Karyomorphological Studies on Five Varieties of Clitoria Ternatea L. Accepted August 22, 1988 Clitoria Ternatea L. Belonging To

_??_1989 by Cytologia, Tokyo Cytologia 54: 401-407 , 1989

Karyomorphological Studies on Five Varieties of Clitoria ternatea L.

George Mathew1 and C. A. Ninan

Department of Botany, University of Kerala, Kariavattom , Trivandrum, India AcceptedAugust 22, 1988

Clitoria ternatea L. belonging to the family Fabaceae (Papilionaceae), commonly known as butterfly pea, is a pretty perennial climber. The plant is common all over the tropical parts of India, being cultvated in gardens everywhere and often also found growing wild over hedges and thickets. Besides being an ornamental, it is also cultivated for medicinal properties (Srivastav and Raina 1982). Its roots are aperient, laxative, diuretic and demulcent and are given in fever, croup, chronic bronchitis, ascites, dropsy and enlargement of the abdominal viscera (Khory and Katarak 1984). The seeds have powerful cathartic action and root bark is demulcent, diuretic and laxative (Nadkarni 1982). A dye is extracted from its flowers and seeds in ad dition to its use in medicine (Aiyer and Kolammal 1964). This species includes several varieties and are distinguished mainly on the basis of colour and nature of flowers. Perusal of available literature reveals that the cytological reports of this species are rather meagre and are mostly chromosome number reports (Fedorov 1974, Sanjappa and Dasgupta 1977, Bir and Kumari 1978, 1979, George and George 1978, Lackey 1980, Srivastav and Raina 1980a, b, 1982). Detailed studies on the karyomorphology of different varieties of C. ternatea are lacking. The present communication concerns karyomorphology of five garden varieties.

Materials and methods

Materials of the five varieties were collected from different localities of Trivandrum and Kottayam districts. For the identification of flower colour and their grades, the Wilson colour chart volumes (1938, 1941) were used. Accordingly the five varieties were classified as: 1. C. ternatea var. blue single (moorish blue-739/1) 2. C. ternatea var. blue double (moorish blue-739) 3. C. ternatea var. violet single (methyl violet-39/1) 4. C. ternatea var. violet double (methyl violet-39/1) 5. C. ternatea var. white single (white). Somatic chromosomes were studied from root tip cells obtained from well watered potted

plants grown in the medicinal plant gardens, University of Kerala. Young root tips were fi xed in 1:3 acetic alcohol, after pretreatment with 0.002M aqueous solution of 8-hydroxy

quinoline at 4 to 5•Ž for 2 hours. Squashes were made in 2 per cent acetocarmine. Karyo type analysis was carried out according to the system proposed by Levan et al. (1964) and Stebbins (1971). F% and TF% were calculated following Sikka and Sharma (1979) and Huziwara (1962).

1 Present address: Botany Division, Rubber Research Institute of India, Kottayam-686 009, India. 402 George Mathew and C. A. Ninan Cytologia 54

Observations

C. ternatea var. blue single This is a common variety with blue flowers. Flowers are typically papilionaceous with vexillary aestivation and diadelphous stamens. Root tip cells showed 16 chromosomes ranging in length from 1.75 to 4.59ƒÊm (Fig. 1 and

Figs. 1-5. Idiograms of five varieties of Clitoria ternatea. 1, C. ternatea var. blue single, 2n=16. 2, C. ternatea var. blue double, 2n=16. 3, C. ternatea var. violet single, 2n=16. 4, C. ternatea var. violet double, 2n=16. 5, C. ternatea var. white single, 2n=16. Scale: 1ƒÊm. 1989 Karyomorphological Studies on Clitoria ternatea L. 403

Table 1. Details of karyotypes of five varieties of C. ternatea

Table 1). The karyotype consisted of 3 pairs of median chromosomes and five pairs of sub median chromosomes (Table 1). Secondary constrictions were noticed on the long arm of second and third homologous pairs. The karyotype was found to be moderately asymmetrical and belonged to 3B category. 404 George Mathew and C. A. Ninan Cytologia 54

C. ternatea var. blue double It is a garden variety with blue double flowers having imbricate aestivation and non adelphous stamens. Root tip cells showed 16 chromosomes which ranged in length from 1.17 to 4.37ƒÊm (Fig.

2 and Table 1). The karyotype consisted of three pairs of median chromosomes and five pairs of sub-median chromosomes. Long arm of chromosome No. 2 possessed secondary constric tion (Table 1). The karyotype was moderately asymmetrical and belonged to 2B category. C. ternatea var. violet single This variety is characterised by violet single flowers with typical papilionaceous characters.

Fig. 6. Karyomorphology of five varieties of Clitoria ternatea showing arm ratio (long arm/ short arm).

Somatic cells of this variety showed 16 chromosomes which ranged from 2.25 to 5.46ƒÊm in length (Fig. 3 and Table 1). The attachment constrictions were maedian in two pairs and sub-median in the other six pairs. The karyotype was of the 2B category.

C. ternatea var. violet double It is a rare variety with violet double flowers. Flowers are not papilionaceous with im bricate aestivation and non-adelphous stamens. Somatic cells showed 16 chromosomes which ranged in length from 1.83 to 4.93ƒÊm (Fig. 4 and Table 1). Of the eight pairs of chromosomes, three were median and other five pairs sub-median. Secondary constriction was observed in the long arm of chromosome No. 2

(Fig. 4). The karyotype belonged to 2B category. 1989 Karyomorphological Studies on Clitoria ternatea L. 405

C. ternatea var. white single

This is a very popular garden variety with white single flowers . Flowers are typically papilionaceous with vexillary aestivation and diadelphous stamens. Root tip cells of this variety showed 16 chromosomes which ranged 2.17 to 5.34ƒÊm in length (Fig. 5 and Table 1). The karyotype consisted of five pairs of median chromosomes, two pairs of sub-median chromosomes and one pair of subterminal chromosomes. Secon dary constriction was noticed in the long arm of chromosome No. 5 (Fig. 5). The karyotype was moderately asymmetrical and belonged to 2B category.

Discussion

All the five varieties of C. ternatea investigated in the present study showed n=8 and 2n= 16. The same numbers have been reported by earlier workers also (Fedorov 1974, Sanjappa and Dasgupta 1977, George and George 1978, Lackey 1980, Srivastav and Raina 1980a, b, 1982). It appears therefore that the basic chromosome number of C. ternatea is x=8. However, Bir

Table 2. Comparison of the haploid chromosome set of the five varieties of C. ternatea

and Kumari (1979) reported n=7 and 2n=14 in materials of this species from Punjab plain. This suggests the existence of antother basic number in this species (x=7). Jacob (1940) recorded four satellited chromosomes in C. ternatea and suggested that the basic chromosome number in this species as x=4. However, such a situation has not so far been reported in any other species of Clitoria or allied genera in the family. Karyomorphological studies of the five varieties of C. ternatca reveal almost uniform features. All of them belong to 2B category (Stebbins 1971) except the blue single variety which belongs to 3B category. Fach variety however, has its own distinctiveness with repsect to the finer details of the morphology of their chromosomes as shown in Table 2. Perusal of the above table shows that TCL varies from 25.51 to 29.67ƒÊm among the varieties. TSL is higher in white single variety (9.92ƒÊm) followed by violet single (9.89ƒÊm), violet double (9.49ƒÊm), bule double (8.90ƒÊm) and blue single (8.34ƒÊm). ACL values are 3.56ƒÊm and 3.54ƒÊm in white single and violet double varieties. In blue single and blue double varieties ACL is the same i.e. 3.19ƒÊm. Besides these differences, slight variations can be noticed in RCL, F%, TF% and 'r•L-value among the five varieties. 406 George Mathew and C. A. Ninan Cytologia 54

Stebbins (1971) has stated that the two basic features which bring about karyotype asym metry are (1) shifting of the centromere from median to sub-median and sub-terminal position and (ii) increasing intrakaryotypic size difference of chromosomes. Of the five varieties studied, a sub-terminal pair of chromosomes is noticed only in white single variety whereas all the others show only median and sub-median chromosomes (Table 1). In blue single variety 50% of the chromosomes possess arm ratio greater than 2, a progressive step in karyotype evolution. Added to this is the lower TF% in this variety which together make it more evolved compared to other varieties. Comparison of karyomorphological features of the five varieties reveals that blue single and blue double on one hand and violet single and violet double on the other are more uniform (Table 2). This points to the close relationship of single and double varieties. Discussing the origin of the doubles, Thombre and Atale (1974) pointed out that single varieties are wild types and the doubles are of mutant origin from the singles. George and George (1978) also agree that alteration in floral morphology from single to double is due to spontaneous mutation. Karyomorphological studies thus support the mutant origin of double varieties from singles. Studies on meiosis in these varieties carried out in the present study reveal that there are no gross structural chromosomal changes in them. The origin of the doubles from singles might therefore be the result of gene mutations or cryptic structural changes of chromosomes.

Summary

Detailed karyomorphology of five garden varieties of Clitoria ternatea (2n=16) namely blue single, blue double, violet single, violet double and white single have been studied. They shared many karyotype features in common. In finer details of karyomorphology, some recognizable differences were noticed among the five varieties such as total chromosome length, total short arm length, TF %, number and distribution of secondary constriction and especially the position of centromere on certain individual chromosomes. In the absence of gross structural chromo somal changes it is suggested that gene mutations or cryptic structural changes of chromo somes have played a role in the evolution of morphologically distinct varieties in the species.

References

Aiyer, K. N. and Kolammal, M. 1964. Pharmacognosy of Ayurvedic Drugs Karala. Department of Pharmacognosy, University of Kerala, Trivandrum. Bir, S. S. and Kumari, S. 1978. IOPB chromosome number reports LIX. Taxon 27: 53-61.- 1979. Cytological evolution of the leguminous flora of Punjab plain. Recent Res. Pl. Sci. (New Delhi) 7: 252-260. Fedorov, A. 1974. Chromosome Number of Flowering Plants. Otto Koeltz Science Publishers, West Germany. George, M. and George, K. 1978. Reverse somatic mutation in Clitoria. Sci. and Cult. 44: 459-461. Huziwara, Y. 1962. Karyotype analysis in some genera of Compositae VIII. Further studies on the chromo somes of Aster. Amer. J. Bot. 49: 116-119. Jacob, K. T. 1940. Chromosome numbers and the relationship between satellites and nucleoli in Cassia and certain other Leguminosae. Ann. Bot. 4: 201-226. Khory, R. N. and Katarak, N. N. 1984. Materia Medica of India and Their Therapeutics. Neeraj Publishing House, Delhi. Lackey, J. A. 1980. Chromosome numbers in the Phaseoleae (Fabaceae: Faboideae) and their relation to taxonomy. Amer. J. Bot. 67(4): 595-602. Levan, A., Fredga, K. and Sandberg, A. A. 1964. Nomenclature for centromeric position of chromosomes. Hereditas 52: 201-220. Nadkarni, A. K. 1982. Indian Materia Medica 1. (Third edition). Popular Prakashan Pvt. Ltd., Bombay. Sanjappa, M. and Dasgupta, A. 1977. IOPB chromosome number reports LVI. Taxon 26: 257-274 . Sikha, K. and Sharma, A. K. 1979. Chromosome evolution in certain genera of Brassicaceae. Cytologia 44: 467-477. 1989 Karyomorphological Studies on Clitoria ternatea L. 407

Srivastav, R. K. and Raina, S. N. 1980a. Cytomixis in Clitoria ternatea L. var. pleniflora Fantz. f. pleniflora. Curr. Sci. 49: 824-825.- and - 1980b. A new basic number in Clitoria Linn. Curr. Sci. 49: 915-916.- and - 1982. Cytogenetics of Clitoria I. Induced autotetraploidy in C. ternatea. Cytologia 47: 99-107. Stebbins, G. L. 1950. Variation and Evolution in Plants. Columbia University Press, New York.- 1971. Chromosomal Evolution in Higher Plants. Addison Wesley Publishing Co., Massachussets. The Wilson Colour Chart, 1931 and 1941. I & II (ed.). The British Colour Council. Thombre, P. G. and Atale, S. B. 1974. A note on spontaneous mutation in Gokarna (Clitoria ternatea L.). Sci. and Cult. 40: 75-76.