Abstract Detail

Macroevolution

Graham, Sean [1], Gerelle, Wesley [2], Jost, Mathias [3], Logacheva, Maria [4], Sauquet, Hervé [5], Moore, Michael [6], Les, Donald [7], Macfarlane, Terry [8], Remizowa, Margarita [9], Conran, Dr John [10], Wanke, Stefan [11], Rudall, Paula J [12], Sokoloff, Dmitry [13], Marques, Isabel [14].

Connecting phylogenetic and microevolutionary views on dioecy evolution: insights from an ancient angiosperm lineage (Hydatellaceae, Nymphaeales).

We do not have a good understanding of why so few (~6-7%) flowering-plant species are dioecious, despite an apparently high number of origins across angiosperm phylogeny (hundreds, perhaps thousands of transitions to dioecy). This discrepancy may reflect lower diversification rates in dioecious than cosexual lineages, or frequent reversals to cosexuailty. Reconstructions of sexual-system shifts may indicate whether instances of dioecy represent recent transitions (originating convergently on/near tree tips), or older retained primitive states, and whether there are frequent reversions of dioecy to cosexuality. Here we use a plastid phylogenomic approach to reconstruct sexual-state transitions in Hydatellaceae (Nymphaeales), in the broader context of related lineages including Amborella, Nymphaeales, Austrobaileyales (= ANA taxa) and beyond. All 13 described species of Trithuria (Hydatellaceae) are included, nine of which are cosexual; four dioecious species in the family are distantly related to each other. A microsatellite study of a species complex that includes two widespread cosexual species (T. submersa, T. bibracteata) and a geographically limited dioecious species (T. occidentalis) supports the existence of additional cosexual species in the complex. The plastid tree recovers T. occidentalis as being nested among cosexual taxa in this complex, overturning earlier phylogenetic inferences based on more limited data. Parsimony reconstructions imply multiple origins of dioecy across Hydatellaceae and relatives, but likelihood reconstructions and stochastic mappings indicate broad ambiguity in ancestral states across angiosperm phylogeny. Nonetheless, at least two of four instances of dioecy in Hydatellaceae appear to have evolved both independently and recently.

1 - University Of British Columbia, Department Of Botany, 3529 - 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
2 - University of British Columbia, Department of Botany
3 - Technische Universität Dresden, Institut für Botanik, Dresden, Germany
4 - Evolutionary Biochemistry, Leninskie Gory 1/40, Moscow, 119991, Russian Federation
5 - Royal Botanic Gardens and Domain Trust, National Herbarium of New South Wales (NSW), Mrs Macquaries Rd, Sydney, Sydney, NSW 2000, Australia
6 - Oberlin College, Department Of Biology, 119 Woodland St., Science Center K111, Oberlin, OH, 44074, United States
7 - University Of CT, Department Of Ecology & Evolutionary Biology, 75 N. Eagleville Road, Unit 3043, Storrs, CT, 06269, United States
8 - Department of Parks & Wildlife, Western Australian Herbarium, Manjimup, WA, Australia
9 - M.V. Lomonosov Moscow State University, Moscow, Russia
10 - The University Of Adelaide, School Of Biological Sciences, Benham Bldg, DX650 312, Adelaide, SA 5005, Australia
11 - Technische Universität Dresden, Dept. Of Biology, Institut Of Botany, Zellescher Weg 20b, Dresden, 01062, Germany
12 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Richmond, Surrey, UK
13 - M.V. Lomonosov Moscow State University, Higher Plants, 12, 1, Leninskie Gory, Faculty Of Biology, Moscow, MOW, 119234, Russian Federation
14 - University of Lisbon, Centre for Ecology, Evolution and Environmental Changes, Lisbon, Portugal

Keywords:
Dioecy
Hydatellaceae
Plastid phylogenomics
Ancestral states.

Presentation Type: Oral Paper
Session: MACRO2, Macroevolution II
Location: Tucson B/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 2:30 PM
Number: MACRO2005
Abstract ID:1033
Candidate for Awards:None