3.2.Correlations
between genetic variation and environmental versus geographical factors
The Mantel test showed a significant correlation between genetic
distance and environmental distance (r = 0.4871, P =
0.001), but between genetic distance and geographical distance was a
non-significant correlation (r = 0.0971, P = 0.028). When
geographical factors were controlled, a partial Mantel test also showed
isolation by environmental distance (r = 0.4797, P =
0.001). Whereas environmental factors were controlled, we could not
detect significant correlations between genetic differentiation and
geographical distance (r = 0.0118, P = 0.378). The MMRR
analysis indicated that the environment factors had large regression
coefficient, whereas the effects of geographic distance were not
significant (geographic distance: β = 0.0094, P = 0.1075;
environment distance: β = 0.2372, P = 0.0001;Table 3 ).
Table 3. Results of the Mantel test, partial Mantel test and
MMRR analyzing the correlation between geographical distances,
environmental distances and Nei’s genetic distance based on AFLP
data.