Zygote-derived seedling production of Sargassum thunbergii: focus on two frequently experienced constraints in tank culture of seaweed

Abstract

Mass collection of germlings and growth of fouling algae are two main constraints for the seedling production of Sargassum thunbergii. In this study, 65% and 40% of reproductive output (allocation of biomass to sexual reproductive tissue) for farmed and natural populations respectively, were recorded during peak reproduction. In terms of germlings per kilogram wet weight of plants, the farmed population gave a higher yield than the natural population (3.2×10 5 and 1.2×10 5 germlings kg -1 , respectively). These results indicate that farmed populations could be used as parental plants for germling collection in seedling production. During the experiment, fouling was controlled by jet washing and high-density seeding. A germling detachment of less than 10% was observed when, after 48 h of attachment, collectors were jet-washed with an intensity of 1 kg cm -2 . High-density seeding had adverse effects on length mean, size equality, and occurrence of branches of germlings. However, 30-50 individuals cm -2 are thought to be usable in the seedling production of S. thunbergii because of less density effects. Seedlings of>0.5 cm length could be achieved after 1 month of tank culture.

Impact of Environmental Factors on the Photosynthesis and Respiration of Young Seedlings of <i>Sargassum thunbergii</i> (Sargassaceae, Phaeophyta)

“…Studies on the ecology [7][8][9], population genetic structure [10][11][12][13], and cultivation [6,[14][15][16][17] of S. thunbergii have been conducted recently. However, the photosynthetic physiology of S. thunbergii is poorly understood.…”

Phenological study of Sargassum thunbergii (Fucales, Phaeophyta) in Lidao Bay, Rongcheng, China

“…The S . thunbergii in Lidao Bay (37°12′N, 122°36′E) matured at a later date than those at Dongtou (27°54′N, 121°09′E) in Zhejiang and Pingtan (25°30′N, 119°46′E) in Fujian (Zheng and Chen, 1993;Zhang et al, 2012), likely because of lower temperatures in Lidao Bay. Indeed, S .…”

Responses of Germlings to Acute Environmental Stress

“…However, the natural populations of S. thunbergii along the coast of China have evidently deteriorated in recent years [3]. It is necessary to explore the reason for this phenomenon.…”