Dr. Joel S. Shore

Dept. Biology, York University, Toronto, Ontario, Canada M3J 1P3

Tel: (416) 736-2100 ext 33492, Fax: 736-5989, Email:


| Courses | Research | Publications | Students | Photographs |



Turneraceae website





Research in my lab currently focuses on the evolution of plant breeding systems although we have carried out studies of plant population genetics and plant/butterfly interactions. We have continued to study the genetics and evolution of breeding systems in a largely Neotropical plant family, the Turneraceae, and especially in the genus Turnera. A majority of species in the genus are distylous and strongly self-incompatible, while other species are self-compatible often having anthers and stigmas in close proximity, leading to high rates of self-fertilization. We have been working towards a molecular genetic dissection of the distyly locus in Turnera species using both a proteomics based approach as well as genetic mapping. We have now cloned, sequenced and identified two genes that appear to be tightly associated with the short-styled morph, although their expression is morph-limited, not the result of linkage to a gene complex determining distyly. Both proteins occur only in the styles of short-styled plants (in the transmitting tissue). We are constructing a fine scale genetic map using a range of molecular markers, in order to positionally clone genes at the distyly locus by probing a BAC library.




Refereed journal articles

Barrett, S.C.H., S.D. Price and J.S. Shore. 1983. Male fertility and anisoplethic population structure in tristylous Pontederia cordata (Pontederiaceae). Evolution 37:745-759.

Shore, J.S. and S.C.H. Barrett. 1984. The effect of pollination intensity and incompatible pollen on seed set in Turnera ulmifolia (Turneraceae). Canadian Journal of Botany 62:1298-1303. pdf

Barrett, S.C.H. and J.S. Shore. 1985. Dimorphic incompatibility in Turnera hermannioides Camb. (Turneraceae). Annals of the Missouri Botanical Garden 72:259-263.

Shore, J.S. and S.C.H. Barrett. 1985. Morphological differentiation and crossability in the Turnera ulmifolia complex (Turneraceae). Systematic Botany 10:308-321.

Shore, J.S. and S.C.H. Barrett. 1985. Genetics of distyly and homostyly in the Turnera ulmifolia complex (Turneraceae). Heredity 55:167-174.

Shore, J.S. and S.C.H. Barrett. 1986. Genetic modifications of dimorphic incompatibility in the Turnera ulmifolia L. complex (Turneraceae). Canadian Journal of Genetics and Cytology 28: 796-807. pdf

Barrett, S.C.H., A.H.D. Brown and J.S. Shore. 1987. Mating patterns in tristylous Eichhornia paniculata (Pontederiaceae). Heredity 58:49-55.

Shore, J.S. and S.C.H. Barrett. 1987. Inheritance of floral and isozyme polymorphisms in Turnera ulmifolia L. Journal of Heredity 78:44-48.

Barrett, S.C.H. and J.S. Shore. 1987. Variation and evolution of breeding systems in the Turnera ulmifolia L. complex (Turneraceae). Evolution 41:340-354.

Shore, J.S. and S.C.H. Barrett. 1990. Quantitative genetics of floral characters in homostylous Turnera ulmifolia var. angustifolia. Heredity 64:105-112.

Shore, J.S. 1991. Tetrasomic inheritance and isozyme variation in Turnera ulmifolia vars. elegans Urb. and intermedia Urb. (Turneraceae). Heredity 66: 305-312.

Galen, C., J.S. Shore and H. Deyoe. 1991. Ecotypic divergence in alpine Polemonium viscosum: Genetic structure, quantitative variation, and local adaptation. Evolution 45: 1218-1228.

Shore, J.S. 1991. Chromosomal evidence for autotetraploidy in Turnera ulmifolia. Canadian Journal of Botany 69:1302-1308. pdf

Shore, J.S. and C.M. OBrist. 1992. Variation in cyanogenesis within and among populations and species of Turnera series Canaligerae Urban (Turneraceae). Biochem. Syst. Ecol. 20:9-15.

Rodriguez, L., M. Sokolowski and J.S. Shore. 1992. Habitat selection in Drosophila melanogaster larvae. Journal of Evolutionary Biology 5:61-70.

Learn, G.H., J.S. Shore, G.R. Furnier, G. Zurwaski and M.T. Clegg. 1992. Constraints on the evolution of chloroplast introns: The group II intron in the gene encoding tRNA-Val (UAC). Molecular Biology and Evolution 9:856-871.

Wolfe, L.M. and J.S. Shore. 1992. The mating system of Hydrophyllum appendiculatum, a protandrous species. Sexual Plant Reproduction 5:239-245.

Shore, J.S. 1993. Pollination genetics of the common milkweed, Asclepias syriaca L. Heredity 70:101-108.

Gibson, D., D.R. Bazely and J.S. Shore. 1993. Responses of brambles, Rubus vestitus, to herbivory. Oecologia 95:454-457.

Shore, J.S., K. McQueen and S.H. Little. 1994. The inheritance of plastid DNA in Turnera ulmifolia. Amer. J. Botany 81:1636-1639. pdf

Baker, A.M. and J.S. Shore. 1995. Pollen competition in Turnera ulmifolia. Amer. J. Botany 82:717-725. pdf

Belaoussoff, S. and J.S. Shore. 1995. Floral correlates and fitness consequences of mating system variation in Turnera ulmifolia. Evolution 49:545-556.

Schappert, P.J. and J.S. Shore. 1995. Cyanogenesis in Turnera ulmifolia L. (Turneraceae). I. Phenotypic distribution and genetic variation for cyanogenesis on Jamaica. Heredity 74: 392-404.

Gold, J.J. and J.S. Shore. 1995. Multiple paternity in Asclepias syriaca using a paired fruit analysis. Canadian Journal of Botany 73:1212-1216. pdf

Galen, C., M.L. Stanton, J.S. Shore and R.A. Sherry. 1997. Source-sink dynamics along environmental gradients: Environmental effects on gene flow and genetic substructure in a population of the Alpine Buttercup, Ranunculus adoneus. Opera Botanica 132:179-188.

Stanton, M.L., C. Galen and J.S. Shore. 1997. Population structure along a steep ecological gradient: consequences of flowering time and habitat variation in the snow buttercup, Ranunculus adoneus. Evolution 51:79-94.

Athanasiou, A. and J.S. Shore. 1997. Morph-specific proteins in pollen and styles of distylous Turnera (Turneraceae). Genetics 146:669-679.

Shore, J.S. and M. Triassi. 1998. Paternally biased cpDNA inheritance in Turnera ulmifolia L. (Turneraceae). American J. Botany 85:328-332. pdf

Schappert, P.J. and J.S. Shore. 1998. Euptoieta hegesia Cramer (Nymphalidae) on Jamaica: Ecology, population biology and mortality. Journal of the Lepidopterists' Society 52:9-39.

Schappert, P.J. and J.S. Shore. 1999. Effects of cyanogenesis polymorphism in Turnera ulmifolia on Euptoieta hegesia, a specialist herbivore. Journal of Chemical Ecology 25:1455-1479.

Schappert, P.J. and J.S. Shore. 1999. Cyanogenesis, herbivory and plant defense in Turnera ulmifolia on Jamaica. Ecoscience 6: 511-520.

Schappert, P.J.and J.S. Shore. 2000. Cyanogenesis in Turnera ulmifolia L. (Turneraceae). II. Developmental expression, heritability and cost of cyanogenesis. Evolutionary Ecology Research 2: 337-352. pdf

Tamari, F., A. Athanasiou and J.S. Shore. 2001. Pollen tube growth and inhibition in distylous and homostylous Turnera and Piriqueta (Turneraceae). Canadian Journal of Botany. 79: 578-591. pdf

Athanasiou, A., D. Khosravi, F. Tamari, and J.S. Shore. 2003. Characterization and localization of short-specific polygalacturonase in distylous Turnera subulata (Turneraceae). American Journal of Botany 90: 675-682. pdf

Pither, R., J.S. Shore and M. Kellman. 2003. The genetic diversity of the tropical tree species, Terminalia amazonia (Combretaceae) in naturally fragmented populations. Heredity 91: 307-313.

Khosravi, D., R. Joulaie, and J. S. Shore. 2003. Immunocytochemical distribution of polygalacturonase and pectins in styles and pollen of distylous and homostylous Turneraceae. Sexual Plant Reproduction 16: 179-190.

Tamari, F. and J.S. Shore. 2004. Distribution of style and pollen polygalacturonases among distylous and homostylous Turnera and Piriqueta spp. (Turneraceae). Heredity 92: 380-385.

Khosravi, D, C.-C. Yang, K. W. M. Siu, and Joel S. Shore 2004. High Level of a-Dioxygenase in short styles of distylous Turnera spp. International Journal of Plant Sciences 165: 995-1006. pdf

Tamari, F., D. Khosravi, A.J. Hilliker, and J.S. Shore 2005. Inheritance of spontaneous mutant homostyles in Turnera subulata x krapovickasii and in autotetraploid T. scabra (Turneraceae). Heredity 94: 207-216.

Truyens, S., M.M. Arbo, and J.S. Shore. 2005. Phylogenetic relationships, chromosome andbreeding system evolution in Turnera (Turneraceae): inferences from ITS sequence data. American Journal of Botany 92: 1749-1758. pdf

Tamari, F. and J.S. Shore. 2006. Allelic variation for a short-specific polygalacturonase in Turnera subulata: Is it associated with the degree of self-compatibility? International Journal of Plant Sciences 167: 125-133. pdf

Shore, J.S., M. M. Arbo, and A. Fernandez. 2006. Breeding system variation, genetics and evolution in the Turneraceae. New Phytologist 171: 539-551.

Moens, P.B., E. Marcon, J.S. Shore N. Kochakpour, B. Spyropoulos. 2007. Initiation and resolution of interhomolog connections: crossover and non-crossover sites along mouse synaptonemal complexes. Journal of Cell Science 120: 1017-1027. pdf

Labonne, J.D.J., A.J. Hilliker, and J.S. Shore. 2007. Meiotic recombination in Turnera (Turneraceae): Extreme sexual difference in rates, but no evidence for recombination suppression associated with the distyly (S) locus. Heredity 98:411-418.

Labonne, J.D.J., A. Vaisman, and J.S. Shore. 2008. Construction of a first genetic map of distylous Turnera and a fine-scale map of the S-locus region. Genome 51: 471- 478. pdf

Labonne, J.D.J., A. Goultiaeva, and J.S. Shore. 2009. High-resolution mapping of the S-locus in Turnera leads to the discovery of three genes tightly associated with the S-alleles. Molecular Genetics and Genomics: 281: 673-685.

Safavian, D. and J.S. Shore. 2010. Ultrastructure of styles and pollen tubes of distylous Turnera joelii and T. scabra (Turneraceae): Are there different mechanisms of incompatibility? Sexual Plant Reproduction. 23: 225-237.

Labonne, J.D.J., F. Tamari, and J.S. Shore. 2010. Characterization of X-ray-generated floral mutants carrying deletions at the S-locus of distylous Turnera subulata. Heredity 105:235-243 and see News and Commentary

Labonne, J.D.J., and J.S. Shore. 2011. Positional cloning of the s haplotype determining the floral and incompatibility phenotype of the long-styled morph of distylous Turnera subulata. Molecular Genetics and Genomics 285: 101-111

Thulin, M., S.G. Razafimandimbison, P. Chafe, N. Heidari, A. Kool and J.S. Shore. 2012. Phylogeny of the Turneraceae clade (Passifloraceae s.l.): Trans-Atlantic disjunctions and two new genera in Africa. Taxon. 61: 308-323.

Lopez, A., A. Fernandez, and J.S. Shore. 2013, Inferences on the origins of polyploid Turnera species (Passifloraceae) based on molecular data. Botany. 91: 167-175.

Chafe, D.J., T. Lee, and J.S. Shore. 2014.Development of a genetic transformation system for distylous Turnera joelii (Passifloraceae) and characterization of a self-compatible mutant. Plant Cell, Tissue and Organ Culture (PCTOC). 10.1007/s11240-014-0617-y

Dutton, E.M., E.Y. Luo, A.R. Cembrowski, J.S. Shore, M.E. Frederickson. 2016. Three’s a crowd: Trade-offs between attracting pollinators and ant bodyguards with nectar rewards in Turnera. American Naturalist 188: 38-51.


Dutton, E.M., J.S. Shore, M.E. Frederickson. 2016 Extrafloral nectar increases seed removal by ants in Turnera ulmifolia.   Biotropica 48: 429-432

Shore, J.S., H.J. Hamam, P.D.J. Chafe, J.D.J. Labonne, P.M. Henning, A.G. McCubbin. 2019. The long and short of the S-locus in Turnera (Passifloraceae). New Phytologist. F1000 recommended

Henning, P.M., J.S. Shore, A.G. McCubbin. 2020. Transcriptome and network analyses of heterostyly in Turnera subulata provide mechanistic insights: Are S-loci a red-light for pistil elongation.  Plants 20209(6), 713;

Matzke, C.M., J.S. Shore, M.M. Neff, A.G. McCubbin. 2020. The Turnera style S-locus gene TsBAHD possesses brassinosteroid-inactivating activity when expressed in Arabidopsis thaliana. Plants 2020, 9, 1566; doi:10.3390/plants9111566




Barrett. S.C.H. and J.S. Shore. 1989. Isozyme variation in colonizing plants, pages 106-126. In:Isozymes in Plant Biology. Soltis, D.E. and Soltis, P.S. (eds.). Dioscorides Press, Portland.

Khosravi, D., K.W.M. Siu, and J.S. Shore. 2006. A proteomics approach to the study of distyly in Turnera species. In: Jaime A. Teixeira da Silva (ed.), Floriculture, Ornamental and Plant Biotechnology: Advances and Topical Issues, Volume 1, pp. 51-60. Global Science Books, UK. pdf

Barrett. S.C.H. and J.S. Shore. 2008. New insights on heterostyly: Comparative biology, ecology and genetics, pages 3-32. In Franklin-Tong V (ed) "Self-Incompatibility in Flowering plants: Evolution, Diversity and Mechanisms". Springer-Verlag, Berlin. online




Graduate Students 


Former Students

Dr. Phil J. Schappert

Dr. Andreas Athanasiou

 Dr. Davood Khosravi.

Dr. Farshad Tamari, Department of Biological Sciences, Kean University, New Jersey.  U.S.A.

Darya Safavian

Dr. Jonathan Labonne

Paul Chafe (PhD) - Molecular genetics of distyly in Turnera

Deanna Harris (MSc)




FALL 2019 BIOL2060 STATISTICS FOR BIOLOGISTS (Sept 2019 – Dec 2019)