Exploration of the Genetic Diversity of Solina Wheat and Its Implication for Grain Quality

Abstract

Different Solina wheat accessions (n = 24) collected in the Abruzzo region (Italy) were studied using 45,000 SNP markers generated from the DarTseq platform. The structure of genetic data was analyzed by Principal Component Analysis and Hierarchical Cluster analysis that revealed the existence of two main clusters (Clu1 and Clu2) characterized by samples with different geographical origin. The Solina genetic dataset was further merged and analyzed with a public genetic one provided by CIMMYT containing 25,963 genotypes from all over the world. The Solina accessions occupied a vast space, thus confirming a high heterogeneity of this landrace that, nevertheless, is considerably unique and placed quite far from other clusters. Clu1 and Clu2 divergence were clearly visible. Solina clusters were genetically closer to landraces from Turkey and the central fertile crescent than to the Italian genotypes present in the dataset. Selected commercial quality traits of accessions of the two Solina clusters were analyzed (yield, thousand kernel weight, test weight, and protein content), and significant differences were found between clusters. The results of this investigation did not highlight any relationships of Solina with Italian genotypes, and confirmed its wide genetic diversity by permitting to identify two genetic groups with distinct origin and quality traits.

Long-Term In Situ Conservation Drove Microevolution of Solina d’Abruzzo Wheat on Adaptive, Agronomic and Qualitative Traits

“…High variability was present for this trait among early spring sown plants ( Table 1 ): the blue Solina accessions had 18.5 g TKW, whereas the red ones had 0.91 g TKW. It is noteworthy that Solina 21, considered an outlier between the red and blue clusters according to De Flaviis et al [ 5 ], in the February sowing resulted phenotypically closer to red accessions than to blue ones for the characters measured ( Figure 2 C). The joint analyses of relative ranks for the sowing dates with heading plants resulted in a significant population x sowing date interaction and a significant ( p < 0.001) between cluster difference.…”

“…In autumn sowing, all accessions reached the heading stage after 162–164 days, whereas no accession flowered when sown in late spring sowing (4 June), as shown in Figure 2 A, in which the Solina accessions belonging to the two major clusters distinguished by De Flaviis et al [ 5 ] are indicated with red and blue bars. According to the statistical analysis reported in Table 1 , there were no significant differences in the heading date between accessions for November sowing, when the accessions of the red cluster headed slightly later (1.4 days) than the blue cluster.…”

“…In the sample set obtained with the in-situ experiment ( Table 5 and Table 6 ), the blue cluster, which in a previous study resulted in higher protein content [ 5 ], was the one with the highest kernel width (3.22 vs. 3.06 mm) and lowest thickness (3.14 vs. 3.23 mm), as well as the lowest kernel elongation (2.21 vs. 2.32).…”

“…The genetic differentiation between the “red” and “blue” Solina genetic groups was evaluated by F st using previously developed DArTseq data [ 5 ]. F st values were calculated for each marker individually and plotted according to their genomic position ( Figure 7 ).…”

“…In the work of Khan et al, the characterization of genetic diversity within Solina was accomplished using a small number of single nucleotide polymorphism (SNP) markers and a small number of samples [ 4 ]. In a deeper study by De Flaviis et al, a high number of SNP markers were used to evaluate genetic diversity in a panel of Solina samples collected in different Abruzzo farms and located in different areas [ 5 ]. The clustering analysis based on these datasets has clearly outlined the existence of two major clusters ( Figure 1 ).…”