Seed germination and conservation of endangered species from the Italian Alps: Physoplexis comosa and Primula glaucescens

Physoplexis comosa and Primula glaucescens, endemic to calcareous grasslands of the Lombardy Prealps, northern Italy, are protected under Annex IV of European Community Directive 92/43/EEC. Seed germination dynamics of these species were studied with the aim of producing appropriate germination protocols for use in ex situ conservation. Seeds were collected from Monte Barro (922 m a.s.l.) and for Primula glaucescens from three additional sites in a more central part of its range (1217–2521 m a.s.l.). Physoplexis comosa germinated only in sterile in vitro conditions, in which germination percentages were extremely low without a supply of gibberellic acid (GA3; 1.7%); the optimum GA3 concentration was 100 mg l−1 (> 90% germination), with lower germination at higher doses of 250–500 mg l−1. Primula glaucescens germinated in both sterile and non-sterile conditions and, although total germination was not affected by GA3 concentration, doses of 10–500 mg l−1 acted equally to prompt earlier and more rapid germination. Primula glaucescens from Monte Barro was characterised by slower and poorer germination than from central sites.