Allena Volskay

Allena pollinating Nicotiana alata

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Allena is working on the comparative developmental morphology of Nicotiana Section Alatae, a group containing seven species with several pollination syndromes (see Table below) Anthony Ippolito's work has shown that flower size and color are important traits that influence which pollinators will visit N. alata versus N. forgetiana. Allena is exploring the developmental differences that give rise to the different morphologies. Another interesting change in functional floral morphology involves the switch in mating system (facultative outcrossing versus autogamy) in N. longiflora versus N. plumbaginifolia. Allena is studying the cell-level changes in floral organ growth in both pairs of species, as well as perianth growth in all seven Alatae species.

See Allena's dissertation proposal abstract here.

Figure 1: Comparison of calyx ("cx") and corolla ("ca") lengths for Nicotiana forgetiana ("forg") and N. alata ("ala"), for two plants of each species, averaged over several flowers per plant. Graphs are standardized by the day of corolla opening, arbitrarily day 12. The mature corolla length differences among these species are due to faster growth of N. alata corollas during days 8-12. Corolla tube length is an important trait for pollinator discrimination among F2 hybrids between these species, (F2 discrimination evidence here), and so is a likely trait that pollinators use to discriminate among the species (among-spp discrimination evidence here).

Species	primary pollinators	mating system
N. longiflora	hawkmoths	Self-compatible (SC), facultative outcrosser but at least one population selfs regularly in the glasshouse
N. plumbaginifolia	hawkmoths	SC, autogamous & cleistogamous
N. alata	hawkmoths	Self-incompatible (SI)-enforced outcrossing
N. langsdorfii	hummingbirds, Bombus, Halictids	SI-enforced outcrossing but some populations studied by Bruce McClure are SC.
N. forgetiana	hummingbirds, Halictid bees	SI-enforced outcrossing
N. mutabilis	hummingbirds, others?	SI-(new flrs white, older ones pink)
N. bonariensis	small perching moths	SI-enforced outcrossing
N. sp. novo ?	hummingbirds, Halictids and small moths	SI-enforced outcrossing

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