Rhynchospora fusca is a pioneer amphiatlantic species of acid peatlands which has in the Iberian Peninsula a southern distributioin limit, specifically in the Atlantic valleys and transition mountains of the Cantabrian Coast. Currently only 3 populations are known throughout the Iberian Peninsula, and therefore the taxon is placed in the category of Critically Endangered in both the autonomous level (CAPV, Navarra and Asturias) and state level (Spain).The most relevant populations is found in Izki (CAPV) in which different conservation measures have been carried out in the past years: population monitoring, germplasm collection and conservation, germination test, production of new individuals and population reinforcements. Until now, the germination rates obtained were very low compromising the effectiveness of some conservation actions. In this study, we compared several germination protocols with the objective of increasing the germination rate of R. fusca and reducing the germination time. We carried out six protocols with different periods of cold stratification from 2 to 12 weeks. Each protocol consisted of three cycles of stratification (6°C) of the corresponding length followed each cold cycle by a germination period of 28 days (30/20°C and photoperiod 12/12h). Preliminary results indicate, first, that the longer the stratification time is, the higher the germination rate will be; and, second, the results highlight the need to perform protocols with even longer cold stratification periods, until reaching the maximum germination rate (despite that extends the duration of the protocol) or the trade-off between time and germination rate.

Garcia-del Bao, Ana Irene, Otamendi, Maddi, Etxeberria-Okariz, Mikel, Tejero, Pablo, Arrieta, Maialen, 2024. Stratification length, the key to breaking deep dormancy of Rhynchospora fusca (L.) W.T. Aiton. XX International Botanical Congress 2024 [Póster]. https://doi.org/10.13140/RG.2.2.35272.53766