Construction of a SNP-based linkage map and identification of QTLs for woody biomass-related traits using an interspecific F₂ population derived from Jatropha curcas x Jatropha integerrima

Jatropha curcas (known as jatropha and physic nut) can be used as an alternative source for biodiesel and biomass production. However, conventional breeding of J. curcas needs time, labor and land for characterization and evaluation of the progenies owing to its perennial growth habit. Quantitative trait loci (QTL) mapping can help identifying marker-trait association and accelerate breeding process of perennial crops through marker-assisted selection. However, the genetic basis for woody biomass improvement in jatropha has not yet been studied. In this manuscript, we report the construction of a SNP-based linkage map and detection of QTLs for woody-biomass-related traits using an F2 population of the interspecific cross between J. curcas and Jatrophaintegerrima. A high-density genetic linkage map containing 2,179 SNPs was constructed. As high as 89.26% of the SNP markers developed from these interspecific progenies expressed significant segregation distortion. Most of the distorted markers showed neither gametophytic nor zygotic selection, except those on linkage groups 3, 5 and 6 which showed gametophytic and zygotic selection. The F2 population showed high variation and transgressive segregation for plant height, canopy width and wood density. QTL analyses detected 5, 8, and 7 loci for plant height, canopy width, and wood density, respectively. The SNPs linked to these QTLs could be incorporated into marker-assisted breeding to maximize the selection gain in jatropha biomass breeding.