Background: Genetic diversity and genetic variation of 10 populations and subpopulations of
Magnolia wufengensis
, a new and endangered endemic species, were examined by inter simple sequence repeat (ISSR)
and sequence-related amplified polymorphism (SRAP) molecular markers. Compared with other endangered
endemic Magnolia taxa,
M. wufengensis holds a relatively high level of genetic variation.
Result: Total genetic diversity was found to be 87.7% for ISSR and 88.0% for SRAP markers. For polymorphic loci
(
P), the effective mean number of alleles (
Ae) was 1.414 for ISSR markers and 1.458 for SRAP markers, while
the mean expected heterozygosity (
H) was 0.256 using ISSR and 0.291 for SRAP markers. Within-population
variation was estimated for
P as 74.9% using ISSR and 74.6% with SRAP markers; the number of alleles
Ae was
1.379 with ISSR and 1.397 for SRAP and
H 0.235 with ISSR and 0.247 for SRAP markers.
Conclusion: The analysis of molecular variation of both ISSR and SRAP marker systems indicated that most genetic
variation is within populations,with values of 90.64% and 82.92% respectively. Mantel tests indicated a moderate
association between the two marker systems and a low correlation between genetic and geographic distances.
High levels of genetic diversity and low levels of population divergence suggest that genetic drift is not
currently of great concern for this species. Severe habitat loss and fragmentation, predominantly ascribed to
anthropogenic pressures, caused
in-situ developing restriction of this species. Action for conserving this rare
species for its long-term survival should be taken immediately.
