Biodiv Sci ›› 2017, Vol. 25 ›› Issue (6): 647-653.  DOI: 10.17520/biods.2017001

• Original Papers • Previous Articles     Next Articles

Asymmetric hybridization of Primula secundiflora and P. poissonii in three sympatric populations

Yanping Xie1, Jianli Zhao2, Xingfu Zhu1, Li Li1, Qingjun Li1,2,*()   

  1. 1 Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303
    2 Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091
  • Received:2017-01-01 Accepted:2017-06-17 Online:2017-06-20 Published:2017-07-10
  • Contact: Li Qingjun


Natural hybridization is one of the research hotspots in evolutionary biology. The direction of hybridization is a critical aspect to understanding natural hybridization and interspecific reproductive isolation. Although natural hybridization between Primula secundiflora and P. poissonii has been confirmed in overlapping areas in the Hengduan Mountains, the interspecific hybridization directions among different populations remain unclear. We chose three sympatric populations to test interspecific hybridization directions. Biparentally inherited nuclear internal transcribed spacer (ITS) and maternally inherited chloroplast sequence trnH-psbA techniques were used to confirm hybridization and to test directions. Moreover, hand pollination of intraspecies and interspecies populations were performed to detect which factors influence seed numbers and hybridization patterns. Results of DNA marker analysis suggested that the direction of hybridization was asymmetric in each population, and P. poissonii was found to be the most maternal parent. Intraspecific crossing produced significantly more seeds than interspecific crossing. Primula poissonii produced significantly higher seed numbers when it was treated as the maternal parent. The asymmetric direction may be the result of the asymmetric strength of reproductive barriers between P. secundiflora and P. poissonii. Similar mechanisms of reproductive isolation may contribute to the asymmetric hybridization among the three sympatric sites.

Key words: Primula, sympatric distribution, hybridization direction, asymmetric