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A methodology for characterizing vegetal taxonomic groups using microextraction-assisted voltammetry of microparticles is described. It is based on recording the voltammetric response of microparticulate films of polyphenolic compounds of leaf extracts using different organic solvents. As a result, characteristic voltammetric profiles, tentatively defining an electrochemolomic response, are obtained. Bivariant and multivariant chemometric evaluation of the voltammetric responses of such films allows characterizing vegetal families. Analysis of voltammetric responses for a set of species of the Rosales order suggests that electrochemical data can be correlated with phylogenetic trees.

The influence of seed testa color, temperature and seed water content on dormancy release and seed viability loss in the endangered, endemic species Silene diclinis (Lag.) M. Laínz was evaluated. Dormant heterogeneous seeds (black, red and grey colored) were exposed to three different temperatures (5, 20, and 35°C) and two relative humidities (33 and 60%) in order to assay their dormancy release. Longevity behavior was studied for the three colored seeds, storing samples at nine different combinations of temperature (5, 20 and 35°C) and relative humidities (33, 60 and 90%). According to our findings, seed heteromorphism was not related to neither break of dormancy nor seed storage behavior. Silene diclinis seeds present dormancy after collection, and need an after-ripening period to germinate. Temperature and relative humidity are positively correlated with dormancy release and seed ageing. Therefore, both factors must be carefully controlled during seed manipulation in the laboratory for long term seed conservation purposes. When seeds are stored immediately after collection (dormant), if the temperature of storage is above the base temperature for dormancy release found in this work (between 2.7 and 1.6°C), seeds may eventually overcome dormancy. On the other hand if seeds are stored after an afterripening period, storage at low temperature does not induce secondary dormancy.

Spore longevity is comparable to orthodox seed longevity under ambient storage conditions, with wide variation among species and shelflife extended by drying or cooling. However, faster aging during freezer storage may indicate a similar syndrome of damage experienced by seeds categorized as "intermediate". The damage is avoided by storage at -80°C or liquid nitrogen temperatures, making cryoconservation an effective and broadly applicable tool to extend fern spore longevity. The study demonstrates that spore banks are a feasible approach for ex situ conservation of this important plant group.

1IntroductionIntersection of electrochemistryw ith vegetal matterh as av ariety of aspects.A part from the electrochemical determinationo fb ioactivec ompounds [1],c ontaminants [2,3] and antioxidant capacities [4][5][6][7],r ecognizing growth conditions and type of plants [8] and varietal discrimination of fruits [9] and leaves [10] have been reported. Conversely,v egetal matter can be used for electrode modification [11],e lectrochemical sensing [12,13] and as as upport for electrode modification [ 14,15].Electrochemical methods have as ignificant place in biological and environmentala nalyses. Much of electroanalytical methodsa re devotedt ot he determination of selected natural products in biological samples.T hese approaches,b ased on solution-phase electrochemistry, involve different types of modifiede lectrodes in order to achieve the levelso fs ensitivity and selectivity demanded by the individual analytest ob ed etermined in the presence of complex biological matrices [16][17][18][19].Itispossible, however, aiming av ariety of analytical targets which are based on the recordo ft he global electrochemicalr esponse of biological systems without determination of individual analytes [20,21].I nt his context, we have recently described the application of the voltammetry of immobilized particles (VIMP),asolid state electrochemical technique developed by Scholz et al. whichp rovidesa nalytical data on sparingly soluble solids [22][23][24],f or acquiring phylogenetici nformationb ased on the record of the "electrochemical fingerprint"d ue to the electroactive compounds existing in plantl eaves [20][21].H ere,w e presenta ne xpansiono ft his electrochemolomic approach focused on two objectives:i )r ecognition of the presence of characteristic voltammetric fingerprints at different taxonomic levels (family,g enus,s pecies), and ii) testing the possibility of discriminating different genetic linesw ithin different species of the same genus,i nb oth cases using the voltammetric response of seed extracts. Them ain objective was to test the hypothesis that the chemical composition of seed extracts should be less sensitive to local environmental factors and hence much more representative of geneticd ifferences,t han that of leaf extractsp reviously studied [20,21],i no rder to apply electrochemical data in phylogenetic studies.Molecularp hylogenyp lays an essential role in contemporary botany.P hylogenetic trees,t raditionally basedo n morphological/functional features,a re mainly derived fromg enetica nalysis mostly based in the identificationo f nucleotide sequences of nuclear and chloroplast regions [25].I ns everalc ases,c himeric nucleotide sequences are obtained so that discrepancies between molecular and morphological/functional classifications appear [26][27][28][29].Abstract:Am ethodology for characterizing vegetal taxonomic groupsf rom the voltammetric fingerprintso fp olyphenolic components of seeds is described. It is based on recording the voltammetric response of microparticulate films depositedo ng lassy...