Research progress of single nucleotide polymorphisms in forest trees

Single nucleotide polymorphisms (SNPs) are the most abundant form of genetic variation in many organisms. Forest is an important plant group and key component of the terrestrial plant ecosystem. As a new marker system, SNP has been applied in genetic and breeding studies in some tree species of genera Pinus, Populus, Pseudotsuga, Eucalyptus, and Picea, and the related genetic information, such as nucleotide diversity, linkage disequilibrium (LD) and population structure has been generated. These studies are mainly based on sequencing and analysis of candidate genes. SNP-based association genetics analysis or LD mapping has become a useful tool for dissection of complex traits in forest trees. Association studies in Eucalyptus spp. and Pinus taeda L. found that some SNP sites in various genes were associated with distinct wood property traits. Meanwhile, estimation of genetic parameters has revealed the evolutionary and ecological significance at different extents in several tree species. Intensive applications of SNP approach are expected to greatly accelerate the development of research on forest genetics and breeding.