Conflict between parent and offspring in plants: predictions, processes and evolutionary consequences

Abstract

In plants, as in animals, conflict occurs between parents and offspring over a range of issues such as allocation of maternal resources to seeds and number of seeds to be packed in a fruit. We have reviewed theoretical bases and empirical evidences for such conflict in plants and present the predictions, processes and evolutionary consequences of such conflict. We have shown that though 'plants can neither sing nor dance' they do indulge in sibling rivalry, fratricide and kin cooperation as intensely as animals do. For this, maternal parents and offspring have evolved strategies that are subtle, yet as effective as those in animals in upholding their respective interests. We argue that the evolution of a number of plant reproductive features can be profitably viewed as strategies and counter-strategies of the offspring and maternal parent towards ensuring their respective interests. For example, features such as polyembry-ony, endosperm, multi-carpellary ovaries which had thus far remained poorly explained, appear to have evolved as maternal counter-strategies against offspring-driven sibling rivalry. Thus, these 'highly anthropomorphic, sociobiological hypotheses' which were suggested to be 'best not applied to plants', have indeed been helpful in providing a new framework to view the evolution of plant reproductive strategies.