Evidence of Delayed Selfing inFumana juniperina(Cistaceae)

Abstract

Several aspects of the reproductive biology of Fumana juniperina were analyzed to find out whether delayed selfing occurs within a representative natural population in southwest Sardinia. Similar fruit set was obtained after autonomous, within-flower, and between-flower self-pollination (0.35, 0.53, and 0.46, respectively), crosspollination (0.45), and control (0.39). Seed set and seed mass did not differ significantly between pollination treatments (P > 0:05). Autonomous self-pollination was favored at the end of floral anthesis, when the petals fell and the sepals closed and pushed the anthers onto the stigma, making contact. No pollinators were seen visiting the flowers during the 42-h observation period, and the stigmatic pollen load on open-pollinated flowers, collected after the petals had fallen and before anther and stigma contact had occurred, was not enough to fertilize all the ovules. Low levels of inbreeding depression were found for fruit set (d ¼ À0:167), seed set (d ¼ À0:086), seed mass (d ¼ 0:008), and seed germination (d ¼ À0:052). These results support the idea that F. juniperina is selfcompatible and capable of autonomous self-pollination through changes in the position of the stigma and anthers at the end of floral anthesis. This is a case of how delayed selfing can be an efficient mating strategy that ensures reproduction in this plant when pollinators are scarce. This is the first time that a mechanism of delayed selfing has been described within the family Cistaceae.

Reproduction and Propagation of Some Rare Species of the Crimean Flora

“…At the end of flowering flowers in the case of lack of allogamy, they can also have autogamy. A similar phenomenon is observed, for example, in some other species of the genus Fumana (Güemes, Boscaiu, 2001;Carrio et al, 2008).…”

The best of both worlds? A review of delayed selfing in flowering plants

“…A special case of abscission-induced selfing occurs in Incarvillea sinensis (Bignoniaceae), whose senescent corollas are dragged off the inflorescence by wind (Qu et al, 2007). Finally, closure or wilting of flowers contributes to selfing by forcing stigma and anthers together in Fumana juniperina (Cistaceae; Carrió et al, 2008) and 11 other genera.…”

“…In contrast, six species clearly displayed a "selfing syndrome" (Ornduff, 1969;Sicard and Lenhard, 2011), including small flowers, low pollen production and low pollen/ovule ratios (e.g., Fumana juniperina, Carrió et al, 2008; Geranium carolinianum (Geraniaceae), Shirk and Hamrick, 2014). To gain more insight, we asked how flower size or pollen production in delayed-selfers compared with their obligately outcrossing relatives.…”

“…In some, floral traits that promote outcrossing are reduced and/or strong benefits of outcrossing are lacking, as indicated by low inbreeding depression. Inbreeding depression was reported for only one species with a reduced floral display (Fumara juniperina) and, notably, outcrossed offspring were found to have no fitness advantage over selfed (Carrió et al, 2008). On the selfing side, most species have high capacity for autonomous selfing, but in some cases autofertility is lower than that of related species with earlier modes of selfing.…”

“…Delayed selfing by corolla closure or abscission clearly represents a secondary function for a pre-existing phenomenon. For example, selfing occurs in Fumana juniperina when flowers close at senescence, yet floral closure is widespread in the predominantly SI family (Carrió et al, 2008). When a trait takes on a different function in a derived species, we might expect it to have been altered in some way to accomplish the new task (Gould and Vrba, 1982).…”