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Title: Convergent evolution of root system architecture in two independently evolved lineages of weedy rice
Summary

Root system architecture (RSA) is a critical aspect of plant growth and competitive ability. Here we used two independently evolved strains of weedy rice, a de‐domesticated form of rice, to study the evolution of weed‐associatedRSAtraits and the extent to which they evolve through shared or different genetic mechanisms.

We characterised 98 two‐dimensional and three‐dimensionalRSAtraits in 671 plants representing parents and descendants of two recombinant inbred line populations derived from two weed × crop crosses. A random forest machine learning model was used to assess the degree to which root traits can predict genotype and the most diagnostic traits for doing so. We used quantitative trait locus (QTL)mapping to compare genetic architecture between the weed strains.

The two weeds were distinguishable from the crop in similar and predictable ways, suggesting independent evolution of a ‘weedy’RSAphenotype. Notably, comparativeQTLmapping revealed little evidence for shared underlying genetic mechanisms.

Our findings suggest that despite the double bottlenecks of domestication and de‐domestication, weedy rice nonetheless shows genetic flexibility in the repeated evolution of weedyRSAtraits. Whereas the root growth of cultivated rice may facilitate interactions among neighbouring plants, the weedy rice phenotype may minimise below‐ground contact as a competitive strategy.

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Award ID(s):
1638507
NSF-PAR ID:
10461458
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
New Phytologist
Volume:
223
Issue:
2
ISSN:
0028-646X
Page Range / eLocation ID:
p. 1031-1042
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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