Abstract
BackgroundCatalpa bungei is an important tree species used for timber in China and widely cultivated for economic and ornamental purposes. A high-density linkage map of C. bungei would be an efficient tool not only for identifying key quantitative trait loci (QTLs) that affect important traits, such as plant growth and leaf traits, but also for other genetic studies.ResultsRestriction site-associated DNA sequencing (RAD-seq) was used to identify molecular markers and construct a genetic map. Approximately 280.77 Gb of clean data were obtained after sequencing, and in total, 25,614,295 single nucleotide polymorphisms (SNPs) and 2,871,647 insertions-deletions (InDels) were initially identified in the genomes of 200 individuals of a C. bungei (7080) × Catalpa duclouxii (16-PJ-3) F1 population and their parents. Finally, 9072 SNP and 521 InDel markers that satisfied the requirements for constructing a genetic map were obtained. The integrated genetic map contained 9593 pleomorphic markers in 20 linkage groups and spanned 3151.63 cM, with an average distance between adjacent markers of 0.32 cM. Twenty QTLs for seven leaf traits and 13 QTLs for plant height at five successive time points were identified using our genetic map by inclusive composite interval mapping (ICIM). Q16–60 was identified as a QTL for five leaf traits, and three significant QTLs (Q9–1, Q18–66 and Q18–73) associated with plant growth were detected at least twice. Genome annotation suggested that a cyclin gene participates in leaf trait development, while the growth of C. bungei may be influenced by CDC48C and genes associated with phytohormone synthesis.ConclusionsThis is the first genetic map constructed in C. bungei and will be a useful tool for further genetic study, molecular marker-assisted breeding and genome assembly.
Highlights
Catalpa bungei is an important tree species used for timber in China and widely cultivated for economic and ornamental purposes
Catalpa bungei (2n = 2 × =40) is a woody plant belonging to the genus Catalpa, family Bignoniaceae [1], and an important ornamental tree species widely used in urban forests in central and northern cities in China due to its beautiful flowers, straight stems and moderate
As C. bungei is a timber and urban forest tree, its growth traits are its most important economic traits, and recent studies have demonstrated that leaf traits such as leaf area (LA), petiole length (PL) and others are associated with its capacity to capture particles from the air [11]
Summary
Catalpa bungei is an important tree species used for timber in China and widely cultivated for economic and ornamental purposes. As C. bungei is a timber and urban forest tree, its growth traits are its most important economic traits, and recent studies have demonstrated that leaf traits such as leaf area (LA), petiole length (PL) and others are associated with its capacity to capture particles from the air [11]. These traits are complex quantitative traits that may be determined by several factors, including cell division and expansion, phenology, and photosynthesis efficiency [12]. An understanding of quantitative trait loci (QTLs) would be beneficial to reveal the genetic architecture of these important traits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
