Data from: Patterns of genotype variation and demographic history in Lindera glauca (Lauraceae), an apomict-containing dioecious forest tree

Aim: The historical circumstances promoting the transition from sexual to
apomictic reproduction in dioecious plant species remains poorly
understood. Here, we investigated the divergence and demographic history
of Lindera glauca, a dioecious tree considered to be facultatively
apomictic in China while comprising only females (obligate apomicts) in
Japan. Location: East Asia (China and Japan) Methods: Samples from 42
populations were genotyped using chloroplast DNA and nuclear
microsatellite (nSSR) loci to assess genetic diversity and structure. The
nSSR genotypes were also used to detect the mode of reproduction in
Chinese and Japanese populations, respectively. Approximate Bayesian
Computation on nSSRs and palaeoclimatic niche models provided further
insights into the evolutionary and population demographic history.
Results: Chinese L. glauca was found to harbour both sexual and asexual
genotypes. Chinese and Japanese L. glauca underwent roughly
contemporaneous bottlenecks during a mid-Pleistocene glacial period,
possibly marking the split-time of the island lineage from its mainland
ancestor. In contrast to Chinese L. glauca, the Japanese lineage
experienced a massive range contraction during the Last Glacial Maximum
and postglacial expansions. Main conclusions: While reproductive assurance
plays an important role in the selection of apomixis in Chinese L. glauca,
the lack of male plants in Japan likely reflects population demographic
history driven by (Late) Quaternary climate change. Hence, the present
study demonstrates a possible link between palaeoclimate change and the
transition to exclusively apomictic reproduction in a dioecious tree.