QTL Mapping for Growth-Related Traits by Constructing the First Genetic Linkage Map in Simao pine

Abstract

Simao pine is one of primary economic tree species for resin and timber production in southwest China, the exploitation and utilization are constrained by relatively lacking the genetic information. Construction a fine genetic linkage map and detecting QTLs for growth-related traits is an important section in molecular breeding program for Simao Pine. In our study, a high-resolution Simao pine genetic map employing specific locus amplified fragment sequencing (SLAF-seq) with an F1 population has been constructed. There were 11,544 SNPs assigned to 12 linkage groups in the map, and the total length of the map was 2,062.85 cM with a mean distance of 0.37 cM between markers. According to the phenotypic variation analysis during three consecutive years, seventeen QTLs for four traits which including six for plant height (Dh.16.1, Dh16.2, Dh17.1, Dh18.1-3), five for basal diameter (Dbd.17.1-5), four for needle length (Dnl17.1-3, Dnl18.1) and two for needle diameter (Dnd17.1 and Dnd18.1) were identified. These QTLs individually explained phenotypic variance from 11.0-16.3 %, and the LOD value ranged from 2.52 to 3.87. The result in this study provide helpful information for genomic studies and marker-assisted selection (MAS) in Simao pine.