Contents lists available at ScienceDirect Plant Gene journal homepage: www.elsevier.com/locate/plantgene High levels of gene flow constraints population structure in Mucuna pruriens L. (DC.) of northeast India Pankaj Kumar Tripathi a , Satya Narayan Jena b , Tikam Singh Rana b , N. Sathyanarayana a, ⁎ a Department of Botany, Sikkim University, Gangtok 737102, Sikkim, India b CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow 226001, India ARTICLE INFO Keywords: Mucuna pruriens Northeast India AFLP marker Genetic diversity Population structure ABSTRACT Medicinal legume Mucuna pruriens L. (DC.) is an ecologically and economically important species known world- wide for anti-Parkinson's drug L-Dopa. The plant is native to eastern India which includes parts of northeast India where it has long history of cultivation. Recently, with the discovery of novel medicinal properties and agro- nomic benefits, the prospects for its large-scale cultivation in the region is growing necessitating development of improved cultivars. However, little data is available on genetic diversity and population structure from its native range to use as resource base for future molecular breeding works and conservation planning. Here we describe first empirical study on genetic diversity and gene flow of M.pruriens from northeast India based on AFLP markers. The high estimates of Jaccard's coefficient and Shannon's index reveal good genetic diversity supporting centre of origin theory. However, pair-wise estimates of genetic differentiation (F ST , Nei's D) were low and AMOVA revealed no evidence for genetic structuring suggesting high levels of gene flow and absence of genetic drift or bottleneck events. Clustering based on UPGMA and STRUCTURE analyses were in conformity with these findings, but point to existence of two independent gene pools representing perhaps Assam plains and eastern Himalayas – the two disparate components of geographically diverse northeast India. The mechanisms under- lying such variation besides implications on genetic diversity along with scope for future investigations are discussed. 1. Introduction Mucuna pruriens (L.) DC. is a diploid tropical legume (2n = 2x = 22) classified within the phaseoloid clade of leguminosae. It is perhaps the most important domesticated species of the genus Mucuna grown world-wide in a range of environments including temperate conditions (Duke, 1981; Russell et al., 1992; CABI, 2015) as food, feed, fodder and cover crop (Siddhuraju and Becker, 2001; Pulikkalpura et al., 2015). The seeds contain L-Dopa (L-3,4 dihydroxy phenylalanine) - a non- protein amino acid well-known for the symptomatic treatment of Par- kinson's disease. The species comprise three botanical varieties of which wild var. pruriens and var. hirsuta (itching beans) shows orange or silvery-grey trichomes which induce highly itching skin reactions upon contact due to presence of proteinaceous substances, mucunain and serotonin (Agharkar, 1991). They often colonize open fields, hedge- rows, by woodland margins or on lake shores (Duke, 1981; Lampariello et al., 2012). The cultivated var. utilis (velvet bean) bears smooth non- itching trichomes and is mostly grown as cover-crop for superior bio- mass, nitrogen fixing ability and in homestead gardens for edible pods and nutritious seeds (Haridas et al., 2013). The centre of origin of a crop plant is normally associated with broad genetic diversity contributed by wild and weedy relatives (Harlan, 1971; Guo et al., 2014). M.pruriens is thought to be native of eastern India or southern China (Burkill, 1966; Duke, 1981; Wilmot- Dear, 1984) which includes parts of northeast India; but concrete data to support this theory is not yet available and wild ancestor of the species is yet to be discovered. The region however showcase abundant distribution of wild variety represented by var. pruriens and there is a long history of cultivation of velvet bean (var. utilis) in the region by several indigenous groups of northeast India such as Khasi, Naga, Kuki, Jaintia, Chakma and Mizo etc. who have used it as a minor food for centuries (Arora, 1991). Recently, with the discovery of highly im- portant medicinal properties, the prospects for its large-scale cultiva- tion in the region are growing. As a result, widening the genetic re- source base to develop improved cultivars with better agronomic and nutritional potential is gaining momentum (Sathyanarayana et al., 2017). In this background, the present investigation was carried out to analyze genetic diversity and population structure of M. pruriens from https://doi.org/10.1016/j.plgene.2018.05.005 Received 1 February 2018; Received in revised form 9 May 2018; Accepted 24 May 2018 ⁎ Corresponding author at: Department of Botany, Sikkim University, 6th Mile, Samdur, P.O. Tadong, 737102 Gangtok, Sikkim, India. E-mail address: nsathyanarayana@cus.ac.in (N. Sathyanarayana). Plant Gene 15 (2018) 6–14 Available online 25 May 2018 2352-4073/ © 2018 Elsevier B.V. All rights reserved. T