In vitro Propagation of Red Lotus (Nelumbo nucifera Gaertn) - An Aquatic Edible Plant in Vietnam

Background: Lotus is an important aquatic plant with great economic value, not only as an ornamental flower but also as a source of herbal medicine. In general, lotus is usually propagated through the rhizome or tuber but the normal propagation rate is very low and it often depends on the quality of water environment and the weather conditions where it is grown. Lotus propagation by tissue culture has many predominant advantages compared with the traditional propagation methods. The current study aims to study the in vitro propagation of Hue’s Red Lotus, a famous local lotus in Hue city, Vietnam. Methods: Fresh mature seeds of Red lotus (23 to 25 days old) were used as initial materials for in vitro propagation. Experiments are carried out to assess sterilization ability by HgCl2, 0.1% and determine the appropriate formula for shoot regeneration, multiple shoot clumps induction, root induction of multiple shoot clumps and acclimatization. Result: The optimum formula for seeds of Vinh Thanh Red Lotus is to sterilize surface of seeds by 70% ethanol for 30 seconds and then HgCl2 0.1% for 16 minutes. The samples were cultured on MS (Murashige Skoog) medium supplemented without plant growth regulators for in vitro shoot regeneration. MS medium added with 0.5 mg/L BAP gave the highest multiplication rate (5.60 shoots per explant) and good quality shoots. Adding 0.5 mg/L NAA in rooting medium provided the highest rooting effect and good root quality (18.17 roots/shoot clumps). The survival rate of transplanting plants was 40% on mud medium which were soaked for one week in 2g/L KMnO4 after two weeks in the greenhouse.