Zygotic embryos rescue for ex situ conservation of the palm Butia noblickii

APARICIO, G.; HOPECHEK, L.; BUSTAMANTE, K.; KESNEL QUIEFL, S.; PIZZINI, C. S.; THALMAYR, P.; GIOMBINI, M.; GATTI, M. G.; NIELLA, F.; ROCHA, P.

Cincinnati

Simposio; Virtual Global Symposium and Workshop, Conserving Exceptional Plants: Cryobiotechnology and the Model of Oaks; 2021

Cincinnati Zoo & Botanical Garden

Butianoblickii , commonly known as Bonpland's palm, is a speciesendemic to the southeast of the province of Corrientes (Argentina) and has beendescribed very recently. Its spatial distribution is notably fragmented, with anincreasing risk of population patches becoming isolated due to humantransformation of the landscape. According to IUCN (2010) criteria, its currentconservation status should be categorized as endangered. The pronounceddormancy that delays the germination of seeds of the genus Butia,represents a limitation for natural regeneration. To generate a methodology forin vitro germination of zygotic embryos for subsequent encapsulation in sodiumalginate, dehydration, and cryopreservation, we performed in vitro embryoculture assays under controlled laboratory conditions.A random sample of 40 seeds ofB. noblickii, obtained from mature fruits, was disinfected with ethanoland bleach, and their embryos were mechanically extracted under magnifyingglass. The embryos were cultured in vitro, in Murashige and Skoog nutrientmedium, in dark conditions and at an average temperature of 30 02º C. A controlex vitro treatment of whole seed, sown in plastic containers with sand, at roomtemperature, was developed.About 2 weeks of in vitroculture, 45% of the embryos were germinated as inferred from thickening andelongation of their cotyledonary petioles. After 6 months, the seedlingscontinued their normal development, with the formation of leaf sheaths androots. In ex vitro conditions, the germination capacity was 2%, requiring atleast 3 to 12 months to germinate.Results suggest that the exposure of the embryoto in vitro culture conditions allowed to accelerate the germination of B.noblickii (45% of germination in less than 1 month) and the normal developmentof seedlings. Implying a greater development, in less time, compared to exvitro germinated seedlings. These constitute the first step towards generatinga long term ex situ conservation protocol by encapsulation and cryopreservationof zygotic embryos.