Cytological Investigations on Central Indian Compositae Compositae
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Cytologia 49: 427-435, 1984 Cytological Investigations on Central Indian Compositae R. C. Gupta and B. S. Gill Department of Botany, Punjabi University , Patiala-147002, India Received January 10, 1983 Compositae, one of the largest, highly evolved, and cosmopolitan families, is represented in India by 712 wild species (Santapau and Henry 1973) distributed from tropical to alpine regions. Cytologically, it has been studied quite extensively from Southern and Northern India, inclusive of Himalayas (Koul 1964, Mehra et al. 1965, Mehra and Remanandan 1974, 1975, 1976, Remanandan and Mehra 1974, Shetty 1967, Subramanyam and Kamble 1967, Gupta 1969, Gupta et al. 1972, Koul and Gohil 1973, Mathew and Mathew 1975a, b, 1976, 1978, Bir and Sidhu 1979, Gill et al. 1979, etc.). However, Compositae of Central India remained totally neglected. Compositae flora of this region is of particular interest for it shares some elements of North and South India. In view of these facts, cytological studies were undertaken on the Central Indian taxa, The Pachmarhi hills were purposely select ed as the representative area for investigations, which falls within the altitude range of 400-1,300m, covering tropical and subtropical zones. Material and methods For meiotic studies, usual acetocarmine smears of appropriate sized capitula were made after fixing them in Carnoy's fluid. Pollen fertility was estimated by mounting mature pollen grains in glycero-acetocarmine. Voucher specimens are available in Herbarium, Department of Botany, Punjabi Unuversity, Patiala (PUN). Results and discussion Data on the presently worked out 58 species (45 genera) are summarised in Table 1, which covers source of material, accession number, chromosome number, ploidy level and pollen fertility. Chromosome determination, for each species, is based on at least 10 individuals of each population. Vernonieae The populations of Centratherum anthelminticum from Central, Northern (Mehra et al. 1965) and southern India (Mathew and Mathew 1976) and elsewhere (Jones 1970) are diploid (2n=20) on x=10. Whereas, hexaploids (2n=54) based on x=9 exist in South India (Parameswar 1960). Morphovariants of Vernonia cinerea with violet, pink, and white capitula and glabrous to woolly leaf surface, share the same chromosome number (n=9). The Pachmarhi populations show correlation of leaf tomentum with altitude. Leaves are intensely woolly at the higher altitudes but almost glabrous in the plains. Of 428 R. C. Gupta and B. S. Gill Cytologia 49 Table 1. Cytological data on the Central Indian Compositae 1984 Cytological Investigations on Central Indian Compositae 429 Table 1. (Continued) 430 R. C. Gupta and B. S. Gill Cytologia 49 Table 1. (Continued) * Species worked out for the first time ** Varied chromosome number report •ª Abbreviation of the specific locality along with altitude in Pachmarhi hills. a. Bariam 950m; b. Bharat Scouts 1,000m; c. Air Strip 1 ,000m; d. Youth Centre 1,000m; e. Chauragarh 1,150m; f. Dhupgarh 1,100m; g. Big Fall 700m; h . Pagara Garden 700m; i. Apsara Vihar 900m; j. Holiday Homes 1 ,000m; k. Little Fall 950m; 1. Down Fall, 900m; m. Pachmarhi plateau 1 ,000m; n. Dukrikhera 400m; o. Ramyakund 900m; p. Singanama 500m; q . Company Garden 1,000m; r. Bindakhera 400m; s. Pipariya 400m; t. Bara Mahadeo 1,000m; u. Matkuli 450m; v . Tamia 1,500m; w. Neoton Chikkli 1,000m; x. Bijouri 1,050m. the intraspecific cytotypes, diploid (n=9) is the most widely represented as compar ed to the tetraploid, which is recorded only from Africa (Jones 1979). Eupatorieae The Central Indian populations of Ageratum conyzoides are exclusively tetra ploid, in spite of the fact that diploid and tetraploid cytotypes are quite common in other parts of India (Gupta 1969, Koul 1971, Mehra and Remanandan 1975, Dey 1979). Eupatorium conyzoides is known to have 2n=c .64 (Mangenot and Mangenot vide: Fedorov 1969). Its Central Indian populations , however, are meiotically abnormal tetraploids (2n=40) with quadrivalents (0-1 per PMC) , trivalents (0-2 per PMC) and univalents (0-2 per PMC), besides 16-20 bivalents. The incidence of multivalents (0.5 per PMC), which is rather low, might be due to heterozygosity f or chromosomal interchanges. Astereae Conyza leucantha (n=9) is counted for the first time. So far studied Indian taxa of C. stricta from Northern and Southern India (Mehra et al. 1965, Shetty 1967, Mehra and Remanandan 1974, Shukur et al. 1977) are diploid (n=9). In terestingly, its tetraploids (n=18) are represented in Central India . The tetraploid cytotype, which is indistict from the diploid morphologically , is recorded for the fi rst time. 1984 Cytological Investigations on Central Indian Compositae 431 Cyathocline purpurea in India is reported to have n=9 (Koul and Wakhlu 1975) and n=11 (Koul 1964, Mehra et al. 1965, Shetty 1967, Subramanyam and Kamble 1967). Wide sampling on the Pachmarhi populations confirm that number is actu ally n=9. The miscounting is due to the presence of two very large sized bivalents, which are easily mistaken as multiple associations of four chromosomes or two entities of two bivalents each. Inuleae Blumea fastulosa, well represented in the Pachmarhi hills, is triploid (2n=30). The obligate apomictic nature seems to have facilitated the establishment of this unbalanced polyploid. In spite of abnormal meiosis with trivalents (2-5 per PMC), bivalents (5-10 per PMC) and univalents (1-10 per PMC), and complete failure of meiosis II, seed setting is excellent. It is interesting that the diploid (2n=18) re presented in the South India has altogether different chromosome number (Mathew and Mathew 1975a). Both the diploid (2n=18, Peng and Hsu 1977) and hexaploid (2n=54, Miyagi 1971) cytotypes of B. lanceolaria studied from elsewhere are based on x=9. How ever, all the individuals studied presently have 10 bivalents. The Pachmarhi population of Gnaphalium indicum is diploid (n=7), whereas both diploid and tetraploid cytotypes are represented in other parts of India (Mehra et al. 1965, Banerjee and Sharma 1974, Mehra and Remanandan 1975). Helichrysum bracteatum, an ornamental, seeems to be quite amenable to aneu ploidy as is evident from the existence of cytotypes with 2n=24 (Chatterjee and Sharma 1968, Banerjee and Sharma 1974), 2n=26 (the present studies), 2n=28 (vide: Fedorov 1969) and 2n=30 (Gupta 1969). Laggera alata (2n=2x=20) and L. falcata (2n=4x=40) are at different poly ploid levels, of which latter is counted for the first time. The count of 2n=10 by Shetty (1964) on L. alata needs verification. Heliantheae Wedelia urticaefolia, worked out for the first time, is tetraploid with 2n=72. The formation of one quadrivalent, besides 34 bivalents, in most of the cells, seems to be the consequence of heterozygosity for interchanges. Bridge formation at Al in the few cells is probably due to the delayed segregation of the multivalent. Diploid and tetraploid cytotypes of Siegesbeckia orientalis are represented in the Himalayas (Mehra et al. 1965, Mehra and Remanandan 1974), whereas Central Indian population is of tetraploids. Aneuploid cytotypes with 2n=20 (Hsu 1967) and 2n=24 (Subramanyan and Kamble 1967) ane known from Taiwan and East India, respectively. Parthenium hysterophorus, a recently introduced and fast colonising weed, is counted for the first time from India with n=17. Whereas, it is known to have chromosomal races 2n=18, 34 and 36 from elsewhere. The rest of the species, Acanthospermum hispidum (2n=22, 40), Blainvillea acmel la (2n=34, 72), Cosmos sulphureus (2n=24, 26), Eclipta alba (2n=18, 20, 22), Galin soga parviflora (2n=16, 32, 36), Spilanthes acmella (2n=14, 52) and Synedrella nodfora (2n=32, 36, 38, 40) are quite variable chromosomally, the Central Indian 432 R. C. Gupta and B. S. Gill Cytologia 49 1984 Cytological Investigations on Central Indian Compositae 433 populations of which are counted to have n=11, 17, 12, 11, 8, 26 and 20, respectively. Helenieae Flaveria trinervia, counted for the first time from India, is tetraploid with n= 18. Arthemideae The diploid (2n=18) and tetraploid (2n=36) of Artemisia parviflora are repre sented in South India (Mehra and Remanandan 1974), whereas its Pachmarhi popu lations are diploid (2n=18). Centipeda minima, the only cytologically known species of the genus, is quite variable chromosomally (2n=14, 18, 20). The species is counted for the first time from India with n=10, Senecioneae Senecio grahami and S. saxatilis, worked out for the first time, are diploid with n=10. Table 2. Habit-polyploidy correlation in Central Indian Compositae Cynareae The present count of n=16 in Goniocaulonglabrum is the first chromosome report for this monotypic genus. Tricholepisglaberrima and T. radicans, worked out for the first time, are diploid with n=16. Polyploidy So far habit is concerned, perennials are considered to have high incidence of polyploidyas compared to annuals. Analysis of 370 cytologically known species shows that same holds good for Indian Compositae. The incidence is 42.4% in perennials and 24.4% in the annuals. However, the Central Indian Compositae showno significant differencewith respect to the frequency of polyploidy in annuals (21.1%) and perennials (20.0%, Table 2). The incidence of polyploidy in the Central Indian Compositae is 20.3% aga inst 32.4% estimated for the Indian Compositae. Area-wise, polyploidy is low in the Central India as compared to the Himalayas (34.7%) and South India (37.9%,), Figs. 1-14. 1, Eupatorium conyzoides, M-I, 1IV+17II+2I. 2, Conyza leucantha, M-I, 9II. 3, C, stricta, mixed A-I, n=18. 4. Blumea fistulosa, M-I, 5III+7II+1I. 5, B. lanceolaria, M-I, 10II, 6, Helichrysum bracteatum, diakinesis, 13II. 7, Laggera falcata, diakinesis, 20II. 8 and 9. Wedelia urticaefolia: 8, diakinesis, 1IV+34II. 9, A-I with chromatin bridge.