spatial genetic structure within four tamarack (larix laricina (du roi) k. koch) populations in northwestern ontario
abstract
this study was conducted to test the null hypothesis
that tamarack (larix laricina (du roi) k. koch) populations
are random assemblages of genotypes, and that this absence
of pattern can be observed on sites with differing
ecological and demographic characteristics. a total of
1715 trees in four populations with distinct ecological and
demographic characteristics were surveyed and sampled for
isozyme analysis. these trees were mapped for later
plotting and spatial autocorrelation analysis. seven
variable and three monomorphic allozyme loci were resolved.
visual examination of the distribution of single alleles
over space revealed pattern in 22.2 percent of the 36
plots. spatial autocorrelation analysis resulted in
calculation of 313 moran's i autocorrelation coefficients,
8.9 percent of which were significant (95 percent
confidence level). in addition, results of tests of the
correlograms constructed from these 313 coefficients
revealed that 38.9 percent of the correlograms were
significant using bonferroni's criterion (90 percent
confidence level). these results suggested that the null
hypothesis be rejected for a modest, but still important
proportion of the tests. the spatial pattern that was
observed, both by eye and through statistical tests, was
manifested mainly as a tendency for similar genotypes to
occur in trees that were near to each other.
collections
- retrospective theses [1604]