Cohniella jonesiana (Orchidaceae) seed storage behaviour.

DOLCE, N.R.

Congreso; XXXIII Argentinian meting of Plant Physiology (RAFV2021); 2021

Sociedad Argentina de Fisiología Vegetal

Cohniella jonesiana is a wild orchid with great ornamental value that inhabits in northern Argentina. This species is threatened because of the extensive disturbance of their natural habitat and indiscriminate harvesting of naturally growing plants. Consequently, it is imperative to develop effective preservation strategies for this orchid species. Seed storage has particular application for germplasm conservation of wild endangered and rare species since it allows conservation of diverse genotypes, besides the small storage space requirements due to minute size. In this study, it was examined the storage behaviour of C. jonesiana seeds at different temperatures. Green capsules containing mature seeds were collected 140, 145 and 150 days after hand pollination. Capsules were surface sterilized, opened in a laminar flow hood and then seed samples were removed and stored at 27, 4, -20, and -196ºC up to 36 months. Moisture content (MC) and in vitro germination were determined for fresh seeds from each capsule. Seeds from 140 to 150 days-old capsules (6-7% MC) stored at -196 ºC showed high germinability (85-90 %) even 36 months after collection, revealing no significant differences with fresh seeds. On the other hand, germinability decreased rapidly in seeds stored at 27º or 4ºC (3 months) and more slowly in seeds kept at -20ºC (18 months). Thus, long-term storage of C. jonesiana seeds is feasible by cryopreservation through direct immersion in liquid nitrogen without any previous treatment. This is a key knowledge when facing the genetic diversity preservation of this wild orchid.