Reproductive ecology of Seseli ghafoorianum (Apiaceae) restricted to rocky cliffs in Iran

Abstract

: Endemic and relict species are of particular interest when evaluating the ecological intactness of a given area. In this paper, thereproductive ecology of Seseli ghafoorianum (Apiaceae) is investigated, aiming to contribute to its protection. The species is considered asa Tertiary relict species in Iran. Both dwarf form and cliff habitats are rare in the family, raising the question of how the plant has adaptedto this environment. Population structure, plant architecture and flowering sequence, pollinators, pollen quantification, and seed set(bagging experiment) were investigated. Individuals produce about 20 flowering branches with ca. 120 umbels. Flowers and umbels areprotandrous. The female stage of the terminal umbels usually overlaps the maleness of the 1st order umbels promoting geitonogamy. Thepollen/ovule ratio is about 30,000:1, indicating outcrossing. The degree of andromonoecy (>70%) and pollen vitality (~90%) indicatethat pollen availability is not a limiting factor. In contrast, fruit set is low (~7%). It depends on the presence of pollinators (Lasioglossum),which is low, most likely due to the use of pesticides. The population furthermore suffers from the low survival rate of seedlings (0.02%).S. ghafoorianum appears to be an outcrossing species suffering from low pollinator and survival rates. To protect the species, use ofpesticides and grazing should be reduced.