(228) In Vitro Rooting of Surinam Cherry

Surinam cherry ( Eugenia uniflora L.) has value as a minor tropical fruit crop and as an ornamental plant in tropical and subtropical regions. In the United States, Surinam cherry is propagated by seed, as stem cuttings do not root. Elite selections are propagated by grafting, but grafts have not had high rates of success. Micropropagation of Surinam cherry has also been mostly unsuccessful. In this trial, 100 seeds from a self-cross of the cultivar Zill Dark were surface-disinfested and placed in vitro in 150 × 25-mm tubes on a medium of deionized water solidified with 8 g/L of agar. Seed cultures were placed on unlighted shelves. After 3 weeks without lights, seed cultures were transferred to lighted shelves where they readily germinated (100%) over the next 7 to 14 days. Seedlings were strongly tap-rooted and the roots quickly reached the bottoms of the tubes. After the 2 weeks under lights, 2 mL of autoclaved, half-strength liquid McCown's Woody Plant Medium (WPM) were added to each tube, creating a two-phase culture environment. Every 4 weeks, another 2 mL of half-strength WPM liquid medium were added to the cultures. Most seedlings elongated and produced three or more stems nodes with leaves after 10 weeks under lights. After this 10-week growth period, several of the seedlings had also produced adventitious roots at the first, second, and third stem nodes. After an additional 4 weeks in culture, 50% of the seedlings (50) had produced adventitious roots at one or more nodes. Additionally, tip cuttings taken from some of the seedlings that did not initially produce adventitious roots, produced roots at nodes when the stems were inserted directly in WPM medium supplemented with 20 g/L sucrose and various auxins.