Contents lists available at ScienceDirect Ecological Genetics and Genomics journal homepage: www.elsevier.com/locate/egg ISSR and ITS analyses to assess genetic diversity and phylogeny to conserve an endemic and critically endangered tree, Memecylon subcordatum, in India Madepalli Byrappa gowdu Viswanathan * , Chinnaiyan Rajasekar, Perumal Sathish Kumar Department of Plant Science, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India ARTICLE INFO Keywords: Polymorphic bands Bayesian STRUCTURE Mantel test AMOVA Principal coordinates analysis MrBayes ABSTRACT Memecylon subcordatum (Melastomataceae) is an endemic and critically endangered species of the Kalakkad- Mundanthurai Tiger Reserve in India. Twenty five inter-simple sequence repeat primers were used to screen 86 individuals. Nine primers produced a total of 61 bands (6.77 bands primer -1 ) ranging from 200 to 1900 bp wherein 48 bands were of polymorphic. Polymorphism was 78.69% within the species, 26.60% within the populations and 7.41%–48.15% among the populations. Genetic variation varied from 0.3069 (within species) to 0.1182 (within populations). The poor gene flow among the populations (N m : 0.3133) could be due to the genetic barriers caused by the tributaries of Tambraparani river. The coefficient of genetic differentiation be- tween the populations (G ST ) was 0.6148. The Bayesian analysis, multidimensional scaling analysis and principal coordinates analysis grouped all the 11 populations under 4 clades. The Mantel test showed significant corre- lation between the matrices of genetic and geographic distances (r = 0.652, P < 0.001) ranging from 8 to 44 km. The phylogram constructed by internal transcribed spacers to 13 Memecylon species showed 2 distinct clades wherein Memecylon angustifolium, an associate present along the river banks and at damp localities in the southern Tropical wet evergreen forests from 678 to 1432 m MSL, revealed close affinity. In addition to conserve all the existing natural populations in this protected area, the authors suggest to utilize genetic diversity-rich saplings and stem cuttings from 6 populations and to sow seed coat-removed seeds to enhance the percentage of germination. 1. Introduction The genus Memecylon L. belongs to the family of Melastomataceae [1] and has about 300 species [2–4] or 300–400 species [5]. Members of the family are of shrubs and or trees. It is represented by 30 species in Sri Lanka [2], 43 in Borneo, Java, Malaya and Sumatra [3], 27 in Borneo [4], 40 in Guineo-Congolian Africa [5], 78 in Asia, Oceania and Madagascar [6], 70 in Africa [7], and 39 in India [8]. It is mostly dis- tributed in the Western Ghats region of India and the Sri Lanka. It is known as ‘one of the 36 Hot Spots in the world’ [9]. A plethora of new species in Memecylon that have been published include M. subramanii, M. balakrishnanii, M. manickamii, M. sivadasanii, M. tirunelvelicum, M. kollimalayana, M. bremeri, M. mundanthuraianum, M. agastyamalaianum, M. jadhavii, M. courtallense, and M. wayanadense. Several new records such as M. hookeri, M. scutellum, M. rivulare, M. sylvaticum, M. gra- cillimum, M. leucanthemum, M. rostratum and M. royenii, M. macrocarpum and M. clarkeanum have been reported to India. The present study species, M. subcordatum was described by K.C. Jacob from Kannikatti in the Kalakkad-Mundanthurai Tiger Reserve (KMTR) on the basis of holotype specimen (MH Acc. No. 85417) collected on 22.9.1921. Molecular markers were used as technical tools to assess affinity, origin and divergence time, and distinguish close relatives in Memecylaceae and Melastomataceae. On the basis of parsimony and maximum likelihood analysis of cpDNA sequences of rbcL and ndhF genes and rpl16 intron, these two groups were treated as sister ones [10]. An ndhF analysis of 91 species belonging to 59 genera provided strength to this treatment and linked the Eurasian and North American fossils by molecular clock approach in biogeographical reconstruction [11]. The Bayesian analysis of combined chloroplast loci provided molecular estimates of divergence time to Memecylaceae and Mela- stomataceae in Africa and Madagascar [12]. Nine samples of Memecylon species were scrutinized by 20 RAPD primers using the unweighted pair group method with arithmetic mean (UPGMA). At the end, the process led to describe a new species of M. wayanadense and placed it along with its close relatives of M. sivadasanii and M. rivulare under cluster A. M. angustifolium was included under cluster B [8]. Population analyses reveal the relevance of molecular markers to prepare genetic linkage maps [13]. The ISSRs are found to be highly sensitive, reproducible and https://doi.org/10.1016/j.egg.2018.03.004 Received 15 April 2017; Received in revised form 15 July 2017; Accepted 7 March 2018 * Corresponding author. E-mail address: vinaabdu@gmail.com (M.B.g. Viswanathan). Ecological Genetics and Genomics 7–8 (2018) 6–12 Available online 13 March 2018 2405-9854/ © 2018 Published by Elsevier Inc. T