Great Basin Naturalist

Volume 39 Number 4 Article 3

12-31-1979

Karyotypes of four species: A. carruthii, A. filifolia, A. Frigida, and A. spinescens

E. Durant McArthur Intermountain Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Ogden,

C. Lorenzo Pope Rice Researchers, Inc., Glenn,

Follow this and additional works at: https://scholarsarchive.byu.edu/gbn

Recommended Citation McArthur, E. Durant and Pope, C. Lorenzo (1979) "Karyotypes of four Artemisia species: A. carruthii, A. filifolia, A. rigida,F and A. spinescens," Great Basin Naturalist: Vol. 39 : No. 4 , Article 3. Available at: https://scholarsarchive.byu.edu/gbn/vol39/iss4/3

This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. KARYOTYPES OF FOUR ARTEMISIA SPECIES: A. CARRUTHIl A. FIUFOLIA, A. FRICIDA, AND A. Sn\'ESCENS'

E. Dui;l Arthur and C. l.ornizo Pope-

.\bstract.- Artg»u,sia CMirtithii and A. frigida of the subgenus Artemisia and A. filifului and A. spincsccns of tht- subgenus Dracunculus all have chromosome numbers based on x = 9. Diploid (2n = 18) karyotypes of each species are composed of large, medium, and small chromosomes that are mainly metacentric and submetacentric. The individ- ual karyotypes are similar but distinctive. Artemisia filifolia's karyotype and chemistry is (juite similar to that of Section Tridentatae, but A. filifolia has significant morphological differences with respect to the Tridentatae. Arte- misia spinescens includes a tetraploid (2ri = 36) population as well as diploid populations. Karyofypic analysis of a tetraploid A. spinescens suggests that it is an autotetraploid, thus carrying out a common theme in Artcmi^i'i :.iii..- polyploidy).

The genus Artemisia (, Com- are most common (Table 1), but aneuploidy positae) is principally a temperate northern and amphiploidy based on other .t's are also hemisphere group (Good 1974, Bailey known (Suzuka 1950, 1952, Kawatani and Hortorium Staff 1976). A few of its 250 spe- Ohno 1964). The euploid complexes may be cies, however, extend to South America and flNfopolyploid with one basic genOnie or allo- southern Africa. Most Artemisia phylogenists polyploid with different genomes (Persson have suggested an origin for Artemisia in Eu- 1974) or somewhere in between— a segmental rasia because of the preponderance of diverse autopolyploid or allopolyploid (Stebbins species growing there and because most of its 1971), in which case, genomes are partial!)' Anthemideae relatives occur there (Stebbins differentiated. 1974, Cronquist 1978, McArthur and Plum- Our work with Artetnisia has been mainly mer 1978, McArthur 1979). Beetle (1979) re- with the A. tridentata Nutt. complex ( = sec- cently suggested an American origin for the tion Tridentatae) (Hanks et al. 1973, McAr- genus. Even disallowing Beetle's hypothesis. thur and Plummer 1978, McArthur et al.

North America is without question a center 1979, Welch and McArthur 1979). To better of diversity for Artemisia. Several Artemisia imderstand the Tridentatae, we have also species complexes (Clausen 1951: groups of looked at sympatric, non-Tridentatae, per- closely related capable of intragroup ennial Artemisia. This paper reports first gene exchange) appear to be evolving in publication of karyotypes of four non-Triden- North America (Hall and Clements 1923, tatae species. Two species represent the sub- Keck 1946, Ward 1953, Beetle 1960, Estes genus Artemisia (A. carnithii Wood and A. 1969, McArthur and Plummer 1978). frigicUi Willd.) and two represent the sub- Artemisia has chromosome numbers based genus Dracunculus (A. filifolia Torr. and A. third subgenus on x = 6,7,8, and 9 (Kawatani and Ohno 1964, spinescens D. C. Eaton), the is princi- Wiens and Richter 1966). By far the most in Artemisia is Seriphidiuni, which and North African. The sec- common base number for Arternisia is x = 9, pally Eurasian Tridentatae has been assigned to Seriphi- however, as it is for the whole of the Anthe- tion are probably mideae (Persson 1974). Several Artemisia spe- diuni, but the Tridentatae parallel to the Seriphidia cies and species complexes are composed of independent of and 1978). polyploid series. Euploid series based on x = 9 (McArthur and Plummer

is therefore in the pubHc domain. I .- time and 'Thisarticle was written and prepared bv U.S. Government emplo,^ official , . ,. <-, j lu \. uaam \^^,^ Service.Service, U.S.^Depart-::',!^^Department of Agriculture, ^Research Genet..,, Intermountam Forest and Range Experiment Stat.on. ForestFores^t y Researchers. Inc..^''^liri";^^^^^^Glenn, California 95943. formerly I and Plant Breeder, Rice at the Inteniiountain Station's Sciences Laboratory, Prove, Utah Biological Technician at the Shrub Sciences Laboratory.

419 420 Great Basin Naturalist Vol. 39, No. 4

Materials and Methods Table 2.— Artemisia accessions studied.

Plant Materials.— The plant materials studied were from the native collection sites and from transplanted wildings at the Snow Field Station in Ephraim, Utah. Each collec- tion was assigned a culture number preceded by U to indicate its order of accession. Origi- nal locations of plant populations are given in Table 2. Voucher herbarium specimens for each accession have been deposited in the Shrub Sciences Laboratory Herbarium (SSLP). Karyotyping.— Seed was collected from open-pollinated plants at the Snow Field Sta- tion for A. carruthii, A. filifolia, and A. frig- ida, and from the natural populations for A. spinescens. Root tips from seedlings germi- December 1979 McArthur, Pope: Artemisia KAHYOTYI'ES 421 nated in petri dishes were pretreated with and Pope 1977), but karyotypes were pre- colchicine, fixed in 1:3 acetic alcohol, stained pared from one slide per accession-a slide in acetocannine, and s(juashed on a micro- with flat photogenic cells. Five randomly se- scope slide in Hover's solution (McArthur lected metaphase plates from each slide were and Plummer 1978). Slides are stored at the photomicrographed (Fig. 1). Prints at a mag- Shrub Sciences Laboratory. nification of ;3120X were used to prepare the Several seedlings of each accession were karyotypes in a manner slightly modified checked for chromosome numl)er (McArthiu- from that outlined in our earlier paper

A 422 Great Basin Naturalist Vol. 39, No. 4

(McArthur and Pkimmer 1978). Each into the nine classes and paired by relative chromosome complement was assigned 100 length and centromere position within each arbitrary length units so that the actual mea- class. Interclass pairing was occasionally re- surement per chromosome was proportion- quired so that all chromosomes could be alized. For diploid accessions, large chromo- paired. In such cases, length was given prior- somes (L) were defined as those > 12.6 units, ity over centromere position. To confirm fit medium (M) as 9.6-12.6, and small (S) <9.6. of pairing choices, each chromosome pair For the tetraploid accession, these values was visually inspected on the photo- were halved. The centromere position was micrographs. The five samples for each ac- recorded as the proportional length of the cession were then averaged (x) for each short chromosome arm with respect to the chromosome pair and a standard error of the length of the long arm. Metacentric chromo- mean (se) computed. somes (M) were defined as those with a ratio A means of measuring karyotype asym- >0.75, submetacentric (SM) as 0.50-0.75, metry (Wiens and Richter 1966), F percent is and subteliocentric (ST) <0.50. Thus nine obtained for a karyotype by averaging the classes of chromosomes were possible: proportional length of each short chromo- LST = large subteliocentric, LSM = large sub- some arm in respect to its long arm. In our metacentric, LM = large metacentric, case, F percent was obtained by halving the MST = medium subteliocentric, MSM = centromere position values of Table 3. As F medium submetacentric, MM = medium percent decreases from a maximum of 50, a metacentric, SST = small subteliocentric, more asymmetric karyotype is indicated. SSM= small submetacentric, SM = small Metaphase plates were available for A. car- metacentric. For preparation of the karyo- mtJiii (Keck 1946) and A. frigida (Knaben types of Table 3, chromosomes were grouped 1968). We compared our F percent results

Table 3. Karyotypic data for Artctuiski species.

Taxon 1979 December McArthur, Pope: Artemisia K VHYOTYI'FS 423 with values obtained from these previously relatively similar karyotype. We believe this published metaphase plates. tendency for a relatively similar karyotype is In order to compare the diploid (2n = 18) present in the genus, but some Artemisia taxa and tetraploid (2m = 36) chromosome com- have quite different karyotypes (Filatova plements of A. spiiiescens, we used a paired 1971, 1974a, 1974b), as well as probable t-test (Woolf 1968). The assiunption was that aneuploid chromosome number reductions the relative lengths of the doubled pairs (1 (Wiens and Richter 1966). with 2, 3 with 4, . . .17 with 18 of Table 3) Artemisia carruthii.- The accession of ,-\. would be significantly different (P<0.05) carruthii that we examined has chromosome from tlie diploid pairs (1,2,. ..9) if the diploid pairs as follows: 1 LSM, 1 LM, 5 MM, I chromosome complement had not doubled to SSM, and 1 SM (Table 3). Artemisia carruthii form the tetraploids. We point out that be- is a member of the A. hidoviciana Nutt. spe- size the first cause was pairing criterion, the cies complex of the subgenus .Vrtemisia. It possible doubled pairs' relative length of tet- occurs in inland western North America and raploids are systematically biased (e.g.,l>2, is known only as a diploid (2n = 18). Keek's 3>4, ...17>18). For centromere position, the (1946) metaphase plate has an F percent of average of tetraploid pairs was compared to 37 as compared to our 44. Despite the appar- the diploids (1 and 2 with 1, 3 and 4 with 2, ent difference, the chromosomes are prob- ...17 and 18 with 9). ably similar. Estes's (1969) evidence (hybridi- Results and Discussion zation along with meiotic chromosome pairing) supported autopolyploidy in the A. The four diploid accessions have different, ludoviciami complex. but not radically different, karyotypic pat- Artemisia frigida.— Like A. carruthii, A. terns (Table 3, Fig. 1). Persson (1974:168) re- frigida is also a member of the subgenus Ar- ported that the whole genus Artemisia has a temisia. Artemisia frigida, however, forms its 424 Great Basin Naturalist Vol. 39, No. 4 own species complex. It ranges from Mexico the tetraploid has a karyotype of 2 LSM, 2 through Alaska to Siberia (McArthur et al. LM, 4 MSM, 6 MM, 1 SST, 1 SSM, and 2 SM 1979). Artemisia frigida is known only as a chromosome pairs with an F percent of 36. diploid (2n = 18) (Love and Love 1964, Kna- The tetraploid karyotype appears to be an ben 1968, Kovanda 1972, Mulligan and Cody approximate doubling of the diploid one. Our 1972, Hartman 1977, McArthur and Pope paired t-tests for relative length and centro- 1977). Its karyotype consists of 1 pair LM, 1 mere position showed tetraploid chromo- pair MSM, 5 pair MM, 1 pair SST, and a pair somes to be about what would be expected in of SM chromosomes with an F percent of 41 doubling the diploid chromosomes. The ap- (Table 3, Fig. lA). Knaben's (1968) cell had proximate doubling was especially true for an F percent of 43. relative length (P<0.50). The centromere

Artemisia filifolia.— This species is as- positions were not significantly different signed to the subgenus Dracunculus, but has from doubling (0.10>P>0.05), but did not no close relatives (Hall and Clements 1923). indicate an exact doubling. Another measure Beetle (1979) recently suggested a possible of centromere position, F percent, was about affinity between A. filifolia and the Triden- the same for the diploid and tetraploid acces- tatae. Our analyses show it to have pairs of sions (Table 3). chromosomes as follows: 1 LSM, 2 LM, 1 Of particular interest were two pairs of MSM, 3 MM, 1 SST, 1 SM with an F percent LSM and SM and the single pairs of SST and of 39 (Table 3, Fig. IB). This karyotype is SSM in the tetraploid. The LSM and SM quite similar to the Tridentatae— differing by could have been derived from the largest two chromosome pairs. The mean Triden- MSM and the smallest MM pairs (Pairs 3 and tatae F percent is 38 (calculated from McAr- 8: Table 3) of the diploids by translocation. thur and Plummer 1978). When compared to The SST and SSM pairs of the tetraploid the Tridentatae karyotype, A. filifolia has an could, with repatterning (e.g., pericentric in- extra LM pair in place of an MSM (McAr- versions), have been derived from the diploid thur and Plummer 1978). Kelsey and Shafiza- SSM pair 9. Persson (1974) illustrated the deh (1979) point out that the sesquiterpene analogous nonsimilar 4.v and 6.r polyploid lactone colartin is shared by A. filifolia and grouping that occurs in the A. maritima L. the Tridentatae. Our chromatographic data complex.

(Hanks et al. 1973 and unpublished data It is hard for us to visualize the tetraploid stored at the Shrub Sciences Laboratory) of A. spinescens as anything other than auto- phenolic compounds also show some sim- tetraploid. Artemisia spinescens has no close ilarities between the two taxa. Before any relatives. Although the diploid genome may close relationship can be inferred, however, have differentiated in various populations so more definitive chemotaxonomic and system- that the tetraploid(s) may have arisen from atic study is required. The taxa differ widely hybrids between slightly different parents, in floral characteristics and wood anatomy the hypothetical differentiated diploids must (Moss 1940, McArthur 1979) and apparently surely have had a common soiuce in the re- do not hybridize despite areas of sympatric cent past. Further support for the autotetra- distribution. ploid nature of tetraploid A. spinescens is the

Artemisia spinescens.— This species is also apparent tendency for autopolyploidy in the currently assigned to the subgenus Dracim- genus A)iemisia. Table 1 certainly suggests culus (McArthur 1979). It differs from other such a tendency. Furthermore both the A. lii- species of Artemisia because it is both spring ckwiciana (Estes 1969) and the A. tridentata flowering and deciduous. Only four popu- (Ward 1953, McArthur and Plummer 1978) lations have had chromosome numbers deter- complexes are riddled with autopolyploidy. mined (Powell et al. 1974, McArthur and Pope 1977). Of these, three were diploid Conclusions (2n= 18) and one was tetraploid (2/i = 36). In the present study, the diploid karyotype has The four species examined in this report 1 LM, 3 MSM, 4 MM, and 1 SSM chromo- mirror much of the genus Artemisia's some pairs with an F percent of 39, whereas chromosomal picture. Their karyotypes are. December 1979 McArthur, Pope: Artemisia Karyotypes 425 in general, quite similar although there are Fu.atova, N. S. 1971. De caryotipis sjH.'cieruin Arlemiaii distinctive differences. The four species are e subgeiicre Dracunculus (Bess.) Rydb. in arenis vigenliuin. all .v = 9, as is most of Atiemisia. Artemisia Bot. Mater. Gerb. Inst. Bot. Akad Nauk Ka/ahsk. SSR 7:46-49. spinescens shows apparent autopolyploidy, a 1974a. Ad stadio de caryotaxoMoiniciuii Artt'misii phenomenon quite common in Artemisia. Ar- Kazachstaniae e subgenere Seriphidiiiin (Bess.) temisia has filifolia a karyotype quite similar Rouy. Bot. Mater. Gerb. Inst. Bol. Akad Nauk to that found in the A. tridentata complex, Kazahsk. SSR 8:66-75. 1974b. but morphological and anatomical differ- Karyotaxonomy of two species of worm- wood of the subgenus Seriphidimu ences do not support a close relationship be- (Bess.) Rouy. Izvestiia Akademii Nauk Kazahsk. .SSR Sehia Bi- tween these taxa. ologicheskaia 1 : 16-20. Good, R. 1974. The geographv oi flowering plants. 4th

ed. Longmans Ciroup Ltd. London. .557 p. Acknowledgments Hall, H. M., a.nd F. E. Cleme.nts. 192.3. The phyloge- netic method in . The North American This study was aided by federal fimds for species of Artemisia, Cbrysothamnus and Atri- wildlife habitat restoration through Pittman- plex. Carnegie Inst. Wash. Publ. .326:l-.^55. IIanks, D. L., E. D. Mc.\rthi r, R. Robertson W-82-R Project (Cooperators: In- .Steve.ns, a.nd A. P. Pll'mmer. 1973. Chromatographic characteristics termountain Forest and Range Experiment and phylogenetic relationships of Artemisia sec- Station, USDA Forest Service, Ogden, Utah; tion Tridentatae. USD.\ For. Serv. Res. Pap. and Utah State Division of Wildlife Re- INT-14I. 24 p. Intermt. For. a«d Range Expl. sources, Salt Lake City, Utah). The Snow Sta., Ogden, Utah. R\RTMAN, R. L. 1977. In: A. Love lOPB Chromosome Field Station is cooperatively maintained by number reports LVI. Taxon 26:257-274. the above agencies, Utah State University, Kaw.ata.m, T., and T. Ohno. 1964. Chromosome num- and Snow College. bers in Artemisia. Bull. Nat. Inst. Hyg. Sci. (Tokyo). 82:18.3-193. Keck, D. D. 1946. A revision of the Artemisia vulgaris Literature Cited complex in North .\merica. Proc. Calif. .\cad. Sci. 25:421-468. Arano, H. 1962. Cytological studies in subfamily Car- Kelsey, R. G., and F. Shafizadeh. 1979. Sesquiterpene duoideae of Japanese Compositae VI. Karyotype lactones and systematics of the genus .\rtemisia analysis in the genus Artemisia. Bot. Mag. (.\steraceae). P'hytochemistry 18: 1591-1611. (Tokyo) 7.5:.356-368. 196.3. Cytological studies in subfamily Car- Knaben, G. 1968. Chromosome numbers of flowering duoideae (Compositae) of Japan XIV. The karyo- plants from central Alaska. Nytt Mag. Bot. 15:240-254. type analysis on genus Artemisia (3). Bot. Mag. (Tokyo) 76:459-465. Korobkov, a. a. 1972. On the cytotaxonomical charac- genus Artemisia L. 1968. The karyotypes and geographical distribu- teristics of some species of the in northeast of the USSR. Bot. Zurn. tion in some groups of subfamily Carduoideae the (Compositae) of Japan. Kromosomo 57:1316-1.327. 72-73:2371-2.388. Kovanda, M. 1972. Somatic chromosome numbers for . Rhodora 74:102-116. Bailey Hortorium Staff, L. H. 1976. Hortus third. some Love, .\., and D. Love. 1964. In: .\. Love and O. T. Sol- Macmillan Publ. Co., Inc. New York. 1290 p. Chromosome number reports I. Taxon Beetle, A. A. 1960. A study of sagebrush, the section brig lOPB 13.99-110. Trideutatae of Artemisia. Univ. Wyoming Agric. E. D. 1979. Sagebrush systematics and evo- Expt.Sta. Bull. 368:1-83. McArthur, In: G. F. Gifford, F. E. Busby, and K. 1979. Autecology of selected sagebrush species. lution. J. (eds.). Sagebrush Ecosystem Symp.. p. K. Shaw Shaw In: G. F. Gifford, F. E. Busby, and J. 14-22. Utah State Univ. Press, Logan. 251 p. (eds.). Sagebrush Ecosystem Symp., p. 23-26. Mc.\rthur, E. D., a. C. Blauer, A. P. Plimmer, and Utah State Univ. Press, Logan. 251 p. R. Stevens. 1979. Characteristics and hybridiza- 1951. Stages in the evolution of plant spe- Clausen, J. tion of important intermountain shmbs 111. Sun- cies. Cornell Univ. Press. Ithaca, New York. 206 flower family. USDA For. Serv. Res. Pap. INT- P- 220. 82 Intermt. For. and Range Expt. Sta.. Chonquist, a. 1978. The biota of the Intermountain Re- p. Ogden, Utah. gion in geohistorical context. Great Basin Nat. McArthur, E. D., and A. P. Plummer. 1978. Biogeo- Mem. 2:3-15. graphy and management of native western Ehrendorfer, F. 1964. Notizen zur cytotaxonomic und : a case study section Tridentatae of Arte- evolution der gattung Artemisia. Osterr. Bot. misia. Great Basin Nat. Mem. 2:229-243. Zeitschr. 111:84-142. McArthur, E. D., and C. L. Pope. 1977. In: A. L6ve EsTES, R. 1969. Evidence for autoploid evolution in J. lOPB Chromosome number reports LV. Taxon the Artemisia hidoviciana complex of the Pacific 26:107-109. Northwest. Brittonia 21:29-43. 426 Great Basin Naturalist Vol. 39, No. 4

Moss, E. H. 1940. Interxylary cork in Artemisia with ref- 19.52. Chromosome numbers in Artemisia. Rep.

its significance. Bot. Kihara Inst. Biol. Res. erence to taxonomic Am. J. (Seiken Ziho) 5:68-77. 27:762-768. Taylor, R. L., L. S. Marchand, and C. W. Crompton. A., 1972. In: A. Love 1964. Cytological observations Mulligan, G. and W. J. Cody. on the Artemisia lOPB Chromosome number reports XXXV. Tax- tridentota (Compositae) complex in British Co-

on 21:161-166. lumbia. Can. J. Genet. Cytol. 6:42-45. Persson, K. 1974. Biosystematic studies in the Artemisia Ward, G. H. 1953. Artemisia, .section Seriphidium, in maritima complex in Europe. Opera Botanica North America, a cytotaxonomic study. Contr. .35:1-188. Dudley Herb. 4:155-205. Powell, A. M., D. W. Kyhos, and P. H. Raven. 1974. Welch, B. L., and E. D. McArthur. 1979. Feasibility in X. of improving big Chromosome numbers Compositae. Am. J. sagebrush (Artemisia tridentata) Bot. 61:909-913. for use on mule deer winter ranges. In: R. J. Goo- Rousi, A. 1968. Cytogenetic comparison between two din and D. K. Northington (eds.). Arid land plant kinds of cultivated tarragon [Artemisia dractin- resources, p. 451-473. Tech Univ. Press,

cidus). Hereditas 62:193-213. Lubbock. 724 p. evolution in WiENS, D., A. Stebbins, G. L. 1971. Chromosomal higher AND J. RiCHTER. 1966. Artemisia patter- plants. Addison-Wesley Publ. Co., Reading, Mas- sonii: a 14-chromosome species of alpine sage. Bot. sachasetts. 216 p. Am. J. 53:981-986. 1974. Flowering plants: evolution above the spe- WooLF, C. M. 1968. Principles of biometry. D. Van Nos-

cies level. Harvard Univ. Press, Cambridge, Mas- trand Co., Inc., Princeton, New Jersey. 3.59 p. sachusetts. 399 p. Suzuka, O. 1950. Chromosome counts in the genus Arte- 25:17-18. misia. Jap. J. Genetics