J Syst Evol ›› 2014, Vol. 52 ›› Issue (3): 363-367.DOI: 10.1111/jse.12082

• Research Articles • Previous Articles     Next Articles

Better than nothing: Evolution of autonomous selfing under strong inbreeding depression in an alpine annual from the Qinghai–Tibet Plateau

1,2Chan ZHANG 3Guo‐Ying ZHOU 1,4,5Yong‐Ping YANG 1,4,5Yuan‐Wen DUAN*   

  1. 1(Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China)
    2(University of the Chinese Academy of Sciences, Beijing 100049, China)
    3(Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China)
    4(Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China)
    5(Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China)
  • Received:2013-11-17 Published:2014-05-09

Abstract: In plants with infrequent pollinator services, the benefits of reproductive assurance could be eroded by severe ovule discounting and inbreeding depression (ID). However, it remains unclear how selfing evolves under complete pollinator failure and strong ID. We examined the mating system and ID under netting and robbing conditions in Comastoma pulmonarium (Turcz.) Toyok. (Gentianaceae), an alpine annual experiencing a high ratio of nectar robbery on the Qinghai–Tibet Plateau.Comastoma pulmonarium produced seeds via selfing at the study site. No pollinator was observed and thus the nectar was consumed exclusively by robbers. Inbreeding depression occurred in the life stages of seed mass and germination, and the cumulative ID was much higher than 0.5 under netting and robbing conditions. Overall, in comparison with netting, the magnitude of ID under robbing conditions tended to decrease. Our results suggested that selfing could assure reproduction for plants under complete pollinator failure and strong ID, supporting the “better than nothing” role of selfing and providing one of the few cases of the evolution of selfing under strong ID.

Key words: autonomous selfing, Comastoma pulmonarium, Gentianaceae, inbreeding depression, nectar robbery, pollinator failure, reproductive assurance.