RNA-Seq and Bulked Segregant Analysis of Genes Related to High Growth in Ginkgo biloba Half-Sibling Families

The lifetime of G. biloba is very long, and its growth is relatively slow. However, little is known about growth-related genes in this species. We combined mRNA sequencing (RNA-Seq) with bulked segregant analysis (BSA) to fine map significant agronomic trait genes by developing polymorphism molecular markers at the transcriptome level. In this study, transcriptome sequencing of high growth (GD) and low growth (BD) samples of G. biloba half-sib families was performed. After assembling the clean reads, 601 differential expression genes were detected and 513 of them were assigned functional annotations. Single nucleotide polymorphism (SNP) analysis identified SNPs associated with 119 genes in the GD and BD groups; 58 of these genes were annotated. Two Homeobox-leucine zipper protein genes were up-regulated in the GD group compared with the BD group; therefore, these are very likely related to high growth of G. biloba. This study provides molecular level data that could be used for seed selection of high growth G. biloba half-sib families for future breeding programs.