A Colloquium Honoring Leslie D. Gottlieb
Harbert, Robert , Doyle, Jeff .
Climate niche, invasiveness, and allopolyploidy: The case of perennial Glycine (Leguminosae).
Whether polyploid species are inherently more adaptable, invasive, and “successful” than their diploid progenitors has been the subject of longstanding debate. Polyploids often show physiological differences from their diploid progenitors, which could lead to their occupying distinct ranges. However, range alone is a very indirect reflection of physiology. We used available information on locality presence and absence of four Glycine (Leguminosae) allopolyploid species and their diploid progenitors to build models of the theoretically available Australian ranges based on climate and to characterize the multidimensional statistical climate space for each species. This allowed us to look for consistent patterns across closely related but independently formed allopolyploid species. Comparison of the Australian range of a given polyploid to its progenitors revealed that each of the polyploids occupies a unique niche relative to its progenitors, but the extent of overlap with diploids does not follow a predictable trend (e.g., polyploids do not always occupy the entire progenitor ranges). Three of these polyploid species and none of the diploids exhibit extra-Australian colonization, but based on these studies it appears that this is not due to expansion into sites where the climate is unsuitable for the progenitor species, and therefore must be due to some other trait that enhances either dispersal or ability to colonize. Principal components analysis of multidimensional climate space suggests that each allopolyploid is intermediate between its diploid progenitors, as might be expected under a model of hybridity, but statistical tests revealed that three of the four polyploid species were significantly differentiated from only one progenitor. In contrast, all relevant pairs of diploids differed significantly from one another. The analysis of multidimensional climate space did not show that these Glycine allopolyploids occupy a larger climate niche than their diploid progenitors or diploids as a rule. The research presented here suggests that each Glycine polyploid event is unique and unpredictable with regard to the ecological manifestation of complex traits. Despite our inability to detect a common effect of polyploidy on Australian ranges, the fact that, in Glycine, only allopolyploids have populations outside of Australia and adjacent Papua New Guinea suggests that allopolyploidy plays a role in invasiveness that is not correlated with their expansion into novel climatic space.
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1 - Cornell University, 412 Mann Library Building, ITHACA, NY, 14853-4301, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Grand Ballroom A/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 11:15 AM
Candidate for Awards:None