195 native potato cultivars collected in Chahuaytire community and 246 native potatoes repatriated to Potato Park Communities Association (ACPDP) by the International Potato Center (CIP) were characterized using nine primer pairs that amplify the ten most polymorphic microsatellite loci from the potato genetic identification kit (STM0019, STPoAc58, STM0037, STM0030, STM1104, STM1052, STM1106, STM2013, STM2022), located in 9 of the 12 chromosomes of potato. The molecular characterization differentiated the 93.33% of the native potatoes from the Chahuaytire community and the 92.68% of repatriated native potatoes from CIP. 114 and 130 alleles and average diversity index between 0.762 and 0.776 were obtained in the Chahuaytire community and the repatriated potatoes, respectively. The clustering of potato cultivars was performed using the UPGMA (Unweighted Pair Group Method with Arithmetic mean) method applied to similarity matrix obtained with Jaccard coefficient. Clustering analysis revealed that no differentiation according to origin was found. Similarly, Analysis of Molecular Variance (AMOVA) revealed that the molecular variation between evaluated groups was 0.73% (p- value=0.05), indicating a basically similar genetic constitution between both groups. The main source of molecular variation, 99.27% (p-value=0.05), was found within the native potatoes inside groups. However, the finding of 6 private alleles in the native potatoes from Chahuaytire suggests that some genetic diversity maintained in the Chahuaytire native potatoes is not represented in the 246 repatriated potatoes from CIP.

Wild potato species (genus Solanum, section Petota) represent a tremendously diverse gene pool which is traditionally utilized as a source of diverse traits for potato breeding. Abiotic and biotic stress tolerance and resistance belong to the most frequently utilized traits of wild species in potato breeding programs. This review provides an introduction to the taxonomy, centre of diversity, genetic characteristics, evolution and important tolerance and resistance traits of wild potatoes and their use for potato breeding. The review has been written for readers who are interested in the problems of finding and utilization of new resistance genes from the wild genetic resources.

Wild potato species (genus Solanum, section Petota) represent a tremendously diverse gene pool which is traditionally utilized as a source of diverse traits for potato breeding. Abiotic and biotic stress tolerance and resistance belong to the most frequently utilized traits of wild species in potato breeding programs. This review provides an introduction to the taxonomy, centre of diversity, genetic characteristics, evolution and important tolerance and resistance traits of wild potatoes and their use for potato breeding. The review has been written for readers who are interested in the problems of finding and utilization of new resistance genes from the wild genetic resources.

Genetic diversity of 10 potato cultivars was investigated at the DNA level with the random amplified polymorphic DNA (RAPD) procedure and at the phenotypic level using morphological characters. The results indicated that there were considerable variations among the different studied cultivars. Cultivars Victoria, Frizia and Safaren had the highest chlorophyll content compared to the other cultivars in both seasons. The largest leaf area and leaf dry weight were measured in cultivar Safaren and Mondial in both seasons. Cultivars Aboulx and Mondia produced the highest tuber yield in both seasons. On the other hand, cultivars Victoria and Edward were characterized by their considerably lower yield than other studied cultivars. Specific gravity varied considerably among the different potato cultivars. Thirteen random decamer primers were used to amplify DNA via the polymerase chain reaction and 75 RAPDs were generated. The RAPD profiles obtained were successfully used to differentiate potato cultivars. Based on the pair-wise comparison of amplification products, genetic similarity was estimated. The genetic similarity among all potato cultivars ranged from 50 to 92 %. Cultivars Victoria and Etfadoal presented the least similarity (0.50) while cultivars Mondial and Citrix had the greatest similarity (0.92). Etfadoal cultivar displayed the greatest genetic diversity of all cultivars. A dendrogram was constructed using UPGMA analysis. On the basis of this analysis, the cultivars were grouped into three clusters. The polymorphism detected suggests that RAPD markers are reliable for identification of potato cultivars and could be exploited in genetic mapping of populations to tag economically important traits.

To analyse the genetic diversity and relationships among Chinese sweet potato landraces and cultivars in China, one hundred landraces from six geographical regions of China and eight cultivars were assessed using inter-simple sequence repeat (ISSR) markers. Fourteen ISSR primers generated 239 polymorphic bands with an average of 17 polymorphic bands per primer. A high average genetic distance and wide variation range were found among Chinese landraces, which were also distantly related to the cultivars with an average genetic distance of 0.6428 (range 0.2591 to 1.6428). The UPGMA dendrogram showed the same genetic relationship among the cultivars in agreement with their known origin and the very wide genetic diversity of the Chinese landraces. The cluster analysis classified the materials into two groups: a major and a minor group. The minor group comprised 14 landraces collected mainly in Guangdong and Fujian, and two cultivars (cv. Nancy Hall and cv. Xu78-1) that are distantly related to each other. The major group consisted of the other 92 accessions. These results indicate that the Chinese sweet potato landraces not only exhibit a high level of genetic diversity but also have a different genetic background from cultivars in China.

Sweet potato feathery mottle virus (SPFMV) is one of the most prevalent viruses infecting sweet potatoes and occurs widely in sweet potato cultivating areas in Korea. To assess their genetic variation, a total of 28 samples infected with SPFMV were subjected to restriction fragment length polymorphism (RFLP) analysis using DNAs amplified by RT-PCR with specific primer sets corresponding to the coat protein (CP) region of the virus. The similarity matrix by UPGMA procedure indicated that 28 samples infected with SPFMV were classified into three groups based on the number and size of DNA fragments by digestion of CP-encoding regions with 7 enzymes including SalI, AluI, EcoRI, HindIII, FokI, Sau3AI, and DraI bands.

Andean potato varieties are cultivated in the northwest of Argentina and constitute the most important staple food for the local farmers. The genetic diversity of 155 accessions conserved at the Genebank of Balcarce (INTA) was tested using four microsatellites. Three commercial potato varieties of Tuberosum group and one accession of Curtilobum group were used as outgroups. The presence of bands was scored for each microsatellite and for each accession and the data were analysed by principal coordinate analysis. The polymorphism information content was obtained for each molecular marker from banding patterns. Analysis of molecular variance was carried out with a variable number of accessions for each landrace, from different departments and sites within departments. More than one genotype was detected in the majority of the potato landraces. Some accessions within each landrace did not differentiate. AMOVA revealed that most of the genetic variation occurred among sites within departments and among local varieties. These findings are discussed considering the agricultural practices carried out in the Andean farming system.

This paper analyzes the genetic diversity of mashua cultivars grown in six communities in the Cusco region of Peru´, of non-cultivated forms collected in the same region, and a sample of cultivars from the germplasm collection at the International Potato Center (CIP). From the DNA fingerprinting generated by SRAP markers, it is clear that mashua is a genetically variable crop with a range of similarity ranging from 65 to 99%. The widest range of variation was found for the most isolated community, Sayllafaya. Another important finding was that most of the non-cultivated accessions are likely feral races resulting from escape to cultivation rather than wild relatives. In general the range of variation of the cultivars from the communities and their feral relatives are not represented in the cultivars sampled of the collection maintained at the International Potato Center, Peru´.

Potato tubers were evaluated as a source of antioxidants and minerals for the human diet. A genetically diverse sample of Solanum tuberosum L. cultivars native to the Andes of South America was obtained from a collection of nearly 1000 genotypes using microsatellite markers. This size-manageable collection of 74 landraces, representing at best the genetic diversity among potato germplasm, was analyzed for iron, zinc, calcium, total phenolic, total carotenoid, and total vitamin C contents. The hydrophilic antioxidant capacity of each genotype was also measured using the oxygen radical absorbance capacity (ORAC) assay. The iron content ranged from 29.87 to 157.96 micrograms g-1 of dry weight (DW), the zinc content from 12.6 to 28.83 micrograms g-1 of DW, and the calcium content from 271.09 to 1092.93 micrograms g-1 of DW. Total phenolic content varied between 1.12 and 12.37 mg of gallic acid equiv g-1 of DW, total carotenoid content between 2.83 and 36.21 micrograms g-1 of DW, and total vitamin C content between 217.70 and 689.47 micrograms g-1 of DW. The range of hydrophilic ORAC values was 28.25-250.67 micromol of Trolox equiv g-1 of DW. The hydrophilic antioxidant capacity and the total phenolic content were highly and positively correlated (r = 0.91). A strong relationship between iron and calcium contents was also found (r = 0.67). Principal component analysis on the studied nutritional contents of the core collection revealed that most potato genotypes were balanced in terms of antioxidant and mineral contents, but some of them could be distinguished by their high level in distinct micronutrients. Correlations between the micronutrient contents observed in the sample and the genetic distances assessed by microsatellites were weakly significant. However, this study demonstrated the wide variability of health-promoting micronutrient levels within the native potato germplasm as well as the significant contribution that distinct potato tubers may impart to the intake in dietary antioxidants, zinc, and iron.