Genetic Diversity Assessment in Plant Species Conservation

Genetic diversity assessment underpins the conservation of plant species by revealing the extent and distribution of heritable variation within and among populations. Such assessments employ molecular markers—ranging from simple sequence repeats to genome-wide single nucleotide polymorphisms—to characterise the genetic structure, levels of inbreeding and historical demography of target taxa. Understanding these parameters guides the design of in situ and ex situ strategies, the identification of management units and the selection of source material for restoration or breeding. Recent advances in high-throughput sequencing have accelerated the generation of large SNP datasets, allowing for finer resolution of population connectivity, the detection of adaptive variation and the reconstruction of past population collapses. Integrating genetic data with ecological modelling further illuminates how habitat fragmentation and climate change may erode diversity and shift suitable ranges. Globally, such insights inform prioritisation of critically endangered taxa, the delimitation of genetic refugia and the maintenance of evolutionary potential in the face of ongoing environmental change.

Research from Nature Portfolio

Recent studies have applied genotyping-by-sequencing to critically endangered tree species and uncovered marked reductions in heterozygosity indicative of severe population bottlenecks. In one case, genome-wide SNP surveys of a tiny endemic tree revealed an observed heterozygosity below 15 %, weak genetic differentiation across remnant stands and evidence that natural selection rather than random drift is driving loss of diversity. These findings have prompted targeted sampling of genetically distinct clusters for propagation programmes. A seminal genomic analysis of another endangered ironwood tree compared demographic histories with a widespread congener, demonstrating that prolonged decline and the accumulation of deleterious mutations were partly offset by purging of recessive variants. This work provided a framework for predicting future recovery potential and highlighted the importance of mating systems in conservation planning.

Genetic Diversity Assessment in Plant Species Conservation publication trend

The graph below shows the total number of articles in genetic diversity assessment in plant species conservation across all publications each year (not limited to Nature Index journals).

Technical terms

Genetic diversity: The total variation of heritable traits within and between populations, essential for adaptive potential.

Single nucleotide polymorphism (SNP): A one-base variation in the DNA sequence among individuals, widely used for high-resolution genotyping.

Genotyping-by-sequencing (GBS): A reduced-representation approach that leverages restriction enzymes and next-generation sequencing to discover and genotype SNPs across genomes.

Double-digest RAD sequencing (ddRAD-seq): A protocol using two restriction enzymes to fragment DNA, enabling reproducible sampling of genomic regions for SNP discovery.

Effective population size (Ne): An estimate of the number of individuals contributing genetically to the next generation, reflecting susceptibility to drift and inbreeding.

Heterozygosity: The proportion of individuals carrying two different alleles at a locus, serving as a measure of genetic variation.

References

1. Strict biennial lifecycle and anthropogenic interventions affect temporal genetic differentiation in the endangered endemic plant, Pedicularis hallaisanensis. Frontiers in Plant Science (2024).
2. Conservation genetics and potential geographic distribution modeling of Corybas taliensis, a small ‘sky Island’ orchid species in China. BMC Plant Biology (2024).
3. Assessing genetic diversity in critically endangered Chieniodendron hainanense populations within fragmented habitats in Hainan. Scientific Reports (2024).
4. Genomic effects of population collapse in a critically endangered ironwood tree Ostrya rehderiana. Nature Communications (2018).