“…In most self-incompatible plant species that have been studied, SI is controlled by a single multiallelic S locus (Takayama and Isogai, 2005;Yang et al, 2008). Grasses that have been examined display gametophytic SI controlled by two multiallelic, independent loci, S and Z (Cornish et al, 1979;Gertz andWricke, 1989, Yang et al, 2008). Grasses that have been examined display gametophytic SI controlled by two multiallelic, independent loci, S and Z (Cornish et al, 1979;Gertz andWricke, 1989, Yang et al, 2008).…”