Cytologia 40: 453-462, 1975

Cytological Studies in Some Central and Eastern Himalayan Grasses. IV. The Arundinelleae, Eragrosteae, Isachneae, Chlorideae, Sporoboleae, Meliceae, Stipeae, and Garnotieae

P. N. Mehra and M. L. Sharma

Department of Botany, Panjab University, Chandigarh,

Received December 20. 1973

The present paper is fourth of the series on the cytology of Central and Eastern Himalayan grasses. A total of 21 species belonging to 14 genera of the tribes Arundinelleae, Eragrosteae, Isachneae, Chlorideae, Sporoboleae, Meliceae, Stipeae, Arundineae and Garnotieae have been investigated. The course of meiosis was normal in all the species excepting stricta.

Material and methods

Material for meiotic studies was collected from the hills of Darjeeling and

Nainital. The unopened inflorescences were fixed in 1:3 acetic alcohol. The anthers were subsequently squashed in 1-2% aceto-carmine. The slides were made permanent in euparal. Voucher specimens were deposited in the Herbarium of the Department of Botany, Panjab University Chandigarh. Photomicrographs have been taken at a uniform magnification of •~1510.

Observations

Table 1 summarises the results of observations on 21 species belonging to 14 genera. In the succeeding pages, only the interesting features in some of the species are given.

Tribe: Arundinelleae bengalensis (Spreng.) Druce. This grass was found growing on exposed hill slopes near Lebong (Darjeeling). Cattle do not like it much. At metaphase-I, 16 bivalents were discernible along with 2 B chromosomes (Fig. 1). The B's were slightly smaller in size than the normal bivalents of the set and they lagged at anaphase-I and telophase-I (Fig. 2). About 72% pollen fertiligy was recorded. A. hookeri Munro ex Keng. This grass is distributed in the high mountains of Northeast India and Burma. Seven bivalents were clearly counted at metaphase-I (Fig. 3). Meiosis was found to undergo normal course with 100% pollen fertility. A. setosa Trin. 454 P. N. Mehra and M. L. Sharma Cytologia 40

Table 1. 1975 Cytological Studies in Some Central and Eastern Himalayan Grasses IV 455

Table 1. (cont'd)

* Species worked out for the first time . •õ New report for the species (New cytotype). Literature cited in Table I according to Darlington and Wylie (1955), Cave et al. (1956-68), Love and Love (1961), Fedrov (ed.) (1969) and Taxon (1969-73). 456 P. N. Mehra and M. L. Sharma Cytologia 40

This species is usually separated by the kneed awn flanked by two bristles. The pedicels of the spikelet are most commonly decorated with well defined bristles or setae (Bor 1960). The grass has some fodder value in scarcity areas.

Figs. 1-7. 1-2. Arundinella bengalensis, n=16+2B. 1, Ml, n=16+2B. (Arrows indicate B chromosomes). 2, telophase I showing the 2B's lagging. 3. A. hookeri, Ml, n=7. 4, A. nepalensis, A,, n=20. 5, A. setosa, Diakinesis, n=16. 6, Eragrostis unioloides, M1, n=9. 7, Tripogon fili formis, A1, n=10. Sixteen bivalents were discernible at diakinesis (Fig. 5). Earlier, this species is known to possess 2n=20, 32, 48, 54 (cf. Table 1). In the present taxon, a normal course of meiosis was observed with 100% pollen fertility. 1975 Cytological Studies in Some Central and Eastern Himalayan Grasses IV 457

Tribe: Eragrosteae Eragrostis unioloides (Retz.) Nees ex Steud. A highly variable species but is easily recognised from the pinkish or purplish spikelets.

Figs. 8-13. 8, Tripogon trifidus, Mi, n=20. 9, Isachne albens, M1, n=20. 10, Cynodon dactylon, M1, n=18. 11, diander, M1, n=18. 12-13. S.fertilis, n=18, 24. 12, M1, n=18. 13, Ml, n=24.

Larsen (1963) reported 2n=20 and c. 40 for this species. Presently, a meiotic chromosome count of 9 bivalents is made (Fig. 6). Meiosis was quite normal with 458 P. N. Mehra and M. L. Sharma Cytologia 40

nearly 100% pollen fertility. Tripogonfiliformis Nees ex Steud. It is a slender grass which usually grows on rocks and old walls. Meiotic studies revealed a haploid set of 10 chromosomes. The course of

Figs. 14-20. 14, Melica scaberrima, diakinesis, n=9. 15, Oryzopsis aequiglumis, Ml, n=12. 16, Stipa jacquemontii, A1, n=12. 17, Cortaderia selloana, M1, n=36. 18-20. Garnotia stricta, n=30. 18, M1, showing 28 bivalents and 4 univalents. 19, M1, showing secondary associations among the bivalents. (Circles indicate extraneous partices). 20, diakinesis showing 1 X-valent, 2 VI-valent and 19 bivalents. 1975 Cytological Studies in Some Central and Eastern Himalayan Grasses IV 459

meiosis was normal and 10: 10 separation of chromosomes was noted at anaphase-I (Fig. 7). Nearly 100% pollen fertility was recorded. T. trjfidus Munro ex Stapf. This is a robust grass which grows in huge tufts on rocks bordering lakes and pools in the hills. Metaphase-I revealed 20 bivalents (Fig. 8). Further stages of meiosis were normal with 20: 20 separation of chromosomes at anaphase-I. About 98% pollen fertility was recorded. Tribe: Isachneae Isachne albens Trin. This grass usually grows in moist localities. Larsen (1963) reported 2n=20 for this species, whereas a count of n=30 was made by Chen and Hsu (1961). Presently, a new cytotype with n=20 is reported from Darjeeling (Fig. 9). The species is thus based on x=10 and three euploid races with n=10 (diploid), n=20 (tetraploid) and n=30 (hexaploid) are now known.

Tribe: Chlorideae Cynodon dactylon Pers. This is one of the best fodder grass of India and is equally valued as a grass. It is extensively investigated and various chromosome numbers such as 2n=18, 18+1-3B, 30, 36, 36+1-2B, 40 and 54 are known for this species (cf. Table 1). Presently a meiotic number of n=18 is reported (Fig. 10) with nearly 100% pollen fertility. Tribe: Sporoboleae Sporobolus diander (Retz.) P. Beauv. This is a common grass in the hills and plains of India but is nowhere liked by cattle. Various collections were made from different localities in Darjeeling and Nainital but in each case the meiotic studies revealed n=12 (Fig. 11). Larsen (1963) also reported 2n=24 for this species, whereas Avdulov (1931) and Mehra, P. N. et al. (1968) reported n=18 and n=27 respectively. Thus the species seems dibasic with x=9 and 12. S. fertilis (Steud.) Clayton Not recorded by Bor (1960) in his work on Indian grasses. The species was presently collected from Darjeeling and Nainital. The Darjeeling taxon was found to possess n=24 (Fig. 13), whereas the Nainital taxon revealed the meiotic number n=18 (Fig. 12). Phenotypic diversity in the two cytotypes was neglegible. Both of them possessed 100% fertile pollen. Tribe: Meliceae Melica scaberrima (Nees) Hook. f. This grass is distributed from North-West India to Kumaon. It can be of use as fodder in fodder-scarce areas. Nine bivalents of fairly large size were discernible at diakinesis (Fig. 14). The course of meiosis was normal with nearly 100% pollen fertility. 460 P. N. Mehra and M. L. Sharma Cytologia 40

Tribe: Stipeae Oryzopsis aequiglumis Duthie This is a robust grass with broad flat leaves and widely spreading panicles. Meiotic studies revealed a haploid set of 12 chromosomes (Fig. 15). About 98% pollen fertility was recorded. Stipa jacquemontii Jaub. et Spach. This is a hardy species, often growing in the crevices of rocks and possesses loose, erect peanicles, The meiotic chromosome number n=12 was observed at anaphase-I (Fig. 16). Meiosis was normal with nearly 100% pollen fertility.

Tribe: Arundineae Cortaderia selloana (Schult) Aschers et Graebn. This is an introduced ornamental grass with large inflorescence. The leaves are crowded at the base of stems. At metaphase-I, 36 bivalents were discernible (Fig. 17). Previously, Avdulov (1931) reported 2n=72+IB for this species, whereas a count of 2n=76 was made by Hunter (1934). The latter appears to be erroneous. Meiosis was normal in the present taxon with nearly 100% pollen fertility.

Tribe: Garnotieae Garnotia stricta Brongn. It grows gregariously in shady and humid places and is grazed by cattle. Presently, this grass was collected from Jalapahar and Lebong in Darjeeling. In each case, a haploid set of 30 chromosomes was observed (Figs. 18-20). Meiosis in the Jalapahar taxon was found to undergo a normal course with nearly 100 pollen fertility. However, univalents, multivalents and secondary associations amongst the bivalents were observed at metaphase-I in the Lebong taxon (Figs. 19,20).

Discussion

Arundinelleae A total of four species of Arundinella have been presently investigated in this tribe. Of these, A. bengalensis and A. hookeri have been investigated for the first time. On the basis of present finding of smallest chromosome number (n=7) for A. hookeri, with normal meiosis, another base number x=7 is suggested for the Arundinella. Earlier, Darlington and Wylie (1955) reported x=10 and 14 as the base numbers for this genus. The latter base number is now ruled out in view of n=7 in A. hookeri. The present reports of n=16 for A. bengalensis and A. setosa is suggestive of yet another base number x=8 for the genus. Eragrosteae This tribe is represented in the Indian flora by about 90 species and 17 genera (cf. Bor 1960). The members are annual or perennial grasses possessing small chromosomes based on x=9 or 10. Presently, a total of five species belonging to 1975 Cytological Studies in Some Central and Eastern Himalayan Grasses IV 461 four genera have been investigated in this tribe conforming to these numbers. Tripogon faliformis and T. trifidus are cytologically recorded for the first time. Whereas all the previously investigated species of Eragrostis were based on x=10 , new haploid chromosome number, n=9, is reported for E. unioloides. Isachneae Three species of the genus Isachne have been worked out in this tribe. I . clarkei and I. sikkimensis are the first chromosomal reports for the species, whereas in L albens, a new chromosome number, n=20, is reported. All the three species possess small chromosomes based on x=10, which is the base number for this tribe. Sporoboleae The tribe Sporoboleae is represented in the Indian sub-continent by only three genera viz., , Sporobolus and Urochondra, with about 24 species. The members possess open or contracted panicles of usually very small spikelets. They are characterised by the possession of small chromosomes. In the present studies, only two species of Sporobolus have been worked out. S. fertilis with two cytotypes (n=18, n=24) is cytologically recorded for the first time. Meliceae In the Indian sub-continent, the tribe is represented by a single genus Melica with only 9 species (cf. Bor 1960). The members possess fairly large chromosomes based on x=9. Melica scaberrima, the only species presently studied in this tribe, is the first chromosomal report for the species. Stipeae The members of Stipeae inhabit dry and inhospitable localities. They possess small chromosomes based on x=7-13 and 17 (Bor 1960). Oryzopsis aequiglumis and Stipa jacquemontii, both with n=12, have been presently worked out in this tribe and both are first chromosomal records. The chromosomes in these species are small in size and are based on x=12, which in cidentally is also the most common base number for Oryzeae to which it seems related. Arundineae The members of Arundineae are perennial reeds with broad leaf blades and large plumose panicles. They possess small chromosomes based on x=12. Cortaderia selloana, the only species of the genus found in India, is presently reported with n=36, which thus is hexaploid. The chromosomes are of medium size. Garnotieae This is a small tribe, being represented in the Indian sub-continent by only two genera and 14 species (cf. Bor 1960). The members are characterised by the pos session of cylindrical spikelets borne in panicles and falling entire at maturity. They possess small chromosomes with basic number x=10. Garnotia stricta, the only species worked here under this tribe is hexaploid with n=30 and possesses medium sized chromosomes. Larsen (1963) reported 2n= c. 36 for this species which appears to be erroneous. 462 P. N. Mehra and M. L. Sharma Cytologia 40

Abstract

Cytological data on 26 taxa of the tribes Arundinelleae, Eragrosteae, Isachneae, Chlorideae, Sporoboleae, Meliceae, Stipeae, Arundineae and Garnotieae is pre sented from the hills of Darjeeling (E. Himalayas) and Nainital (C. Himalayas). Ten species marked * in Table 1 are cytologically reported for the first time. New chromosome numbers are reported for another 4 species marked t in the same table.

Acknowledgements

Our sincere thanks are due to the U.S. Government for the financial aid from PL 480 funds to the senior author under which the present work was carried out. We are most grateful to late Dr. N. L. Bar for the confirmation of various deter minations.

Literature cited

Avdulov, N. P. 1931. Karyosystematische Untersuchungen der Familie Gramineen. Bull. Appl. Bot. Pl. Breed. Suppl. 44, 1. Bor, N. L. 1960. The Grasses of Burma, Ceylon, India and . Pergamon Press London. 767 p. Cave, M. S. and Hommersand, H. F. C. 1956-1968. Index to Chromosome Numbers. Univ. of North Carolina press. P.O. Box 510. Chapel Hill. North Carolina. Chen, C. C. and Hsu, C. C. 1961. (cf. Cave et al. 1962). Darlington, C. D. and Wylie, A. P. 1955. Chromosome Atlas of Flowering . George Allen and Unwin Ltd. London. Fedrov, An. A. (ed.) 1969. Chromosome numbers of Flowering Plants. Komarov Botanical In stitute U.S.S.R. 926 p. Hunter, A. W. S. 1934. A karyosystematic investigation in the Gramineae. Canadian Jour. Res. 11: 213-241. Larsen, K. 1963. Studies in vascular plants of Thailand. Dan. Bot. Art. 20: 211-275. Love, A. and Love, D. 1961. Chromosome numbers of central and North-west European plant species. Opera Botanica (Lund) 5: 1-581. Mehra, P. N., Khosla, P. K., Kohli, B. L. and Koonar, J. S. 1968. Cytological studies in the North-Indian grasses (Part I). Res. Bull. Panjab Univ. 19: 157-230.