Cytological Studies in Some Members of Tribe Senecioneae (Asteraceae) from North and Central India

Raghbir C. Gupta, Santosh Bala*, Henna Goyal, Reyaz A. Malik and Santosh Kumari

Department of Botany, Punjabi University, Patiala-147002, Punjab, India

Received July 24, 2010; accepted August 24, 2010

Summary Cytological studies have been made of 12 species of tribe Senecioneae (Asteraceae) from north and central India. Of these, 3 species, namely S. grahami Hook. f. (n10), S. kunthianus Wall ex DC. (n20) and S. sexatilis Sensu Hook. f. (n10), are counted for the first time. Additional and/or variable cytotypes are recorded for 2 species, namely S. nudicaulis Buch.-Ham D. Don. (n5, 10) and S. rufinervis DC. (n10). Existence of B-chromosomes has been recorded in S. krascheninnikovii Schischk. (n1002B). Two species, S. vulgaris L. (n20) and S. krascheninnikovii Schischk. (n10), are explored for the first time from India. Besides these, cytomorphological variabilities have been observed in S. rufinervis (2n20, 40) and S. nudicaulis Buch-Ham ex D. Don (2n10, 20 and 40). Great variation in morphological characteristic have been noticed in different accessions of S. laetus Edgew, however all the accessions are found to exist at 2n40. Meiotic configurations in the form of multivalents and/or secondary association of bivalents are found in Gynura nepalensis DC., Senecio laetus Edgew, S. kunthianus Wall ex DC., S. krascheninnikovii Schischk. and S. nudicaulis Buch-Ham ex D. Don.

Key words Senecioneae, Base number, B-chromosome, Cytomorphovariants, Multivalents, Secondary associations.

Senecioneae is one of the largest tribes in the family Asteraceae, comprised of approximately 3,100 species and 155 genera, and has a more or less cosmopolitan distribution and show remarkable cytomorphological as well as ecological diversity. Senecio is the largest genus with approximately 1,000 species, with 43 species reported in India (Hajra et al. 1995). Phylogenetically, the tribe Senecioneae is proposed as the most primitive tribe of the family Asteraceae (Small 1919). The proposed base number for the tribe is x5. From an economic point of view, the members of this tribe have a signiﬁcant importance in the ﬁeld of medicine and for the perfumery.

Materials and methods For meiotic studies, usual acetocarmine smears of appropriate sized young capitula were made after ﬁxing them in Carnoy’s ﬁxative. Pollen fertility was estimated by mounting mature pollen grains in glycerol-acetocarmine. Voucher specimens are available in Herbarium, Department of Botany, Punjabi University, Patiala (PUN) (Table 1).

Results and discussion Information on taxa, speciﬁc locality, accession number (PUN), chromosome number and meiotic observations of the presently investigated 12 species of the tribe Senecioneae is

* Corresponding author, e-mail: [email protected] 370 R. C. Gupta et al. Cytologia 75(4)

Table 1. Information on taxa, voucher data, accession number, chromosome number and meiotic conﬁgurations of presently investigated 12 species of the tribe Senecioneae.

Accession Chromo- S. Voucher data Meiotic Taxa some no. (Locality with altitude) conﬁgurations number number (n)

1. Gynura nepalensis DC. Palampur, 1219 m 52812 20 20 II (70%) 1 IV18 II (20%) 2 IV16 II (10%) 2. Emilia sonchifolia (L.) Kangra, 530 m 52813 5 5 II (38.46%) DC. Sangrur, 250 m 24964 5 2 II6 I (61.53%) Dehra Dun, 1200 m 24502 5 Pachmarhi, 1000 m 24955 5 3. S. laetus Edgew Lohardi; Chhota Banghal, 2200 m 52604 20 20 II (83.33%) Manali, 2050 m 52807 20 1IV18 II (8.33%) Ahrarbal; Kashmir, 2400 m 52814 20 Secondary associations Swar; ChhotaBanghal, 2500 m 52605 20 of 2–8 bivalents (8.33%) Zispa; Lahaul -Spiti, 3142 m 52806 20 Koksar; Lahaul-Spiti, 3160 m 52805 20 Marhi; Kullu, 3320 m 52815 20 Keylong; Lahaul-Spiti, 3350 m 52804 20 Zingzingbar; Lahaul-Spiti, 52803 20 4328 m 4. S. elegans Linn. Patiala, 250 m 24416 10 10II (100%) 5. S. graciliﬂorus DC. Lohardi; Chhota Banghal, 52606 20 Secondary associations 2200 m of 2–6 bivalents (100%) 6. * S. grahami Hook f. Pachmarhi, 1000 m 24386 10* 10II (100%)

7. * S. kunthianus Chatru; Spiti, 4270 m 52802 20* 20 II (63.63%) Wall ex DC. 2IV16 II (27.27%) 4IV12 II (9.09%) 8. * S. krascheninnikovii Aharbal; Kashmir, 2400 m 52810 10* 10 II (44.44%) Schischk. 10 II2B (22.22%) 9 II2 I (11.11%) 1IV8 II (11.11%) 1 IV7 II2 I (11.11%) 9. * S. nudicaulis Buch.- Palampur, 1219m 52607 20 1IV18 II (10%) Ham. ex D.Don 2IV16 II (7.14%) 3IV + 14 II (5.71%) Secondary associations of bivalents (31.4%) Killar; Pangi valley, 2600 m 52808 10* 10 II (100%) Badagaon; Chhota Banghal, 52809 5* 5 II (76.05%) 3300m 1IV3 II (5.63%) 3 II4I (18.30%) 10. * S. ruﬁnervis Dalhousie, 2200 m 24601 10* 20 II (100%) DC. Shimla, 2400 m 24602 20 Mussoorie, 2000 m 49308 20 Lohardi; Chhota Banghal, 2500 m 52608 20 11. * S. sexatilis Sensu Hook. f. Pachmarhi, 1000 m 25569 10* 10 II (100%) 12. * S. vulgaris L. Pulwama; Kashmir, 2000 m 52811 20* 20 II (100%)

* New records 2010 Cytological Studies in Some Senecioneae of North and Central India 371 summarised in Table 1. Features of cytological and/or morphological interest are discussed under each genus. Three species, namely S. grahami Hook. f. (n10), S. kunthianus Wall ex DC. (n20) and S. sexatilis Sensu Hook. f., are worked out cytologically for the ﬁrst time on a worldwide basis. New cytotypes are recorded for 2 species, namely S. nudicaulis Buch.-Ham D. Don. (n5 and 10) and S. ruﬁnervis DC. (n10). Two species, namely S. vulgaris L. (n20) and S. krascheninnikovii Schischk. (n10), are newly reported in India. The degree of pollen stainability was high in all the studied species, ranging from 82 to 100%.

Gynura nepalensis DC. (G. foetens Wallich ex DC.) The species is found distributed throughout India up to 2300 m. Meiotic analysis shows the presence of n20 and is in conformity with the previous reports (Mehra et al. 1965, Shetty 1967). 1–2 quadrivalents are present in some PMCs, besides bivalents (Fig. 1, Table 1). Further meiotic course was normal with 100% pollen fertility.

Emilia sonchifolia (L.) DC. (Cacalia sonchifolia DC.) The species is found distributed throughout India up to 2000 m. Present studies conﬁrm the previous reports of n5 (Fig. 2) both from south India (Mathew and Mathew 1988) and north India (Mehra and Remanandan 1975), and the rest of the world (Afzelius 1924). Besides this, an aneuploid cytotype with 2n16 is also reported (Gupta et al. 1972). Some of the PMCs show the occurrence of early separation of (4–6) bivalents at metaphase-I (Fig. 3, Table 1). Pollen fertility was cent per cent and pollen size ranges between 25.9–29.2 mm.

S. laetus Edgew (S. chrysanthemoides DC.S. spectabilis Wallich ex DC.S. sisymriiformis DC.) It is a common species of Temperate Himalayas and distributed up to 2000–4250 m. Present studies were made on 9 populations of the species from different areas of central and north India (Table 1). All showed n20 (Fig. 4) and conﬁrms the previous report (Mehra et al. 1965). Meiosis is normal but secondary associations of 2–8 bivalents are observed only in the Lohardi population in 8.33% of cells (Fig. 5). Some quadrivalents (1–2) are also found, besides bivalents (Table 1). Pollen fertility varies between 89–97%. Morphologically, all the accessions show lot of variations due to different altitudinal distribution range (2050–4328) m. Comparison of some characters of different accessions of Senecio laetus is given in Table 2. At high altitude (4328 m), the height of the plant gradually decreases to 9.5 cm as compared to plants at 2050–3350 m altitude that attain maximum of 30–50 cm height. Number and size of capitula/plant show lot of variation in different altitudinal accessions (Fig. a–i). Leaves also show lot of diversity in the shape, color and size in the different accessions (Fig. a1–i1; Table 2).

S. elegans Linn. It is a cultivated species with n10 (Fig. 6) and conﬁrms the previous report from India (Mehra et al. 1965) and elsewhere (Nordenstam 1967). Pollen fertility was cent per cent and pollen size ranges between 22.7–25.9 mm.

S. graciliﬂorus DC. It is commonly found in open places in Temperate Himalayas between 2000–4100 m. The present meiotic studies showed the presence of n20 at diakinesis with interbivalent connections in some bivalents (Fig. 7, Table 1). This conﬁrms the previous chromosome reports (Mehra et al. 1965, Mehra and Remanandan 1975). Meiotic abnormality in the form of unsynchronized (1–3) bivalents at metaphase I was observed in 41.93% cells. Further segregation of chromosomes was found to be normal but some cells show late disjunction of 2–3 bivalents and chromatin bridges at 372 R. C. Gupta et al. Cytologia 75(4)

Figs. 1–12. Meiotic analysis. 1) Gynura nepalensis. Metaphase I, 1 IV18 II. (2–3) Emilia sonchifolia. 2) Metaphase I, 5 II. 3) Metaphase I, 2 II6 I. (4–5) Senecio chrysanthemoides. 4) Diakinesis, 1 IV19 II. 5) Metaphase I, secondary association of bivalents. 6) S. elegans. Metaphase I, 10 II. 7) S. graciliﬂorus. Diakinesis, interbivalent connections. 8) S. grahami. Metaphase I, 10 II. 9) S. kunthianus. Diakinesis, 4 IV12 II. (10–11) S. krascheninnikovii. 10) Metaphase I, 10 II. 11) Metaphase I, 10 II2 B. 12) Metaphase I, 1 IV8 II. Scale bar10 mm. anaphase I in 5.12%.

S. grahami Hook f. The species is quite common at the Pachmarhi hills, and is counted for the ﬁrst time with n10 (Fig. 8). Meiosis is normal with equal distribution of chromosomes at anaphases. Pollen fertility was found to be high 94.2% and pollen size is 19.4–24.3 mm.

S. kunthianus Wall ex DC. The species is quite common at the Lahaul-Spiti at 4000–4270 m and counted for the ﬁrst time with n20 (Fig. 9). Meiosis is normal with equal distribution of chromosomes at anaphases. 2–4 2010 Cytological Studies in Some Senecioneae of North and Central India 373

Table 2. Comparison of some characteristics of different accessions of Senecio laetus

Manali Lohardi Ahrarbal Swar Zispa Koksar Marhi Keylong Zingzingbar Characteristic 2050 m 2200 m 2400 m 2500 m 3142 m 3160 m 3320 m 3350 m 4328 m

Plant height (cm) 30–40 40–60 47–50 50–70 23–25 30–60 35–60 30–45 9–9.5 Leaf size (cm) 52.5 6.51.5 4.52 3.51.1 101.5 11.54.4 64.3 6.52.3 2.50.5 Leaf shape lobed cleft lyrate cleft superﬁ- superﬁc- runcin- lobed spathulate margin margin (Fig. c1) margin cially ially ate margin, (Fig. i1) (Fig. a1) (Fig. b1) (Fig. d1) incised incised (Fig. g1) incised (Fig. e1) (Fig. f1) near base (Fig. h1) Leaf color dark dark upper dark dark dark upper dark dark green green light surface green green surface green green green light light Average number 45 35 9 40 4 26 20 11 5 of capitula/plant Capitulum size 0.50.3 0.40.2 0.10.15 0.41 0.50.5 0.61 0.91.2 0.50.6 0.50.4 (cm) (Fig. a) (Fig. b) (Fig. c) (Fig. d) (Fig. e) (Fig. f) (Fig. g) (Fig. h) (Fig. i)

(Fig. a–i and a1–i1)

quadrivalents are present in some PMCs, besides bivalents (Table 1). Further meiotic course was normal with 96% pollen fertility.

S. krascheninnikovii Schischk. (S. pedunculatus EdgewS. kashmirianus Balakr.) The species is distributed in north-west Himalayas between 2800–3600 m. The species is counted for the first time from India and has n10 (Fig. 10) and confirms previous reports from outside India (Razaq et al. 1994). However 2n18 chromosome number is also reported in the species (Khatoon and Ali 1988). In some cells up to 2B chromosomes also reported for the first time in the species (Fig. 11). The most frequent meiotic configuration was 10 II but few cells with 8 II1 IV, 7 II1 IV2 I and 9 II2 I (Fig. 12, Table 1) were also observed.

S. nudicaulis Buch.-Ham ex D. Don The species distributed throughout India in forests and grassy slopes. Present studies have been made on 3 accessions of the species. Cytologically, all 3 accessions represent 3 cytotypes with 2n10, 20 and 40. The chromosome number 2n10 and 20 are new cytotypes and are reported for the first time. The Palampur accession is found to exist at the octaploid level with n20 at diakinesis (Fig. 13) and confirms the previous report from India (Mehra et al. 1965). Chromatin stickiness in the form of clump-like structures was noticed in 20.20% cells at metaphase I. A noticeable presence of secondary associations of 2–4 bivalents (31.4% cells) and 1–3 quadrivalents were observed at diakinesis/metaphase I. The most common meiotic configuration was 1 IV18 II (10% PMCs) followed by 2 IV16 II (7.14% PMCs) and 3 IV14 II (5.71% PMCs) (Fig. 14). Unoriented bivalents (1–2 per PMC) at metaphase I were observed in 11.42% PMCs. Laggards (1–3) and chromatin bridges (1–2) were observed in 4.67 and 1.43, per cent of PMCs respectively. Pollen fertility was 82% and pollen size of 19.13–21.75 mm. Accession from Pangi valley is found to exist at tetraploid level and show n10 at metaphase I (Fig. 15). Further meiotic course was normal and pollen fertility was cent per cent. Badagaon population show n5 and exist at diploid level (Fig. 16). The most common meiotic configuration 374 R. C. Gupta et al. Cytologia 75(4)

Figs. 13–26. Meiotic analysis. (13–20) S. nudicaulis. (13, 14) PUN-52607. 13) Diakinesis, 20 II. 14) Metaphase I, 1 IV18 II. 15) PUN-52808. Metaphase I, 10 II. (16–20) PUN-52809. 16) Metaphase I, 5 II. 17) Diakinesis, 1 IV3 II. 18) Metaphase I, 1 IV3 II. 19) Metaphase I, early separation of 2 bivalents. 20) Anaphase I, 2n10. (21–24) S. ruﬁnervis. 21) PUN- 24601. Diakinesis, 10 II. (22–24) PUN-52608. 22) Diakinesis, 20 II. 23) Metaphase I, unsynchronized bivalents. 24) Telophase I, chromatin bridge. 25) S. sexatilis. Metaphase I, 10 II. 26) S. vulgaris. Diakinesis, 20 II. Scale bar10 mm. was 1 IV3 II (Figs 17, 18). Early separation of 1–2 bivalents was observed in 54.32% pollen mother cells (Fig. 19). Further segregation of chromosomes at anaphases was normal (Fig. 20). Pollen fertility was 87.50% and pollen size ranges 18.75–22.5 mm. Morphologically, all the accessions show variations due to different altitudinal distribution range (1219–3300) m and difference in ploidy level (2x, 4x and 8x). Comparison of some characteristics of 3 cytotypes of Senecio nudicaulis is given in Table 3. Diploid cytotype plants show the characteristics which are comparatively more prominent than in tetraploids and octaploids. 2010 Cytological Studies in Some Senecioneae of North and Central India 375

Table 3. Morphological characteristics of 3 cytotypes of Senecio nudicaulis

Characteristic Diploid (2n10) Tetraploid (2n20) Octaploid (2n40)

Plant height (cm) 47 36 21 Number of leaves/plant 11 9 20 Leaf size (cm) 6.61 8.52.5 4.71.4 Number of branches arising from a common base 12 4 6 Number of capitula/plant 80 38 55 Stem surface pubescent pubescent glabrous Number of rays/capitulum 9 11 12 Capitulum size (cm) 1.00.15 1.10.2 0.60.2 Pollen size (mm) 18.7522.5 18.7521.75 19.1321.75 Pollen fertility (%age) 87.50 80 82

Table 4. Morphological characteristics of diploid and tetraploid cytotypes of Senecio ruﬁnervis

Diploid Tetraploid Characteristic (2n20) (2n40)

Leaf size (cm) 13–154–7 12–176–8 Stomata: (Hypostomatic) Size (mm) 24.3–35.621.1–30.8 22.7–29.216.2–24.3 Frequency/mm2 217.7 288.7 Stomatal index 15.9 18.8 Capitulum size (mm) 72 7–92 Pollen grains: Size (mm) 29.2–32.4 27.5–32.4 Fertility (%age) 81.6 71.0

S. rufinervis DC. S. rufinervis is a woody species which is quite common in the temperate Himalayan forests. Population from Dalhousie is found to exist at diploid level and have 10 bivalents (Fig. 21) and normal course of meiosis. However, accessions from Mussoorie, Shimla and Chhota Banghal are tetraploids and have 2n40 (Fig. 22). The present count of n10 is a new chromosome report for the species as the earliar reports for the species from the Himalayas are of 2n36 (Mehra and Remanandan 1975) and 2n40 (Mehra et al. 1965). It thus establishes the existence of intra- specific polyploidy in the species. Further meiotic course was found to be abnormal in the Chhota Banghal accession. At metaphase I, 2–6 unsynchronised bivalents were observed in 66.37% cells (Fig. 23). Chromatin stickiness was the prominent feature observed during metaphase I and anaphases/ telophases. Irregularity in the form of laggards and bridges was reported in 48.61% and 6.94% PMCs, respectively (Fig. 24). Tetraploid cytotype has luxuriant growth with large sized leaves and capitula but with reduced stomatal size as compared to diploid cytotype (Table 4). The pollen fertility in diploid as well as tetraploid is found to be 81 and 71%, and with pollen size of 29.2–32.4 mm and 27.5–32.4 mm, respectively.

S. sexatilis Sensu Hook. f. The species is quite common in the Pachmarhi hills; it is counted for the ﬁrst time and has 10 bivalents (Fig. 25). Meiosis is normal with equal distribution of chromosomes at anaphases. Pollen fertility was 89% and pollen size ranges between 21.1–22.7 mm. 376 R. C. Gupta et al. Cytologia 75(4)

Fig. Senecio laetus (a–i): Capitula of 9 different accessions. (a1–i1): Leaves of 9 different accessions.

S. vulgaris L. The species is found distributed in the Nilgiri Hills, Jammu and Kashmir, Assam and Tamil Nadu between 300–2300 m. This species is known to be toxic to humans and animals. It is used in medicines in amenorrhoea, dysmenorrhoea and diaphortics, diuretics. The infusion of plant is reported to be used in chronic mastitis (Singh et al. 1983). The species is counted for the ﬁrst time from India with n20 (Fig. 26). However outside India, 2n40 is already known to exist (Khatoon and Ali 1993). Meiosis is normal and high pollen fertility (97%).

Conclusion Three genera have been worked out from this tribe, of which Senecio (2n10–180) is definitely more variable chromosomally than Emilia (2n10–30) and Gynura (2n10–40). Except for one report (2n16) for Emilia and (2n34) for Gynura, the chromosome number in these is based on x5. The chromosome number 2n10 is also represented in Senecio. Some authors consider 5 to be the original for Senecio and also for the tribe Senecioneae (Afzelius 1949, Beaman et al. 1962, Mehra 1977). On the other hand, Ornduff et al. (1963, 1967) and Nordenstam (1977) believe x10 to be the basic for the tribe and low numbers as derived through reduction, which is supported by the fact that these taxa have specialized features. In the genus Senecio, large number of the species of which are yet to be counted, is highly polybasic (x5, 9, 10, 11, 19, 23). All these numbers exhibit polyploid series but those based on x10 are the most prevalent. Nordenstam (1977) pointed out that ‘Senecioid complex’ is characterised by the basic number 10 whereas high base numbers (x25–29, 30) are represented in ‘Cacalioid genera’. Genus Senecio is known to have 3,100 species out of which 373 species are cytologically worked out (85 diploid and 288 polyploid). Percentage of polyploidy is found to be 77.2% with the level of polyploidy ranging between 2x to 18x. The total number of cytotypes reported is 452 and chromosome number ranges between 2n10 to 2n180. The most common number is 2n40 in 180 species, and is 2n180 in 2 species. Thirty-four species are known to show intra-specific 2010 Cytological Studies in Some Senecioneae of North and Central India 377 , 11 5 9, 10 5, (8) 19, 23 (12, 13, 14), – – 2 – 3(5) 1(10) 4 (23) is given in is given cytotypes Number of parentheses species with Number of the same base base numbers number/s 28(10), 2(12), 36 5, 9, 10 number which number which or aneuploid species represent number of Known chromosome numKnown intra-specific species with Probable 26(2), 28(1), 30(1), 32(1), 36(3), 38(3), 40(180), 42(1), 44(9), 45–50(1), 46(39), 48(24), 50(4), 52(1), 56(1), 60(45), 62(1), 64(1), 69(1), 76(2), 80(25), 80–90(2), 90(6), 90–100(1), 92(11), 96(4), 100(6), 104(1), 120(4), 130(1), 138(2), 160(2), c.175(1), 180(2) 2 10(2) 8 20(6), 22(1), 34 (1), 40(1) – – 10,11, 17 1312 10(1), 20(8), 40 (4) 10(6), 16(1), 20 (4), 30(1) 1(10)20 20(9), 36(1), 40(8), 60(1), 62(1) – 5, 10 452 10(5), 18(2), 20(54), 24(2), Total Total Diploid Polyploid Total Total known known out worked polyploidy ploidy cytotypes species species number of Number of Data on total number of taxonomically known species; level and frequency of polyploidy; frequency of different cytotypes and probable base number/s in the genera and probable cytotypes of different frequency of polyploidy; and frequency species; level known Data on total number of taxonomically from India (++) basis (+) and separately on world studied during present investigations, ++ 4 2 2 – 0.0 2 x ++ 8 12 8 4 33.33++ 2 x , 4 75 17 8 9 52.9 2 x , 4 6 Linn.+ 2000–3100 373 85 288 77.2 2 x –18 Cass. + 100 9 6 3 33.33 2 x , 4 Cass. + 30 7 3 4 5 2 x , 4 6 Table 5. Genera taxonomically cytologically %age of of Level number of in parentheses bers (2 n ) Figures at polyploidy more than one base Senecio Gynura Emilia 378 R. C. Gupta et al. Cytologia 75(4) polyploidy based on different base numbers (x10, 12 and 23). Thirty-six species have more than one base numbers or aneuploid cytotypes. On the basis of these observations, the probable base numbers for the genus are x5, 9, 10, 11 (12, 13, 14), 19, 23 (Table 4). Similar data has been prepared for the total number of species of Emilia and Gynura genera and their status in India and the world (see Table 5). The most common number observed in Gynura is 2n20, both in India and the world, but presently 2n40 is reported. The most common number in Senecio is 2n40 on a world-wide basis whereas in India both 2n20 and 40 are equally common. The predominant number for the species is 2n40 outside India and 2n20 within India. Present studies also show 2n40 in most Indian species of Senecio.

Acknowledgements Authors are thankful to UGC, New Delhi for ﬁnancial assistance under DRS-SAP II, ASIST programme and to DST for grant under FIST programme.

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