If you want to make an omelette: using cutting tests to estimate viability in Ziziphus celata (Rhamnaceae)

Philip Gonsiska,Bok Tower Gardens

Ziziphus celata is an endangered shrub endemic to Polk and Highlands Counties in central Florida. Germination in this species has generally been very low, and previous observations have suggested that upwards of 75% of seeds set by Z. celata may not be viable. In January 2019, cutting tests were conducted to estimate the viability of Z. celata seeds harvested in summer 2018. Dissected seeds were categorized as “normal”, empty, moldy, “spongy”, and those having shrunken embryos. Those in the “normal” category were thought to be viable. Of the 103 seeds dissected, 36 (34.95%) appeared “normal”, 35 (33.98%) were empty, 24 (23.3%) were moldy, six (5.83%) had shrunken embryos, and two (1.94%) were “spongy”. In earlier work, soaking seeds in a 0.1% liquid smoke solution resulted in a germination rate of 26.7%, which thus far is the highest germination rate in our data set from any experimental seed treatment applied to Z. celata. Therefore, seeds from 2018 were soaked in either a 0.1% liquid smoke solution or reverse osmosis water for 24 or 48 hours. They were then sown in 72-cell trays along with unsoaked control seeds. These trays will be monitored for germination for six months, and the realized germination rate will be compared to the hypothetical percentage of viable seeds from the cutting tests. Preliminary results of this experiment will be presented.