Authors:G. Mangini, F. Taranto, S. Giove, A. Gadaleta, and A. Blanco
A quick and reproducible tool for cultivar identification is useful to assess in certified seed production programs and to resolve legal conflicts. Simple Sequence Repeats (SSRs) have been the elected markers to carry out cultivar identification studies. The main aim of this research was to define the minimum number of SSR markers to distinguish 80 durum wheat cultivars. Preliminary, an analysis of 11 SSRs informativeness was carried out on a subset of 28 durum wheat cultivars. The discriminating ability of each primer was estimated both with Polymorphism Information Content (PIC) and with Resolving power (Rp). Rp resulted the best parameter for assessing the discriminatory power of SSR primers (r=0.94***; P≤0.001). The marker
was able to discriminate all the 28 cultivars. Successively, 80 genotypes were analysed using three SSR markers with the higher Rp value. Two SSRs were able to distinguish all the 80 genotypes. Particularly,
was able to distinguish 69/80 genotypes while
identified the other cultivars. An identification key was obtained combining the data of these two markers.
Authors:G. Mangini, D. Nigro, B. Margiotta, P. De Vita, A. Gadaleta, R. Simeone, and A. Blanco
During the last century wheat landraces were replaced by modern wheat cultivars leading to a gradual process of genetic erosion. Landraces genotyping and phenotyping are strategically useful, as they could broaden the genetic base of modern cultivars. In this research, we explored Single Nucleotide Polymorphism (SNP) markers diversity in a collection of common and durum wheats, including both landraces and Italian elite cultivars. A panel of 6,872 SNP markers was used to analyze the genetic variability among the accessions, using both the Principal Components Analysis (PCA) and the Neighbour Joining clustering method. PCA analysis separated common wheat accessions from durum ones, and allowed to group separately durum landraces from durum elite cultivars. The Neighbour joining clustering validated PCA results, and moreover, separated common wheat landraces from common elite cultivars. The clustering results demonstrated that Italian durum landraces were poorly exploited in modern breeding programs. Combining cluster results with heterozygosity levels observed, it was possible to clarify synonymy and homonymy cases identified for Bianchetta, Risciola, Saragolla, Timilia and Dauno III accessions. The SNP panel was also used to detect the minimum number of markers to discriminate the studied accessions. A set of 33 SNPs were found to be highly informative and used for a molecular barcode, which could be useful for cultivar identification and for the traceability of wheat end-products.