Abstract
PREMISE: Inbreeding depression, or the reduction in fitness of progeny with related parents, has the potential to adversely affect the long-term viability of both wild and captive plant populations. Silphium integrifolium, a prairie plant native to the central United States, has been identified as a potential candidate for domestication as a perennial oilseed crop. Little is known about the potential for inbreeding depression in this species, but it is expected to be nonnegligible because S. integrifolium is both perennial and self-incompatible. Here, we measure lethal inbreeding depression expressed through embryo deaths, and nonlethal inbreeding depression expressed through changes in vigor and fitness phenotypes of progeny. METHODS: First, we made controlled crosses among related and unrelated individuals to determine the effect of two different levels of inbreeding on seed production. Then, we grew inbred and outbred progeny from this population to reproductive maturity and measured 11 key traits. RESULTS: We found that within an improved S. integrifolium population, individuals carried an average of slightly less than one lethal allele per gamete. In progeny, significant inbreeding depression was observed in at least one family for eight of the 11 measured traits. CONCLUSIONS: Inbreeding depression is likely to be an important challenge to S. integrifolium domestication, reducing overall population fecundity and values for important phenotypes. These effects may grow worse as selection reduces effective population size. We recommend several strategies for S. integrifolium breeding to help mitigate these problems.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 980-992 |
| Number of pages | 13 |
| Journal | American journal of botany |
| Volume | 108 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2021 |
Bibliographical note
Funding Information:Funding for this work was provided by The Perennial Agriculture Project in conjunction with The Land Institute and the Malone Family Land Preservation Fund, and the United States Department of Agriculture’s National Institute of Food and Agriculture Grant no. 2019‐67011‐29607. The authors thank Dr. David Van Tassel for providing the original plant material for this study and insights in the writing process; Karen Beaubien for her assistance in making crosses for this experiment; and Dr. Ruth Shaw, Dr. Jeffrey Neyhart, and Laura Price for their helpful feedback and input in the writing of this manuscript. The authors also thank our anonymous reviewers and associate editor, who provided valuable and thoughtful feedback that helped to substantially improve this manuscript.
Funding Information:
Funding for this work was provided by The Perennial Agriculture Project in conjunction with The Land Institute and the Malone Family Land Preservation Fund, and the United States Department of Agriculture?s National Institute of Food and Agriculture Grant no. 2019-67011-29607. The authors thank Dr. David Van Tassel for providing the original plant material for this study and insights in the writing process; Karen Beaubien for her assistance in making crosses for this experiment; and Dr. Ruth Shaw, Dr. Jeffrey Neyhart, and Laura Price for their helpful feedback and input in the writing of this manuscript. The authors also thank our anonymous reviewers and associate editor, who provided valuable and thoughtful feedback that helped to substantially improve this manuscript.
Publisher Copyright:
© 2021 Botanical Society of America
Keywords
- Asteraceae
- Silphium integrifolium
- conservation genetics
- domestication
- genetic load
- inbreeding depression
- lethal equivalents
