Fatty acid compositions associated with high-light tolerance in the intertidal rhodophytes Mastocarpus stellatus and Chondrus crispus

Table 6 Photosynthetic responses of experimental specimens of M. stellatus and C. crispus: amplitudes of the maximum quantum yield (F_v/F_m) for the high-light stress phase and the recovery phase of thallus branches collected on four sampling events (October 2011, March 2012, May 2012 and August 2012)

F_v/F_m amplitudes of thallus branches	Sampling event
F_v/F_m amplitudes of thallus branches	October 2011	March 2012	May 2012	August 2012
High-light stress phase
Mast-ex	0.124 ± 0.026^c	0.059 ± 0.014^a	0.181 ± 0.023^a	0.193 ± 0.026^b
Mast-ov	0.197 ± 0.024^b	0.044 ± 0.017^a	0.234 ± 0.027^a	0.112 ± 0.026^c
Chon-ov	0.292 ± 0.033^a	0.038 ± 0.011^a	0.219 ± 0.027^a	0.270 ± 0.035^a
Recovery phase
Mast-ex	0.135 ± 0.028	0.024 ± 0.013	0.069 ± 0.022	0.080 ± 0.036
Mast-ov	0.200 ± 0.024	0.035 ± 0.013	0.188 ± 0.028	0.081 ± 0.025
Chon-ov	0.128 ± 0.063	0.024 ± 0.007	0.145 ± 0.024	0.191 ± 0.048

For this, differences between the beginning and end of the high-light stress phase (beginning of experiment and 120 min of high-light exposure) and the recovery phase (120 min of high-light exposure and 120 min of recovery) were calculated from absolute F_v/F_m values, respectively. Table shows mean ± SEM (n = 5). Different letters (a, b and c) indicate significant differences among algal isolates within one of the four sampling events (significant interaction isolate × sampling event of 2-way ANOVA followed by a Fisher’s LSD test, p < 0.05)
Mast-ex, Mastocarpus stellatus from higher levels of the lower intertidal; Mast-ov, Mastocarpus stellatus from overlapping zone in deeper levels of lower intertidal; Chon-ov, Chondrus crispus from overlapping zone in deeper levels of lower intertidal; SEM, standard error of the mean

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