Low genetic differentiation among altitudes in wild Camellia oleifera, a subtropical evergreen hexaploid plant
- 232 Downloads
Camellia oleifera is a subtropical evergreen plant. Cultivated C. oleifera is the most important woody oil crop in China. Wild C. oleifera is an essential genetic resource for breeding. The patterns of genetic differentiation among altitudes/latitudes in wild C. oleifera are still unknown. Camellia oleifera may be predominantly hexaploid. The characteristics of polyploidy may lead to considerable biases in estimates of genetic diversity and differentiation. Our study used C. oleifera as a case study for analysing genetic diversity, structure and differentiation in polyploid plants using simple sequence repeats (SSRs). Wild C. oleifera samples were collected at different altitudes on the Jinggang and Lu mountains of China. The ploidy levels were determined with flow cytometry analysis. Eight highly polymorphic SSRs were used to genotype the samples. Genetic diversity and structure were analysed. Various estimates of genetic differentiation were compared. The flow cytometry results indicated that wild C. oleifera samples were all hexaploid at various altitudes of the Jinggang and Lu mountains. High levels of genetic diversity were found on both the Jinggang and Lu mountains. Genetic structure analyses indicated clear genetic differentiation between the Jinggang and Lu mountains and lower genetic differentiation among altitudes within each mountain. Classical genetic differentiation estimates of Fst failed to discriminate genetic differentiation between and within mountains. The Rho statistic showed a moderate level of genetic differentiation between mountains and lower levels of genetic differentiation within each mountain. Our study demonstrates that Rho is the statistic of choice for estimating genetic differentiation in polyploids.
KeywordsCamellia oleifera Genetic differentiation Genetic diversity Genetic structure Polyploid Simple sequence repeat
We thank Dr. Patrick G. Meirmans for suggestions for the data analyses.
This work was supported by the National Natural Science Foundation of China (NSFC Grant No. 31460072) and the “Gan-Po Talent 555” Project of Jiangxi Province, China.
Compliance with ethical standards
Data archiving statement
The SSR primers used in the study are available in Table 1.
- Ackerman WL (1971) Genetic and cytological studies with Camellia and related genera. Technical bulletin no. 1427, Agricultural Research Service, USDA. US Government Printing Office, Washington, DCGoogle Scholar
- Clark LV (2016) Assigning alleles to isoloci in polysatGoogle Scholar
- Hedrick PW (2005) A standardized genetic differentiation measure. Evolution 59(8):1633–1638. https://doi.org/10.1111/j.0014-3820.2005.tb01814.x CrossRefPubMedGoogle Scholar
- Meirmans PG (2006) Using the AMOVA framework to estimate a standardized genetic differentiation measure. Evolution 60(11):2399–2402. https://doi.org/10.1111/j.0014-3820.2006.tb01874.x CrossRefPubMedGoogle Scholar
- Ming TL (2000) Monograph of the genus Camellia. Yunnan Science and Technology Press, KunmingGoogle Scholar
- Shi M-M, Michalski SG, Chen X-Y, Durka W (2011) Isolation by elevation: genetic structure at neutral and putatively non-neutral loci in a dominant tree of subtropical forests, Castanopsis eyrei. PLoS One 6(6):e21302. https://doi.org/10.1371/journal.pone.0021302 CrossRefPubMedPubMedCentralGoogle Scholar
- Zhao Y, Vrieling K, Liao H, Xiao M, Zhu Y, Rong J, Zhang W, Wang Y, Yang J, Chen J, Song Z (2013) Are habitat fragmentation, local adaptation and isolation-by-distance driving population divergence in wild rice Oryza rufipogon? Mol Ecol 22(22):5531–5547. https://doi.org/10.1111/mec.12517 CrossRefPubMedGoogle Scholar
- Zhuang RL (2008) C. oleifera in China, 2nd edn. China Forestry Publishing House, BeijingGoogle Scholar