An efficient method for economic micropropagation of three aquatic plant species ( Lobelia cardinalis , Staurogyne repens , and Alternanthera reineckii )

Nowadays use of aquatic plants for aquarium ornamentation as well as maintaining water quality is getting increasing interest. To fulfil the ever-growing demand in these areas, there is a need for non-conventional methods of massive and cost-effective clonal propagation of such plants. The present work was carried out with the purpose to set up a commercial in vitro micropropagation for three aquatic plant species ( Lobelia cardinalis , Staurogyne repens , and Alternanthera reineckii ). The explants were successfully surface sterilized and cultured in the solid Murashige and Skoog culture medium supplemented with 30 g L −1 sucrose, 5 g L −1 agar, and different combinations and concentrations of plant growth regulators (kinetin: 1, 2, and 3 mg L −1 and Indole-3-acetic acid [IAA]: 0, 0.2, and 0.5 mg L −1 ). Moreover, the effects of different explant types (shoot tip and nodal segments) were investigated on the multiplication rate as well as growth-related parameters such as plant length, number of roots, and root length. According to our results, the nodal explants were superior to shoot tip for micro shoot induction and leaflet production in three aquatic species. Both shoot and root induction were successfully achieved in the same medium, resulting in the plantlet regeneration through a single-step protocol without the need to further costly and time-consuming sub-culturing activities. Although the MS medium containing 2 mg L −1 kinetin gave the highest proliferation rate in three aquatic plants, however, there were some differences in response of each species to the IAA levels, highlighting the importance of specific behavior of each species. In general, enrichment of culture media with trace amount of IAA (0.2 and 0.5 mg L −1 ) significantly improved the proliferation rate and subsequent plantlet regeneration. The hardening and acclimatization of in vitro raised plantlets were successfully undertaken with 100% survival rate in water containing culture trays under maintaining of overwater relative humidity of 85% in greenhouse conditions. Altogether, the procedure presented here has great commercialization potential for rapid and large-scale micropropagation of these aquatic species especially in aquarium industries.