Utilizzazione di marcatori molecolari SSR e AFLP per l'identificazione varietale in patata

Obiettivo. La tracciabilità dei prodotti alimentari tra- mite la caratterizzazione varietale delle produzioni agricole è uno degli aspetti di maggior rilievo nel cam- po della valorizzazione del patrimonio agroalimentare italiano e della tutela del consumatore. Le moderne tecniche di biologia molecolare offrono strumenti ana- litici di grande ef cacia nell’identi cazione varietale. Tra i prodotti caratteristici dell’agricoltura italiana, la patata precoce, coltivata tipicamente in Campania, Pu- glia, Sicilia e Sardegna, riveste un ruolo di primaria importanza, ma è oggetto di frodi alimentari tramite il supplemento di materiale proveniente dall’Africa set- tentrionale o da Cipro. L’obiettivo di questa ricerca è stato l’ottenimento di un ngerprinting molecolare di varietà di patata comunemente utilizzate per la produ- zione extrastagionale. Metodi. Il materiale genomico è stato estratto dai tu- beri di 22 varietà, raccolte nelle zone di origine, e ana- lizzato con otto microsatelliti e cinque combinazioni di primer AFLP. Risultati. Dal confronto dei pro li allelici è risultato che il numero minimo di loci SSR necessario per di- stinguere le varietà analizzate è stato cinque (STI0032, STG0001, STI0012, STM5127 e STM1106). L’analisi AFLP, invece, ha permesso di individuare 83 frammen- ti speci ci per le quattro varietà maggiormente colti- vate nei cicli extrastagionali e, in particolare, 34 per Sieglinde, 23 per Spunta, 15 per Elvira e 11 per Agria. Conclusione. In conclusione, è stato possibile svilup- pare nuovi marcatori molecolari speci ci di varietà di patata precoce, utili per la tracciabilità molecolare e per garantire la veridicità delle indicazioni presenti sulle etichette dei prodotti

Genetic diversity among potato species as revealed by phenotypic resistances and SSR markers

The evolutionary diversity of wild potato species makes them excellent materials for improving the narrow genetic basis of the cultivated potato Solanum tuberosum. Understanding their genetic diversity is important not only to choose the best parents for breeding, but also to design proper crossing schemes and selection strategies. The objectives of this study were to determine the resistance response to Ralstonia solanacearum, Potato virus Y and low temperatures of 21 clones of 12 potato species, and to determine their genetic diversity through simple sequence repeat (SSR) markers. Sources of resistance have been found for all the investigated traits, with high resistance variability not only between but also within species. Combined resistances were also identified, with positive implications for efficient breeding. SSR analysis allowed the detection of 12 loci and 46 alleles across all genotypes, with an average value of 3.8 alleles per locus. Both unique and rare alleles useful for marker-assisted selection were found. SSR-based cluster analysis revealed that resistant genotypes were distributed among all clusters, suggesting that genetically different resistant genotypes were identified. The information obtained in this study is discussed from a breeding perspective

Secondary metabolite profile in induced tetraploids of wild Solanum commersonii Dun.

The main aim of this work was to study the leaf secondary metabolite profiles of artificially induced tetraploids (2n1⁄44x1⁄448) of Solanum commersonii, a diploid (2n1⁄42x1⁄424) wild potato species. The tetraploid genotypes of S. commersonii were produced by oryzalin treatment. Both HPLC-UV and LC/ MS analyses revealed that there were no qualitative differences in the metabolite profiles between the diploid S. commersonii and its tetraploids. By contrast, the results showed that the phenylpropanoid content was generally significantly higher in the tetraploids than in the diploid S. commersonii. Concerning the glycoalkaloids (GAs), the results provided evidence that the content of minor GAs (solanidenediol triose, solanidadienol lycotetraose, and solanidenol lycotetraose) was higher in tetraploids than in the diploid progenitor, while the content of major GAs (dehydrodemissine and dehydrocommersonine) was significantly higher in diploid S. commersonii than in its tetraploid genotypes. The results are discussed from the practical perspective of potato biodiversity enhancement

Chipping ability, specific gravity and resistance to Pectobacterium carotovorum in advanced potato selections

The availability of potato varieties combining good tuber quality and resistance traits is very important for both processors and supermarkets. In the present study, post-harvest quality traits as well as resistance to tuber bacterial soft rot were evaluated in 42 advanced potato clones belonging to seven hybrid families. Differences in specific gravity were found among families and among clones, with about 30% of clones showing a high specific gravity (>1.080). Clones and varieties were assayed also for a comprehensive chipping profile. Overall, 43% of clones presented an acceptable chipping score (≤4.5) at harvest. In addition, following cold storage with and without reconditioning, various clones performed acceptably. Five clones from three families (Bolestra X MC 329, Spunta X Victoria and Majestic X Alcmaria) were classified as resistant to bacterial soft rot. An evaluation index is proposed to help identify clones with interesting combinations of traits

SSR markers distinguish traditional Italian bean (Phaseolus vulgaris L.) landraces from Lamon

In this study, 12 microsatellite markers (SSR) were evaluated for their applicability to protect from frauds and misuse the Italian Protected Geographical Indication (PGI) product “Common bean from Lamon”. SSR analysis generated polymorphic alleles, with an average of 4 alleles per locus and all in the range of molecular weight between 181 and 284 bp. Twenty-nine variety-specific fragments were identified, which might be reasonably adopted for characterization and traceability purposes. Cluster analysis well outlined the relationships between the genotypes studied. Overall, our study underlines the use and usefulness of molecular markers to protect both farmers and consumers from frauds

Biochemical Characterization and Effects of Cooking Methods on Main Phytochemicals of Red and Purple Potato Tubers, a Natural Functional Food

Potato is a staple food crop and an important source of dietary energy. Its tubers contain several essential amino acids, vitamins, minerals and phytochemicals that contribute to the nutritional value of this important product. Recently, scientific interest has focused on purple and red potatoes that, due to the presence of anthocyanins, may be considered as natural powerful functional food. The aim of this study was to evaluate the characteristics of pigmented varieties, the types of anthocyanins accumulated and the level of both beneficial phytochemicals (vitamin C and chlorogenic acids, CGAs) and anti-nutritional compounds (glycoalkaloids) following various cooking methods. The analyses described the presence of a mix of several acylated anthocyanins in pigmented tubers along with high level of CGA. The amount of antioxidants was differently affected by heat treatments according to the type of molecule and the cooking methods used. In some cases, the beneficial compounds were made more available by heat treatments for the analytical detection as compared to raw materials. Data reported here describe both the agronomic properties of these pigmented varieties and the effects of food processing methods on bioactive molecules contained in this natural functional food. They may provide useful information for breeders aiming to develop new varieties that could include desirable agronomical and industrial processing traits

Secondary metabolite profile in induced tetraploids of wild Solanum commersonii Dun.

The main aim of this work was to study the leaf secondary metabolite profiles of artificially induced tetraploids (2n=4x=48) of Solanum commersonii, a diploid (2n=2x=24) wild potato species. The tetraploid genotypes of S. commersonii were produced by oryzalin treatment. Both HPLC-UV and LC/MS analyses revealed that there were no qualitative differences in the metabolite profiles between the diploid S. commersonii and its tetraploids. By contrast, the results showed that the phenylpropanoid content was generally significantly higher in the tetraploids than in the diploid S. commersonii. Concerning the glycoalkaloids (GAs), the results provided evidence that the content of minor GAs (solanidenediol triose, solanidadienol lycotetraose, and solanidenol lycotetraose) was higher in tetraploids than in the diploid progenitor, while the content of major GAs (dehydrodemissine and dehydrocommersonine) was significantly higher in diploid S. commersonii than in its tetraploid genotypes. The results are discussed from the practical perspective of potato biodiversity enhancement