title: Eco-geographically divergent diploids, Caucasian clover (Trifolium ambiguum) and western clover (T. occidentale), retain most requirements for hybridization
abstract: Partially fertile hybrids between Trifolium ambiguum and T. occidentale were obtained for the first time. The F(1) hybrids produced seeds after open-pollination, and also produced triploid progeny in backcrosses to T. occidentale from the functioning of unreduced gametes in the hybrids. These plants were fertile and produced progeny with T. occidentale and with T. repens. Meiotic chromosome pairing in the F(1) showed six to eight bivalents per pollen mother cell, indicating pairing between the p
journal: Annals of Botany