Micropropagation and sea-based nursery growth of selected commercial Kappaphycus species in Penang, Malaysia

The increasing demands for seaweeds have promoted the designation of the seaweed industry as the third Entry Point Project (EPP) under the National Key Economic Area (NKEA) initiative of the Economic Transformation Programme (ETP) of the Malaysian government. The farming of carrageenophytes has emerged as a successful enterprise and provides a promising alternative livelihood option for low-income coastal communities in several countries. However, over time, the productivity of the red seaweed crop has declined in some regions due to sourcing of seedlings from single, selected genetic stocks considered to have initially higher yield potential but which resulted in strain fatigue or loss of vigour. To circumvent the crop productivity issues arising from clonal propagation, the raising of planting materials from the development and successful micro-propagation of Kappaphycus has been initiated in order to support the sustainability of selected, farmed carrageenophytes. Three species of Kappaphycus (K. alvarezii (to include 2 strains-brown and green) K. malesianus (aring-aring) and K. striatus) were used in the present study to optimize the use of Ascophyllum Marine Plant Extract Powder (AMPEP K+) which had previously been demonstrated to be effective as a culture medium ingredient, acting as a biostimulant, when applied with the addition of terrestrial plant growth regulators (PGRs). The optimum combination of 3 mg L-1 AMPEP K+ + PGRs was used in out-planting the microplantlets to a sea-based nursery. Salinity and turbidity were found to be positively correlated with growth rates in open water. The use of the brown seaweed-derived extract acting as a biostimulant and as the main ingredient of the cost-effective culture medium for the micro-propagation for all four strains of Kappaphycus tested was highly encouraging, so much so that the treatment has the potential to be promoted as a generic protocol for the economic and commercial mass production of new plantlets (asexual seedlings) which are urgently required for Malaysian seaweed farming to meet its fullest potential.