Andromonoecy functional through heterostyly and large carpenter bees as principal pollinators in Solanum carolinense L. (Solanaceae)

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Suvarna Raju Palathoti
https://orcid.org/0000-0003-1713-6943
Jacob Solomon Raju Aluri
https://orcid.org/0000-0002-0028-2621

Abstract

Solanum carolinense is a perennial shrubby weed. In this species, andromonoecy is functional through heterostyly represented by the production of long, semi-long, medium, & short-styled flower types and another flower type lacking style & stigma completely. All plants produce long-styled flowers while all individuals do not produce other flower types. The long- and semi-long-styled flowers are functionally co-sexual and produce fruit while the other flower types are functionally female-sterile and do not produce fruit. The position of style in long- and semi-long-styled flowers facilitates the act of pollination by pollinator bees. Xylocopa bees are large-bodied specialist bees which collect pollen from poricidal anthers efficiently in this plant by displaying buzzing behaviour and are treated as principal pollinators. The other bees are small-bodied and do not display buzzing behaviour to release pollen from poricidal anthers but they simply collect residual pollen available around the rim of the apical pore of the anthers, and hence they act as supplementary pollinators only. In this plant, the style length has a positive relationship with pollen deposition and a negative relationship with pollen removal in flowers visited by large carpenter bees of Xylocopa genus and hence, pollinator-specific interactions with flower morphology are important in the maintenance and perfect evolution of andromonoecy in this plant species. Florivory by Mylabris pustulata could vary with the flower production rate in S. carolinense and could favor higher floral-sex ratios biased in favour of higher proportion of female-sterile flowers. 

Article Details

Section
Communications

References

Bawa, K.S. & J.H. Beach (1981). Evolution of sexual systems in flowering plants. Annals of Missouri Botanical Garden 68: 254–274. https://doi.org/10.2307/2398798.

Bertin, R.I. (1982). The evolution and maintenance of andromonoecy. Evolutionary Theory 6: 25–32.

Buchmann, S.L. (1983). Buzz-pollination in angiosperms, pp. 73–113. In: Jones, C.E. & R.J. Little (Eds.). Handbook of Experimental Pollination Biology. Van Nostrand Reinhold, New York.

Buchmann, S.L., C.E. Jones & L.J. Colin (1989). Vibratile pollination of Solanum douglasii and S. xanti (Solanaceae) in Southern California. Wasmann Journal of Biology 81: 289–294.

Connolly, B. & G. Anderson (2003). Functional significance of the androecium in staminate and hermaphroditic flowers of Solanum carolinense (Solanaceae). Plant Systematics & Evolution 240: 235–243.

Dafni, A., P.G. Kevan & B.C. Husband (2005). Practical Pollination Biology. Enviroquest Ltd., Ontario, 590 pp.

Diggle, P.K. (1991). Labile sex expression in andromonoecious Solanum hirtum: pattern of variation in floral structure. Canadian Journal of Botany 69: 2033–2043. https://doi.org/10.1139/b91-256

Elle, E. (1999). Sex allocation and reproductive success in the andromonoecious perennial Solanum carolinense (Solanaceae). I. Female success. American Journal of Botany 86: 278–286. https://doi.org/10.2307/2656944

Hardin, J., G. Doerksen, H. Herndon, M. Hobson & F. Thomas (1972). Pollination ecology and floral biology of four weedy genera in southwestern Oklahoma. Southwestern Naturalist 16: 403–412.

Heithaus, E.R., T.H. Fleming & P.A. Opler (1974). Foraging patterns and resource utilization in seven species of bats in a seasonal tropical forest. Ecology 56: 841–854. https://doi.org/10.2307/1936295

Kariyat, R.R., S.R. Scanlon, M.C. Mescher, C.M. De Moraes & A.G. Stephenson (2011). Inbreeding depression in Solanum carolinense (Solanaceae) under field conditions and implications for mating system evolution. PloS One 6: e28459. https://doi.org/10.1371/journal.pone.0028459

Kumari, M.R. (2004). A taxonomic revision of Indian Solanaceae. Ph.D. Thesis, Bharathiar University, Coimbatore.

Lloyd, D.G. (1980). Sexual strategies in plants. I. An hypothesis of serial adjustment of maternal investment during one reproductive season. New Phytologist 86: 69–79. https://doi.org/10.1111/j.1469-8137.1980.tb00780.x

Martine, C.T. & G.J. Anderson (2006). Dioecy, pollination and seed dispersal in Australian spiny Solanum. Acta Horticulturae 745: 2.

Meagher, T.R. (1992). The quantitative genetics of sexual dimorphism in Silene latifolia (Caryophyllaceae). I. Genetic variation. Evolution 46: 445–457. https://doi.org/10.2307/2409863

Michael, J.W. (2007). The herbivores of Solanum carolinense (Horsenettle) in Northern Virginia: natural history and damage assessment. Southeastern Naturalist 6: 505–522.

Michael, J.W. & F.S. Christopher (1996). Impact of two specialist insect herbivores on reproduction of horse nettle, Solanum carolinense. Oecologia 108: 328–333. http://doi.org/ 10.1007/BF00334658

Olmstead, R.G., L. Bohs, H. Abdel Migid, E. Santiago-Valentin, V.F. Garcia & S.M. Collier (2008). A molecular phylogeny of the Solanaceae. Taxon 57: 1159–1181. https://doi.org/10.1002/tax.574010

Olmstead, R.G., J.A. Sweere, R.E. Spangler, L. Bohs & J.D. Palmer (1999). Phylogeny and provisional classification of the Solanaceae based on chloroplast DNA, pp. 111–137. In: Nee, M., D. Symon, R.N. Lester & J. Jessop (Eds.), Solanaceae IV: Advances in Biology and Utilization. Royal Botanic Gardens, Kew.

Quesada-Aguilar, A. (2001). Flower morphology, gender functionality, and pollinator dynamics in Solanum carolinense: implications for the evolution of andromonoecy. M.S. Thesis, University of Pittsburgh, Pittsburgh.

Quesada-Aguilar, A., S. Kalisz & A. Tia-Lynn (2008). Flower morphology and pollinator dynamics in Solanum carolinense (Solanaceae): implications for the evolution of andromonoecy. American Journal of Botany 95: 974–984. https://doi.org/10.3732/ajb.0800106

Samuels, J. (2009). The Solanaceae-novel crops with high potential. Organic Grower 9: 32–34.

Travers, S.E., J. Mena-Ali & A.G. Stephenson (2004). Plasticity in the self-incompatibility system of Solanum carolinense. Plant Species Biology 19: 127–135. https://doi.org/10.1111/j.1442-1984.2004.00109.x

Vallejo-Marin, M. & M.D. Rausher (2007). The role of male flowers in andromonoecious species: energetic costs and siring success in Solanum carolinense L. Evolution 61: 404–412. https://doi.org/10.1111/j.1558-5646.2007.00031.x

Venkatappa, V. (2011). Solanaceae, pp. 266–310. In: Pullaiah, T., S.S. Rani & S. Karuppasamy (Eds.). Flora of Eastern Ghats (Stylidaceae to Plantaginaceae). Regency Publications, Delhi.

Vorontsova, M.S., S. Stern, L. Bohs & S. Knapp (2013). African spiny Solanum (Subgenus Leptostemomum, Solanaceae): a thorny phylogenetic tangle. Botanical Journal of Linnean Society 173: 176–193. https://doi.org/10.1111/boj.12053

Whalen, M.D. & D.E. Costich (1986). Andromonoecy in Solanum, pp. 284–302. In: D’Arcy, W.G. (ed.). Solanaceae Biology and Systematics. Columbia University Press, New York.

Wise, M.J. & J.B. Hebert (2010). Herbivores affect natural selection for floral-sex ratio in a field population of horsenettle, Solanum carolinense. Ecology 91: 937–943. https://doi.org/10.1890/09-1373.1

Zapata, T.R. & M.T.K. Arroyo (1978). Plant reproductive ecology of a secondary deciduous tropical forest in Venezuela. Biotropica 10: 221–230.