Affiliations 

  • 1 Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008 USA
  • 2 Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Cambridge, Massachusetts 02138 USA
  • 3 National Aeronautics and Space Administration, Washington, D.C. 20546 USA
  • 4 Rimba Ilmu Botanic Garden, Institute of Biological Sciences, University of Malaya 50603 Kuala Lumpur, Malaysia
  • 5 Queen Sirikit Botanic Garden 50180 Chiang Mai, Thailand
Am J Bot, 2017 09;104(9):1382-1389.
PMID: 29885244 DOI: 10.3732/ajb.1700117

Abstract

PREMISE OF THE STUDY: Partitioning of population genetic variation in plants may be affected by numerous factors including life history and dispersal characteristics. In parasitic plants, interactions with host populations may be an additional factor influencing partitioning. To test for hierarchical population genetic patterns related to obligate endoparasitism, we studied three species of Rafflesiaceae, which grow as extremely reduced endophytes infecting Tetrastigma vines in Southeast Asia.

METHODS: Microsatellite markers were developed and multilocus genotypes were determined for Rafflesia cantleyi, Rafflesia tuan-mudae, and Sapria himalayana and each of their Tetrastigma hosts. Relatedness among parasite individuals was estimated, and AMOVAs were used to determine levels of population genetic subdivision.

KEY RESULTS: Microsatellite genotypes for 340 paired parasite and host samples revealed that host vines were infected by numerous Rafflesiaceae individuals that may spread for up to 14 m within stem tissues. Surprisingly, Rafflesiaceae parasites within a given host are significantly more closely related to each other than individuals of the same species in other host individuals. The pattern of hierarchical population genetic subdivision we detected across species is likely due to limited seed dispersal with reinfection of natal host vines.

CONCLUSIONS: These findings demonstrate common population genetic patterns between animal and plant parasites, potentially indicating advantages of close relatives infecting hosts. This study also has important conservation implications for Rafflesiaceae since our data suggest that destruction of a single infected host vine could result in large genetic losses.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.