Picture of Athyrium sinense [IMAGE: IBCAS]

Gene flow plays a key role in diluting specialized adaptive variation, maintaining genetic homogeneity and impeding population differentiation during the evolutionary process. Ferns represent an important vascular plant lineage, which can produce massive amounts of light-weight spores that can travel a long distance and prevent the formation of genetic structure. The relationship between spore dispersal capacity and population genetic structure in ferns remains largely unknown in the context of the “dispersal-gene flow paradox.

A research team led by Professor Zhang Xianchun from the Institute of Botany of the Chinese Academy of Sciences (IBCAS) has revealed the genetic structure of ferns shaped by ecological adaptation against strong dispersal capacity.

The study was published in Molecular Ecology on March 7.

Researchers selected the Athyrium sinense complex, a diploid homosporous fern lineage distributed widely in temperate Asia, as the target group, and conducted a population genomic study based on the reduced-representation genomic data generated by high-throughput sequencing technology (SLAF-seq).

They revealed a clear north-south genetic, morphological and ecological divergence between both sides of 35°N in East Asia.

By modelling demographic history and species distribution, researchers showed that this lineage was able to migrate southward and colonize new habitats as a result of the Quaternary climatic fluctuation.

Results of correlation testing and redundancy analysis suggested that the present genetic structure is attributed to the adaptation to heterogeneous environments despite the presence of strong dispersal capacity.

In addition, researchers demonstrated that canopy density and wind direction as well as habitat continuity were all likely to constrain the effect of gene flow.

“This study provides new insights for our present knowledge on ferns spatiotemporal evolutionary pattern, and highlights the influence of environmental heterogeneity in driving genetic divergence against strong dispersal capacity, said Professor Zhang Xianchun from IBCAS.

For more information, please contact:

Dr. & Professor Zhang Xianchun

E-mail: zhangxc@ibcas.ac.cn

Institute of Botany,

Chinese Academy of Sciences

Source: Institute of Botany,

Chinese Academy of Sciences