Breeding system in Trifolium glanduliferum (Fabaceae)

Abstract

Trifolium glanduliferum Boiss. var. nervulosum (Boiss. & Heldr.) Zoh., glandular (or gland) clover is an annual pasture species, with Mediterranean origin, recently introduced into Australia. The species was previously reported as self-pollinating. Studies with four accessions originating from Israel clearly suggest that Trifolium glanduliferum is a highly self-incompatible species, which requires vectors including bees to ensure pollination. Unpollinated bagged and hand tripped florets showed no signs of pollen tube growth and no seed set, while cross-pollinated florets showed pollen tube growth and gave high seed set. A high pollen:ovule ratio suggested that the species is between facultative outcrossing and obligate outcrossing.