Genetic and Morpho-Agronomic Characterization of Sicilian Tetraploid Wheat Germplasm

Cereal landraces are a very valuable resource in contemporary agriculture. A renewed focus for breeding purposes could ameliorate some negative consequences of modern agriculture and conventional breeding, such as the loss of genetic diversity. One strategy combining molecular genotyping and characterization of morpho-agronomic traits related to productivity is proposed to assess a group of tetraploid wheat landraces named Bufala, historically cultivated in the mountain areas of Sicily and characterized by adaptability in terms of cold tolerance, ability to grow in marginal soils, weed competitiveness and resistance to diseases. A total of 55 SSR molecular markers were used to detect patterns of diversity in 30 rivet and durum wheat genotypes. Furthermore, phenotyping was then conducted for 8 morpho-agronomic traits. Discriminant analysis of principal components (DAPC), STRUCTURE and phylogenetical analysis allowed to identify three groups, two of them genetically close and including both Bufala and Bufala-related rivet landraces. To the third group, old and more recent durum wheat varieties, constituting the outgroup, were assigned. Clustering was confirmed by Principal Component Analysis (PCA). Finally, a correlation analysis showed that Bufala genotypes are characterized by lower ear density, major ear length and later earing time compared with the other studied genotypes. The levels of diversity and population structure could be an important contribution to parent selection in tetraploid wheat breeding programs, as well as to germplasm conservation and management.