Genetic Characterization of Chinese fir from Six Provinces in Southern China and Construction of a Core Collection

Hongjing Duan,Jun Lin,Bo Wu,Dehuo Hu,Binbin Cui,Huiquan Zheng,Yun Li,Ruiyang Hu,Sen Cao,Huazhong Lin,Yuhan Sun

doi:10.1038/s41598-017-13219-0

Abstract

Large ex situ germplasm collections of plants generally contain significant diversity. A set of 700 well-conserved Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) clones from six provinces in southern China in the ex situ gene bank of Longshan State Forest, was analyzed using 21 simple sequence repeat markers, with the aim of assessing the genetic diversity of these germplasm resources. Genetic analysis revealed extensive genetic variation among the accessions, with an average of 8.31 alleles per locus and a mean Shannon index of 1.331. Excluding loci with null alleles, we obtained a low level of genetic differentiation among provinces, consistent with the interpopulation genetic variation (1%). Three clusters were identified by STRUCTURE, which did not match the individuals’ geographical provenances. Ten traits related to growth and wood properties were quantified in these individuals, and there was substantial variation in all traits across individuals, these provide a potential source of variation for genetic improvement of the Chinese fir. Screening large collections for multiple-trait selective breeding programs is laborious and expensive; a core collection of 300 accessions, representative of the germplasm, was established, based on genotypic and phenotypic data. The identified small, but diverse, collections will be useful for further genome-wide association studies.

Highlights

To assess genetic variability, morphological characteristics are often used, they can be affected by environmental conditions
Twenty-one simple sequence repeat (SSR) markers were used to evaluate the genetic diversity among 700 clones of the Chinese fir from six different provinces
The substantial variation identified provides a potential opportunity for genetic improvement of the Chinese fir

Summary

Introduction

Morphological characteristics are often used, they can be affected by environmental conditions. To improve conservation and the effective use of genetic resources, core collections[15] are often used as materials for association analyses[16,17]. The Chinese fir [Cunninghamia lanceolata (Lamb.) Hook], belonging to the Taxodiaceae family, which is diploid (2n = 2x = 22)[18], is the principal indigenous tree species in subtropical southern China. It is an economically valuable conifer with high yield, good wood quality, high pest resistance, and many uses, including as furniture or paper material. A core collection is needed to establish a program of molecular marker-assisted selection breeding to improve the efficient use of Chinese fir in the future. A core collection that can represent the whole collection was built

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Conclusion