PCR amplification of
promoter region. a- PCR amplification with primers VrnA1F/Int1R. b- Msp I restriction digestion of corresponding PCR products. c- PCR amplification with primers VRN1F_F/VRN1F_R followed by Taq I restriction digestion. Accession numbers, species and genotypes are given at the top. The main restriction fragments more than 100 bp in length are indicated by arrows.