Molecular phylogeny of musaceae in India

Abstract

The family of bananas, or "Musaceae", is does not require any special introduction to the human race. The present study is a marker based (nuclear ITS, chloroplast trnL-F and rps16) molecular phylogeny of wild bananas found in India. The classification of Indian Musaceae has been done earlier in terms of overall morphology, anatomy of leaves and micromorphological characters of seeds and pollen grains. However, molecular study is essential for the precise identity of some problematic taxa in India. Moreover, none of the molecular studies of Musaceae conducted globally have included Indian bananas. All these reasons validate the feasibility of the present study. According to this study, a total of 34 taxa of wild bananas are present in India, including two species of Ensete and 32 taxa of the genus Musa. About 90% of India's wild bananas are distributed in the Northeast India. The rest are confined to the Western Ghats, Eastern ghats and the Andaman and Nicobar Islands. In contrast to the traditional classification by the morphological features of wild bananas, our molecular study found that two sections under the genus Musa viz., Eumusa and Rhodochlamys should be merged into one section. This study helps to reveal the actual identity of M. kattuvazhana and reinstatement of M. sabuana and M. balbisiana var. andamanica from the synonymy of M. balbisiana. In addition, our study confirms the molecular identity of several Indian narrow endemic Musa taxa and reveals genetic distance between M. acuminata and M. balbisiana is greater than between it and ornamental bananas. Character evolution study reveals that bananas with small pseudostem, erect inflorescence and bright coloured bracts are evolved from bananas with large pseudostem, pendant inflorescence and dull coloured bracts. This study also discussed about the pollination switch happened in wild bananas during the course of evolution. Moreover, the study reveals that the diversification of Indian Musaceae, Indian Ensete and Indian Musa happened during c. 60 mya, 39 mya and 36.8 mya respectively. In addition, this study proposed several wild bananas with prominent agronomic traits for future breeding programmes.