Reproductive Assurance through Autogamous Self-pollination across Diverse Sexual and Breeding Systems

2015 ◽  
Vol 109 (7) ◽  
pp. 1255 ◽  
Author(s):  
K. R. Shivanna
1990 ◽  
Vol 38 (2) ◽  
pp. 217 ◽  
Author(s):  
AJ Willis ◽  
JE Ash

The breeding systems of Stylidiurn grarninifolium and S. producturn (= S. grarninifoliurn var. caulescens) were studied by observing the phenology of individual flowers and inflorescences, and relating the data to a series of pollination experiments within and between the species. Inter-specific pollinations yielded similar levels of seed-set to crosses within the species indicating a close relationship between the taxa. Self-pollination of either species is uncommon; however, when it occurs, the majority of selfed ovules are aborted post-zygotically, probably by a system of recessive lethals, as there is no indication of an incompatibility system. It is concluded that the breeding systems of S. grarninifoliurn and S. productum, two of the few eastern Australian species, are similar to those of many Stylidiurn species from the south-west, casting doubt upon hypotheses that the breeding system has led to high rates of speciation in the south-west.


Hoehnea ◽  
2020 ◽  
Vol 47 ◽  
Author(s):  
Inara Carolina da Silva-Batista ◽  
Cristiana Koschnitzke ◽  
Claudia Petean Bove

ABSTRACT (Reproductive assurance in three Neotropical species of Podostemaceae: strategies of self-pollination and the first report of apomixis). The aspects of reproductive assurance of the Lophogyne lacunosa (Gardner) C.P.Bove & C.T.Philbrick, Podostemum weddellianum (Tul.) C.T. Philbrick & Novelo, and Tristicha trifaria (Bory ex Willd.) Spreng. were investigated and, the mechanisms correlated to the flower morphology and floral biology. The mating system of L. lacunosa was also described, as well as the first report of apomixis in Podostemaceae. The reproductive assurance strategies used by L. lacunosa were autonomous competitive self-pollination, wind pollination, and apomixis. This species has floral attributes that ensure the dispersion of pollen by wind and its capture by the stigmas. Podostemum weddellianum and Tristicha trifaria presented autonomous competitive self-pollination before and during anthesis, respectively; both lack floral attributes for wind pollination. Considering that these species can be found in the same running water environment and that they are not phylogenetically close related, it was concluded that the different reproductive strategies are related to their evolutionary lineages.


2019 ◽  
Vol 124 (5) ◽  
pp. 869-881 ◽  
Author(s):  
Laura S Hildesheim ◽  
Øystein H Opedal ◽  
W Scott Armbruster ◽  
Christophe Pélabon

Abstract Background and Aims To predict the evolutionary consequences of pollinator declines, we need to understand the evolution of delayed autonomous self-pollination, which is expected to evolve as a mechanism of reproductive assurance when cross-pollination becomes unreliable. This involves estimating the costs of increased levels of selfing as well as those associated with floral senescence. Methods We studied the mechanisms and costs of delayed self-pollination in the mixed-mating vine Dalechampia scandens (Euphorbiaceae) by first assessing among-population variation in herkogamy and dichogamy, which together determine the rate and timing of autonomous self-pollination. We then tested whether floral longevity responds plastically to delayed pollination. Finally, we assessed the costs of delayed self-pollination in terms of seed number and size, explicitly separating inbreeding depression from effects of floral senescence. Key Results Herkogamy varied extensively, while variation in dichogamy was more limited. Unpollinated blossoms increased their longevity, but seed quantity and quality decreased with increasing delays in pollination, independently of inbreeding depression. Conclusions In D. scandens, earlier autonomous selfing is facilitated by reduced herkogamy rather than reduced protogyny, providing reproductive assurance while maintaining the possibility for outcrossing events. Effective early autonomous self-pollination may evolve under reduced cross-pollination reliability in response to costs associated with floral senescence.


2010 ◽  
Vol 58 (2) ◽  
pp. 115 ◽  
Author(s):  
Nan Jiang ◽  
Wen-Bin Yu ◽  
Hong-Zhe Li ◽  
Kai-Yun Guan

Flowers of Clematis display showy corollas and diversified shapes. This diversity motivates study of adaptive evolution of flower–pollinator interactions and the functional association between floral traits and plant mating strategies. An integrative study was undertaken, which focused on pollination and reproductive biology of three species representing all three floral types of Clematis. Floral traits were measured, and pollinator assemblages were observed in the field. Bagging, hand-pollination and removal treatments were used to examine breeding systems. The inbreeding depression and pollen limitation were estimated by fruit-set and seed production obtained from pollination treatments. Their floral traits are distinctly different, but are highly associated with pollination syndrome and breeding system. Among them, Clematis akebioides and C. rehderiana may be facultative autogamy (the former was delayed selfing, and the later competing selfing), and C. chrysocoma may be nearly obligate outcrossing. These conclusions are reflected in their stamen-pistil ratios. The levels of inbreeding depression are negatively associated with autonomous self-pollination. Evolution of self-pollination in C. akebioides and C. rehderiana, and pollen limitation in reproduction of the three Clematis species are discussed. This present study, integrating with previous results, will help us to comprehensively recognise and understand the pollination system and reproductive characteristics of Clematis.


2020 ◽  
Vol 26 ◽  
Author(s):  
Daniel S Weiherer ◽  
Kayla Eckardt ◽  
Peter Bernhardt

We compared the floral biology of two sympatric populations of closely related species over two seasons. In 2018, Nothoscordum bivalve (L.) Britton bloomed from April 23 to May 7 and Allium stellatum Nutt. Ex Ker Gawl bloomed from August 28 to October 4. Erect, white flowers of N. bivalve were scented and had septal nectaries. Erect, pink-purple flowers of A. stellatum had septal nectaries, no discernible scent, and a style that lengthened over the floral lifespan. Both species were pollinated by bees with the most common geometric mean of body dimensions between 2-3 mm. Most bees carried pure loads of the host plant’s pollen. Despite phenological isolation, the two herbs shared three bee species. Allium stellatum was also pollinated by the beetle Chauliognathus pensylvanicus DeGeer (Cantharidae). Tepal nyctinasty ensured mechanical self-pollination in N. bivalve. Protandry occurred in A. stellatum. In N. bivalve, the proportion of pollen tubes penetrating ovules was highest in bagged, self-pollinating flowers. However, in A. stellatum it was highest in exposed flowers and hand cross-pollinated flowers. Fruit set in N. bivalve was highest in exposed and bagged, self-pollinating flowers. In A. stellatum, fruit set was highest in both exposed and hand cross-pollinated flowers. Seed set was the same among all treatments for both species. We interpret these results as evidence that A. stellatum is a self-incompatible, obligate outcrosser. Nothoscodum bivalve is a self-compatible, obligate inbreeder employing mechanical and insect-mediated self-pollination. Outbreeding depression appears to occur in N. bivalve with a partial trend towards intraspecific cross-incompatibility.


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