Floral and pollination biology of three sympatric Vaccinium (Ericaceae) species in the Upper Ardennes, Belgium

1996 ◽  
Vol 74 (2) ◽  
pp. 210-221 ◽  
Author(s):  
A. -L. Jacquemart ◽  
J. D. Thompson

Comparative studies of the reproductive biology and pollination ecology of closely related species allow us to test several ideas related to the evolution of selfing taxa from outcrossing ancestors. The existence of closely related species in the same habitat provides a particularly useful opportunity to examine this issue. A variety of floral traits likely to be associated with the reproductive system of three sympatric Vaccinium species (V. myrtillus, V. vitis-idaea, and V. uliginosum) were quantified in a heathland in the Upper Ardennes, Belgium. These traits included the length and width of the corolla, the number and size of the anthers, the number of pollen tetrads and ovules, and the length of the style. Pollen to ovule ratios suggest a mixed mating system in the three species. The greater pollen to ovule ratio and stigma–anther separation in V. vitis-idaea suggest that it functions more as an outcrosser than the two congeners. The effects of caging, emasculation, and artificial pollination on fruit and seed set differed among years and among the three species. Supplementary pollination increased fruit set and fruit characteristics (particularly seed number) relative to natural pollination in the three species. The three species showed a varied but poor capacity to self in the absence of pollinators. Seed set per fruit was lower in the spontaneously selfed flowers in comparison with hand-crossed pollinated flowers in V. myrtillus and V. vitis-idaea but not in V. uliginosum. This higher ability to self in V. uliginosum indicates a lower capacity to self in the absence of pollinators. However, all the three species were at least partially self-compatible. Together the floral traits and selfing ability suggest that the polyploid V. uliginosum appears to be more highly selfing than the two diploids, particularly V. vitis-idaea. Keywords: floral biology, mixed mating, mating system, Vaccinium, seed set.

2019 ◽  
Author(s):  
Åsa Lankinen ◽  
Maria Strandh

AbstractPremise of the ResearchThe wide diversity of floral traits seen among plants is shaped by neutral and selective evolutionary processes. In outcrossing species, sexual selection from competing pollen donors is expected to be important for shaping mating system-related traits but empirical evidence is scarce. In a previous evaluation of experimental evolution lines crossed with either one or two pollen donors (monogamous, M, or polyandrous, P, lines) at early floral stages in mixed-mating Collinsia heterophylla (Plantaginaceae), P showed enhanced pollen competitive ability and reduced maternal seed set compared to M, in accordance with sexually antagonistic evolution of pollen. Here, we asked whether the presence of sexual selection during pollen competition affect mating system-related floral traits in the same lines.MethodologyWe compared flowering start, timing of anther-stigma contact (as an indication of timing of self-pollination), timing of stigma receptivity and first seed set between M and P, and with a source line, S (starting material). The former three traits are later in outcrossers than in selfers of Collinsia. The latter trait was expected to be earlier in P than in M because of sexual selection for early seed siring of pollen.Pivotal ResultsArtificial polyandry for four generations resulted in later flowering start and later anther-stigma contact in P compared to M, and the latter trait was intermediate in S. Thus, P appeared more ‘outcrossing’ than M. Stigma receptivity did not differ between lines. First seed set was earlier in P than in M, as expected from sexual selection.ConclusionsOur results from C. heterophylla experimental evolution lines suggest that a component of sexual selection during outcross pollination could enhance the patterns of floral divergence commonly found between outcrossers and selfers.


Botany ◽  
2014 ◽  
Vol 92 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Isabel Marques ◽  
David Draper ◽  
José María Iriondo

Small fragmented populations often exhibit reduced plant–pollinator interactions and scarce outcrossing opportunities. In this context, mixed-mating systems can be advantageous since selfing can provide reproductive assurance, but they may also carry relevant costs such as those involved in inbreeding depression. This study examines the advantages and costs of selfing in Narcissus serotinus L., a mixed-mating geophyte that currently occurs in several fragmented populations in Portugal, that resulted from the construction of the largest European dam. Observation of pollinators revealed that cross-pollination is less frequent in small than in large populations. Manual self-pollinations significantly increased fruit and seed set in small-size populations, also suggesting limited insect pollination. The existence of selfing may provide reproductive assurance in small-size populations of N. serotinus where outcrossing pollination is reduced. Although floral biology and experimental pollinations showed that N. serotinus is capable of autonomous selfing, four of the six fitness traits studied showed significant inbreeding depression in all populations. The high levels of inbreeding depression found in N. serotinus suggest that the initial reproductive assurance advantage of selfing may be counterbalanced by lower survival of the resulting individuals and a decrease in the evolutionary potential of the populations.


PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0123445 ◽  
Author(s):  
Naoki Tani ◽  
Yoshihiko Tsumura ◽  
Keita Fukasawa ◽  
Tomoyuki Kado ◽  
Yuriko Taguchi ◽  
...  

2019 ◽  
Vol 123 ◽  
pp. 41-52 ◽  
Author(s):  
Aquillah M. Kanzi ◽  
Emma T. Steenkamp ◽  
Nicolaas A. Van der Merwe ◽  
Brenda D. Wingfield

Botany ◽  
2018 ◽  
Vol 96 (7) ◽  
pp. 425-435 ◽  
Author(s):  
Devin E. Gamble ◽  
Megan Bontrager ◽  
Amy L. Angert

The benefits of self-fertilization can vary across environments, leading to selection for different reproductive strategies and influencing the evolution of floral traits. Although stressful conditions have been suggested to favour self-pollination, the role of climate as a driver of mating-system variation is generally not well understood. Here, we investigate the contributions of local climate to intraspecific differences in mating-system traits in Clarkia pulchella Pursh in a common-garden growth chamber experiment. We also tested for plastic responses to soil moisture with watering treatments. Herkogamy (anther–stigma spacing) correlated positively with dichogamy (timing of anther–stigma receptivity) and date of first flower, and northern populations had smaller petals and flowered earlier in response to experimental drought. Watering treatment alone had little effect on traits, and dichogamy unexpectedly decreased with annual precipitation. Populations also differed in phenological response to watering treatment, based on precipitation and winter temperature of their origin, indicating that populations from cool and dry sites have greater plasticity under different levels of moisture stress. While some variation in floral traits is attributable to climate, further investigation into variation in pollinator communities and the indirect effects of climate on mating system can improve our understanding of the evolution of plant mating.


2011 ◽  
Vol 122 (8) ◽  
pp. 1631-1639 ◽  
Author(s):  
Moses M. Muraya ◽  
Evans Mutegi ◽  
Hartwig H. Geiger ◽  
Santie M. de Villiers ◽  
Fabrice Sagnard ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document