From competition to cooperation:kin selection against selfish shade avoidance behavior promotes plant invasions

CHEN, LIRU; PAN, YUANFEI; PAN, XIAOYUN; YU, LIANGRUI; ALEJANDRO JOAQUÍN SOSA; YANG, JI; LI, BO

JOURNAL OF ECOLOGY (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023 vol. 111 p. 645 - 654

0022-0477

1.There is conflicting evidence from studies on the fitness consequences of plant kininteractions, suggesting that kinship is not the only important factor in determiningthe outcome of kin interaction.2. Here, we tested whether density-dependent kin interactions have evolved fromcompetition to cooperation by kin selection of reduced shade avoidance responsesfollowing the introduction of an invasive plant. We measured how plants respondto kin neighbors (the same accession) and to simulated vegetation shade (lowerPPFD and R:FR ratio treatments using transparent green plastic filters) anddetermine whether shade avoidance responses affect the outcome of kininteractions using five native (Argentina) and five invasive (USA) accessions ofAlternanthera philoxeroides.3. Our results show that invasive accessions show constant stem elongation butincrease total biomass as canopy density increases, while native accessions showthe opposite. Furthermore, invasive accessions reduce stem elongation, butincrease biomass and defense allocation in response to an experimental treatmentcausing a low R:FR ratio, while native accessions show the opposite.4. Synthesis. Our results support the hypothesis that kin selection against shadeavoidance may effectively promote the evolution of density-dependent kincooperation. This suggests that kin selection pressures may have a larger impact infinetuning plant shade-avoidance responses than generally thought. Kin selectionagainst selfish shade avoidance behavior and release from negative densitydependentregulation provides a new mechanism to explain plant invasion successfor future studies.