• Aquilegia
• comparative taxonomy
• high-mountain flora
• plant conservation
• seed dormancy
• Seed morphology

The interpretation of the taxonomic rank of different taxa within the Aquilegia genus in Italy and their taxonomic relationship is controversial. Moreover, the potential application of seed morphology and ecology in taxonomic categorisation has not been explored yet. Therefore, the main aim of this thesis project was to perform a comparative study of seed morphological features and germination adaptations of five related high-mountain Aquilegia species from Northern Italy to investigate their taxonomic relationships. The study species are Aquilegia alpina, A. bertolonii, A. lucensis, A. ophiolithica, and A. reuteri, divided into 11 populations. Seed length, width, thickness, sphericity, mass, embryo to endosperm length ratio (E:S) at dispersal, and four additional categorical variables were explored jointly through a Multiple Factor Analysis (MFA), which highlighted two main species clusters: one composed of A. lucensis and A. alpina, with bigger and heavier seeds; the other grouping together A. bertolonii, with the smallest and lightest seeds, A. ophiolithica, and A. reuteri. Germination experiments comprised fresh seeds (F), warm (W), cold (C), and warm plus cold (W+C) pre-treatments, after which seeds were redistributed to 6 different germination temperatures (5, 10, 15, 20, 25, 30 ºC). Moreover, a “move-along” experiment consisting of seeds periodically shifted to different temperatures was performed, accompanied by seed sections to monitor embryo growth over time. Since no germination had occurred for nine months, in the last month of experiments a part of the seeds in each pre-treatment and in the move-along was subjected to alternated temperatures to test their effect. Germination was low and occurred only at temperatures ≥ 20 ºC, which led to a reduction of the experimental conditions to 5 couples of treatments (1 couple each pre-treatment+1 for the move-along), each divided into one ending at fixed and the other at alternated temperatures. Alternated temperatures generally promoted germination and resulted being essential to A. ophiolithica and A. reuteri. In general, warm treatments were the most effective ones to induce germination. The only species germinating after the move-along were A. bertolonii, A. ophiolithica, and A. reuteri, although A. bertolonii germinating only at fixed temperatures. A Principal Component Analysis (PCA) was also performed on germination data, and its results partially traced the clusters identified in the morphological analyses, although in this case A. ophiolithica and A. reuteri seemed to diverge more from A. bertolonii.