Organogenesis and efficient in vitro plantlet regeneration from nodal segments of an ornamental aquatic plant, Lobelia cardinalis L., using BAP

Abstract

Aquatic plants show a high diversity of plant species in the world. Aquatic plants are grown in aquaria for their beauty and to maintain the quality of water. High demand for aquatic plants mainly from the developed countries has created an aquatic plant industry in both developed and developing countries. The effect of 6-benzylamino-purine (BAP) has been investigated in shoot multiplication for a simple, efficient, rapid, and commercially applicable regeneration protocol of an important ornamental aquatic plant, Lobelia cardinalis L. Multiple shoots were induced in nodal segments obtained from young plantlets on Murashige and Skoog (MS) medium containing cytokinins in various concentrations (BAP; 0.5, 1.0, 2.0, or 3.0 mg L-1 and kinetin; 0.5, 1.0, 2.0, or 3.0 mg L-1). The highest shoot proliferation (100%) and maximum number (7.20±0.12) of shoots explant-1 with shoot length of (8.96±0.10 mm) and maximum number (56.40±0.97) of leaves explant-1 was recorded on MS medium supplemented with 1.0 mg L-1 BAP after 45 days of culture. The highest rooting in the micro shoots (3 cm) was achieved on full strength MS medium supplemented with 0.5 mg L-1 α-naphthaleneacetic acid (NAA) which produced 28.00±0.46 mean roots shoot-1 with 18.69±0.10 mm mean root length. Regenerated plantlets were subsequently hardened, acclimatized, and successfully established in aquariums after 30 days of transfer to the greenhouse with 100% survival rate. The present in vitro propagation protocol would facilitate an alternative method for rapid and large-scale production of this important ornamental aquatic plant.