Developing a modified technique to assess desiccation tolerance in leaf tissue.

Desiccation-tolerant “resurrection” plants can lose nearly all available water and subsequently recover upon rehydration. As remarkable as this trait may seem, desiccation tolerance (DT) is still being discovered and quantified in many plants. Previous studies have developed a field portable technique for quantifying DT in leaf tissue (the “Falcon tube method”; Lopez-Pozo et al., 2019). However, we found that the published protocol needed adjustment to accurately quantify DT in some fern species. In this study, we have developed a modified Falcon tube method, with several novel components. 1) We lengthened the drying time from two days to six days, because two days was insufficient time for the fern leaves to fully desiccate. 2) We lengthened the rehydration time from one day to three days, because one day was insufficient time for the fern leaves to fully resurrect. 3) We added a hydrated control treatment, to demonstrate that the duration of the entire experiment was not so long as to allow natural senescence of excised leaves. We plan to use this modified protocol to broadly assess fern desiccation tolerance across several fern lineages.