Self-incompatibility Franklin-Tong 2002 Franklin-Tong 2002 Igic and Kohn 2001 Kachroo et al. 2001 Kusaba et al. 2001 Matton et al. 1994 Nasrallah 2000 Nasrallah 2002 Shiba et al. 2001 Shiba et al. 2002 Takayama et al. 2000 Takayama et al. 2001