 |
Dr Mario Vallejo-MarinLecturer in Evolutionary BiologyPh.D. - Duke University (2006) School
of Biological & Environmental Sciences tel: +44 1786 467822 |
NEWS! PhD Position available to study the ecology and evolution of plant reproduction. For more info and how to apply click here.
Research interests
I am interested in determining the role of adaptation in the evolution of plant reproductive strategies. Reproductive strategies determine patterns of gene transfer, and thus are tightly linked to the reproductive success and evolutionary potential of plant populations. Managing and conserving natural populations requires an integrative approach including the study of both ecological interactions and evolutionary dynamics. My goal is to continue my research of the ecology and evolution of reproductive strategies, and expand it to explore the role of adaptive evolution on the origin and maintenance of population differentiation and, ultimately, speciation.
I am currently involved in different research projects addressing the ecology and evolution of plant reproduction, including:
- The adaptive role of intra-individual variation in floral traits.
- Plant speciation and reproductive character displacement.
- Consequences of clonal propagation for plant sex.
- Shifts in reproductive characteristics during plant invasions.
Below I briefly describe three examples of my recent research.
How does pollen-eating favour the division of labour within flowers?
Thousands of species of flowering plants lack nectar and have to use pollen to attract pollinators. Pollen in these species has a dual function: on one hand pollen is the carrier of male gametes and on the other is food consumed by pollinators. In many of these pollen-only species, the male organs (stamens) have been modified to produce two types within the same flower, a phenomenon known to botanists as heteranthery. Using a combination of experimental manipulations and detailed pollinator observations, we have recently demonstrated that this within-flower dimorphism represents the division of labour of pollen into feeding and pollinating functions. In addition, we used theoretical models of the pollination process to show that this functional division of labour can explain the evolutionary maintenance of stamen dimorphism. Our work showed that pollinators can interact in precise ways with the flower, and proved that morphological differences between floral organs result in dramatic changes in the fate of pollen.
 |
 |
|
Two heterantherous species showing division of labor within flowers. The small anthers serve to attract and feed pollinators, while the large anther participates disproportionately in fertilizing ovules. Left panel: Solanum citrullifolium (Solanaceae) visited by Bombus impatiens . |
Solanum rostratum showing a colour polymorphism of the large anther |
Ecological and evolutionary consequences of asexual reproduction in plants
A large number of plant species concurrently reproduce both sexually (via seeds) and clonally (e.g. via tubers, rhizomes, or runners). However, until recently sexual and asexual reproduction were seen as mutually exclusive strategies. I am investigating what are the ecological and evolutionary consequences of mixed sexual and asexual strategies of reproduction. Previously I have used phylogenetic and theoretical approaches to show that plant clonality may have a significant influence on the evolutionary dynamics of particular reproductive strategies. I am currently conducting an investigation to establish the general ecological and evolutionary consequences of clonality for plant sexual reproduction. My collaborators in these projects are Prof. Marcy Uyenoyama, Prof. Spencer Barrett, Dr. Heath O’Brien and Dr. Josef Stuefer.
Massive flowering of a clonal patch of Eichhornia crassipes in a temporary pool in Sinaloa, Mexico.
The genetic architecture of flower morphology in the transition to self-fertilization.
The evolution of selfing from outcrossing in flowering plants is characterized by a series of morphological changes to flowers culminating in the selfing syndrome. However, which morphological traits initiate increased self-pollination and which are accumulated after self-fertilization becomes established is poorly understood. In collaboration with Prof. Spencer Barrett I am investigating this problem by comparing floral morphology among Brazilian populations of Eichhornia paniculata (Pontederiaceae), an annual aquatic that displays variation in traits associated with the evolutionary breakdown of tristyly to semi-homostyly. We are also analyzing segregation patterns of crosses between contrasting genotypes to determine the genetic basis of changes in floral morphology.
Floral modifications associated with the transition towards self-fertilization in Eichhornia paniculata. The image shows parental plants in the left- and right-hand sides, corresponding to outcrossing and self-fertilizing phenotypes, respectively. The F1 offspring is shown in the center.
Publications
(click 
to see the PDF)
| 14. | Goodwillie, C., R. D. Sargent, C. G. Eckert, E. Elle,S. Kalisz, M. A. Geber, M. O. Johnston, D. A. Moeller, R. H. Ree, M. Vallejo-Marín and A. A. Winn. 2010. Correlated evolution of mating system and floral display traits in flowering plants and its implications for the distribution of mating system variation. New Phytologist. 185: 311-321. |  |
| 13. | Eckert, C. G., S. Kalisz, M. A. Geber, R. Sargent, E. Elle, P.O. Cheptou, C. Goodwillie, M. O. Johnston, J. K. Kelly, D. A. Moeller, E. Porcher, R. H. Ree, M. Vallejo-Marín and A. A. Winn. 2010. Plant mating systems in a changing world. Trends in Ecology and Evolution. 25:35-43. | |
| 12. | Barrett, S.C.H., R. W. Ness, and M. Vallejo-Marin. 2009. Evolutionary pathways to self-fertilization in a tristylous plant species. New Phytologist. 183: 546-556. | |
| 11. | Vallejo-Marin, M., J.S. Manson, J.D Thomson, and S.C.H. Barrett. 2009. Division of labour within flowers: Heteranthery, a floral strategy to reconcile contrasting pollen fates. Journal of Evolutionary Biology. 22: 828-839. | |
| 10. | * Vallejo-Marin, M. , and S.C.H. Barrett. 2009. Modification of flower architecture during early stages in the evolution of self-fertilization. Annals of Botany. 103: 951-962. | |
| 9. | Aguirre, A., M. Vallejo-Marin, E.M. Piedra-Malagon, R. Cruz-Ortega and R. Dirzo. 2009. Morphological variation in the flowers of Jacaratia mexicana A. DC. (Caricaceae), a subdioecious tree. Plant Biology. 11(3): 417-424. | |
| 8. | Johnston, M., E. Porcher, P.O. Cheptou, C.G. Eckert, E. Elle, M. A. Geber, S. Kalisz, J. K. Kelly, D. A. Moeller, M. Vallejo-Marin and A. A. Winn. 2009 . Correlations among fertility components can maintain mixed mating in plants. The American Naturalist. 173(1):1-11. |  |
| 7. | Vallejo-Marin, M., and M.K. Uyenoyama. 2008. On the evolutionary modification of self-incompatibility: Implications of partial clonality for allelic diversity and genealogical structure. (Ed.) V. E. Franklin-Tong. Self-Incompatibility in Flowering plants: Evolution, Diversity and Mechanisms. Springer. pp 53-71. |
 |
| 6. | Vallejo-Marin, M., and M.D. Rausher. 2007. Selection through female fitness helps to explain the maintenance of male flowers. The American Naturalist. 169(5):563-568. | |
| 5. | Vallejo-Marin, M., and M.D. Rausher. 2007. The role of male flowers in andromonoecious species: Energetic costs and siring success in Solanum carolinense. Evolution. 61(2):404-412. | |
| 4. | Vallejo-Marin, M., and H.E. OBrien. 2007. Correlated evolution of self-incompatibility and clonal reproduction in Solanum. New Phytologist. 173(2): 415-421. | |
| 3. | Aguirre, A., M. Vallejo-Marin, L. Salazar Goroztieta, D.M. Arias and R. Dirzo. 2007.Variation in sexual expression in Jacaratia mexicana (Caricaceae) in Southern Mexico: Frequency and relative seed performance of fruit-producing males. Biotropica. 39(1): 79-86. | |
| 2. | Vallejo-Marin, M., C.A. Dominguez, and R. Dirzo. 2006. Simulated seed predation reveals a variety of germination responses of neotropical rain forest species. American Journal of Botany. 93(3):369-376. | |
| 1. | Vallejo-Marin, M., and M.K. Uyenoyama. 2004. On the evolutionary costs of self-incompatibility: incomplete reproductive compensation due to pollen limitation. Evolution. 58(9):1924-1935. | |
* Highlighted for ContectSelect section in Annals of Botany.
Other
Vallejo-Marin, M. 2007. The paradox of clonality and the evolution of self-incompatibility. Plant Signaling & Behavior. 2(4):265-266. (Invited commentary).
Have you seen this plant in the United Kingdom? If so, please fill in this PDF form, or just send me an email.
- Olivia Judson at the University of Stirling: "Glad to have evolved". April 16, 2009. 6pm. Cottrell Building CA3.
- Darwin 200th celebration at the University of Stirling
