Fecha de publicación: 09/05/1996 Fuente: WIPO "pollen" Plants in which flavonol activity has been impaired are conditionally male fertile (CMF), and male fertility can be rescued or restored by providing fertility restoring flavonols at pollen sites in the plant. Although viable pollen is produced by flavonol deficient plants, pollen germination and tube growth are severely reduced both $i(in vivo) and $i(in vitro), resulting in plants which are self sterile. However, by contacting pollen of the plant with an amount of a fertility restoring flavonol effective to enhance germination of the pollen, full pollen germination and tube growth may be restored. Useful fertility restoring flavonols include compounds of formula (I), wherein R1, R2, R3, R4, R5, R7, and R8 are hydrogen, hydroxyl or alkoxy having from 1 to 3 carbon atoms. Particularly preferred flavonols include galangin, kaempferol, $i(iso)-rhamnetin, quercetin and morin.