Breeding systems in the grasses: a survey

Abstract

The grasses, a family of about 700 genera and 10 000 species, display a range of breeding systems from dioecism at one extreme, to autonomous apomixis at another. Between these points are systems common to flowering plants as a whole: self-incompatibility but with a specialised two-gene system, protogyny, self-compatibility, cleistogamy including subterranean cleistogenes, and various grades of monoecism and dioecism. Significant absences are heterostyly, and sporophytic control in incompatibility. For many genera, structural details of the flower are incomplete and limit an interpretation of the probable reproductive system.