Explant priming with bio-effectors improves regeneration by 6-benzylaminopurine treatment while adventitious lateral shoot development by kinetin in marine red alga Gracilaria dura (Rhodophyta)

The use of bio-effectors for sustainable seaweed cultivation has gained much traction lately. This study investigated the effect of priming with 6-benzylaminopurine (BAP), Kinetin (KIN), and Ascophyllum nodusum extract (AMPEP) on survival, regeneration, and adventitious lateral shoot formation in red seaweed Gracilaria dura. Treatment with varying concentrations (0.0001, 0.001, & 0.01%) and exposure times (15, 30, & 60 min) was studied. There were no statistically significant differences in AMPEP, BAP, and KIN treatments either individually or in combination on the survival of explants. Individual treatments improved regeneration (89 ± 5.48%) with BAP (0.01%, 60 min), and adventitious lateral shoot development (5.18 ± 0.84 shoots explant−1) with KIN (0.001%, 30 min) compared to controls. The effect of the combination of treatments of the bio-effectors was considerably lower. The highest regeneration (56 ± 5.48%) was reported in AMPEP (0.001%, 30 min): KIN (0.0001%, 60 min): BAP (0.1%, 60 min), while the highest adventitious lateral shoot development (2.36 ± 0.22 shoots explant−1) was reported in BAP 0.01%, 60 min: KIN (0.0001%, 60 min): AMPEP (0.001%), 30 min treatment. The study would benefit sustainable seaweed aquaculture. However, open-sea performance and agar quality studies require further evaluation.