Abstract Detail

Systematics

NS, Prasanna [1], Gowda, Vinita [2].

Disentangling Didymocarpus: Molecular phylogeny and biogeography of Didymocarpus Wall. (Gesneriaceae).

The phylogenetic relationship and biogeographic history of old-world gesneriads remain poorly understood since the group is plagued with taxonomic issues. The genus Didymocarpus Wall. (Gesneriaceae) is one such morphologically diverse group comprising about 105 species distributed in Western Himalayas, North-East India, South-West China, Indo-Burma, Thailand, and Peninsular Malaysia. Despite recent taxonomic revision and re-circumscription, the genus has been shown to be not monophyletic. The only molecular phylogeny available for Didymocarpus had only about one-fourth of the known species in the genus and did not include any taxa from India where it is also known to be diverse. Therefore the origin and diversification of the Indian Didymocarpus has not been studied. In this study, we are revising the Didymocarpus phylogeny using a nuclear and three chloroplast markers and 65 taxa from the Sino-Himalayan and Indo-Malay region. We dated the tree using secondary calibration points known for old-world Gesneriaceae. Preliminary results indicate that the genus Gyrochelos is nested within Didymocarpus s.l. and they are sister to the genera Liebigia and Allocheilos from China. Didymocarpus formed a strongly supported monophyletic group with the exception of four morphologically distinct species, inferring the need for taxonomic re-adjustments. Five clades were distinguished within Didymocarpus s.s., largely in congruence with their biogeographic affinities. Members of the sect. elati from the Malay peninsula formed a separate clade. Taxa from India did not form a monophyletic group suggesting that the Indian Didymocarpus spp. may have a history of multiple dispersals and back-dispersals, and that local adaptation may have played a critical role in its high endemicity within India.

1 - Indian Institute of Science Education and Research Bhopal, Department of biological sciences, 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:
Gesneriaceae
biogeography
Didymocarpus
phylogeny.

Presentation Type: Oral Paper
Session: COOLII, ASPT Cooley Award Talks II
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 1:30 PM(EDT)
Number: COOLII005
Abstract ID:1094
Candidate for Awards:George R. Cooley Award