Breeding systems and related floral traits in severalErysimum(Cruciferae)

摘要

The breeding system of 13 populations belonging to eight species ofErysimum(Cruciferae) was studied and its relation with the life-span of the plants is discussed. To assess the breeding system of each population, greenhouse tests for apomixis, self-compatibility, and self-pollination were carried out, morphological characters like petal size and anther length were measured and pollen to ovule ratios were computed. The evidence gathered supports the selfing behavior of the three annuals,E.cheiranthoidesL.,E.incanumG. Kunze, andE.repandumL., and the outcrossing behavior of the perennialsE.linifolium(Pers.) Gay,E.asperum(Nutt.) DC, andE.menziesii(Hook.) Wettst. Among those two groups,E.inconspicuum(S. Wats.) MacMillan andE.suffruticosumSprengel apparently occupy an intermediate position, although the former tends more towards autogamy, whereas the latter tends towards allogamy. The importance of the breeding system data in the systematics of this genus, particularly, in studying the apparent links between the Mediterranean annuals and the temperateE.hieracifoliumL. group is briefly discussed.Key words:Erysimum, breeding systems, pollen to ovule ratio, life-span.