Interspecific Gene Flow and Selective Sweeps in <i>Picea wilsonii</i>, <i>P. neoveitchii</i> and <i>P. likiangensis</i>
Yifu Liu,
Aili Qin,
Ya Wang,
Wen Nie,
Cancan Tan,
Sanping An,
Junhui Wang,
Ermei Chang,
Zeping Jiang,
Zirui Jia
Affiliations
Yifu Liu
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
Aili Qin
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
Ya Wang
State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China
Wen Nie
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
Cancan Tan
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
Sanping An
Research Institute of Forestry of Xiaolong Mountain, Gansu Provincial Key Laboratory of Secondary Forest Cultivation, Tianshui 741002, China
Junhui Wang
State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China
Ermei Chang
State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China
Zeping Jiang
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
Zirui Jia
State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China
Genome-wide single nucleotide polymorphism (SNP) markers were obtained by genotyping-by-sequencing (GBS) technology to study the genetic relationships, population structure, gene flow and selective sweeps during species differentiation of Picea wilsonii, P. neoveitchii and P. likiangensis from a genome-wide perspective. We used P. jezoensis and P. pungens as outgroups, and three evolutionary branches were obtained: P. likiangensis was located on one branch, two P. wilsonii populations were grouped onto a second branch, and two P. neoveitchii populations were grouped onto a third branch. The relationship of P. wilsonii with P. likiangensis was closer than that with P. neoveitchii. ABBA-BABA analysis revealed that the gene flow between P. neoveitchii and P. wilsonii was greater than that between P. neoveitchii and P. likiangensis. Compared with the background population of P. neoveitchii, the genes that were selected in the P. wilsonii population were mainly related to plant stress resistance, stomatal regulation, plant morphology and flowering. The genes selected in the P. likiangensis population were mainly related to plant stress resistance, leaf morphology and flowering. Selective sweeps were beneficial for improving the adaptability of spruce species to different habitats as well as to accelerate species differentiation. The frequent gene flow between spruce species makes their evolutionary relationships complicated. Insight into gene flow and selection pressure in spruce species will help us further understand their phylogenetic relationships and provide a scientific basis for their introduction, domestication and genetic improvement.
