**Acknowledgements**

This study was supported by SECURE Himalaya project, a collaborative initiative between the Ministry of Environment, Forest and Climate Change, Government of India, and the United Nations Development Programme in India, with the financial support from the Global Environment Facility. We are highly grateful to The Mountain Institute India and Sikkim Biodiversity Board for facilities. We acknowledge the knowledge of the local and indigenous people i.e. Nepalese, Bhutia and Lepcha of six districts of Sikkim for their valuable knowledge on maize cultivation and conservation of maize genetic diversity.
