Identification of hybridization and introgression between Cinnamomum kanehirae Hayata and C. camphora (L.) Presl using genotyping-by-sequencing

Chia-Chen Wu,Yolanda Gogorcena,Fang-Hua Chu,Shu-Hwa Chang,Chih-Wei Tung,Cheng-Kuen Ho

doi:10.1038/s41598-020-72775-0

Abstract

Cinnamomum kanehirae Hayata and C. camphora (L.) Presl are important tree species in eastern Asia. The wood of C. kanehirae is in increasing demand for culturing Antrodia cinnamomea, a medicinal fungus that naturally grows inside the trunk of C. kanehirae. Putative hybrids between C. kanehirae and C. camphora were previously reported but with no scientific evidence, leading to confusion or misplanting. First, to identify the female parent of putative hybrids, the maternal inheritance InDel (insertion/deletion) markers were developed by using low-coverage sequencing. SNPs were developed by using genotyping-by-sequencing (GBS) approach in C. kanehirae, C. camphora and putative hybrids. The results indicated that the female parent of the studied hybrids was C. camphora. Eight hundred and forty of the 529,006 high-density SNPs were selected and used for analysis. Hybrids were classified as F1 (C. kanehirae × C. camphora), F2 and backcrosses. Hybridization has occurred in the human-developed area of eastern and southwestern Taiwan, and the introgression was bidirectional. For producing pure wood, buffering zones should be established around seed orchards to avoid cross-species pollination and to preserve the genetic purity of C. kanehirae. The DNA markers developed in this study will also be valuable for further wood identification, breeding and evolutionary research.

Highlights

Cinnamomum kanehirae Hayata and C. camphora (L.) Presl are important tree species in eastern Asia
All of the genotypes of ZS_CK InDel_1 in putative hybrid samples showed the same profile as C. kanehirae, different from the C. camphora profile (Fig. 1A,B)
The marker JLH2_CK InDel_4 is recognized as a nuclear and codominant marker, and its profile in all putative hybrids (F1) showed two clear double bands (152 bp and 227 bp), where one DNA fragment is identical to C. kanehirae (152 bp) and the other DNA fragment is identical to C. camphora (227 bp) (Fig. 1C,D)

Summary

Introduction

Cinnamomum kanehirae Hayata and C. camphora (L.) Presl are important tree species in eastern Asia. SNPs were developed by using genotyping-by-sequencing (GBS) approach in C. kanehirae, C. camphora and putative hybrids. Genotyping-by-sequencing (GBS) is a direct sequencing approach based on the high-throughput next-generation sequencing (NGS) of genomic subsets targeted by restriction enzymes[5] This approach can be generalized for any plant species at a low per-sample cost, providing an incredible number of markers. Its wood is in high demand due to its unique usage for culturing the naturally parasitized fungus Antrodia cinnamomea Chang and Chou. This fungus parasitizes inside of the C. kanehirae wood and has been used as a Chinese medicine known to have many pharmacological effects, with prices above 10,000 US$ per k ilogram[12,13,14]. To avoid the loss of C. kanehirae genetic diversity and the misuse of hybrid woods, it is very important to further understand hybrids between these two species in the wild

Results

Discussion

Conclusion