COTYLEDON STORAGE PROTEINS IN EUROPEAN SWEET CHESTNUT

The storage seed proteins have shown to be a useful tool in the evaluation of the genetic variability in those species where these techniques have been employed. Sweet chestnut (Castanea sativa) is a European species cultivated both for wood and for fruit since ancient times in the Mediterranean region. These uses imply that some stands have seed origin while other ones come from graft. The existence of both reproductive systems together with the marginal use of this species, has complicated the knowledge of its genetic diversity that has been scarcely studied. In this study, the usefulness of the cotyledon storage proteins as marker of the genetic diversity in C. sativa has been analysed. Cotyledon storage proteins were extracted by sequential procedures, where albumins and globulins were obtained separately. The addition of reduction (dithiothreitol) and alkylation (4-vinilpiridine) agents was essential for a clear resolution in the identification of the different bands. Each protein fraction was characterized by electrophoresis in polyacrylamide gels. The evaluated samples were highly polymorphic for the albumins located between the molecular masses 30 and 14 kDa and the adequate gel concentration for the analysis resulted to be 12%. For this reason, we consider that this method of analysis of the nut storage proteins could be an useful tool for the evaluation of genetic diversity in this and other species of Fagaceae.