Inter-parent distance affects reproductive success in two clonal dwarf shrubs,Vaccinium myrtillusandVaccinium vitis-idaea(Ericaceae)

Abstract

Clonal propagation and limited dispersal of seeds lead to genetic population structures in which most potential mates are relatives. If the species suffers from inbreeding depression or is self-incompatible, the number of seeds matured per fruit may be limited by the lack of outcrossing by unrelated pollen. We tested for distance-related genetic structure by hand-pollinating plants at increasing distances and measuring fruit set (berries/pollinated flowers) and seed number per fruit in natural populations of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.). Bagging of the flower buds without natural (pollination by insects) or hand-pollination yielded almost no fruit or seed, suggesting that the species are obligately insect pollinated. Self-pollination led to a significant reduction in seed number per fruit and increased seed abortion compared with cross-pollination. Moreover, seed number increased with increasing distance between the pollen donor and pollen recipient. Flight distances of bumblebees were estimated for bilberry by monitoring between-flower and, for lingonberry, between-inflorescence flight distances. About 90% of all flights were at distances of less than 1 m. At this distance, we observed less than the maximum seed number per fruit in hand-pollinations in both study species. Consequently, clonal growth is likely to be an important factor that constrains fruit and seed number in these species.Key words: bumblebee forage distance, clonal, hand-pollination, inter-parent distance, reproductive success, Vaccinium.

Genetic patterns in range-edge populations of <i>Vaccinium</i> species from the central Balkans: implications on conservation prospects and sustainable usage

“…They are all insect-pollinated, and their seeds are dispersed by birds (Ritche 1955(Ritche , 1956Jacquemart 1996;Jacquemart and Thompson 1996;Nuortila et al 2002). They are clonal plant species which reproduce sexually (outcrossing predominates) and vegetativelly through rhizomes.…”

Flavonoid Biosynthesis in Bilberry (Vaccinium Myrtillus L.)

“…Research has been performed on its morphology, growth habit, pollination system, and population dynamics (Flower-Ellis 1971, Sjörs 1989, Jacquemart 1994, Tolvanen 1995, Nuortila et al 2002. Also, its carbon-, nutrition-and water economy has been explored (Havas 1971, Gerdol et al 2000, Grelet et al 2001.…”

Floral distribution, clonal structure, and their effects on pollination success in a self-incompatible Convallaria keiskei population in northern Japan

“…Nevertheless, because spatial distribution by clonal growth often exhibits a nonuniform pattern owing to phenotypic plasticity under heterogeneous environmental conditions (Hutchings and de Kroon 1994;Price and Marshall 1999;Fischer and van Kleunen 2002), the clonal distribution (clumped or intermingled) is not necessarily uniform even within a population. 5 Clonal structure influences patterns of pollen dispersal and mating opportunities of individual plants (Charpentier 2002;Nuortila et al 2002) and, thus, has an impact on reproductive success. For example, in the case of outcrossing entomophilous plants, large clone size and multiplication of flowering shoots from clonal growth may enhance geitonogamy (Handel 1985;Silander 1985;Wilcock and Jennings 1999;Eckert 2000).…”

“…This impact also depends on the magnitude of pollen dispersal, which is affected by the distance pollinators travel between successive flowers (Nuortila et al 2002;Somanathan et al 2004); especially, self-incompatible rather than self-compatible species are exposed to the risks of a deficiency in compatible pollen (Beattie 1976;Feinsinger et al 1991). 6 Convallaria keiskei Miq.…”