purity are the important key aspects to be maintained in seed multiplication and production to enhance yield and productivity. The aim of this study was to assess genetic purity of yellow bean varieties traded in the major markets in Tanzania using DNA fingerprint (Single Nucleotide Polymorphisms (SNPs)). A total of 300 grain samples were collected from different Tanzanian markets were compared with 14 reference seed samples maintained at the International Centre for Tropical Agriculture (CIAT) gene bank in Uganda and by the Tanzania Agricultural Research Institute (TARI). The seed samples were planted in the field near a screen house at CIAT-Uganda and at leaf stage, leaf samples were taken and genotyped with 50 quality control (QC) SNP markers at the Intertek laboratory in Australia. Molecular variance analysis (AMOVA) results showed that there was no significant variability in reference seeds, while market seeds showed that there was significant variability. Fixation index for reference seeds showed that maintained at 1.000, while for market seeds it varied from 0.871 to 0.978, heterozygosity showed that the reference seed (TARI and CIAT) and market seed samples from showed that expected heterozygosity (He) was greater than observed heterozygosity (Ho). The genetic distance of reference seeds was lower (0.040) than genetic distances of market seeds.

Keywords: Yellow common bean, DNA fingerprinting, SNPs, Quality control, Genetic diversity.