Biodiv Sci ›› 2010, Vol. 18 ›› Issue (4): 414-419.DOI: 10.3724/SP.J.1003.2010.414

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Identifying cryptic species in pollinating-fig wasps by PCR-RFLP on mtDNA COI gene

Yiyi Long, Liyuan Yang, Wanjin Liao()   

  1. Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University, Beijing 100875
  • Received:2010-04-22 Accepted:2010-06-26 Online:2010-07-20 Published:2010-07-20
  • Contact: Wanjin Liao

Abstract:

Cryptic species are morphologically undetected yet genetically divergent species. The presence of cryptic pollinating-fig wasp species has potentially important implications for understanding fig/fig-wasp mutualisms and the coexistence of cryptic species. It is essential to identify cryptic species quickly and accurately using molecular markers since the species are morphologically undistinguishable. We used PCR-RFLP to analyze the mtDNA COI gene in cryptic species of Ceratosolen emarginatusandC. gravelyi. The PCR-RFLP was useful for determining the composition of cryptic pollinating-fig wasp species. Ceratosolen emarginatus included two cryptic species (A and B) with an XhoI and a BssSI digesting site in the COIgene, respectively. Ceratosolen gravelyi included two cryptic species with a BmrI and an AvaI digesting site, respectively. Genomic DNA samples were extracted from a mixture of cryptic species A and B withinC. emarginatus, and XhoI andBssSI endonucleases were used to digest the amplified COIfragments. XhoI-specific fragments were found when cryptic species A was present, and BssSI-specific fragments were found when cryptic species B was present. The digestion of COI gene with BmrI andAvaI in two cryptic species ofC. gravelyi showed similar results. Taken together, PCR-RFLP, based on PCR and DNA restriction enzyme digestion, can quickly and accurately identify cryptic pollinating-fig wasp species.

Key words: cryptic species, PCR-RFLP, COI, pollinating-fig wasp, species identification