Differential responses of bio-effector treatment in life history phases of marine red alga Gracilaria dura (Rhodophyta)
摘要
Declining natural populations of Gelidium due to over-harvesting, coupled with challenges in propagation, have placed Gracilaria aquaculture as one of the fastest-growing sectors of the global aquaculture industry. Protocols for artificial seedling production through clonal propagation with treatment of bio-effectors [0.25 mg L−1 6‐benzyl amino purine (BAP) for 60 min: 1 g L−1 AMPEP for 60 min: 0.25 mg L−1 kinetin (KIN) for 30 min] have been developed, and the seeedlings have been cultivated in the field successfully in the industrially important agarophyte Gracilara dura. Further, it was investigated that if the gametophyte and tetrasporophyte life history phases of this species responded differently to bio-effectors such as AMPEP and plant growth hormones and if such responses could be exploited for phase-based germplasm selection and seedling production in commercial farming. It was confirmed that, a high survival (100%), regeneration (72 – 81.78%), and the emergence of lateral shoots per explant (1.81 to 1.9) make reproductively mature fronds an excellent donor source for seed production technologies. The study also confirmed differential modulation of Chlorophyll-a, R-phycocyanin, R-phycoerythrib, respiration, TAC, protein, and carbohydrate content of G. dura gametophytes and tetrasporophytes. The knowledge gained during this study will aid in improving the existing seedling production protocol for sustainable feedstock production, and commercial applications. Further targeted studies on how bio-effectors modulate differentially expressed genes among these life- history phases should also be extended to have a better insight into the specific pathways they influence.