Germination and embryo rescue from Passiflora species seeds post-cryopreservation.

Seeds of Passiflora species have been reported to have intermediate or orthodox storage behavior. The development of cryopreservation protocols for recalcitrant or intermediate seeds can provide a feasible way for long term germplasm conservation. Seed germination of three Passiflora species (P. pinnatistipula, P. tarminiana and P. mollissima) was studied after desiccation and cryopreservation. The three species showed an intermediate response to desiccation: at 3-3.5% water content their germination was reduced to 23-45%, with P. pinnatistipula showing the maximum desiccation tolerance (62% germination after drying to 4.2% water content). The safest seed water contents for cryopreservation: 4.5-4.8% for P. pinnatistipula and P. mollissima, and 9% for P. tarminiana, resulting in 84%, 73%, and 63% germination, respectively. This is the first report of seed cryopreservation for these species.