Plant Diversity ›› 2019, Vol. 41 ›› Issue (05): 347-351.DOI: 10.1016/j.pld.2019.09.003

• Articles • Previous Articles    

Root hemiparasitism in Malania oleifera (Olacaceae), a neglected aspect in research of the highly valued tree species

Ai-Rong Lia,b, Ping Maoc, Yun-Ju Lid   

  1. a Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China;
    b Yunnan Key Laboratory for Conservation of Plant Species with An Extremely Small Population Size, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China;
    c Guangnan Forestry and Grassland Bureau, Guangnan 663300, China;
    d The State Phosphorus Resource Development and Utilization Engineering Technology Research Centre, Yunnan Phosphate Chemical Group Co. Ltd, Kunming, PR China
  • Received:2019-05-13 Revised:2019-08-28 Online:2019-10-25 Published:2019-11-21
  • Contact: Ai-Rong Li,E-mail;Yun-Ju Li,E-mail
  • Supported by:
    Many thanks to Professor Aizhong Liu from Southwest Forestry University for discussion of problems encountered in cultivation of M. oleifera and for mention of the tuberous structures, which inspired this study. The research was financially supported by funding for Airong Li from Yunnan Ten Thousand Talents Plan Young and Elite Talents Project (YNWR-QNBJ-2018-092), Youth Innovation Promotion Association of Chinese Academy of Sciences (2011276), and Young Academic and Technical Leader Raising Foundation of Yunnan Province (2014HB047), funding for Yunju Li from Young Academic and Technical Leader Raising Foundation of Yunnan Province (2019HB060),and Yunnan Science and Technology Innovation Team Program (Grant No. 2019HC015).

Abstract: Malania oleifera (Olacaceae) is a valued tree species, mostly because its seeds have high precious fatty acid content (particularly nervonic acid). However, seedling mortality rates are often high and regeneration of this tree has been problematic, which greatly hinders its utilization at a large scale. Cultivation difficulties of some tree species in the family Olacaceae have been attributed to their root hemiparasitic habit. Prompted by field observations and the taxonomic proximity of M. oleifera to root hemiparasites in Olacaceae, we hypothesized that tuberous structures observed on the roots of M. oleifera are parasitic organs known as haustoria. To test this hypothesis, we collected root samples from M. oleifera plants of various ages and growth conditions, investigated the morphological and anatomical features of tuberous structures and their connections to neighboring roots. Our analyses confirmed that M. oleifera are root hemiparasites. To the best of our knowledge, this is the first empirical report on root hemiparasitism in M. oleifera. Because life strategies of root hemiparasitic plants differ greatly from autotrophic plants, the root hemiparasitic habit needs to be taken into account for successful seedling regeneration of M. oleifera. This study establishes the foundation for investigations into a long-neglected but essential aspect in research of these highly valued tree species.

Key words: Malania oleifera, Tuberous structures, Haustoria, Root hemiparasitic plants, Olacaceae