J Syst Evol ›› 2014, Vol. 52 ›› Issue (4): 500-507.DOI: 10.1111/jse.12077

• Research Articles • Previous Articles     Next Articles

Evidence for natural hybridization between Primula beesiana and P. bulleyana, two heterostylous primroses in NW Yunnan, China

1Yong-Peng MA 1Xiao-Ling TIAN 2Jing-Li ZHANG 1,3Zhi-Kun WU* 1Wei-Bang SUN*   

  1. 1(Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China)
    2(Yunnan Agricultural University, Kunming, China)
    3(Lijiang Forest Ecosystem Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China)
  • Received:2013-10-17 Published:2014-03-07

Abstract: Natural hybridization was assumed to play an essential role for the diversification of Primula; however, only one study of hybridization in the region of the Himalayas has been undertaken. In the present study, we examined another natural hybrid zone where morphologically putative hybrids as well as P. beesiana Forrest, P. bulleyana Forrest, and P. poissonii Franch. co-occurred. We used molecular data to confirm the parental species of putative hybrids and the unidirectional hybridization pattern between P. beesiana and P. bulleyana. Moreover, with reference to synthetic F1s, most hybrids examined are possibly advanced generations, although the possibility of F1 hybrids currently examined could not be completely excluded. In addition, pollinator observations on experimental arrays of transplanted parental species showed interspecific pollen flows during visitations of shared pollinators, indicating an incomplete pre-zygotic barrier between P. beesiana and P. bulleyana. Seed productions from both flower morphs of putative hybrids were significantly lower than parental species, suggesting lower reproductive success in these hybrids. Combined with the evidence of recent habitat disturbance in the study area, we might witness the early process of hybridization between P. beesianaand P. bulleyana.

Key words: natural hybridization, P. beesiana, P. bulleyana, reproductive success, pollinator behavior, synthetic F1s.