Abstract Detail

Systematics

ASHOKAN, AJITH [1], Gowda, Vinita [2].

Floral evolution in ginger lilies: one of the Darwinian fantasies from the Indo-Malayan Realm.

Indo-Malayan Realm (IMR), despite being one of the floristically megadiverse regions on Earth, is still underrepresented in floral evolution studies, especially for its monocot lineages. We identified that the lack of suitable study systems and the scarcity of phylogenetic trees of endemic lineages have hindered floral evolution studies within the IMR. Hedychium J.Koenig (Ginger lilies: Zingiberaceae) is an endemic genus to the IMR and is the only genus representing the monocot order Zingiberales with flowers that possess an exquisite fragrance. Hedychium is identified to have at least two distinct floral syndromes (bird flowers and moth flowers) and the temporally modulated floral fragrance is believed to be one of their key innovations. Among those who were enticed by the floral traits in Hedychium, included Charles Darwin, who predicted that the wings of moths would perform the transfer of pollen in Hedychium flowers. Darwin's predictions were later validated by the observations of his contemporary natural historians. Although studies in Hedychium touched all major research aspects, there were not many attempts to understand the evolution of floral traits in this genus. To obtain a clear understanding of the floral evolution in this genus, we built a time-tree of Hedychium inferring evidence from two nuclear and five plastid markers across 75% of the known species diversity in the genus. We used the resulting ultrametric tree to estimate the ancestral character-states, phylogenetic signal, and character correlations for thirteen discrete and eight continuous floral traits in Hedychium. Further, diversification rate estimation analyses were employed to understand if there is any trait-dependent diversification in Hedychium. From the ancestral character-state reconstruction, we confirmed that the cincinnus capacity is the only character that can be used for distinguishing each of the distinct clades of Hedychium. The Fritz-Purvis' D-statistic estimated for characters such as slender cylindrical inflorescence, cincinnus capacity, and bending of floral tubes revealed a strong phylogenetic dependence, whereas, characters such as the number of flowers open per day, the color of central labellum blotch, and position of stigma revealed higher ecological effects. Further, from the diversification rate estimation analyses, we observed that the central labellum width, floral tube length, and central labellum color played a major role in the diversification of Hedychium. We are optimistic that our results are of considerable value for future integrated studies that should incorporate a more comprehensive understanding of pollinator behavior among Hedychium within the IMR.

1 - Indian Institute of Science Education and Research Bhopal, Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal, Madhya Pradesh, 462066, India
2 - IISER Bhopal, Room 223, AB3, Dept. Of Biological Sciences,, IISER- Bhopal, Bhopal Bypass Road, Bhauri,, Bhopal, MP, 462066, India

Keywords:
Charles Darwin
cincinnus capacity
floral fragrance
Hedychium
Indo-Malayan Realm
pollination syndrome
Trait evolution
Zingiberaceae.

Presentation Type: Oral Paper
Session: COOLII, ASPT Cooley Award Talks II
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 1:15 PM(EDT)
Number: COOLII004
Abstract ID:1072
Candidate for Awards:George R. Cooley Award