Abstract Detail



Hybrids and Hybridization

SARYAN, PREETI [1], Gowda, Vinita [1].

Do neighbors make it complex? Understanding the origin of species complexes in sympatric Hedychium spp. in northeast India using multiple lines of evidence.

Species complexes are formed when morphological uniqueness is absent amongst two or more related species. Although species complexes are common in plants, species complexes have been both identified and resolved mostly using a molecular phylogenetic approach by linking their origin to putative hybridization events. Only a handful of studies use a holistic approach where the plant’s ecology and physiology have also been studied to resolve a species complex. Here we present an ecological, physiological, morphological, and phylogenetic analysis to infer the origin and consequence of species complexes and the role of ecology in maintaining species diversity.
We present two case studies within the genus Hedychium (~80 species, Zingiberaceae), from the northeast (NE) India, which is known for several species complexes.  In this study, we used morphology, nectar rewards, and interspecies compatibility tests, specifically in populations where multiple species coexisted in sympatry to understand the role of sympatry in hybrid generation as well as its role in reproductive isolation via inter-species competitions. We found that the sympatric species partitioned their reproductive space, temporally (both diel scale and monthly scale), morphologically and based on their pollinator rewards (nectar energy). We performed interspecies crosses between the sympatric species as well as with their potential hybrid species, and we found that most of the species were compatible with each other and the hybrid seeds were viable. We performed NMDS and cluster analysis to identify the morphological clusters. Our results can explain the presence of hybrid swarms that have been observed across NE India whenever multiple Hedychium spp. coexist. Our results show that among sympatric species floral diversity may be promoted by two opposing phenomenon such as: a) absence of reproductive isolation promotes the formation of hybrid swarms, floral diversity and species complexes, b) presence of reproductive isolation promotes floral diversity via processes involving ecological or pollinator competition. Our study is the first of its kind from the tropics to investigate the role of ecology, physiology and evolution in the formation and maintenance of “species complexes” and its relevance in our understanding of speciation processes.


Related Links:
Tropical Ecology and Evolution Lab


1 - Indian Institute of Science Education and Research Bhopal, Biological Sciences, Lab-303, Academic building 3, IISER-Bhopal, Near Bhauri Village, Bhopal Bypass road, Bhopal, MP, 462066, India

Keywords:
Hedychium
hybrid swarms
species complex
interspecies compatibility.

Presentation Type: Oral Paper
Number: 0003
Abstract ID:353
Candidate for Awards:Margaret Menzel Award


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