Dividing a maternal pie among half-sibs: genetic conflicts and the control of resource allocation to seeds in maize

Resource allocation to offspring is the battleground for various intra-familial conflicts. Understanding these conflicts requires knowledge of how the different actors (mother, siblings with different paternal genotypes) influence resource allocation. In angiosperms, resource to seeds is allocated post-fertilization and the paternally inherited genome in offspring can therefore influence resource allocation. However, the precise mode of resource allocation, and in particular the occurrence of sibling rivalry, has been rarely investigated in plants. In this paper, we develop a new method to analyze the resource allocation traits of the different actors (maternal sporophyte and half-sibs) using the data obtained from a large-scale diallel cross experiment in maize involving mixed hand pollination and colors markers to assess seed weight of known paternity. We found strong evidence for the occurrence of sibling rivalry: all resource to ears was allocated competitively and offspring with di...