Anatomical and histochemical characterization of seeds of Cattleya intermedia subjected to different storage conditions

Abstract

Abstract Studies involving morphological and anatomical changes resulting from seed storage are rare, but relevant to ensure information related to the quality of seeds and seedlings originated from these seeds. The objectives of this work as to carry out the anatomical and histochemical characterization of seeds from the Cattleya intermedia orchid, verifying the occurrence of possible alterations coming from different temperatures and storage periods. The treatments consisted of temperatures of: 25 (± 2 °C) (room), -20 °C (freezer), -80 °C (ultra freezer) and - 196 °C (cryopreservation); and storage periods: two, four and six months. For the anatomical and histochemical analyses, scanning electron microscopy and light microscopy were performed. The following stains were employed: toluidine blue (TBO), Coomassie brilliant blue (CBB), Sudan IV and periodic acid-Schiff (PAS). The dehydration observed in the seeds was considered the main damage resulting from storage. Changes in the internal structures of the seeds were also noted, such as degeneration, mainly in seeds kept at room temperature 25 (± 2 °C), which caused a reduction in the main components of reserves. The -80 °C (ultra freezer) temperature during the two and four months period was efficient in the conservation seed of the tissues and cells, confirming the possibility of using this condition for better conservation of the seeds of this species.