Chronological change and the potential of recovery on the photosynthetic efficiency of Pyropia yezoensis f. narawaensis (Bangiales) during the sporelings frozen storage treatment in the Japanese Nori cultivation

Abstract

The chronological change of photosynthetic efficiency in a frozen storage treatment of the Japanese Nori cultivation industry was examined in the cultivated red alga, Pyropia yezoensis f. narawaensis (Saga-#5 Strain, Bangiales) by using pulseamplitude fluorometry. During the desiccation process that was conducted after the nursery cultivation season in November, the maximum quantum yield (F v /F m ) of the gametophytic sporelings growing on the Nori-net decreased monotonically with decreasing absolute water content (AWC), and was around 0.1 at 20% AWC. During frozen storage of the Norinet, the F v /F m of the frozen gametophyte was low but stable, and ranged between 0.10 AE 0.02 SD and 0.14 AE 0.05 SD. The magnitude of F v /F m for the gametophyte of the freezing treatment, after 10 min and 3 h of immersion in seawater, recovered quickly. After 10 min and 3 h of immersion, these values were 0.29 AE 0.12 SD and 0.47 AE 0.05 SD during the 14 days of freezing treatment, and 0.15 AE 0.02 SD and 0.29 AE 0.04 SD after 71 days of freezing treatment, and suggest that the ability to recover gradually decreased as the storage duration increased. The response of F v /F m from general cultivation (i.e., directly cultivated from the nursery cultivation season) and those after 47 days of freezing were almost identical, suggesting that the current Nori-net frozen storage period (6 or 7 weeks) was not detrimental to the gametophyte.

Effect of Oxidative Stress on Physicochemical Quality of Taiwanese Seagrape (Caulerpa lentillifera) with the Application of Alternating Current Electric Field (ACEF) during Post-Harvest Storage

“…The chlorophyll content and TPC of seagrape in spring has higher physicochemical quality than in summer and winter. The results from this research corresponding to the seasonal effect on the chemical content compositions, physiology, and growth of algae or seaweed [30,62]. Furthermore, Moreira et al [63] and Gosch et al [64] reported PUFA on algae was higher in winter than summer and spring, which results in higher lipids to generate MDA [65].…”

“…Under water-limited conditions, the algae cannot regulate their water content that leads to oxidative stress [29]. Corresponding to the result in Figure 2, the weight loss of the seagrape without seawater during storage in every season is increasing as the representative of water loss [7,30]. While the without-seawater storage loses water content, the within-seawater storage increases their weight up to 10% after nine days of storage (Figure 2).…”

Environmental Stress Tolerance and Antioxidant Response of Palisadaperforata (Rhodophyta) from a Tropical Reef1

“…2011, 2016, Watanabe et al. 2017, Terada et al. 2020) found that desiccation causes water loss from the thallus and can eventually lead to a decrease in the Fv/Fm ratio.…”

“…Changes in the Fv/Fm ratio can be considered an indicative parameter that reflects the PSII efficiency status under stress (Maxwell and Johnson 2000, Adams and Demmig-Adams 2004, Pang and Shan 2008, Gao et al 2013. Some authors (Wang et al 2011, Watanabe et al 2017, Terada et al 2020 found that desiccation causes water loss from the thallus and can eventually lead to a decrease in the Fv/Fm ratio. Yu et al (2013) found that emersed thalli experienced a short-term desiccation effect followed by complete recovery.…”

Preliminary comparison of atmospheric CO2 enhancement to photosynthesis of Pyropia yezoensis (Bangiales, Rhodophyta) leafy thalli and filamentous thalli

“…P. yezoensis leafy thalli inhabit the intertidal zone and are extremely tolerant to stress (Watanabe et al . , ). It was reported that even when they had lost more than 85% of their original weight, they could still survive and recover physiological activity after rehydration (Blouin et al .…”