Assessing Genetic Diversity in Critically Endangered Chieniodendron
hainanense Populations within Fragmented Habitats in Hainan
Abstract
Habitat fragmentation engenders a reduction in the geographic
distribution of species, thereby rendering diminutive populations
susceptible to extinction due to environmental, demographic, and genetic
factors. Chieniodendron hainanense (henceforth C. hainanense)
exemplifies a wild plant with extremely small populations (WPESP) and
faces endangerment, necessitating urgent national conservation efforts.
Elucidating the genetic diversity of C. hainanense is crucial for
uncovering underlying mechanisms and devising protective strategies. In
the present study, 35 specimens from six distinct cohort groups were
genotyped utilizing genotyping-by-sequencing (GBS) and single nucleotide
polymorphism (SNP) methodologies. The results indicated that C.
hainanense exhibits limited genetic diversity. Observed heterozygosity
within C. hainanense populations spanned from 10.79% to 14.55%, with
an average value of 13.15%. The six C. hainanense populations can be
categorized into two distinct groups: (1) Diaoluoshan and Baishaling,
and (2) Wuzhishan, Huishan, Bawangling, and Jianfengling. The degree of
genetic differentiation among C. hainanense populations is relatively
weak. The observed loss of diversity can be attributed to the effects of
natural selection.