Seed cryopreservation is a suitable storage procedure for a range of Piper species

Seed germination of six wild collections of Piper species viz., P. mullesua, P. attenuatum, P. argyrophyllum, P. trichostachyon, P. galeatum and P. nigrum and three cultivars of P. nigrum viz., Karimunda, Panniyoor-I and Kottanadan was studied after storage in liquid nitrogen (LN) for one week. The seeds extracted from ripened fruits weighed 2.5-123.2mg/seed and contained 26.1-39% moisture. After desiccation to 10.2-13.9% moisture, the wild species exhibited 60-87.3% germination which was unaffected by one week storage in LN. Seeds of the three P. nigrum cultivars desiccated to 13% moisture content (m.c.) showed 60-73.3% germination rate after cryopreservation comparable to that of desiccation control. Piper seeds in general performed best at m.c. (~13%) equilibrated to ambient conditions (25±5°C and 65% RH) for maximum survival after desiccation and LN exposure. The study proves seed cryopreservation as an effective method for the germplasm conservation of a range of Piper species.