19 random amplified polymorphic DNA (RAPD) and five Inter-simple sequence repeat (ISSR) primers were used to characterize 35 potato accessions originating from Mexico, Europe and U.S.A, with the aim of generating information on the genetic diversity and relationship among the genotypes for better exploitation in breeding programs. A total of 222 and 82 loci were generated by the RAPD and ISSR primers, respectively. Both RAPD and ISSR primers revealed 81.45 and 82.98% polymorphism, respectively. Mantel test showed no correlation between RAPD and ISSR (0.27), RAPD and RAPD + ISSR (0.47) similarity matrices. However, a high level of correlation (0.74) was observed between ISSR and RAPD + ISSR similarity matrices. The ISSR marker was found to be more efficient compared to RAPD marker, thereby influencing more the consensus data. The use of consensus data generated more information related to genetic diversity in potato. RAPD and ISSR markers successfully differentiated between the potato accessions and subgrouped the genotypes based on origin. Information on genetic diversity and relationships will be useful in the selection of parents and mapping studies.

Prior to Agrobacterium-mediated genetic transformation in vitro regeneration protocol was established for three potato cultivars (Alfa, Cambray Rosa Morelos and Atlantic) grown in Mexico using leaf, node and internodal explants. Regeneration protocol was developed with or without the intervention of callus. Two potato cultivars, namely, Cambray Rosa Morelos and Alpha were transformed using Agrobacterium tumefaciens strain LBA4404 harboring binary plasmid pBI121 containing the GUS and nptII genes. GUS histochemical assay and PCR analysis were conducted on rooted shoots grown in media without hormones but supplemented with antibiotics. Transformed shoots tested positive through GUS histochemical assay and integration of nptII gene was confirmed by PCR analysis DOI: http://dx.doi.org/10.3329/ptcb.v22i2.14193 Plant Tissue Cult. & Biotech. 22(2): 93-105, 2012 (December)