Abstract Detail

Population Genetics/Genomics

Liu, Hanjing [1], Su, Yingjuan [1], Wang, Ting [2].

Genetic structure, local adaptation, and demographic history of Cephalotaxus oliveri based on population transcriptomic sequencing.

Having a comprehensive understanding of population structure, local adaptation, genetic differentiation, and demographic history is critical for the conservation and management of species. Forest trees, especially widely distributed long-lived species are an excellent resource for understanding population differentiation and adaptive genetic variation due to they can adapt to different climates and environments. Cephalotaxus oliveri is a relict conifer endemic to China with significant ecological, timber, and medicinal values. In this study, we generated transcriptome data and identified 17728 high-quality single nucleotide polymorphisms (SNPs) from 180 C. oliveri individuals belonging to 18 populations distributed across the species entire geographic range. There were significant negative correlations between expression diversity and nucleotide diversity within and among populations, suggesting that gene expression and nucleotide diversity have a reciprocal relationship when adapts to the environment. The analyses of population structure showed that C. oliver displays a striking genetic structure with four groups. Both IBD and IBE contributed significantly to genetic divergence, and the contribution of IBE was more influential than that of IBD. FST outlier and latent factor mixed model detected the signatures of local adaptation, and identified that 16 outlier SNPs were associated with temperature, soil pH and topographic variables (slope and aspect) across heterogeneous environmental conditions. Approximate Bayesian computation analyses showed that the first and second divergence occurred in the late Miocene (~10.075 Ma) and middle Pleistocene transition (~0.815 Ma), respectively. C. oliver revealed signs of westward expansion after the Last glacial maximum, while was predicted to experience significant range contractions in future climate change scenarios. Geographical factors and environmental factors in Southern China played a critical role in establishing the current and genetic diversity and population structure of C. oliver. This study provides important references for forest resource management and conservation for C. oliver.

1 - Sun Yat-Sen University
2 - South China Agricultural University

 Cephalotaxus oliveri
Population transcriptome
Genetic differentiation
Local adaptation
Demographic history
Ecological niche model.

Presentation Type: Oral Paper
Number: PGG3004
Abstract ID:276
Candidate for Awards:None

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