Natural selection on floral traits of Caltha scaposa (Ranunculaceae), an alpine perennial with generalized pollination system from Northwest Yunnan

doi:10.1016/j.pld.2017.03.001

Abstract

Abstract: Floral traits, including those invisible to humans but visible to pollinators, that increase pollination efficiency may be selected by pollinators in plant species with pollen limitation of seed production, but the importance of pollinators as selective agents on different floral traits needs to be further quantified experimentally. In the present study, we examined selective strength on flower diameter, flower height, UV bulls-eye size, sepal size and UV proportion via female fitness in Caltha scaposa, based on openpollinated and hand-pollinated flowers, through which pollinator-mediated selection was calculated for each of floral traits. Our results suggest that seed production of C. scaposa is pollen limited in natural conditions. There was directional selection (△β_bpollinator=-0.12) for larger flowers in open-pollinated flowers, while no significant selection was found in flower height, UV bulls-eye size, sepal size or UV proportion. Statistically significant selection was found in UV bulls-eye size, sepal size and UV proportion in hand-pollinated flowers, but interactions with pollinators contributed only to flower diameter. We conclude that in C. scaposa, floral traits that are subjected to selection might be driven by multiple selective agents, and suggest the importance of investigating floral traits that are invisible to human but visible to pollinators in measuring pollinator-mediated selection via male fitness.

Key words: Pollinator-mediated selection Floral display Ultraviolet bulls-eye Female fitness Pollen limitation

Guopeng Zhang, Lihua Meng, Zhikun Wu, Zhiqiang Zhang, Lingjuan Yin, Yongping Yang, Yuanwen Duan. Natural selection on floral traits of Caltha scaposa (Ranunculaceae), an alpine perennial with generalized pollination system from Northwest Yunnan[J]. Plant Diversity, 2017, 39(04): 202-207.

References

Ashman, T.-L., Knight, T.M., Steets, J.A., et al., 2004. Pollen limitation of plant reproduction:ecological and evolutionary causes and consequences. Ecology 85, 2408-2421.
Ashman, T.-L., Morgan, M.T., 2004. Explaining phenotypic selection on plant attractive characters:male function, gender balance or ecological context? Proc.R. Soc. Lond. B Biol. Sci. 271, 553-559.
Bennett, A.T.D., Cuthill, I.C., 1994. Ultraviolet vision in birds:what is its function?Vis. Res. 34, 1471-1478.
Briscoe, A.D., Chittka, L., 2001. The evolution of color vision in insects. Annu. Rev.Entomol. 46, 471-510.
Brock, M.T., Lucas, L.K., Anderson, N.A., et al., 2016. Genetic architecture, biochemical underpinnings and ecological impact of floral UV patterning. Mol.Ecol. 25, 1122-1140.
Castellanos, M.C., Wilson, P., Keller, S.J., et al., 2006. Anther evolution:pollen presentation strategies when pollinators differ. Am. Nat. 167, 288-296.
Chittka, L., 1992. The colour hexagon:a chromaticity diagram based on photoreceptor excitations as a generalized representation of colour opponency. J. Comp.Physiol. A 170, 533-543.
Chittka, L., Shmida, A., Troje, N., et al., 1994. Ultraviolet as a component of flower reflections, and the colour perception of hymenoptera. Vis. Res. 34, 1489-1508.
Duan, Y.-W., He, Y.-P., Liu, J.-Q., 2005. Reproductive ecology of the Qinghai-Tibet Plateau endemic Gentiana straminea (Gentianaceae), a hermaphrodite perennial characterized by herkogamy and dichogamy. Acta Oecol. 27, 225-232.
Eisner, T., Eisner, M., Hyypio, P.A., et al., 1973. Ultraviolet patterns of flowers visible as fluorescent patterns in pressed herbarium specimens. Science 179, 486-487.
Fenster, C.B., Armbruster, W.S., Wilson, P., et al., 2004. Pollination syndromes and floral specialization. Annu. Rev. Ecol. Evol. Syst. 35, 375-403.
Gomez, J.M., 2003. Herbivory reduces the strength of pollinator-mediated selection in the mediterranean herb Erysimum mediobispanicum:consequences for plant specialization. Am. Nat. 162, 242-256.
Guo, W., Wang, L.-L., Sun, S., et al., 2014. Sexual interference in two Chamerion species with contrasting modes of movement herkogamy. J. Syst. Evol. 52, 355-362.
Hodges, S.A., 1997. Floral nectar spurs and diversification. Int. J. Plant Sci. 158, S81-S88.
Horth, L., Campbell, L., Bray, R., 2014. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides. Biol. Open 3, 221-230.
Irwin, R.E., 2006. The consequences of direct versus indirect species interactions to selection on traits:pollination and nectar robbing in Ipomopsis aggregata. Am.Nat. 167, 315-328.
Judd, W.W., 1964. Insects associated with flowering marsh marigold, Caltha palustris L., at London, Ontario. Can. Entomol. 96, 1472-1476.
Kay, K.M., Sargent, R.D., 2009. The role of animal pollination in plant speciation:integrating ecology, geography, and genetics. Annu. Rev. Ecol. Evol. Syst. 40, 637-656.
Kevan, P.G., Chittka, L., Dyer, A.G., 2001. Limits to the salience of ultraviolet:lessons from colour vision in bees and birds. J. Exp. Biol. 204, 2571-2580.
Knight, T.M., Steets, J.A., Vamosi, J.C., et al., 2005. Pollen limitation of plant reproduction:pattern and process. Annu. Rev. Ecol. Evol. Syst. 36, 467-497.
Koski, M.H., Ashman, T.-L., 2013. Quantitative variation, heritability, and trait correlations for ultraviolet floral traits in Argentina anserina (Rosaceae):implications for floral evolution. Int. J. Plant Sci. 174, 1109-1120.
Koski, M.H., Ashman, T.-L., 2014. Dissecting pollinator responses to a ubiquitous ultraviolet floral pattern in the wild. Funct. Ecol. 28, 868-877.
Koski, M.H., Ashman, T.-L., 2015a. An altitudinal cline in UV floral pattern corresponds with a behavioral change of a generalist pollinator assemblage. Ecology 96, 3343-3353.
Koski, M.H., Ashman, T.-L., 2015b. Floral pigmentation patterns provide an example of Gloger's rule in plants. Nat. Plants 1, 14007.
Koski, M.H., Ashman, T.-L., 2016. Macroevolutionary patterns of ultraviolet floral pigmentation explained by geography and associated bioclimatic factors. New Phytol. 211, 708-718.
Lande, R., Arnold, S.J., 1983. The measurement of selection on correlated characters.Evolution 37, 1210-1226.
Larson, B.M.H., Barrett, S.C.H., 2000. A comparative analysis of pollen limitation in flowering plants. Biol. J. Linnean Soc. 69, 503-520.
Morgan, M.T., 1992. The evolution of traits influencing male and female fertility in outcrossing plants. Am. Nat. 139, 1022-1051.
Naruhashi, N., Ikeda, H., 1999. Variation in nectar guides in Himalayan Potentilla (Rosaceae). Himalayan Plants 3, 23-29.
O'Connell, L.M., Johnston, M.O., 1998. Male and female pollination success in a deceptive orchid, a selection study. Ecology 79, 1246-1260.
Parachnowitsch, A.L., Caruso, C.M., 2008. Predispersal seed herbivores, not pollinators, exert selection on floral traits via female fitness. Ecology 89, 1802-1810.
Parachnowitsch, A.L., Kessler, A., 2010. Pollinators exert natural selection on flower size and floral display in Penstemon digitalis. New Phytol. 188, 393-402.
Rasband, W.S., 2012. ImageJ. U.S. National Institute of Health, Bethsda, MD. https://imagej.nih.gov/ij/.
Sandring, S., Ågren, J., 2009. Pollinator-mediated selection on floral display and flowering time in the perennial herb Arabidopsis lyrata. Evolution 63, 1292-1300.
Sandring, S., RiihimÄKi, M.A., Savolainen, O., et al., 2007. Selection on flowering time and floral display in an alpine and a lowland population of Arabidopsis lyrata. J. Evol. Biol. 20, 558-567.
Sapir, Y., Armbruster, S.W., 2010. Pollinator-mediated selection and floral evolution:from pollination ecology to macroevolution. New Phytol. 188, 303-306.
Sheehan, H., Moser, M., Klahre, U., et al., 2016. MYB-FL controls gain and loss of floral UV absorbance, a key trait affecting pollinator preference and reproductive isolation. Nat. Genet. 48, 159-166.
Sletvold, N., Grindeland, J.M., Ågren, J., 2010. Pollinator-mediated selection on floral display, spur length and flowering phenology in the deceptive orchid Dactylorhiza lapponica. New Phytol. 188, 385-392.
Syafaruddin, Kobayashi, K., Yoshioka, Y., et al., 2006. Estimation of heritability of the nectar guide of flowers in Brassica rapa L. Breed. Sci. 56, 75-79.
Thomson, J.D., Wilson, P., Valenzuela, M., et al., 2000. Pollen presentation and pollination syndromes, with special reference to Penstemon. Plant Species Biol. 15, 11-29.
Toräng, P., Ehrlén, J., Ågren, J., 2006. Facilitation in an insect-pollinated herb with a Bfloral display dimorphism. Ecology 87, 2113-2117.
Wang, W.-C., Fu, D.-Z., Li, L.-Q., et al., 2001. Ranunculaceae. In: Wu, Z.Y., Raven, P.H.(Eds.), Flora of China. Science Press & Missouri Botanical Garden Press, Beijing & St. Louis.
Weber, M.G., Strauss, S.Y., 2016. Coexistence in close relatives: beyond competition and reproductive isolation in sister taxa. Annu. Rev. Ecol. Evol. Syst. 47, 359-381.
Whittall, J.B., Hodges, S.A., 2007. Pollinator shifts drive increasingly long nectar spurs in columbine flowers. Nature 447, 706-709.
Yoshioka, Y., Horisaki, A., Kobayashi, K., et al., 2005. Intraspecific variation in the ultraviolet colour proportion of flowers in Brassica rapa L. Plant Breed 124, 551-556.
Zhang, D.-Y., 2003. Plant reproductive ecology. In: Zhang, D.-Y. (Ed.), Plant Lifehistory Evolution and Reproductive Ecology. Science Press, Beijing.