Abstract

Fagopyrum dibotrys (D. Don) Hara is an important plant species of medicinal value. An efficient protocol for in vitro propagation of an F. dibotrys mutant that contains a higher level of (-)-epicatechin was developed. Adventitious buds were directly regenerated from stem nodal explants cultured in Murashige-Skoog (MS) basal medium containing 3% sucrose and appropriate combinations of plant growth regulators. In the presence of 2.0 mg/l 6-benzylaminopurine (6-BA), 0.5 mg /l thidiazuron (N-phenyl-N’-1,2,3-thidiazol-5-urea) (TDZ), and 0.2 mg/l naphthaleneacetic acid (NAA), the frequency of organogenesis was 90%, with a mean of 9.09 shoots per explants. The greatest rooting frequency, root number and length were attained using 1/2 MS medium containing 0.5 mg/l NAA and 2% sucrose. After two years of in vitro propagation and conservation, the regenerating plantlets were successfully transplanted into the field, and none showed morphological variations after one year of field growth. The regenerated rhizomes were assessed for drug-yielding potential through evaluation of (-)-epicatechin contents by HPLC, and then compared with those grown conventionally. The genetic basis of the stable drug yielding potential of the micro-propagated perennial buckwheat was revealed by random amplified polymorphic DNA-based profiling.

Key words: Fagopyrum dibotrys, Shoot organogenesis, (-)-Epicatechin content, High performance Liquid Chromatography (HPLC), RAPD analysis.

Abbreviation

gspbw, green stem perennial buckwheat wild type; rspbm, red-stem perennial buckwheat mutant; TP, Tissue-Cultured plants; CP, Conventionally Propagated (cutting reproduction) plants