_??_ 1992 The Japan Mendel Society Cytologia 57: 309-314 , 1992

Karyomorphology of Three Species of Crinum L

B. Vijayavalli and P. M. Mathew

Department of Botany , University of Kerala, Kariavattom, Trivandrum, India

Accepted December 12, 1991

Crinum L (Tribe Crineae of Amaryllidaceae sensu Hutchinson) is a large genus com

prising about 130 species distributed in the tropical and subtropical regions (Willis 1973). In the Indian subcontinent, the genus is represented by 12 species (Hooker 1894) . Many species are grown as ornamental garden plants for their elegant showy flowers . Concerning the composition and systematic relationships of the tribe Crineae of which Crinum is the type genus , there is much controversy in the different classifications of the monocots (Bentham and Hooker 1883, Engler and Prantle 1930, Hutchinson 1973, Dahlgren et al. 1985). Cytology of about

60 species is known (cf. Fedorov 1969, Goldblatt 1981 , 1984, Nwankiti 1985), and these are mostly chromosome count reports. The present report concerns karyotype features of four

taxa in three species of Crinum from South India such as C . asiaticum L, C. giganteum Andr. and C. moorei L.

Materials and methods

Materials of the three species were procured from different regions, mostly South India. Chromosomes were studied from PMCs and/or root tip cells. Meiosis takes place in very

young flower buds while they are still within the underground bulbs, which make them relative ly inaccessible and difficult to study. However, attempt was made to study the meiotic be haviour by handling quite a large number of bulbs. Flower buds and root tips were fixed in 3: 1 Carnoy's fluid, and chromosome preparations made by acetocarmine smear and squash techniques. Root tips were pretreated in 0.002M solution of 8-hydroxyquinoline at 4•Ž for 2 hrs. Karyotype analysis was done following Levan et al. (1964) based on mean measure ments of somatic chromosomes taken from enlarged photomicrographic prints (•~4000) of five metaphase plates each from ten plants per accession; and karyotype asymmetry and TF determined after Stebbins (1958) and Huziwara (1962) respectively.

Observations

C. asiaticum L This species popularly known as "Grand Crinum" occurs throughout tropical India both

as wild and cultivated forms. Preliminary screening for chromosome numbers in populations from different localities in South India revealed that two cytotypes exist here, one with 2n=22

(diploid) and the other 2n=33 (triploid). Chromosomes of the diploid cytotype ranged in length from 13.50 to 6.00ƒÊm (Fig. 1). Chromosome No. I was strikingly larger than the rest of the chromosomes. The karyotype consisted of 2 pairs of m-type, 5 sm-type and 4 of st type chromosomes. The karyotype was relatively asymmentrical (3B, TF %=30.21). The chromosomes of the triploid cytotype ranged from 15.00 to 6.50ƒÊm in length. Each chro mosome was present in three doses, and homomorphic. Except for the triploid constitution, the karyotype details were comparable to that of the diploid. Meiosis was irregular con sequent on trivalent formation which ranged from 8-4 in number, cells with 6 trivalents pre Table 1. Summary of karyomorphological data in three species of Crinum

TCL: Total chromosome length ACL: Average chromosome length 1992 Karyomorphology of Three Species of Crinum L 311

dominating. Anaphase I separation was irregular and there was only very low pollen fertility

(11%). The triploid cytotype in the species is reported for the first time.

C. gignateum Andr.

This species is commonly known as "Giant spider Lily" . Materials were studied from three localities in South India such as Vattakottai in Tamil Nadu State , Veli (near Trivandrum) and Kottayam in Kerala State. The three accessions differed in colour of the leaf , which in the Vattakottai and Kottayam plants were all green , while the Veli ones had variegated leaves, green in the Centre and edged with white margin. The Kottayam plants were more gigantic in size. The Vattakottai and Veli plants showed 2n=22 (Fig . 2), and the chromosomes ranged in length from 20.50 to 6.00ƒÊm. In karyomorphological features , the two populations show ed recognisable difference in respect of centromeric position of certain chromosomes . In

Figs. 1-4. All figures •~370. 1, Diploid cytotype Fig. 5. Arm ratio of chromosomes of three of Crinum asiaticum 2n=22. 2, C. giganteum 2n= diploid species of Crinum. 22. 3, C. moorei (Cytotype I) 2n=22. 4, C. moorei

(Cytotype III) 2n=20. •~525

Vattakottai plants chromosomes 1, 2 and 9 were heteromorphic for size due to loss of sizable segment of long arm in chromosome 1 and 9 and of short arm in chromosome 2. In the Veli plants, in addition to chromosomes 1, 2 and 9, the 7th pair was also hetermorphic for size. The Kottayam plants consistently showed a small extra chromosome, and the karyotype of this was very similar to the Vattakottai plants (Table 1) except for the extra chromosome and size heteromorphism of chromosome 1, 2 and 9.

C. moorei L This is commonly known as "Long neck swamp Lily". Materials were studied from three localities in South India (Kodaikanal, Ootacamund, Trivandrum) and a fourth one from a northeast Himalayan region (Gangtok). In plant morphology, all the accessions were more or less similar except for flower colour which in the Gangtok plants was light blue and in all the others light pink. The chromosome numbers in the different populations revealed that 312 B. Vijayavalli and P. M. Mathew Cytologia 57

the species exists here as a complex with three cytotypes, both Kodaikanal and Ootacamund

plants with 2n=22 (Fig. 3), Gangtok plants 2n=21 and Trivandrum 2n=20 (Fig. 4). In chromosome size and morphology, the three types exhibited remarkable similarity with the karyotype relatively asymmetrical (3 B) and consisting of 5 pairs of m-type 5 sm-type and I of st-type chromosomes. Chromosome No. 6 showed a conspicuous liniar satellite on the short arm. In the aneuploid 2n-1=21 cytotype it was chromosome No. 10 that was de

ficient in one of the members and in the 2n-2=20 cytotype chromosome numbers 10 and 11. The aneuploid variant types (2n=21 and 20) reported for the first time in the species. In the 2n=22 cytotype there were 8 bivalents and a ring of 6 at diakinesis. The ring configura tion must be the result of translocation involving 3 pairs of chromosomes. Anaphase I was irregular with inbalanced separation of chromosomes to the two poles, and there was notable fall in pollen fertility (55%).

Discussion

Bulk of the earlier chromosome reports show that Crinum is a fairly stable genus with chromosome numbers conforming to the basic number x=11 with diploids predominating

(Sato 1938, Sharma and Ghosh 1954, Mangenot and Mangenot 1958, Bose 1965, Raina 1978, Lakshmi 1980). However, Jones and Smith (1967), who studied a large number of species from different geographic regions, have brought out widespread chromosomal discontinuity within species in euploid series, and have shown that polyploids and B-chromosomes are com mon in the genus. They have come across populations of a species (C. ornatum) in the Accra

plains of Ghana with 2n=24, and suggested a new basic number of x=12 as a derivation from x=11 by chromosome repatterning, probably centromere misdivision. All the taxa reported in the present study fall under the x=11 basic line, C. asiticum occurring in two ploidy types,

diploid (2n=22) and triploid (2n=33). Meiosis in the triploid cytotype was abnormal char acterised by trivalent formation followed by irregular anaphase separation and resulting in very low pollen fertility. This is suggestive of its autoploid nature which appears to gain support from Karyotype features of the taxon characterised by all the 11 chromosomes present in three doses and homomorphic. Karyomorphological data of the three diploid species (Table 1) show that C. asiaticum with the lowest values of TCL (180.0ƒÊm), ACL (8.36ƒÊm) and TF % (30.21) and more st-type chromosomes (4 pairs) has a more asymmetrical karyotype (3 B), C. moorei intermediate and C. giganteum least (2 B) with m-type chromosomes predominating and with no st-type chro mosomes. Shift of centromere position from median to submedian and substerminal in the

group is seen to be most evident in C. asiaticum and least in C. giganteum (Fig. 5). Accessions of C. moorei constituted three chromosome numerical variant types such as type I with 2n= 22 (Kodaikanal and Ootacamund), type II with 2n=21 (Gangtock) and type III with 2n=20

(Trivandrum). Karyotype features of all the three populations, however, were more or less similar. In the C. giganteum complex, both chromosome numerical and structural variations were noticed. The Vattakottai plants with green leaves and Veli ones with variegated leaves were both normal diploids (2n=22); but in them a few chromosomes exhibited heteromor

phism for size due to loss of parts of long or short arms in one of the members in varying degre es. The Kottayam accession which was clearly more gigantic in plant size was an aneuploid variant with 2n+1=23; and in this, however, all the chromosomes were homomorphic.

Between and among the three populations, a few chromosomes exhibited some degree of diff erence in respect of position of centromere as may be noticed from the difference in their r-values. Although of not very significant magnitude, the extent of chromosome numerical and structural differences noticed among the plants of the three populations of C. giganteum 1992 Karyomorphologyof Three Speciesof CrinumL 313

may be considered to have some bearing on the plant morphological difference evident in the species complex. Bentham and Hooker (1883) have placed Crinum in the subtribe Genuineae of the tribe Amarylleae along with three other genera Hippeastrum , Haemanthus and Zephyranthes. Engler and Prantle (1930) have included them all in their subfamily Amarylloideae . However, Hutchinson (1973) and also Traub (1963) have treated them under four separate tribes (Crineae , Hippeastreae, Haemantheae and Zephyrantheae) . Dahlgren et al. (1985) have kept Crinum in the tribe Amaryllideae , Hippeastrum and Zephyranthes together in the Hippeastreae and Haemanthus in the Haemantheae . Morphologically members of the four genera differ re cognisably one from the other in plant size, leaf shape, flower size, size of the bulb and also in the nature of the inflorescence which in Zephyranthes is remarkably different (solitary flowers as against small or large clusters of umbells in the others) . Cytologically also they show obvious distinction, Haemanthus with basic numbers x=8 and 9; Hippeastrum and crinum x=11 and Zephyranthes x=6. Haemanthus has highly asymmetrical and bimodal Karyotype (3 C) in striking contrast with the situation in the others (Vijayavalli and Mathew 1990), where it is fairly less asymmetrical and graded (2 B, 3 B). Morphologically and cytologically Zeph yranthes differs strikingly from both Crinum and Hippeastrum. Between Crinum and Hip peastrum plant morphological difference is relatively less, but they do differ in respect of number and size of leaves and number and size of flowers per umbel . Although both are x=11 basic, in chromosome size they are recognisably different, Crinum possessing significantly larger chro mosomes. On grounds of plant morphological difference, well supported by karyomorpho logical difference as well, the treatment of the four genera under separate tribes as done by Hutchinson appears to be appropriate.

Summary

Cytology of populations of three species of Crinum from South India is reported such as C. asiaticum, C. giganteum and C. moorei. All the species are diploids and x=11 basic, with C. asiaticum occurring here as triploid cytotype also. C. giganteum and C. moorei showed intraspecific aneuploidy, 2n=22 and 23 in the former and 2n=22, 21 and 20 in the latter. Meiotic behaviour and karyomorphology of the triploid C. asiaticum is suggestive of its autrotriploid nature. Karyotypes of all the taxa are relatively asymmetrical and graded, C. asiaticum exhibiting more asymmetry (3 B) and C. giganteum the least (2 B). The extent of chromosome numerical and structural difference noticed in the different populations of C. giganteum is pointed out to have some bearing on the plant morphological differences evident in the species complex. The disputed systematic treatment of the tribe Crineae is considered in the light of cytological data, and the evidence appears to favour Hutchinson's approach.

References

Bentham, G. and Hooker, J. D. 1883. "Genera Plantarum" Vol. III. Reeve London. Bose, S. 1965. Polyploidy in the genus Crinum. Cytologia 30: 349-333. Dahlgren, R. M. T. Clifford H. T. and Yoe, P. F. 1985. The Families of the Monocotyledons,Structure, Evolu tion and Taxonomy. Springer Verlag, Berlin Heridelberg,New York. Engler, A. and Prantle, K. 1930. De Naturichen Pflansen Familien, Berlin. Fedorv, A. 1969. Chromosome Numbers of Flowering Plants (ed) V. L. Komorov. Botanical Institute, Leningrad. Goldblatt, P. 1981. Index to paint chromosome numbers. 1975-78. Missouri Botanical Garden. Vol. 5. Bracin-Bru Botanical Garden Vol. 5. Braun Brumfield Inc, Ann Arbor, Michigan. 314 B. Vijayavalli and P. M. Mathew Cytologia 57

- 1984. Index to plant chromosome numbers. 1979-81. Missouri Botanical Garden Vol. 8. Braun-Brumfield Inc, Ann Arbor, Michigan. Hooker, J. D. 1894. Flora of British India. Vol. 6. L. Reeve and Co. Ltd., London. Hutchinson, J. 1973. "The Families of Flowering plants" (Ed. 3) Clarendon Press. Oxford. Huziwara, Y. 1962. The Karyotype analysis in some genera of compositae; IX. The chromosomes of some European species of Aster. Dot. Mag. 75: 43-150. Jones, K. and Smith, J. B. 1967. Chromosome evolution in the genus Crinum. Caryologia 20: 163-179. Lakshmi, N. 1980. Cytotaxonomical studies in eight genera of Amaryllidaceae. Cytologia 45: 663-673. Levan, A. K., K. Fredga and A. A. Sandberg. 1964. Nomenclature for centromeric osition on chromosomes. Hereditas 52: 201-220. Mangenot. S. and Mangenot, G. 1958. Deuxieme slists de nombers chromosomiques pouvesux chez deversies Dicotyledones et Monocotyledences d's Afrique occidentale. Bull Jard. Bet (Bruxelles) 28: 315-329. Nwankiti. O. C. 1985. Cytotaxonomic survey of some tropical ornamental species. V. Karyotype of two species of the genus Crinum and a related group Hymenocallis. Cytologia 5: 797-803. Raina, S. N. 1978. Genetic mechanism underlying evolution in Crinum. Cytologia 43: 575-580. Sato, D. 1938. Karyotype alteration and phylogeny IV Karyotypes in Amaryllidaceae with special reference to SAT chromosomes. Cytologia 9: 203-242. Stebbins, G. L. 1958. Longevity, habitat and release of genetic variability in higher plants. Cold Spring Harb. Symp. Quart. Biol. 23: 365-378. Sharma, A. K and Ghosh, C. 1954. Further investigation on the cytology of the family Amaryllidaceae and its bearing on the interpretation of its phylogeny. Genetica Iberica 4: 71-100. Traub, H. P. 1963. The Genera of Amaryllidaceae. Am Pl-Life. Sec. La Jolla, California. Vijayavalli. B. and Mathew, P. M. 1990. Cytotaxonomy of the Liliaceae and Allied Families. Continental publishers, Trivandrum. Willis, J. C. 1973. A Dictionary of The Flowering Plants and Ferns. Cambridge Liniv. Press.