2019 Volume 84 Issue 1 Pages 85-87
The genus Curculigo is represented by 17 species and four varieties distributed in worldwide of which seven species and three varieties reported in India. The genus is well-known for its medicinal property. One Indian species C. janarthanamii Gore & Gaikwad was collected in Maharashtra and was investigated its chromosomes for the first time. The mitotic chromosome count was 2n=18. The karyotype was composed of one subterminal, seven submedian and one median chromosomes showing asymmetric feature.
Hypoxidaceae is a small family of herbaceous perennial monocotyledons with approximately 200 species in nine genera. They are mainly found in the Southern hemisphere of the Old World and in North America (Sanchez-Ken 2010). The genus Curculigo is represented by seven species and three varieties from India. Recently C. janarthanamii was described from Balaghat Ranges of Maharashtra (Gore and Gaikwad 2018). C. janarthanamii is an endemic species which grows from swampy margins of seasonally running fresh water stream on black clay soil. It bears rhizomatous roots, raceme inflorescence and polygamous flowers (Fig. 1a, b). It is also being cultivated extensively in India for commercial purpose as C. orchioides. Its tuberous roots and rhizomes are slightly bitter and mucilaginous in taste and are used as a tonic, demulcent, diuretic and restorative (Chopra et al. 1956). It is also used as a medical cure for piles, asthma, jaundice, diarrhea, colic, and gonorrhea (Kirtikar et al. 1987). Curculigo has various medicinal properties like anticancer, anti-diabetic, anti-neurodegenerative and hepatoprotective activities etc. (Wang et al. 2012). Present communication reported a chromosome count (2n) and karyotype of C. janarthanamii to provide basic cytogenetic properties for the conservation of this endemic species.
Several individuals with rhizomatous roots of Curculigo janarthanamii (Fig. 1c) were collected from the wild resources of Osmanabad district of Maharashtra. After dipping rhizomes in freshwater new roots were developed and four-five young roots were used for chromosome studies. The voucher specimen (ARG-601) was deposited in the Herbarium of Department of Botany, Shivaji University, Kolhapur (SUK).
Root tips of 6–10 mm length were obtained from seven individuals and pretreated with a saturated solution of paradichlorobenzene at 8–10°C for 3–4 h. The root tips were quashed in 2% propionic orcein. Ten well-spread somatic chromosome plates were used for karyotype analysis. The somatic chromosome plates were photographed with a Carl Zeiss Axio Imager. Types of chromosomes were evaluated using a centromeric index of Levan et al. (1964) and a category of karyotype was determined by following Stebbins (1971).
Curculigo janarthanamii showed 2n=18 (Fig. 1d). The shortest chromosome was 2.15 µm and the longest one was 10.98 µm. The mean chromosome length (MCL) was 9.34 µm and the total haploid chromosome length (TCL) was 84.09 µm. The numerical values of each parameter for karyotype analysis are given in Table 1. Figure 1e shows the karyogram of C. janarthanamii exhibited the formula of 1m+7sm+1st pairs. The karyotype was moderately asymmetrical and fell into the category 3b of Stebbins (1971). The A1 and A2 asymmetry indices were found to be 1.00 and 0.29, respectively.
| Chromosome pairs | Long arm (l) in µm | Short arm (s) in µm | Total length in µm | d value (l-s) in µm | r value (l/s) in µm | Centromeric position |
|---|---|---|---|---|---|---|
| 1 | 10.98±3.00 | 3.58±0.85 | 14.57±3.49 | 7.41 | 3.16 | st |
| 2 | 8.89±3.14 | 3.36±0.80 | 12.26±3.55 | 5.53 | 2.69 | sm |
| 3 | 6.96±1.70 | 3.05±1.14 | 10.01±2.65 | 3.91 | 2.42 | sm |
| 4 | 6.03±1.70 | 3.33±0.91 | 9.36±2.41 | 2.70 | 1.85 | sm |
| 5 | 5.77±1.63 | 3.09±0.65 | 8.87±2.14 | 2.68 | 1.87 | sm |
| 6 | 5.60±1.54 | 2.79±0.41 | 8.39±1.91 | 2.81 | 1.99 | sm |
| 7 | 4.91±1.14 | 2.89±0.63 | 7.80±1.54 | 2.02 | 1.74 | sm |
| 8 | 4.73±1.04 | 2.47±0.61 | 7.20±1.45 | 2.26 | 1.97 | sm |
| 9 | 3.47±1.17 | 2.15±0.77 | 5.63±1.91 | 1.31 | 1.63 | m |
The cytotaxonomical studies helped the placement of family Hypoxidaceae. Bentham and Hooker (1883) and Engler and Prantl (1930) have placed Curculigo under tribe Hypoxideae of Amaryllidaceae. On the basis of bimodal length variation in the karyotype of Curculigo which was similar in Ophiopogon and Sansevieria, Hutchinson (1957) placed these genera in a separate family Hypoxidaceae along with Hypoxis. Lakshmi (1980) mentioned that the small size of the chromosomes and low chromatin content supported the Hutchinson’s arrangement in constituting Hypoxidaceae as a separate family.
The reported cytological details of C. crassifolia (2n=18) showed karyotype formula of 2m+5sm+2st pairs. Other chromosome numbers i.e., 2n=18, 36 and ca. 50 were reported in C. orchioides previously (Sato 1942, Sharma and Ghosh 1954, Raghavan 1957, Sharma and Battacharyya 1960). In 2n=18 species of C. orchioides karyotype formula of length was given 2L+2M+14S by Sheriff (1946).
Eksomtramage et al. (2013) studied the karyotype of some Thailand Hypoxidaceae species and reported the karyotypic details of genera Curculigo, Hypoxis and Molineria. In Curculigo they reported the karyotypes of C. ensifolia, C. latifolia, C. megacarpa and C. villosa. The longest chromosome (9.55 µm) in C. ensifolia and the shortest chromosome (3.44 µm) in C. villosa. In C. janarthanamii chromosome ranges from 10.98 to 2.15 µm. Karyotype formula of Thailand Curculigo species with an asymmetric karyotype including metacentric, submetacentric and subtelocentric chromosomes i.e., C. ensifolia (4m+8sm+6st), C. latifolia (2m+14sm+2st), C. megacarpa (2m+12sm+4st) and C. villosa (4m+10sm+4st). The C. latifolia and our studied species of C. janarthanamii shared same karyotype formula i.e., (2m+14sm+2st). This might indicate that C. janarthanamii and C. latifolia shared the cytogenetical affinity with each other.
We are grateful to the Principal Walchand College of Arts and Science, Solapur for providing research facilities. Rohit Mane thanks to Rajiv Gandhi Science & Technology Commission (RGSTC) Government of Maharashtra. First author thanks the Science and Engineering Research Board (SERB), Department of Science and Technology, New Delhi for financial assistance (SERB/PDF/2016/001910).
