Biological Invasions (2020) 22, 969-982

José L. Hierro, Özkan Eren, Daniel Montesinos, Krikor Andonian, Liana Kethsuriani, Rabia Özcan, Alecu Diaconu, Katalin Török, Lohengrin Cavieres and Kristine French (2020)
Increments in weed seed size track global range expansion and contribute to colonization in a non-native region
Biological Invasions 22 (3), 969-982
Abstract: Assessing global variation in phenotypic traits and linking that variation to colonization and range expansion is notably rare in invasion biology. Here, we studied variation in seed size in Centaurea solstitialis, a weed with worldwide distribution. Additionally, we explored how seed size variation affects seedling survival of C. solstitialis under favorable precipitation conditions in Anatolia, an ancestral region, and unfavorable precipitation conditions in Argentina, a non-native region. To that end, we conducted seed collections following dispersal pathways of C. solstitialis in ancestral, expanded, and non-native ranges. Locally, collections followed elevation gradients. Also, we performed a greenhouse experiment with C. solstitialis populations varying in seed size and water additions simulating precipitation patterns in Anatolia and Argentina. Seeds from ancestral populations at low elevation were smaller than those from the rest of study populations. Also, seed size in populations at high elevation in the expanded range, the main source of non-native populations, was similar to that in all, but one non-native population, where seeds exhibited further increase. Increments in seed size thus track range expansion in C. solstitialis. Locally, seed size increased with elevation in all three ranges, suggesting convergent responses to that gradient. Seedlings from larger seeds displayed greater survival than those from smaller seeds only under Argentinean conditions. Consequently, populations with large seeds may have been instrumental for colonizing that non-native region. Our findings suggest that ancient and recent dispersal of large-seeded populations contribute to explain the reported global pattern of seed size divergence and worldwide distribution of C. solstitialis.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Daniel Montesinos, Krikor Andonian, Lohengrin A. Cavieres

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Centaurea solstitialis (weed)		Turkey
	Centaurea solstitialis (weed)		Argentina