A Molecular Genetic Linkage Map of Eucommia ulmoides and Quantitative Trait Loci (QTL) Analysis for Growth Traits

Abstract

Eucommia ulmoides is an economically important tree species for both herbal medicine and organic chemical industry. Effort to breed varieties with improved yield and quality is limited by the lack of knowledge on the genetic basis of the traits. A genetic linkage map of E. ulmoides was constructed from a full-sib family using sequence-related amplified polymorphism, amplified fragment length polymorphism, inter-simple sequence repeat and simple sequence repeat markers. In total, 706 markers were mapped in 25 linkage groups covering 2133 cM. The genetic linkage map covered approximately 89% of the estimated E. ulmoides genome with an average of 3.1 cM between adjacent markers. The present genetic linkage map was used to identify quantitative trait loci (QTL) affecting growth-related traits. Eighteen QTLs were found to explain 12.4%–33.3% of the phenotypic variance. This genetic linkage map provides a tool for marker-assisted selection and for studies of genome in E. ulmoides.

Quantitative trait locus analysis of leaf morphological characters, yield-related traits, and secondary metabolite contents in Eucommia ulmoides

“…Similarly, we were able to detect QTLs with a moderate-to-large effect for plant height and diameter growth in the same mapping population (Li et al, 2014c). A few QTLs with relatively large effect have also been observed for growth, phenology, quality, and yield traits in other plant species (Bradshaw and Stettler, 1995;Wang et al, 2000;Ronnberg-Wastljung et al, 2005;McAdam et al, 2013).…”

“…Clusters of QTLs were also observed for growth traits and various leaf traits in poplar (Bradshaw and Stettler, 1995;Wu et al, 1997), for wood properties and growth traits in the genus Eucalyptus (Verhaegen et al, 1997;Freeman et al, 2009;Thumma et al, 2010), for growth traits in Salix (Tsarouhas et al, 2002;Ronnberg-Wastljung et al, 2005), for leaf morphological characters in European beech (Scalfi et al, 2004) and oak (Gailing, 2008;Gailing et al, 2013), and for chemical compositions in peach (Eduardo et al, 2013) and oil palm (Montoya et al, 2013). Furthermore, the clustering of QTLs controlling height and basal diameter has been observed in the same mapping population of E. ulmoides (Li et al, 2014c). In most cases, no clear patterns among phenotypic correlations have been found to coincide with the co-locating QTLs (Tsarouhas et al, 2002;Gailing, 2008;Freeman et al, 2009;Thumma et al, 2010;Li et al, 2014c).…”

“…The parents differ in leaf morphology characters and in secondary metabolite content, and originated from two areas with different climatic and geographic conditions (Li et al, 2014c). Seedlings were grown in a greenhouse in 2010 and transferred to a field at the nursery of Northwest A&F University in March 2011.…”

“…QTL analysis was conducted using the genetic linkage map constructed in a previous study (Li et al, 2014c). MapQTL 5.0 was used for this analysis (Van Ooijen, 2004).…”

“…Recently, we constructed a genetic linkage map of E. ulmoides using an F 1 mapping population (DZ0901) derived from a cross between the wild genotype Xiaoye and the cultivar Qinzhong No.1 (Li et al, 2014c). The female parent, Xiaoye, has small leaves and low levels of secondary metabolites, whereas the male parent, Qinzhong No.1, has large leaves and high levels of secondary metabolites.…”