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Article|01 Feb 2019|OPEN
Genome-wide identification of quantitative trait loci for important plant and flower traits in petunia using a high-density linkage map and an interspecific recombinant inbred population derived from Petunia integrifolia and P. axillaris
Zhe Cao1 , Yufang Guo2 , Qian Yang1 , Yanhong He3 , Mohammed I. Fetouh4 , Ryan M. Warner2 and Zhanao Deng,1 ,
1Department of Environmental Horticulture, Gulf Coast Research and Education Center, IFAS, University of Florida, 14625 County Road 672, Wimauma, FL 33598, USA
2Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA
3Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, Hubei, China
4Department of Horticulture, Faculty of Agriculture, Tanta University, Tanta 31527, Egypt
*Corresponding author. E-mail: zdeng@ufl.edu

Horticulture Research 6,
Article number: 27 (2019)
doi: https://doi.org/10.1038/s41438-018-0091-5
Views: 1047

Received: 09 May 2018
Revised: 09 Sep 2018
Accepted: 19 Sep 2018
Published online: 01 Feb 2019

Abstract

Petunia is a very important flower in the global floriculture industry and has played a critical role as a model in plant genetic studies. Owing to limited genetic variability in commercial germplasm, development of novel petunia phenotypes and new varieties has become increasingly difficult. To enrich petunia germplasm and facilitate genetic improvement, it is important to explore genetic variation in progenitor species that may contain highly valuable genes/alleles. In this study, an interspecific recombinant inbred population (168 recombinant inbreds) derived from Petunia integrifolia × P. axillaris were phenotyped for days to anthesis (DTA), flower count (Flower_C), flower diameter (Flower_D), flower length (Flower_L), plant height (Plant_H), plant spread (Plant_S), and plant size (Plant_Z) in 2014 and 2015. Transgressive segregation was observed for all traits in both years. The broad-sense heritability on a 2-year basis varied from 0.38 (Flower_C) to 0.82 (Flower_L). Ten QTL were consistently identified in both years and by two mapping strategies [multiple QTL mapping (MQM) in MapQTL and inclusive composite interval mapping (ICIM) in IciMapping]. Major QTL explained up to 30.2, 35.5, and 47.1% of the total phenotypic variation for Plant_S, Flower_L, and Flower_D, respectively. These findings should be of significant values for introgression of desirable genes from wild petunias into commercial varieties and future genetic improvement of this important flower.