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Abstract Copy number variation (CNV) is a major part of the genetic diversity segregating within populations, but remains poorly understood relative to single nucleotide variation. Here, we report on atRNAligase gene (Migut.N02091;RLG1a) exhibiting unprecedented, and fitness‐relevant,CNVwithin an annual population of the yellow monkeyflowerMimulus guttatus.RLG1a variation was associated with multiple traits in pooled population sequencing (PoolSeq) scans of phenotypic and phenological cohorts. Resequencing of inbred lines revealed intermediate‐frequency three‐copy variants ofRLG1a (trip+;5/35 = 14%), andtrip+lines exhibited elevatedRLG1a expression under multiple conditions.trip+carriers, in addition to being over‐represented in late‐flowering and large‐flowered PoolSeq populations, flowered later under stressful conditions in a greenhouse experiment (p < 0.05). In wild population samples, we discovered an additional rareRLG1a variant (high+) that carries 250–300 copies ofRLG1a totalling ~5.7 Mb (20–40% of a chromosome). In the progeny of ahigh+carrier, Mendelian segregation of diagnostic alleles andqPCR‐based copy counts indicate thathigh+is a single tandem array unlinked to the single‐copyRLG1a locus. In the wild,high+carriers had highest fitness in two particularly dry and/or hot years (2015 and 2017; bothp < 0.01), while single‐copy individuals were twice as fecund as eitherCNVtype in a lush year (2016:p < 0.005). Our results demonstrate fluctuating selection onCNVs affecting phenological traits in a wild population, suggest that planttRNAligases mediate stress‐responsive life‐history traits, and introduce a novel system for investigating the molecular mechanisms of gene amplification.
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Intraspecific Functional Trait Variation and Coordination in Schizachyrium scoparium
ABSTRACT Plant functional traits are vital tools in ecological restoration and biodiversity conservation. While functional traits and functional diversity are increasingly being used to inform restoration efforts, challenges remain in the characterization of trait variation in many systems, including within‐species. Likewise, understanding axes of trait variation describing trade‐offs in plant function is important for trait‐based restoration frameworks, yet the degree of coordination between above‐ground functional traits and their below‐ ground counterparts is often unknown. Here, we investigate intraspecific trait variation among five populations ofSchizachyrium scoparium(little bluestem), a species commonly used for restoration, from different habitat types across a gradient from southern Wisconsin to Northern Illinois. We asked (1) how regional populations ofS. scopariumdiffer in their functional traits, (2) how functional trait variation inS. scopariumis structured among and within populations, and (3) how above‐ and below‐ground functional traits ofS. scopariumcoordinate and describe axes of functional trade‐offs. We found that populations differed in multivariate trait space, but evidence for differences in individual traits among populations was mixed. Trait relationships with habitat types were idiosyncratic and often misaligned with expectations of plant economic spectra. Variation within populations was as high, or higher, than between populations across traits. We found evidence for weak coordination in several trait pairs, including two above‐ and below‐ground trait combinations, while others appeared to be uncoordinated. Our findings support previous research that trait differentiation can occur at multiple scales, both between and within populations. Extensive within‐population trait variability could be leveraged in trait‐based restoration frameworks targeting intraspecific functional diversity. The lack of strong signals of coordination between above‐ and below‐ground functional traits suggest that sourcing decisions meant to match below‐ground functional traits to recipient restored communities should rely on direct measurement of root traits associated with desired functions rather than above‐ground proxies.
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- Award ID(s):
- 2149888
- PAR ID:
- 10614854
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecology and Evolution
- Volume:
- 15
- Issue:
- 7
- ISSN:
- 2045-7758
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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