Genome and GWAS analysis identified genes significantly related to phenotypic state of bark.

As an important horticultural plant, is often used in urban greening and landscape design. However, factors such as the high rate of genetic recombination, frequent outcrossing in the wild, weak linkage disequilibrium, and the susceptibility of gene expression to environmental factors limit further exploration of functional genes related to important horticultural traits, and make the breeding of new varieties require a longer time. Therefore, we choose bark as the target trait which is not easily affected by environmental factors, but also has ornamental properties. Genome-wide association study (GWAS) of (30 samples), (30 samples) and their generation (200 samples) was conducted on the roughness of bark phenotypes. Finally, we obtained 2416.31 Gbp of clean data and identified 5 328 800 high-quality SNPs. According to the -value and the degree of linkage disequilibrium of SNPs, we further identified 4 out of 11 candidate genes that affect bark roughness. The results of gene differential expression analysis further indicated that the expression levels of and in different bark phenotypes were significantly different. Our study identified functional genes that influence important horticultural traits of , and illustrated the powerful utility and great potential of GWAS in understanding and exploiting wild germplasm genetic resources of .