My long-term objective is to understand the causes and consequences of variation in plant mating strategies. Plants display an amazing diversity of sex conditions, which can be expressed at either the haploid (gametophyte) or diploid (sporophyte) life-stage. The evolutionary consequences of haploid and diploid gene expression for the selection of different mating strategies are applicable to all organisms, regardless of the dominance of the life-stage, yet differences in the timing of expression of mating system traits (i.e. at haploid or diploid stages) may lead to very different evolutionary outcomes. My research examines the selection for the variation in mating strategies using both flowering plants and mosses. At present I am using mosses as a system to understand selection for combined or separate sexes in the haploid life-stage. I am currently using mosses as a model system to examine how differences in breeding system influences population-level selfing rates and inbreeding depression. Additionally, I am examining the role of polyploidy in the evolution of combined and separate sexes.

Jesson LK (2007). Ecological correlates of diversification in New Zealand angiosperm lineages. New Zealand Journal of Botany: 45: 35-51. Eppley, SM, PJ Taylor and LK Jesson (2007). Heterozygosity in mosses: a comparison between species with combined versus separate sexes. Heredity. 98: 33-44. McAlpine KG, LK Jesson & DS Kubien (2007). Photosynthesis and water use efficiency: a comparison between invasive (exotic) and non-invasive (native) species. Austral Ecology. 32: In press. Brookes, RK and LK Jesson (2007). No evidence for pollen and resource limitation in Aciphylla squarrosa: A long-lived, masting herb. Austral Ecology. 32: 370-377. Gamage, H and LK Jesson (2007) Leaf heteroblasty is not an adaptation to shade: anatomical and physiological responses to light in seedlings of heteroblastic and homoblastic species . New Zealand Journal of Ecology 31: In press McAlpine, KG. and LK Jesson. (2007). Biomass allocation, shade tolerance and seedling survival of the invasive species Berberis darwinii (Darwin's barberry). New Zealand Journal of Ecology.31:1-12. Jesson, L.K., L.D. Milicich, and S.C. Newman (2006). Competition-dependent incompatibility in Phormium tenax: Does self-fertilisation provide reproductive assurance? New Zealand Journal of Botany 44: 249-261. Jesson LK and SCH Barrett (2005). Experimental studies of the function of mirror image flowers. Biological Journal of the Linnean Society. 85:167-179 Jesson LK, SCH Barrett and T Day (2003). A theoretical investigation of the evolution and maintenance of mirror-image flowers. American Naturalist 161:916-931. Jesson LK and SCH Barrett (2003). The comparative biology of enantiostyly. International Journal of Plant Sciences 164(5 Suppl.):S237–S249. Jesson LK, J Kang, S Wagner, SCH Barrett and NG Dengler (2003). The development of enantiostyly. American Journal of Botany 90:181-194. Jesson LK and SCH Barrett (2002). Solving the puzzle of mirror-image flowers. Nature 417:707. Jesson LK and SCH Barrett (2002). The genetics of mirror-image flowers. Proceedings of the Royal Society of London: Biological Sciences 269:1835-1839. Jesson LK and SCH Barrett (2002). Enantiostyly in Wachendorfia (Haemodoraceae): The influence of reproductive systems on the maintenance of the polymorphism. American Journal of Botany 89:253-263. Barrett SCH, LK Jesson & AM Baker (2000) The evolution and function of stylar polymorphisms in flowering plants. Annals of Botany 85S (A):253-265. Jesson LK, D Kelly & AD Sparrow (2000). The importance of disturbance, dispersal and competition for exotic plant invasions in Arthur’s Pass National Park (New Zealand). New Zealand Journal of Botany 38:451-468. Barrett SCH, AM Baker & LK Jesson (2000). Mating strategies in monocotyledons. In KL Wilson & D Morrison (eds.) Systematics and evolution in monocots. CSIRO Publishers, Melbourne.