Inspired by the amazing diversity and utility of plants, our research uses phylogenomic, collections-based, and experimental field approaches to explore the evolution and genetic diversity of underutilized crops and their wild relatives, pollination, biogeography, and taxonomic revisionary work. We are also interested in applying findings to conservation of plant genomic resources. 

 

RESEARCH AREAS

Perennial Agriculture 

Crop Origins, Diversity, and Conservation

Phlyogenomics, Biogeography, and Taxonomic Revision

Pollination Biology

 

Crop Origins, Diversity, and Conservation

The world population gets the majority of its food calories from just a few annual crop species that are energy-intensive to grow. However, there are thousands of other plant species (referred to as underutilized, minor, neglected, orphan, or emerging crops), which are often long-lived perennials that may be more well adapted to certain environments than our major crops. These underutilized crops have an important role to play in expanding crop diversity, increasing food security, and decreasing agricultural energy input. In addition to the value of growing many different kinds of crops around the world, it is also important to preserve genetic diversity within each crop and its wild relatives. Identifying and conserving crop wild relatives may provide valuable genetic resources to adapt to future challenges, such as disease and climate change. Our work focuses on identifying crop wild relatives and assessing genetic diversity of underutilized crops to help advance their development as more broadly used crops and increase food security around the world.

 

Selected projects on crop origins, diversity, and conservation

Dickinson, L., H. Noble, E.M. Gardner, A.S.A. Puad, Wan Zakaria, W. and N.J.C. Zerega. 2020. Genetic diversity structure and conservation of critically endangered, Artocarpus annulatus, a crop wild relative of jackfruit. PeerJ. 10.7717/peerj.9897

 

Witherup, C.E., M.I. Zuberi, S. Hossain, and N.J.C. Zerega. 2019. Genetic Diversity of Bangladeshi Jackfruit (Artocarpus heterophyllus) over Time and Across Seedling Sources. Journal of Economic Botany 73: 233–248(2019)

 

Zerega, N.J.C., E.M. Gardner, W. Zakaria & A.S.A. Puad. 2019. Artocarpus annulatus. The IUCN Red List of Threatened Species 2019: e.T86528602A86528612. 

 

Wang, M.M.H., E.M. Gardner, A.R. Milan, Salma, C.M. Yee, R. Chung, L.S. Leong, and N.J.C. Zerega. 2018. Origin and diversity of an underutilized fruit tree crop, Artocarpus integer (Moraceae). American Journal of Botany. https://onlinelibrary.wiley.com/doi/abs/10.1002/ajb2.1094 

 

Zerega, N.J.C. and D. Ragone. 2016. Toward a global view of breadfruit genetic diversity. Special Issue International Breadfruit Conference 2015. Tropical Agriculture 77-91.

 

Zerega, N.J.C., T. Wiesner-Hanks, D. Ragone, B. Irish, B. Scheffler, S. Simpson, and F. Zee. 2015. Diversity of the Breadfruit Complex (Artocarpus, Moraceae): Genetic Characterization of Critical Germplasm. Tree Genetics and Genomes.  http://dx.doi.org/10.1007/s11295-014-0824-z

 

Khan, R., N.J.C. Zerega, S. Hossain, and M.I. Zuberi. 2010. Jackfruit (Artocarpus heterophyllus Lam.) Diversity in Bangladesh: Land Use and Artificial Selection. Economic Botany 64(2): 124-136.

 

Zerega, N.J.C., D. Ragone, and T.J. Motley. 2005. Systematics and species limits of breadfruit (Artocarpus, Moraceae). Systematic Botany 30(3): 603-615.

 

Zerega, N.J.C., D. Ragone, and T.J. Motley. 2004. Complex origins of breadfruit: Implications for human migrations in Oceania. American Journal of Botany 91(5): 760-766.

 

 

Phlyogenomics, Biogeography, and Taxonomic Revision

Various recent and ongoing projects in the lab focus on using phylogenomic approaches to understand plant evolution and biogeography, especially in the Moraceae family, and to inform studies in crop origins (above), and ongoing revisionary work, especially in the genus Artocarpus.

 

Selected projects in Phylogenomics, Biogeography, Taxonomic Revisions

Gardner, E.M. and N.J.C. Zerega. 2021. Taxonomic updates to Artocarpus subgenus Artocarpus (Moraceae)and allied taxa with a particular focus on the species native to Singapore. Gardens’ Bulletin Singapore 73(2): 309-374.

 

Gardner, E.M., M. Garner, R. Cowan, S. Dodsworth, N. Epitawalage, O. Maurin, D. Arifiani, S. Sahromi, W.J. Baker, F. Forest, N.J.C. Zerega, A.K. Monro, A.L. Hipp. 2021. Repeated parallel losses of inflexed stamens in Moraceae: phylogenomics and generic revision of the tribe Moreae and the reinstatement of the tribe Olmedieae (Moraceae). Taxon. https://doi.org/10.1002/tax.12526

 

Gardner, E.M., *L. Audi, Q. Zhang, H. Sauquet, A.K. Monro, and N.J.C. Zerega. 2021. Phylogenomics of Brosimum Sw. (Moraceae) and allied genera, including a revised subgeneric system. Taxon. https://doi.org/10.1002/tax.12503

 

Gardner, E.M., D. Arifiani, and N.J.C. Zerega. 2021. Artocarpus bergii (Moraceae), a new species in the breadfruit clade from the Moluccas. Systematic Botany 46(1) (2021). https://doi.org/10.1600/036364421X16128061189387

 

Gardner, E.M., M.G. Johnson, J.T. Pereira, A.S.A. Puad, D. Arifiani, Sahromi, N.J. Wickett, and N.J.C. Zerega. 2021. Paralogs and off-target sequences improve phylogenetic resolution in a densely-sampled study of the breadfruit genus (Artocarpus, Moraceae). Systematic Biology syaa073,https://doi.org/10.1093/sysbio/syaa073

 

Gardner, E.M. and N.J.C. Zerega. 2020. Proposal to reject the name Radermachia rotunda (Artocarpus rotundus) (Moraceae) (2788). Taxon 69(4): 827-828. https://doi.org/10.1002/tax.12402

 

Gardner, E.M., A,K. Monro and N.J.C. Zerega. 2020. Proposal to reject the name Antiaridiae (Moraceae). Taxon 69(6): 1372-1373 https://doi.org/10.1002/tax.12304

 

Gardner, E.M. and N.J.C. Zerega. 2020. Taxonomic updates to Artocarpus subgenus Pseudojaca (Moraceae), with a particular focuson the taxa in Singapore. Gardens’ Bulletin Singapore 72(2): 173-213. doi: 10.26492/gbs72(2).2020-06 https://www.nparks.gov.sg/sbg/research/publications/gardens-bulletin-singapore/-/media/sbg/gardens-bulletin/gbs_72_02_y2020/72_02_06_y2020_v7202_gbs_pg173.pdf

 

Gardner, E.M., A. Chaveerach, R. Sudmoon, N.J.C. Zerega. 2020. Two new species of Artocarpus (Moraceae) from Thailand and Vietnam. Phytotaxa Vol 453, No 3.

 

Zerega, N.J.C and E.M. Gardner. 2019. Delimitation of the new tribe Parartocarpeae (Moraceae) is supported by a 333-gene phylogeny and resolves tribal level Moraceae taxonomy. Phytotaxa 388 (4): 253–265. https://doi.org/10.11646/phytotaxa.388.4.1

 

Kates, H.R., M.G. Johnson, E.M. Gardner, N.J.C. Zerega, and N.J. Wickett. 2018. Allele phasing has minimal impact on phylogenetic reconstruction from targeted nuclear gene sequences in a case study of Artocarpus(Moraceae). American Journal of Botany https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.1068

 

Gardner, E.M., P. Sarraf, and N.J.C. Zerega. Phylogeny and biogeography of Maclura (Moraceae) and the origin of an anachronistic fruit. 2017. Molecular Phylogenetics and Evolution. https://doi.org/10.1016/j.ympev.2017.06.021

 

Williams, E.W., E.M. Gardner, R. Harris III, A. Chaveerach, J.T. Pereira, and N.J.C. Zerega. 2017. Out of Borneo: Biogeography, phylogeny, and divergence date estimates of Artocarpus (Moraceae). Annals of Botany 119(4):611-627. doi: https://doi.org/10.1093/aob/mcw249

 

Gardner, E.M., M.G. Johnson, D. Ragone, N.J. Wickett, & N.J.C. Zerega. 2016. Low-coverage, whole-genome sequencing of Artocarpus camansi (Moraceae) for phylogenetic marker development and gene discovery. Applications in Plant Sciences, 4(7), apps.1600017. http://doi.org/10.3732/apps.1600017

 

Misiewicz, T. and N.J.C. Zerega. 2012. Phylogeny, Biogeography and Character Evolution of Dorstenia (Moraceae). Edinburgh Journal of Botany 69(3): 413-440.

 

Zerega, N.J.C., M.N. Nur Supardi, and T.J. Motley. 2010. Phylogeny and recircumscription of Artocarpeae (Moraceae) with a focus on Artocarpus. Systematic Botany 35 (4): 766 – 783.

 

Pollination Biology

Pollination is among the most important drivers of floral evolution. Wind pollination has evolved from insect pollination independently at least 65 times and is presently found in ca. 18% of angiosperm families (Culley et al. 2002, TE&E 17, Friedman 2011, New Phytol.191). This shift is associated with the loss of features that attract and reward pollinators. The reverse—a shift from wind back to animal pollination—is thought to be extremely rare because of the perceived difficulty in re-acquiring the lost traits typically associated with biotic pollination. Moraceae comprise an ideal system for studying pollination shifts, including wind to insect pollination. Evolving from a wind-pollinated ancestor, extant species range from Morus, which preserves the ancestral floral state, to Ficus, with its specialized obligate wasp mutualism. However, the pollination biology of most Moraceous species remains understudied. With numerous important crop species, Artocarpus provides an opportunity to study the evolution of pollination shifts. Additionally, Artocarpus contains several underutilized crops that can improve food security and understanding their pollination is critical for developing best practices for crop management. Recent and ongoing work is uncovering the mysteries of Moraceae pollination.

 

Selected projects in Pollination Biology

Gardner, E.M. R. Gagne, P.E. Kendra, W.S. Montgomery, R.A. Raguso, T.T. McNeil and N.J.C. Zerega. 2018. A flower in fruit’s clothing: Pollination of jackfruit (Artocarpus heterophyllus, Moraceae) by a new species of gall midge, Clinodiplosis ultracrepidata sp. nov. (Diptera: Cecidomyiidae). International Journal of Plant Sciences. https://www.journals.uchicago.edu/doi/10.1086/697115

 

Zerega, N.J.C., Mound, L.A., and G.D. Weiblen. 2004. Pollination in the New Guinea endemic Antiaropsis decipiens (Moraceae) is mediated by a new species of thrips, Thrips antiaropsidis (Thysanoptera: Thripidae). International Journal of Plant Sciences 165(6): 1017-1026.