Time‐specific and pleiotropic quantitative trait loci coordinately modulate stem growth in Populus

• DOI: 10.1111/pbi.13002
• Publication Date: 2018-08-22T16:34:36Z
• Authors: Qingzhang Du; Xiaohui Yang; Jianbo Xie; Mingyang Quan; Liang Xiao; Wenjie Lu; Jiaxing Tian; Chenrui Gong; Jinhui Chen; Bailian Li; Deqiang Zhang
• Keywords: Genetic architecture; Linkage Disequilibrium; Epistasis; Association mapping; Genetic Association; Dominance (genetics); Family-based QTL mapping; Genetic linkage

In perennial woody plants, the coordinated increase of stem height and diameter during juvenile growth improves competitiveness (i.e. access to light); however, factors underlying variation in remain unknown trees. Here, we used linkage-linkage disequilibrium (linkage-LD) mapping decipher genetic architecture three traits growth. We two Populus populations: a linkage population comprising full-sib family 1,200 progeny an association panel 435 unrelated individuals from nearly entire natural range tomentosa. mapped 311 quantitative trait loci (QTL) for at 12 timepoints 42 regions 17 groups. Of these, 28 encompassing 233 QTL were annotated as 27 segmental homology (SHRs). Using SNPs identified by whole-genome re-sequencing 435-member panel, significant (P ≤ 9.4 × 10-7 ) within SHRs that affect nine with diverse additive dominance patterns, these exhibited complex allelic epistasis over period. Nineteen genes linked potential causative alleles have time-specific or pleiotropic effects, mostly overlapped signatures selection between climatic represented panel. Five effects showed species-specific temporal expression profiles stages five representative species. Our observations revealed importance considering basis traits, which will facilitate molecular design tree ideotypes.