Ecological differentiation facilitates fine-scale coexistence of sexual and asexual Boechera.

Journal Article (Journal Article)

Premise of the study

Ecological differentiation (ED) between sexual and asexual organisms may permit the maintenance of reproductive polymorphism. Several studies of sexual/asexual ED in plants have shown that the geographic ranges of asexuals extend beyond those of sexuals, often in areas of higher latitude or elevation. But very little is known about ED at fine scales, wherein coexistence of sexuals and asexuals may be permitted by differential niche occupation.


We used 149 populations of sexual and apomictic lineages in the genus Boechera (rock cress) collected across a portion of this mustard's vast range. We characterized reproductive mode, ploidy, and species identity or hybrid parentage of each individual, and then used a multipronged statistical approach to (1) identify ED between sexuals and asexuals; (2) investigate the impacts of two confounding factors, polyploidy and hybridization, on ED; and (3) determine the environmental variables underlying ED.

Key results

We found that sexuals and asexuals are significantly ecologically differentiated across the landscape, despite fine-scale interdigitation of these two reproductive forms. Asexual reproduction was strongly associated with greater disturbance, reduced slope, and greater environmental variability. Although ploidy had little effect on the patterns observed, hybridization has a unique impact on the relationships between asexual reproduction and specific environmental variables.


Ecological differentiation along the axes of disturbance, slope, and climatic variability, as well as the effects of heterozygosity, may contribute to the maintenance of sexuality and asexuality across the landscape, ultimately impacting the establishment and spread of asexual lineages.

Full Text

Duke Authors

Cited Authors

  • Rushworth, CA; Windham, MD; Keith, RA; Mitchell-Olds, T

Published Date

  • December 2018

Published In

Volume / Issue

  • 105 / 12

Start / End Page

  • 2051 - 2064

PubMed ID

  • 30548985

Pubmed Central ID

  • PMC6685206

Electronic International Standard Serial Number (EISSN)

  • 1537-2197

International Standard Serial Number (ISSN)

  • 1537-2197

Digital Object Identifier (DOI)

  • 10.1002/ajb2.1201


  • eng