title: Functional androdioecy in critically endangered Gymnocladus assamicus (Leguminosae) in the Eastern Himalayan Region of Northeast India.
abstract: Gymnocladus assamicus is a critically endangered tree species endemic to Northeast India, and shows sexual dimorphism with male and hermaphrodite flowers on separate trees. We studied phenology, reproductive biology and mating system of the species. The flowers are small, tubular, odorless and last for about 96 hours. Pollen grains in both morphs were viable and capable of fertilization leading to fruit and seed set. Scanning electron micrographs revealed morphologically similar pollen in both male and hermaphrodite flowers. The fruit set in open pollinated flowers was 43.61 percent, while controlled autogamous and geitonogamous pollinations yielded 76.81 and 65.58 percent fruit set respectively. Xenogamous pollinations between male and hermaphrodite flowers resulted in 56.85 percent fruit set and pollinations between hermaphrodite flowers yielded 67.90 percent fruit set. This indicates a functionally androdioecious mating system and pollination limited fruit set in G. assamicus. Phylogenetic analyses of Gymnocladus and the sister genus Gleditsia are needed to assess if the androdioecious mating system in G. assamicus evolved from dioecy as a result of selection for hermaphrodites for reproductive assurance during colonization of pollination limited high altitude ecosystems.
authors.affiliation: Forest and Evolutionary Genomics Laboratory, and Centre for Structural and Functional Genomics, Biology Department, Concordia University, Quebec, Canada ; Québec Centre for Biodiversity Sciences, Montréal, Quebec, Canada ; Department of Forestry, North Eastern Regional Institute of Science & Technology, Nirjuli, Arunachal Pradesh, India.
authors.forename: Baharul Islam
authors.initials: BI
authors.lastname: Choudhury
authors.affiliation: Department of Forestry, North Eastern Regional Institute of Science & Technology, Nirjuli, Arunachal Pradesh, India.
authors.forename: Mohammed Latif
authors.initials: ML
authors.lastname: Khan
authors.affiliation: Forest and Evolutionary Genomics Laboratory, and Centre for Structural and Functional Genomics, Biology Department, Concordia University, Quebec, Canada ; Québec Centre for Biodiversity Sciences, Montréal, Quebec, Canada.
authors.forename: Selvadurai
authors.initials: S
authors.lastname: Dayanandan
mesh_terms: D017753:Ecosystem; D007887:Fabaceae / Q000033:anatomy & histology / Q000145:classification / Q000502:physiology*; D035264:Flowers / Q000033:anatomy & histology / Q000145:classification / Q000502:physiology; D007194:India; D010802:Phylogeny; D011058:Pollen / Q000033:anatomy & histology / Q000145:classification / Q000502:physiology; D054817:Pollination / Q000502:physiology