Donatella Barreca’s research while affiliated with University of Tuscia and other places

Successful germination protocols for the following six dune species are presented: Centaurea sphaerocephala subsp. sphaerocephala, Jacobaea maritima subsp. maritima, Matthiola sinuata, Medicago marina, Pancratium maritimum, and Silene canescens. Seeds were collected in sand dunes along the Tyrrhenian coasts in south Tuscany and north Latium (central Italy). The germination ability was tested at the Tuscia Germplasm Bank (BGT) at six constant temperatures (from 5 to 30°C), under both light (with a 12/12h pho-toperiod) and total dark. Our results show a high germination ability and germination rate for the tested species.

The need to optimize seed banking efforts has stimulated research for rapid methods to estimate quality in seed-lots. For terrestrial orchids, viability testing using tetrazolium (TTC) staining requires chemical scarification, as seeds have an impermeable testa. Different seed-coat permeability may affect TTC staining, thus affecting the results. The aim of this study was to perform a permeability test to assess the effectiveness of the used scarification method and its usefulness to correct TTC viability results. Mature seeds of Anacamptis laxiflora were subjected to eight scarification treatments with sodium hypochlorite solutions with different concentration and duration. Viability tests were performed using the basic tetrazolium (TTC) methodology, followed by a permeability test performed by means of trypan blue dye (TB). The different scarification methods resulted in estimated TTC viability ranging from 0 and 94% for the same seed lot of A. laxiflora seeds. Our results proved that the used scarification protocol significantly affects both seed coat permeability and subsequent TTC staining (2-way ANOVA, p < 0.0001). We describe a new rapid protocol that can be used to test terrestrial orchid seed viability. This double-staining method, providing rapid information on seed coat permeability, can be useful to avoid under-estimation of TTC results. DOWNLOAD: https://www.tandfonline.com/eprint/t3Y9n8xXvRpN8t8vrJPI/full?target=10.1080/11263504.2019.1587541