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

Table 5 Statistical evaluation of fatty acid compositions of M. stellatus and C. crispus: single fatty acids of initial thallus branches, using two-factorial analysis of variance, with the factors sampling event (October 2011, March 2012, May 2012 and August 2012) and isolate (Mast-ex, Mast-ov and Chon-ov) and their interaction

Source of variation	FA 14:0					FA 16:0					FA 16:1(n-7)
Source of variation	SS	df	MS	F	p	SS	df	MS	F	p	SS	df	MS	F	p
Isolate	2.7 × 10⁻⁵	2	1.3 × 10⁻⁵	1.992	0.148	0.001	2	3.3 × 10⁻⁴	3.255	0.047	0.003	2	0.001	175.034	<0.001
Sampling event	0.002	3	0.001	84.675	<0.001	0.016	3	0.005	51.590	<0.001	1.1 × 10⁻⁴	3	3.6 × 10⁻⁵	4.188	0.010
Isolate × sampling event	1.6 × 10⁻⁵	6	2.7 × 10⁻⁶	0.409	0.869	0.002	6	3.8 × 10⁻⁴	3.710	0.004	2.5 × 10⁻⁴	6	4.1 × 10⁻⁵	4.808	0.001
Error	3.2 × 10⁻⁴	47	6.7 × 10⁻⁶			0.005	47	1.0 × 10⁻⁴			4.0 × 10⁻⁴	47	8.5 × 10⁻⁶

Source of variation	FA 18:0					FA 18:1(n-7)					FA 18:1(n-9)
Source of variation	SS	df	MS	F	p	SS	df	MS	F	p	SS	df	MS	F	p
Isolate	2.3 × 10⁻⁴	2	1.1 × 10⁻⁴	4.199	0.021	4.8 × 10⁻⁴	2	2.4 × 10⁻⁴	21.566	<0.001	0.002	2	0.001	4.239	0.020
Sampling event	5.9 × 10⁻⁵	3	2.0 × 10⁻⁵	0.720	0.545	3.1 × 10⁻⁴	3	1.0 × 10⁻⁴	9.365	<0.001	0.001	3	1.8 × 10⁻⁴	0.929	0.434
Isolate × sampling event	2.9 × 10⁻⁴	6	4.8 × 10⁻⁵	1.787	0.122	1.3 × 10⁻⁴	6	2.2 × 10⁻⁵	2.007	0.084	0.004	6	0.001	3.850	0.003
Error	0.001	47	2.7 × 10⁻⁵			0.001	47	1.1 × 10⁻⁵			0.009	47	1.9 × 10⁻⁴

Source of variation	FA 18:2(n-6)					FA 20:4(n-6)					FA 20:5(n-3)
Source of variation	SS	df	MS	F	p	SS	df	MS	F	p	SS	df	MS	F	p
Isolate	0.001	2	2.9 × 10⁻⁴	12.315	<0.001	0.053	2	0.027	125.717	<0.001	0.013	2	0.007	22.987	<0.001
Sampling event	3.5 × 10⁻⁵	3	1.2 × 10⁻⁵	0.493	0.689	0.075	3	0.025	118.942	<0.001	0.191	3	0.064	221.290	<0.001
Isolate × sampling event	2.7 × 10⁻⁴	6	4.5 × 10⁻⁵	1.916	0.098	0.028	6	0.005	22.157	<0.001	0.029	6	0.005	16.761	<0.001
Error	0.001	47	2.4 × 10⁻⁵			0.010	47	2.1 × 10⁻⁴			0.014	47	2.9 × 10⁻⁴

p values in bold highlight significant differences at p < 0.05. The nomenclature of fatty acids (a:b(n-x)) is defined as follows: a = number of C-atoms (chain length), b = number of double bonds and (n-x) = position of the first double bond relative to the methyl-end
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

ISSN: 1438-3888