Vol 117 (2004): Proceedings of the Florida State Horticultural Society

Meristem-tip culture boosts yield of sweetpotato cv. Picadita in South Florida

David Q. Ying
Coral Reef Senior High School
Zhentu Ying
University of Florida
Published December 1, 2004
  • Ipomoea batatas,
  • explant size,
  • plant vigor,
  • tuberous roots


Picadita is the most important cultivar of sweetpotato [Ipomoea batatas (L.) Lam] grown in Miami-Dade County, Florida. Originally introduced from Cuba, it has never been "cleaned-up" by meristem-tip culture, a practice widely used to remove yield-limiting pathogens from sweetpotato cuttings. Meristem-tip culture was investigated as a means to increase the yield of this cultivar. Based on the size of the initial explants used, three groups of lines were developed and designated AD+1 (the apical dome plus one leaf primordium at 200 µm in length), AD+2 (apical dome plus two leaf primordia at 200 to 400 µm), and AD+3 (apical dome plus three leaf primordial at 500 to 1000 µm). Cultures required about 5 months from initiation to distribution of field-ready cuttings. The smaller the explants, the lower the survival rate. Only 8.5% of the AD+1 explants developed into in vitro plantlets whereas 64.4% of the AD+3 explants successfully developed. Total yields of the AD+1, AD+2 and AD+3 groups were increased by 146.7%, 105.5% and 46.5%, respectively, when compared with non-cultured control plants from the adjacent commercial field (control-F) in the first season. Cuttings were taken from the first season AD+1 group and planted for the second season. In the second season, the total yield of these plants was 116.2% greater than that of control-F plants. The chlorophyll content, leaf area, number of leaves, base diameter of vine, and number of lateral vines of these plants were significantly greater than those of control-F. We concluded that meristem-tip culture of the AD+1 explants significantly boosted the yield by reviving the plants to produce larger tuberous roots, presumably through efficient removal of the yield-reducing pathogens from 'Picadita'.