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Article|01 Jul 2020|OPEN
High-density genetic map construction and identification of loci controlling flower-type traits in Chrysanthemum (Chrysanthemum × morifolium Ramat.)
Xuebin Song1,2, Yuhui Xu3,4, Kang Gao1, Guangxun Fan1, Fan Zhang1, Chengyan Deng1, Silan Dai1,, He Huang1, Huaigen Xin3 & Yingying Li3
1Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of the Ministry of Education, Beijing Forestry University, School of Landscape Architecture, Beijing Forestry University, 35 East Qinghua Road, Beijing 100083, China
2College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109 Shandong, China
3Biomarker Technologies Co., LTD, Beijing 101300, China
4LC Science Co., LTD., Hangzhou 310018, China

Horticulture Research 7,
Article number: 20108 (2020)
doi: 10.1038/hortres.2020.108
Views: 103

Received: 14 Feb 2020
Revised: 16 Apr 2020
Accepted: 01 May 2020
Published online: 01 Jul 2020

Abstract

Flower type is an important and extremely complicated trait of chrysanthemum. The corolla tube merged degree (CTMD) and the relative number of ray florets (RNRF) are the two key factors affecting chrysanthemum flower type. However, few reports have clarified the inheritance of these two complex traits, which limits directed breeding for flower-type improvement. In this study, 305 F1 hybrids were obtained from two parents with obvious differences in CTMD and RNRF performance. Using specific-locus amplified fragment sequencing (SLAF-seq) technology, we constructed a high-density genetic linkage map with an average map distance of 0.76 cM. Three major QTLs controlling CTMD and four major QTLs underlying RNRF were repeatedly detected in the 2 years. Moreover, the synteny between the genetic map and other Compositae species was investigated, and weak collinearity was observed. In QTL regions with a high degree of genomic collinearity, eight annotated genes were probed in the Helianthus annuus L. and Lactuca sativa L. var. ramosa Hort. genomes. Furthermore, 20 and 11 unigenes were identified via BLAST searches between the SNP markers of the QTL regions and the C. vestitum and C. lavandulifolium transcriptomes, respectively. These results lay a foundation for molecular marker-assisted breeding and candidate gene exploration in chrysanthemum without a reference assembly.