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Title: Modularity and selection of nectar traits in the evolution of the selfing syndrome in Ipomoea lacunosa (Convolvulaceae)
Summary

Although the evolution of the selfing syndrome often involves reductions in floral size, pollen and nectar, few studies of selfing syndrome divergence have examined nectar. We investigate whether nectar traits have evolved independently of other floral size traits in the selfing syndrome, whether nectar traits diverged due to drift or selection, and the extent to which quantitative trait locus (QTL) analyses predict genetic correlations.

We use F5 recombinant inbred lines (RILs) generated from a cross betweenIpomoea cordatotrilobaandIpomoea lacunosa. We calculate genetic correlations to identify evolutionary modules, test whether trait divergence was due to selection, identify QTLs and perform correlation analyses to evaluate how well QTL properties reflect genetic correlations.

Nectar and floral size traits form separate evolutionary modules. Selection has acted to reduce nectar traits in the selfingI. lacunosa. Genetic correlations predicted from QTL properties are consistent with observed genetic correlations.

Changes in floral traits associated with the selfing syndrome reflect independent evolution of at least two evolutionary modules: nectar and floral size traits. We also demonstrate directional selection on nectar traits, which is likely to be independent of selection on floral size traits. Our study also supports the expected mechanistic link between QTL properties and genetic correlations.

 
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PAR ID:
10361277
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
New Phytologist
Volume:
233
Issue:
3
ISSN:
0028-646X
Page Range / eLocation ID:
p. 1505-1519
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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