Validation by SSRs of Morphometric Markers for Genetic Variability in Araucaria araucana (Molina) K. Koch

MDPI Open Access Journals search menu Journals Forests Volume 14 Issue 3 10.3390/f14030466 settingsOrder Article Reprints Open AccessArticle Validation by SSRs of Morphometric Markers for Genetic Variability in Araucaria araucana (Molina) K. Koch by Stefania Nin 1,*ORCID,Maurizio Antonetti 1ORCID,Gianluca Burchi 1,Massimo Gori 2,3ORCID andLorenzo Bini 2ORCID 1 CREA Research Centre for Vegetable and Ornamental Crops, Via dei Fiori 8, 51017 Pescia, PT, Italy 2 Department of Agriculture, Food, Environment, and Forestry (DAGRI), University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, FI, Italy 3 Interdepartmental Service Centre for Agricultural Chemical and Industrial Biotechnologies (CIBIACI), University of Florence, Via Romana 21, 50125 Florence, FI, Italy * Author to whom correspondence should be addressed. Forests 2023, 14(3), 466; https://doi.org/10.3390/f14030466 Received: 19 January 2023 / Revised: 16 February 2023 / Accepted: 21 February 2023 / Published: 24 February 2023 (This article belongs to the Section Genetics and Molecular Biology) Download Browse Figures Versions Notes Abstract Araucaria araucana is an important seed and timber-yielding tree that grows naturally in the tropical and subtropical regions of the Andes in Argentina and Chile, and has also been introduced as an ornamental species in Europe. Genetic diversity has been observed in A. araucana native populations, but there have been no prior studies on the genetic diversity estimates of this species introduced in Europe. On the other hand, assessment of the genetic variation in Araucaria populations occurring in Europe might be an important tool in the selection of appropriate germplasms for ornamental nursery production and breeding strategies. In this study, morphological and genetic diversity was analysed using a previously defined descriptor list and SSR molecular markers in four putative populations of A. araucana, individuated in the Pistoia Nursery District (Tuscany, Italy). In total, 26 morphological descriptors and 28 SSR primer pairs were used for a diversity assessment of specimens. Results provide evidence for genetic and morphological correspondence among the four putative Araucaria populations. PCA and cluster analyses based on morphological traits clearly revealed three distinct clusters of specimens. SSR primers yielded 68% polymorphic loci among the considered populations, and 18 of them displayed informativeness for population genetics, according to a Polymorphic Information Content value larger than 0.25. This marker set revealed significant genetic differentiation, and UPGMA analysis enabled separation of these populations on the basis of their genetic distances into three main groups, which largely overlapped with clusters in the dendrogram obtained from the morphological data. In particular, in both cluster diagrams, all accessions belonging to a specific population were well separated from all the others due to matrix distances and differences in the canopy density that are more similar to conifers such as spruce, pine, or fir. ANOVA analysis and the FST value indicated a large between-population genetic variation. The Mantel test suggested that genetic differentiation between the four studied populations was positively correlated with morphological distance (r = 0.141, p < 0.05). Thus, both morphological and genetic markers showed applicability across populations of different seed origins and proved suitable for the identification and characterization of A. araucana accessions.