Evolutionary ecology of plant carbon acquisition traits: fitness consequences of plant kin recognition

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My lab has shown plant kin recognition; that is, plant traits are affected by whether neighbours are kin or strangers. Other researchers have now found similar results. The next step is determine how these responses affect plant performance. We hypothesize that plants will compete less and cooperate more with sibling neighbours. However, experimentally demonstrating the fitness consequences of kin recognition is difficult. I am proposing a three-pronged approach to understanding the fitness consequences of kin recognition responses in plants. In parallel research programs, my lab will 1) measure natural selection on traits that show kin recognition in that species; 2 ) determine whether there are fitness benefits of increased mycorrhizal production in siblings; and 3) examine how tradeoffs among life history traits are affected by growing with kin or strangers. In the first component, I will use a multilevel selection analysis approach to determine how plant traits can benefit or harm neighbours. However, because so many of the traits that show plant kin recognition are allocation traits that can only be measured destructively, I propose to incorporate a version of Rausher's family selection, in which early allocation will be measured on some members of a family, while fitness is measured on others. We will scale this methodology up with multiple known lines, measuring kin recognition and its consequences in low and high nutrient levels. In the second component, I will investigate the fitness consequences of the increased mycorrhizal association in sibling groups. Because mycorrhizae are frequently associated with plants and can provide benefits, this increased association sibling groups provides a potential mechanism for increasing fitness in sibling groups. In the third component, we will measure kin recognition in life history traits. Growth with siblings vs. strangers may affects trait such as age-specific survivorship and fecundity, by affecting the tradeoffs among these traits. ***Understanding the fitness consequences of kinship will provide crucial information on how plant kin recognition evolves. It will indicate whether these population processes, through their interaction with mycorrhizae, have implications for ecosystem processes. Knowing how the traits expressed plants in groups of closely related individuals increase their fitness has practical applications for agriculture, horticulture, and forestry in Canada and the world.*****