A total of 3,860 accessions from the global in trust clonal potato germplasm collection w3ere genotyped with the Illumina Infinium SolCAP V2 12K potato SNP array to evaluate genetic diversity and population structure within the potato germplasm collection. Diploid, triploid, tetraploid, and pentaploid accessions were included representing the cultivated potato taxa. Heterozygosity ranged from 9.7% to 66.6% increasing with ploidy level with an average heterozygosity of 33.5%. Identity, relatedness, and ancestry were evaluated using hierarchal clustering and model-based Bayesian admixture analyses. Errors in genetic identity were revealed in a side-by-side comparison of in vitro clonal material with the original mother plants revealing mistakes putatively occurring during decades of processing and handling. A phylogeny was constructed to evaluate inter- and intraspecific relationships which together with a STRUCTURE analysis supported both commonly used treatments of potato taxonomy. Accessions generally clustered based on taxonomic and ploidy classifications with some exceptions but did not consistently cluster by geographic origin. STRUCTURE analysis identified putative hybrids and suggested six genetic clusters in the cultivated potato collection with extensive gene flow occurring among the potato populations, implying most populations readily shared alleles and that introgression is common in potato. Solanum tuberosum subsp. andigena (ADG) and S. curtilobum (CUR) displayed significant admixture. ADG likely has extensive admixture due to its broad geographic distribution. Solanum phureja (PHU), Solanum chaucha (CHA)/Solanum stenotomum subsp. stenotomum (STN), and Solanum tuberosum subsp. tuberosum (TBR) populations had less admixture from an accession/population perspective relative to the species evaluated. A core and mini core subset from the genebank material was also constructed. SNP genotyping was also carried out on 745 accessions from the Seed Savers potato collection which confirmed no genetic duplication between the two potato collections, suggesting that the collections hold very different genetic resources of potato. The Infinium SNP Potato Array is a powerful tool that can provide diversity assessments, fingerprint genebank accessions for quality management programs, use in research and breeding, and provide insights into the complex genetic structure and hybrid origin of the diversity present in potato genetic resource collections.

For sustainable breeding in potato, a better understanding of genetic diversity within germplasm banks for sustainable breeding is needed. This study comprehensively characterised the molecular and phenotypic traits of 62 potato accessions, including advanced clones and indigenous potato varieties from Advanced Chemical Industries Limited (ACI Ltd.), Bangladesh, and 8 varieties from the Bangladesh Agricultural Research Institute (BARI). By using 9 SSR markers and 13 morphological traits, including both quantitative and qualitative traits, we observed correlation coefficients ranging from -0.3 to 0.7 for 8 quantitative traits, and Pearson's chi-square (χ2 value) ranging from 24.3 to 135.4 for 5 qualitative characteristics. Molecular analyses identified 46 unique alleles, with 93.5% polymorphism. The markers STM0031 and STM1016 had the highest PIC value of 0.9. Genetic parameters for SSR markers included effective number of alleles per locus (Ne) = 5.6, unbiased expected heterozygosity (uh) = 0.8, diversity (h) = 0.8 and Shannon's information index (I) = 1.8. Jaccard's similarity coefficients ranged from 0.2 to 0.8, representing significant diversity. Cluster analysis, using unweighted pair-group method with arithmetic average (UPGMA), grouped the accessions into five clusters based on SSR profiles. An association was foud between the marker STM0031 and two traits: the number of tubers per hill and the content of reducing sugars in the tubers. This study provides information on genetic diversity and marker efficacy. It will guide future breeding programmes towards the development of high-yielding and industrially valuable potato varieties.

Excellent germplasm resources are the foundation for cultivating high-quality, disease-resistant, and stress-tolerant varieties. In this study, simple sequence repeat (SSR) markers were used to identify 138 potato accessions collected from worldwide, and genetic cluster analysis was used to characterize the genetic diversity of the tested germplasm resources. The Potato virus Y (PVY) resistance of these potato accessions was identified by artificial friction inoculation combined with molecular marker detection, and potato accessions with different PVY resistance were screened based on disease index and incidence rate. Using SSR markers, 138 potato accessions were identified, and the results showed that the genetic distances between the tested potato germplasm resources ranged from 0.025 to 0.660, and the genetic similarity coefficients ranged from 0.489 to 0.975. The 138 accessions could be clustered into five subgroups using Unweighted Pair-Group Method with Arithmetic Mean (UPGMA). Among them, Z173, Biyin No. 4, Suyin No. 2, XN995, XN987, Biyin No 22, Bibiao104, Sarpo mira, XN996, XN979, Desiree, RUNSHI, Actrice, Jia 1219, Heyin No 12, and Moyin No.1 have relatively distant genetic relationship with another 122 accessions. Based on the disease index, the following different accessions were screened: five highly resistant, 11 resistant, 45 moderately resistant, 35 susceptible, and 42 highly susceptible. Fourteen resource materials with good resistance (disease index ≤ 33.74%, and a grading of high resistance (HR) or medium resistance (MR); incidence rate ≤ 67.58%) were identified. By combining genetic cluster analysis and PVY resistance identification, six accessions showed PVY resistance and had distant genetic relationships with other accessions selected which provided important materials for disease resistance breeding and quality improvement of potato. In this study, the genetic diversity and PVY resistance of global potato germplasm resources was explored, and potato germplasm materials with important utilization value were screened. The results obtained in this study could provide important references for the research and utilization of global potato germplasm resources.

As a globally important food crop, the potato ranks fourth in production, following wheat, rice, and maize. Currently, over 7,000 varieties, developed in the 18th and 20th centuries, are cultivated worldwide. At this stage of agricultural development, where the primary challenge is the creation of new crop varieties and the improvement of existing ones to meet growing population and production demands, both classical breeding methods and modern technologies — such as molecular markers and genetic transformation — are employed. This study investigates the intravarietal and intervarietal diversity of three valuable potato varieties cultivated in Armenia. Genetic polymorphism was assessed using protein markers (11S-globulin protein profiles and electrophoretic spectra) and DNA markers (RFLP). The research utilized a combination of classical agronomic, molecular biological, biotechnological, and genetic-mathematical methods. The results revealed that the 11S-globulin proteins in all studied potato varieties exhibit polymorphism, as evidenced by distinct electrophoretic spectra and protein profiles. Additionally, the DNA restriction fragment patterns showed varying lengths within the same variety, indicating significant intravarietal genetic polymorphism. These findings can serve as genetic markers for the identification and passporting of the studied varieties, as well as for marker-assisted selection in breeding programs.

ABSTRACT The objective was to characterize the genotypes and obtain data on the genetic diversity of sweet potatoes. The experimental design was an RCBD with 26 treatments and three replications. It was evaluated total productivity, commercial and non-commercial root yield, number of roots per plant, biomass, root shape, and root color. The estimation of genetic diversity was obtained by the similar mean dissimilarity measure and, the delimitation group by the UPGMA dendogram. As a measure of proximity distances, the Euclidian Quadratic dissimilarity measure was used. and the number of clusters was determined using the Mojena Criterion. The collection was grouped into seven clusters. The highest number of accessions was grouped in cluster III, with nine accessions, cluster II with six accessions, cluster IV, with six accessions, cluster VII with two accessions and cluster I, V, and VII with one accession each. The greatest genetic distance was found between Morotí Guazú and Ib-019 with 40,443 and the most similar were Morado and Pyta guazú with a Euclidean dissimilarity measure value of 1098. Root productivity is the most important variable for genetic distance. The predominant skin color of the collection is cream and pale yellow flesh color.

Potato is the most important non-cereal crop worldwide, and, yet, genetic gains in potato have been traditionally delayed by the crop’s biology, mostly the genetic heterozygosity of autotetraploid cultivars and the intricacies of the reproductive system. Novel site-directed genetic modification techniques provide opportunities for designing climate-smart cultivars, but they also pose new possibilities (and challenges) for breeding potato. As potato species show a remarkable reproductive diversity, and their ovules have a propensity to develop apomixis-like phenotypes, tinkering with reproductive genes in potato is opening new frontiers in potato breeding. Developing diploid varieties instead of tetraploid ones has been proposed as an alternative way to fill the gap in genetic gain, that is being achieved by using gene-edited self-compatible genotypes and inbred lines to exploit hybrid seed technology. In a similar way, modulating the formation of unreduced gametes and synthesizing apomixis in diploid or tetraploid potatoes may help to reinforce the transition to a diploid hybrid crop or enhance introgression schemes and fix highly heterozygous genotypes in tetraploid varieties. In any case, the induction of apomixis-like phenotypes will shorten the time and costs of developing new varieties by allowing the multi-generational propagation through true seeds. In this review, we summarize the current knowledge on potato reproductive phenotypes and underlying genes, discuss the advantages and disadvantages of using potato’s natural variability to modulate reproductive steps during seed formation, and consider strategies to synthesize apomixis. However, before we can fully modulate the reproductive phenotypes, we need to understand the genetic basis of such diversity. Finally, we visualize an active, central role for genebanks in this endeavor by phenotyping properly genotyped genebank accessions and new introductions to provide scientists and breeders with reliable data and resources for developing innovations to exploit market opportunities.

Sweet potato (Ipomoea batatas L.) is an essential crop in the Paraguayan diet. It plays a crucial role in food security. It is a source of income for family agriculture. It has a significant potential to adapt to various climatic and soil conditions in Paraguay, making it a promising crop for improving productivity. However, Paraguay faces a deficit in the development of sweet potato cultivation technology, resulting in a low productivity of 5.3 ton/ha. Efforts have been made to collect and characterize sweet potato genotypes, covering a diversity of native varieties. These efforts have laid the groundwork for future sweet potato research and development. Still, ongoing research and development of strategies are needed to address existing challenges of improving genetic resource traits and developing cultivation technology and to fully exploit growth opportunities in this sector. This review summarizes sweet potato cultivation in Paraguay, focusing on several key technical aspects. It analyzes current market situation and production conditions as well as the availability of genetic materials adapted to different ecoregions. Additionally, it explores prospects for the development of advanced sweet potato crops, including the production of high-quality, virus-free sweet potato plants with improved productivity.

<i>Phytophthora infestans</i> remains a major threat to global potato production. This study focused on characterizing and assessing the pathogenicity of <i>P. infestans</i> isolates on detached potato leaves and in greenhouse trials across four cultivars. Seven isolates were obtained from high potato-producing regions in the department of Nariño, Colombia. The isolates were analyzed using 12 microsatellite markers to determine genetic distances. Two genetically distinct isolates showed markedly different pathogenicity on detached leaves: isolate P00921 caused complete infection by day five, whereas P00321 showed no symptoms. These two isolates (P00921 and P00321) selected for having the greatest genetic distance and highest pathogenicity among the seven analyzed were further tested in a greenhouse setup on four potato cultivars using a randomized block design. Disease progression was monitored over nine days. The results indicated significant variations in pathogenicity linked to genetic diversity among isolates. Notably, Capiro and Margarita cultivars were more prone to severe disease than Suprema and Única. These findings highlight the complex nature of host–pathogen interactions and suggest the need for tailored approaches in disease management and cultivar selection.