Effects of plant growth regulators on in vitro seed germination and seedling development of Enhalus acoroides, a tropical seagrass

Abstract

The effects of plant growth regulators (PGRs) on seed germination and seedling development of Enhalus acoroides were investigated under axenic conditions. Seeds were cultured in sterile liquid medium supplemented with different concentrations of 6-benzyladenine (BA) × α-naphthylacetic acid (NAA) and N-phenyl-N’-(1,2,3-thidiazol-5-yl) urea (TDZ) × 2,4-dichlorophenoxyacetic acid (2,4-D). All seeds fully germinated (100% germination rates) within 1 d on liquid media without PGRs, while germination of seeds in liquid media supplemented with PGRs was delayed with 94–100% germination within 2–7 d. Embryogenic callus was obtained after 2 wk when cultured in liquid medium supplemented with 18 μM BA and 160 μM NAA. The addition of TDZ and 2,4-D inhibited root emergence. The results showed a significant effect of the culture medium on seedling development, but not on seed germination.