Ana María Ibars

Dormancy release and seed ageing in the endangered species Silene diclinis

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 after-ripening period, storage at low temperature does not induce secondary dormancy.

Electrochemistry-based chemotaxonomy in plants using the voltammetry of microparticles methodology

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.

Situación de las poblaciones valencianas del género Marsilea: medidas para su conservación

ESTRELLES, E., IBARS, A. M. & HERRERO-BORGONON, J. J. 2001. Situation of the Valencian populations of Marsilea: strategies for its conservation. Bot. Complutensis 25: 241-249. The situation of Valencian populations of Marsilea batardae, M. quadrifolia and M. strigosa, as well as the threats that they suffer at present are analysed here. Likewise the measures applied to ensure their conservation, with emphasis on the experimental introductions, are commented.

La sección Rhamnastrum Rouy (Rhamnus, Rhamnaceae) en el norte de la Península Ibérica

Martinez-Solis, I., Iranzo, J., Corbia, J.T., Estrelles, E. & Ibars, A.M. La seccion Rhamnastrum Rouy (Rhamnas, Rhamnaceae) en el norte de la Peninsula Iberica. Lazaroa 19:9-16 (1998). Se presenta un estudio anatomico y morfologico de los taxones pertenecientes a la seccion Rhamnastrum Rouy presentes en el norte de la Peninsula Iberica. Los datos obtenidos se tratan estadisticamente mediante la utilizacion de tecnicas de clasificacion y se concluye que pueden reconocerse tres especies (Rhamnus alpina L., Rhamnus legionensis Rothm. y Rhamnus pumila Turra).