Germinação in vitro e criopreservação de sementes de Paineira-Rosa

Abstract

The paineira-rosa (Chorisia speciosa St. Hil) is an arboreal species of great importance in restoring degraded ecosystems and riparian forests, however, the availability of seeds of this species is low. The objective was to establish in vitro germination protocols and cryopreservation of paineira-rosa seeds. For the in vitro germination, MS culture medium and WPM was tested three concentrations of sucrose (0, 15, 30 g L -1) and three pH levels (4.8, 5.8 and 6.8). For cryopreservation, the seeds were dried on silica gel or laminar flow for different times (0, 1, 2, 3 and 4 h) and then were stored in liquid nitrog en (-196 °C) for 24 h, defrosted in a water bath (38 °C) for four minutes and they were inserted into test tubes containing WPM medium cultivation. The paineira-rosa seeds showed germination when inoculated in WPM (84%). The concentration of 15 g L-1 sucrose and the pH adjusted to 5.8, favored seed germination with 79% and 82% , respectively. The initial water content rose from paineira-rosa seeds was 14%. After 4 h of dehydration on silica gel or laminar flow, the water content was 7.8% and 6.8%, respectively. There was no significant loss of viability of seeds subjected to 4 h of drying in laminar flow (6 3.33%). The results obtained in this study indicate that the in vitro germination and kapok pink seed cryopreservation can be successfull y obtained.