Contents lists available at ScienceDirect Journal of Applied Research on Medicinal and Aromatic Plants journal homepage: www.elsevier.com/locate/jarmap Karyological investigation of Calotropis gigantea (L.) W. T. Aiton and Centella asiatica (L.) Urban: Two important medicinal plants of Bangladesh Chandan Kumar Dash a , Md. Shahidur Rahman b , Mahin Afroz c , Syeda Sharmeen Sultana a, ⁎ a Cytogenetics Laboratory, Department of Botany, University of Dhaka, Dhaka, 1000, Bangladesh b Open School, Bangladesh Open University, Gazipur, 1705, Bangladesh c Department of Botany, Barishal University, Barishal, 8200, Bangladesh ARTICLE INFO Keywords: Chromosome CMA DAPI Karyotype Calotropis gigantea Centella asiatica ABSTRACT Calotropis gigantea (L.) W. T. Aiton and Centella asiatica (L.) Urban have been medicinally used throughout Bangladesh. In this study, karyotypic features of these two species were studied with orcein staining and banding with two base specifc fuorochromes such as chromomycine A 3 (CMA) and 4´, 6 diamidino-2-phenylindole (DAPI) for authentic cytogenetical characterization. 2n = 22 and 2n = 18 somatic chromosomes were found in C. gigantea and C. asiatica, respectively. The total chromosome length of C. gigantea and C. asiatica were 45.35 ± 2.64 μm and 63.63 ± 3.19 μm, respectively. The total form percent (TF%), karyotype asymmetry index (AsK%) and karyotype symmetry index (Syi index) were 47.61, 52.39 and 90.87 in C. gigantea and 39.58, 60.42 and 65.51 in C. asiatica, respectively. Both species were found to possess 1A karyotype. In C. gigantea,2 CMA- and 4 DAPI-bands were observed whereas C. asiatica had 16 CMA- and 6 DAPI-bands. Therefore, the compiled data generated from chromosome analysis on orcein, CMA- and DAPI-banding will be useful for cy- togenetical characterization of these two species. 1. Introduction Bangladesh has tremendous wealth of medicinal plants in terms of genetic diversity. Calotropis gigantea (L.) W. T. Aiton and Centella asia- tica (L.) Urban are the top listed medicinal plants of Bangladesh used by the local and ethnic people for hundreds of years. Calotropis gigantea belongs to Asclepiadaceae, locally known as Crown Flower, Giant Milkweed or Akand, is widely distributed in China, India, Indonesia, Malaysia, Myanmar, Nepal and Thailand. In Bangladesh, it occurs throughout the country (Ahmed et al., 2008). The whole part of C. gi- gantea is used for the treatment of various diseases. Root bark of this plant is diaphoretic, emetic, alterative and purgative; useful in dysen- tery, asthma, elephantiasis, syphilis and heart diseases (Das, 1996; Yusuf et al., 2009). It is efective in scabies and ringworm of the scalp and piles. Leaves of C. gigantea are used as poultice against rheumatism, chest pain due to cold, paralyzed parts and in dropsy. It is also useful in skin diseases, wounds and insect bites (Yusuf et al., 2009). Centella asiatica of Apiaceae family, is commonly known as Asiatic pennywort, Indian pennywort, Indian water navelwort, Wild violet (in English) and Thankuni (in Bangla), distributed throughout tropical and sub-tropical regions of the world. In Bangladesh, it grows naturally in all parts of the country (Ahmed et al., 2008). Sometimes it is com- mercially cultivated for enormous medicinal and economic value. Centella asiatica is astringent, tonic, diuretic, laxative, digestive and anti-pyretic; improves appetite, voice and memory; cures dysentery, loose motion, stomach pain, leucoderma, urinary discharges, bron- chitis, infammations, fevers, convulsive disorders, insanity and syphi- litic skin diseases (Yusuf et al., 2009; Prakash et al., 2017). It’s efcacy as an internal and external remedy in ulcerations, eczema, leprosy and other coetaneous afections are established. It has also a special infu- ence on the genitourinary tracts (Yusuf et al., 2009). According to previous records, the studied species C. gigantea re- presents a mono-basic chromosome number i.e. x = 11 with somatic chromosome number 2n = 22 (Table 1). No other chromosome number has been reported for C. gigantea so far. Almost all the previous research on C. gigantea was confned to chromosome count without karyotyping. On the other hand, C. asiatica possesses diferent somatic chromosome number such as 2n = 18, 2n = 22, 2n = 33, 2n = 36, 2n = 54 and 2n = 76 according to available literatures. B-chromosomes were also reported in C. asiatica (Raghuvanshi and Joshi, 1968; Joshi and Raghuvanshi, 1970)(Table 1). Rakotondralambo et al. (2013) reported some diploids and tetraploid populations of C. asiatica from https://doi.org/10.1016/j.jarmap.2019.100221 Received 29 April 2019; Received in revised form 4 September 2019; Accepted 5 September 2019 ⁎ Corresponding author. E-mail addresses: ckd.du.07@gmail.com (C.K. Dash), shahidurbou@gmail.com (Md. S. Rahman), mahin.afroz@yahoo.com (M. Afroz), syedasharmeensultana@du.ac.bd (S.S. Sultana). Journal of Applied Research on Medicinal and Aromatic Plants 14 (2019) 100221 Available online 07 September 2019 2214-7861/ © 2019 Elsevier GmbH. All rights reserved. T