QTLs Location of Calyx-related Traits in Tetraploid &lt;i&gt;Dendrobium&lt;/i&gt;

Yu Ren,Jinghua Lu,Zhiqun Zhang,Shaohua Huang,Xia Kong

doi:10.5376/mpb.2019.010.0006

Abstract

In order to identify QTL locus of calyx-related traits in Dendrobium, 190 F1 individuals derived from the crossbreed of tetraploid Dendrobium cultivars D. Mangosteen x D. Burana Pink No.2 were used as materials. Through three years observation of four characteristics of calyx (length of dorsal sepal, width of dorsal sepal, length of lateral sepal, width of lateral sepal), the QTL was located on the two genetic maps of parents which had been already constructed. The result showed that the four characteristics were quite different among the individuals of F1 generation, and the observed values of all the characteristics were all positive distribution, which was suitable for QTL analysis. Nine QTLs were detected on the maternal ‘D. Mangosteen’ genetic linkage map, including 1 QTL for dorsal sepal length, 3 QTLs for dorsal sepal width, 2 QTLs for lateral length and 3 QTLs for lateral width, with the genetic contribution rate ranging from 11.9% to 16.8%. Also, two tight linkage markers were acquired (M10E3-146, M8E8-284). A total of 6 QTLs were detected on the paternal ‘D. Burana Pink No.2’ linkage map, including 2 QTLs for dorsal sepal length, 1 QTL for dorsal sepal width, 2 QTLs for lateral length and 1 QTL for lateral width, with the genetic contribution rate ranging from 11.8% to 17.3%. This result of study could provide reference for Dendrobium molecular marker assisted breeding and precise location of correlation gene.

Highlights

Dendrobium is a kind of perennial herb belongs to the genus Dendrobium of the Orchidaceae, which is an ornamental with bright market prospect
A total of 6 QTLs were detected on the paternal ‘D. Burana Pink No.2’ linkage map, including 2 QTLs for dorsal sepal length, 1 QTL for dorsal sepal width, 2 QTLs for lateral length and 1 QTL for lateral width, with the genetic contribution rate ranging from 11.8% to 17.3%
2 Discussion Dendrobium is a kind of flower with high ornamental value, and its flower is the most important parts for ornamental and it is the significant goal of its breeding

Summary

Introduction

Dendrobium is a kind of perennial herb belongs to the genus Dendrobium of the Orchidaceae, which is an ornamental with bright market prospect. Among tropical orchid, it is listed as “the top four ornamental foreign orchid” with Cattleya, Phalaenopsis, and V anda for their high ornamental value (Zeng and Hu, 2004). The breeding of dendrobium is in traditional way. It costs long time and being inefficient. Because of ploidy’ complexity, which is presented as diploid, triploid, tetraploid and hexaploid, most of the species are diploid (2n=2x=38) (Jones et al, 1998), most of the cultivars are tetraploid (2n=4x=76) (Liao et al, 2012), so the process of dendrobium genetic map construction research is slow

Methods

Results

Conclusion