Tree Genetics & Genomes

, 12:93 | Cite as

Pollen-mediated gene flow promotes low nuclear genetic differentiation among populations of Cycas debaoensis (Cycadaceae)

  • Yi-Qing Gong
  • Xun GongEmail author
Original Article
Part of the following topical collections:
  1. Population structure


Cycas debaoensis is a critically endangered cycad species endemic to China. This species is found on two kinds of habitats according to the edaphic differences, sand and karst. A previous chloroplast DNA (cpDNA) study indicated that C. debaoensis had low genetic variation within populations and high genetic differentiation among populations. Because maternally inherited cpDNA does not fully characterize genetic structure of the species, we screened seven low-copy nuclear genes and 17 nuclear microsatellite loci to detect the nuclear genetic diversity, differentiation, and the population structure of C. debaoensis. The nuclear genes revealed higher level of genetic diversity. There were both the same and region-specific haplotypes or alleles between the karst and sand regions. Nuclear gene flow among all the populations was much greater than that of cpDNA, which indicated that pollen-mediated gene flow was much greater than seed-mediated gene flow. This promoted low nuclear genetic differentiation among populations of C. debaoensis. The study suggests that both genetic and anthropogenic disturbances have resulted in the critically endangered status of C. debaoensis.


Cycas debaoensis Genetic differentiation Population structure Gene flow Conservation 



The authors thank Prof. Yu-Chung Chiang from National Sun Yat-sen University, Taiwan for sharing the primers information of low-copy nuclear genes. This research was supported by the United Fund of the NSFC and the Yunnan Natural Science Foundation (U1136602 to X.G.).

Data archiving statement

Our nuclear sequences have been deposited in GenBank, and their accession numbers are KT761200–KT761289, and the details were in Supplemental File 7 Table S5. Primer sequences of the SSR markers used in this study are provided in Supplementary File 2 Table S2.

Supplementary material

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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of BotanyChinese Academy of SciencesKunmingChina

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