Regeneration of the aquatic monocot Aponogeton madagascariensis (lace plant) through callus induction

Abstract

The lace plant ( Aponogeton madagascariensis) is an aquatic monocot native to Madagascar that forms perforated leaves via developmentally regulated programmed cell death (PCD). Although a technique for culturing the lace plant under axenic conditions through corm separation has been developed, it is less productive for mass propagation of this species. Thus, an alternative method was investigated using 27 plant growth regulator (PGR) combinations to induce callus and subsequent whole plant regeneration. Combinations of the auxin picloram and the cytokinin thidiazuron (TDZ) successfully induced callus in corm sections, but no shoot regeneration was observed. Successful results for both callus induction and shoot regeneration were achieved using immature inflorescences with the PGR combination of 2 mg/L of the cytokinin 6-benzyaminopurine (BAP) and 2 mg/L of the auxin 1-napthaleneacetic acid (NAA) under light conditions, resulting in the regeneration of over 70 plants. The protocol shows both reproducibility and consistency in results; therefore, it is concluded that a technique for mass propagation of the lace plant through callus has been established. This technique may be useful in the study of other aquatic plant species, as well as in the study of developmental PCD in the lace plant itself.