Karyomorphological Analysis of Erinocarpus, a Monotypic Endemic Genus from Western Ghats of India

Anjali Dnyaneshwar Nalawade*, Kumar Vinod Chhotupuri Gosavi and Shrirang Ramchandra Yadav

Department of Botany, Shivaji University, Kolhapur-416 004, (MS) India.

Received July 14, 2011; accepted December 28, 2011

Summary Erinocarpus Nimmo ex J. Graham a monotypic endemic genus from Western Ghats represented by E. nimmonii J. Graham is distributed in central and northern Western Ghats. The present paper describes the distribution, meiotic count, mitotic count and karyotype analysis of the genus. The somatic chromosome number (2n)=48 and meiotic chromosome number (n)=24 are re- ported for the ﬁrst time. The karyotype is of 2A Stebbins category of asymmetry and the karyotype formula is categorised as 2n=48=20m+28sm (2 SAT).

Key word Erinocarpus nimmonii, India, Karyotype, Meiosis, Western Ghats.

Erinocarpus Nimmo ex J. Graham is a monotypic endemic genus from Western Ghats (Mabberley 2005, Rana and Ranade 2009) categorised under the vulnerable category (VU) in the Red data book (Ahmedullah and Nayar 1990, Mishra and Singh 2001). It was treated under the tribe Grewieae in the family Tiliaceae by Bentham and Hooker (1862–1867) and Schumann (1895). Hutchinson (1967), however, treated Erinocarpus under the tribe Triumfettae based on fruit charac- ters. Presently it is under the sub-family Grewioideae in the family Malvaceae (Judd and Manchester 1997, Bayer et al. 1999). Erinocarpus nimmonii grows along the stream or riverbanks and hill slopes of moist deciduous forests at an altitude of 600–700 m in central and northern Western Ghats. Economically it is less well known. The bark ﬁber is used in rope making (Mabberley 2001) and the seed as famine food (Freedman 2005). The genus remained neglected from a cytological point of view and the present work aims at determining chromosome counts and karyotype analysis of E. nimmonii.

Materials and ｍethods

Seeds of E. nimmonii were collected from the Malkapur (N 16°53.215 and E 073°52.613) region in the Kolhapur district. Seeds were germinated between 2 moist blotting papers in glass petri- plates. Mitosis was studied from the root tips of germinated seeds. Root tips of 6–10 mm length were pretreated with 0.1% colchicine solution for 3 to 4 h at 9∓3°C. The root tips were squashed in 2% propionic orcein. The well-spread somatic plates were photographed with a Coolpix-4500 Nikon camera at 1000⊗ magnification under a Jenaval microscope. Ten well-spread somatic chromosomes plates were analyzed for karyotype analysis using Levan et al. (1964) formulae. Floral buds were fixed in Cornoyʼs fluid and anthers were squashed in 2% propionic-orcein for meiotic study. Voucher specimens (SUK 5979) are deposited in the SUK Herbarium, Department of Botany, Shivaji University, Kolhapur.

* Corresponding author, e-mail: [email protected] 68 A. D. Nalawade et al. Cytologia 77(1)

Fig. 1. Erinocarpus nimmonii J. Graham.: a: Flower; b: Fruit; c: Somatic plate showing 2n=48; d: Meiocyte showing haploid chromosome number n=24; e: ideograph.

Results

Somatic chromosome number 2n=48 (Fig. 1c) and haploid chromosome number n=24 (Fig. 1d) is recorded in E. nimmonii. Chromosomes ranged from 2.76 to 1.44 μm in length. The chromosomes of the species could be classified into 4 types on the basis of chromosome morphology (Tables 3 and 4). The first pair of chromosomes is very long with sub-median constriction and satellites, followed by 3 pairs of long chromosomes with median to sub-median constrictions, followed by 16 pairs of medium chromosomes with median and sub-median constrictions, and the re- maining 4 pairs are small with median constrictions. The chromosomes of the 1st and 9th pairs were observed to possess satellites on the distal region of long arm. The karyotype analysis of E. nimmonii can be summarized as: diploid chromosome number (2n)=48, haploid chromosome number (n)=24, mean chromosome length: 2.06 μm, total chromosome length of haploid compliment (TCLH): 49.47 μm, range of total chromosome length percentage (TCL%): 5.58–2.91, gradient Index (GI): 54.35. symmetric Index (SI): 62.20 and total form percentage (TF%): 38.35. Karyotype formula 2n=48=20m+28sm (2SAT). Karyotype is of 2A category of asymmetry classification (Stebbins 1971). 2012 Karyomorphological Analysis of Erinocarpus, a Monotypic Endemic Genus from Western Ghats of India 69

Table 1. Grewia species and their chromosome counts

Sr. no. Species 2n/n Author

1. Grewia abutifolia Ventenat ex Jussieu n=9 Sarkar et al. (1973) 2. G. asiatica L 2n=36 Singhal et al. (1982) 3. G. aspera Roxb. 2n=18, 18+2B Krishnappa and Munirajappa (1982) 4. G. disperma Rottb. 2n=18 Krishnappa and Munirajappa (1982) 5. G. elastica Royle I=9 Gill et al. (1979 and 1990) 6. G. hainesiana Hole I=18 Gill et al. (1979); Singhal et al. (1982) 7. G. hainesiana Hole 2n=27, 36 n=18 Gill et al. (1990) 8. G. hainesiana Hole 2n=27 Gill et al. (1979a) 9. G. hirsuta Vahl n=9 Singhal et al. (1980, 1982, 1984) 10. G. laevigata Vahl n=9 Bir et al. (1980); Singhal et al. (1982) 11. G. leptopetala Brandis n=18 Gill et al. (1979 and 1990), Singhal et al. (1982) 12. G. oppositifolia Buch.-Ham. n=9 Bir et al. (1980); Singhal et al. (1982) 13. G. optiva Drumm. n=9 Khatoon and Ali (1993) 14. G. vestita Wall. n=19 Sandhu and Mann (1988) 15. G. villosa Willd. 2n=36 Krishnappa and Munirajappa (1982) 16. G. welwitschii Burret 2n=18 Morawetz (1981b)

Table 2. Triumfetta species and their chromosome counts

Sr. no. Species 2n/n Author

1. Triumfetta annua L. 2n=20 Huang et al. (1989) 2. T. annua L. 2n=32 Krishnappa and Munirajappa (1980) 3. T. batramia L. 2n=32 Lay (1950) 4. T. macrophylla K. Schum. 2n=48 Jacob (1983) 5. T. pentandra L. 2n=16 Krishnappa and Munirajappa (1982) 6. T. pentandra L. n=16 Khatoon and Ali (1993) 7. T. pilosa Roth 2n=64 Krishnappa and Munirajappa (1980) 8. T. rhomboidea Jacq. 2n=32 Paiva and Leitao (1987) 9. T. rhomboidea Jacq. 2n=48 Krishnappa and Munirajappa (1980) 10. T. rotundifolia Lam. 2n=32 Krishnappa and Munirajappa (1982) 11. T. rotundifolia Lam. n=16 Sanjappa (1979)

Discussion

Erinocarpus nimmonii grows in moist to dry deciduous forests in central and Northern Western Ghats. It is categorized as vulnerable (Ahmedullah and Nayar 1990, Mishra and Singh 2001) as it has restricted distribution. Morphologically, the genus Erinocarpus Nimmo ex J. Graham is related to Grewia L., Heliocarpus L. and Triumfetta L. Morphological, anatomical and palynological studies support its close relationship with the neotropical Genus Heliocarpus (Van Heel 1966, Sharma 1969, Rajkumar 2001). The meiosis was found to be normal with bivalent counts n=24 (Fig. 1d). Mitosis was also found normal with 2n=48 (Fig. 1c). Centromeres were located in median to sub-median position of chromosomes. The ﬁrst and ninth pairs of satellite chromosome were found in early metaphase while the secondary constrictions of these chromosomes were invisible in later stages probably due to heavy condensation (Okada 1975). With reference to the basic number x=8, Erinocarpus is closer to Triumfetta (Table 2) than to Grewia which has x=9 (Table 1). Chromosome numbers and karyotypic analysis of Triumfetta, Grewia and Heliocarpus need to be investigated to understand their interrelationship. 70 A. D. Nalawade et al. Cytologia 77(1)

Table 3. Karyotype analysis of Erinocarpus nimmonii

Chromo Long arm Short arm Total length d value r value i value Centromeric Type some pair L (μm) s (μm) c=l+s (μm) l/s l/s s/c⊗100 position

1 1.93∓1.03 0.83∓0.31 2.76∓1.22 1.1 2.33 30.07 sm A 2 1.46∓0.46 1.08∓0.55 2.54∓0.94 0.38 1.35 42.52 m B 3 1.63∓0.71 0.84∓0.41 2.51∓0.95 0.83 1.99 33.47 sm B 4 1.67∓0.52 0.85∓0.54 2.48∓0.88 0.78 1.92 34.47 sm B 5 1.5∓0.50 0.87∓1.59 2.37∓0.9 0.63 1.72 36.71 sm C 6 1.32∓0.62 0.97∓0.28 2.29∓0.81 0.35 1.36 42.36 m C 7 1.34∓0.66 0.86∓0.23 2.2∓0.84 0.48 1.56 39.09 sm C 8 1.34∓0.49 0.84∓0.44 2.18∓0.84 0.5 1.6 38.53 sm C 9 1.41∓0.47 0.75∓0.43 2.16∓0.84 0.66 1.88 34.72 sm C 10 1.22∓0.56 0.88∓0.35 2.1∓0.89 0.34 1.39 41.9 m C 11 1.22∓0.82 0.85∓0.23 2.07∓0.89 0.37 1.44 41.06 m C 12 1.22∓0.54 0.85∓0.42 2.07∓0.78 0.37 1.44 41.06 m C 13 1.24∓0.54 0.8∓0.42 2.04∓0.78 0.44 1.55 39.22 sm C 14 1.34∓0.49 0.68∓0.47 2.02∓0.78 0.66 1.97 33.66 sm C 15 1.21∓0.60 0.78∓0.36 1.99∓0.80 0.43 1.55 39.2 sm C 16 1.21∓0.60 0.78∓0.36 1.99∓0.80 0.43 1.55 39.2 sm C 17 1.3∓0.46 0.65∓0.40 1.95∓0.80 0.65 2 33.33 sm C 18 1.22∓0.42 0.7∓0.43 1.92∓0.80 0.52 1.74 36.46 sm C 19 1.19∓0.49 0.66∓0.39 1.85∓0.85 0.53 1.8 35.68 sm C 20 1.01∓0.60 0.8∓0.47 1.81∓0.76 0.21 1.26 44.2 m C 21 0.92∓0.38 0.75∓0.37 1.67∓0.74 0.17 1.23 44.91 m D 22 0.92∓0.40 0.64∓0.37 1.56∓0.74 0.28 1.44 41.02 m D 23 0.84∓0.42 0.66∓0.37 1.5∓0.71 0.18 1.27 44 m D 24 0.84∓0.32 0.6∓0.30 1.44∓0.60 0.24 1.4 41.67 m D

Table 4. Types of chromosome in of Erinocarpus nimmonii

Type of Chromosome Description

Type A (Chromosome 1): A pair of very long chromosomes (2.76 μm) with sub-median centromeres (sm) and satellites. Type B (Chromosomes 2 to 4): Three pairs of long chromosomes (2.54–2.48 μm) with median (m) to sub-median centromeres (sm) Type C (Chromosomes 5 to 20): Sixteen pairs of medium chromosomes (2.37–1.81 μm) with median (m) and sub- median centromeres (sm) and one pair of chromosome with satellites Type D (Chromosomes 21 to 24): Four pairs of short chromosomes (1.67–1.44 μm) with median centromeres (m)

Acknowledgements

Authors are thankful to the Head of the Department of Botany, Shivaji University, Kolhapur for providing laboratory facilities and to the Department of Biotechnology (DBT), New Delhi for ﬁnancial assistance.

References

Ahmedullah, M. and Nayar, M. P. 1990. Endemic Plants of the Indian Region 1 Peninsular India. Botanical Survey of India, Calcutta. Ba yer, C., Fay M. F., De Bruijn, A. Y., Savolainen, V., Morton, C. M., Kubitzki, K., Alverson, W. S. and Chase, M. W. 1999. Support for an expanded family concept of Malvaceae within a recircumscribed order Malvales: a com- bined analysis of plastid atp B and rbcL DNA sequences. Bot. J. Linn. Soc. 129: 267–303. Bentham, G. and Hooker, J. D. 1862–1867. Genera Plantarum Reeve, London. 2012 Karyomorphological Analysis of Erinocarpus, a Monotypic Endemic Genus from Western Ghats of India 71

Bir, S. S., Gill, B. S., Bedi Y. S. and Singhal, V. K. 1980. Evolutionary status of the woody taxa of Garhwal Himalaya. In: P. K. Khosla (ed.). Improvement of Forest Biomass. Indian Society of Tree Scientists, Nagar. pp. 81–96. Freedman, R. L. Notes on the Famine Foods website [internet]. 2008 Jan. 9. Available from: http://www.hort.purdue.edu/ newcrop/FamineFoods/ff_home.html Gill, B. S., Bir, S. S. and Singhal, V. K. 1979. In IOPB chromosome number reports LXIV. Taxon 28: 403. —, — and —. 1979a In IOPB chromosome number reports LXV. Taxon 28: 630. —, —, Bedi Y. S. and —. 1990. Cytological evolution in the woody taxa of Pachmarhi Hills. J. Cytol. Genet. 25: 308–320. Huang, S. F., Zhao Z. F., Chen, Z. Y., Chen S. J. and Huang, X. X. 1989. Chromosome counts on one hundred species and infraspecific taxa. Acta Bot. Sin. 5: 161–176. Hutchinson, J. 1967. The genera of flowering plants (Angiospermae) Vol. 2. Clarendon Press, Oxford. Jacob, T. V. 1983. In IOPB chromosome number reports LXXX. Taxon 32: 505. Judd, W. S. and Manchester, S. R. 1997. Circumscription of Malvaceae (Malvales) as determined by preliminary cladastic analysis of morphological, anatomical, palynological and chemical character. Brittonia 49: 384–405. Khatoon, S. and Ali, S. I. 1993. Chromosome Atlas of the Angiosperms of Pakistan. Department of Botany, University of Karachi, Karachi. Krishnappa, D. G. and Munirajappa. 1980. In: Chromosome number reports LXVIII. Taxon 29: 535–536. — and — 1982. In IOPB chromosome number reports LXXVI. Taxon 31: 582–583. Levan, A., Fregda, I. and Sandberg, A. A. 1964. Nomenclature for centromeric position on Chromosomes. Hereditas 52: 201–220. Lay, K. K. 1950. The American species of Triumfetta L. Ann. Mo Bot. Gard. 37: 315–395. Mabberley, D. J. 2005. The Plant Book. Cambridge University Press, Cambridge. Mishra, D. K. and Singh, N. P. 2001. Endemic and Threatened Flowering Plants of Maharashtra. Botanical Survey of India, Calcutta. Morawetz, W. 1981b. Zur systematischen Stellung der Gattung Prockia: Karyologie und Epidermisskulptur im Vergleich zu Flacourtia (Flacourtiaceae), Grewia (Tiliaceae) und verwandten Gattunge. xx. Plant Syst. Evol. 139: 57–76. Okada, H. 1975. Karyomorphological Studies of Woody Polycarpieae. Journal of Science of the Hiroshima University Series B, Div. 2, 15: 115–200 Paiva, J. and Leitao, M. T.1987. Números cromosomáticos de plantas de Africa tropical. Fontqueria 14: 37–44. Rajkumar, S. 2001. Studies on Systematics and Biology of Endemic Tree Genera of Western Ghats India. Ph. D. Thesis submitted to Goa University (Unpublished). Rana, T. S. and Ranade, S. A. 2009. The enigma of monotypic taxa and their taxonomic implications. Curr. Sci. 96: 219– 229. Sandhu, P. S. and Mann, S. K. 1988. SOCGI plant chromosome number reports—VII. J. Cytol. Genet. 23: 219–228. Sanjappa, M. 1979. In IOPB chromosome number reports LXIII. Taxon 28: 274–275. Sarkar, A. K., Datta, N. and Chatterjee, U. 1973. Chromosome survey of certain angiosperms. II. Bull. Bot. Surv. India 15: 148. Schumann, K. 1895. Elaeocarpaceae, Tiliaceae, Malvaceae, Bombacaceae, Sterculiaceae. In: A. Engler and K. Prantle (eds.). Die Naturlichen Pflanzenfamilien 3: 1–99. Sharma, B. D. 1969. Pollen morphology of Tiliaceae in relation to plant taxonomy. J. Palynology 5: 7–29. Singhal, V. K., Gill, B. S. and Bir, S. S. 1980. In: Chromosome number reports LXVII. Taxon 29: 355–357. —, — and — 1982. Cytology of some Indian species of Grewia Linn. (Tiliaceae). J. Tree Sci. 1: 88–97. —, — and — 1984. Cytology of cultivated woody species (Polypetalae). Proc. Indian Sci. Congr. Assoc. 71: 143–144. Stebbins, G. 1971. Chromosomal Evolution in Higher Plants. Edward Arnold, London. Van Heel, W. A. 1966. Morphology of the androecium in Malvales. Blumea 13: 177–394.