Corydalis tomentella Franch. (Papaveraceae), a species endemic to Central China, occurs
within specialized habitats of limestone cliffs. To date, extensive harvesting by local people
for medical use has led to a sharp decline in wild populations of this plant. To investigate
the genetic diversity and genetic structure of the species, differences in the composition of
one nuclear DNA (nDNA) locus (NADPH) and two chloroplast DNA (cpDNA) fragments
(trnH-psbA and trnG introns) from wild populations of this plant were analysed. Six
chlorotypes and 17 nuclear genotypes were identified in a survey of 8 populations
distributed in the current geographic regions of C. tomentella. Two cpDNA haplotypes were
shared in two present distribution regions, Shennongjia and Nanchuan in Central China,
while there were no similar nDNA genotypes in these regions. As a whole, Shennongjia's
populations had greater gene diversity than found in Nanchuan's population of C.
tomentella. Greater population differentiation was also detected along with low gene flow
in the distribution regions. This may result from the plants predominantly self-mating
system, the short-distance dispersal system associated with the plant, and the specific
habitat requirements for growth. These data suggest that Shennongjia region should be
regarded as the priority area for conservation of C. tomentella due to its greater diversity of
this plant found there