CHROMOSOMAL CYTOLOGY and EVOLUTION in EUPATORIEAE Title (ASTERACEAE) 著者 Watanabe, Kuniaki / King, Robert M
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Kobe University Repository : Kernel タイトル CHROMOSOMAL CYTOLOGY AND EVOLUTION IN EUPATORIEAE Title (ASTERACEAE) 著者 Watanabe, Kuniaki / King, Robert M. / Yahara, Tetsukazu / Ito, Motoni / Author(s) Yokoyama, Jun / Suzuki, Takeshi / Crawford, Daniel J. 掲載誌・巻号・ページ Annals of the Missouri Botanical Garden,82(4):581-592 Citation 刊行日 1995 Issue date 資源タイプ Journal Article / 学術雑誌論文 Resource Type 版区分 publisher Resource Version 権利 Rights DOI 10.2307/2399838 JaLCDOI URL http://www.lib.kobe-u.ac.jp/handle_kernel/90002998 PDF issue: 2021-10-05 CHROMOSOMAL CYTOLOGY Kuniaki Watanabe,2 RobertM. King,3 Ito,5 AND EVOLUTION IN JunTetsukazu Yokoyama, Yahara,4 Takeshi Motoni Suzuki,7 EUPATORIEAE and Daniel J. Crawford" (ASTERACEAE)' ABSTRACT Reportsof 68 new chromosomecounts attributed to 53 species from25 generaof Eupatorieaeof the Asteraceae, based mostlyon determinationsof mitoticmaterials, include first counts for 2 genera(Acanthostyles and Lepidesmia) and 14 species and new reportsfor 8 species. B chromosomesare reportedfor 4 generaand 12 species. Karyotype analysesmade on 20 species of Eupatorieaeand one species of Heliantheaeshowed that total karyotypic lengths of the taxa withn = 16-19 of helianthoidand eupatorioidtaxa are comparableto thoseof some eupatorioidtaxa withn = 10. This is contraryto the previoushypothesis that the higherchromosome numbers n = 16-19 werederived from n = 10 by polyploidizationfollowed by dysploidloss. Cytologicaldata supplementand are consistentwith the following conclusionspredicted from molecular phylogenetical and biochemicaldata: (1) The ultimatebase numberof Eupatorieae is 17, and thelower numbers are derivedby successivedysploid reductions; (2) A reductionin chromosomaland total karyotypiclength accompanied by evolutionaryadvancement has been revealedfor some generaand species within this tribe;(3) A high base numberof x = 17 in Eupatorieaeis consideredto be deriveddirectly from one of the membersof Heliantheaewith n = 17 to 19. The Eupatorieaeare a verydiversified tribe and chromosomenumbers are amongthe mostreadily consistof morethan 2300 species and 180 genera definedtaxonomically. Therefore, we attemptedto in 18 subtribes(King & Robinson,1987). In spite find clues regardingphylogenetic relationships of its representinga large elementof Asteraceae, throughoutthe tribe by assessing chromosomal the tribeEupatorieae has remainedpoorly under- variation,restriction site mutationsin chloroplast stoodbecause its centersof diversity are in Central DNA (Ito et al., in prep.),and the utilityof isozyme Americaand South America,which were remote numberfor determining ploidy level (Suzukiet al., fromthe early centers of study. Recent monograph- unpublished). ical (King & Robinson,1987), cladistical (Karis, Our purposesin thispaper are to reportoriginal 1993; Bremer,1987, 1994; Bremeret al., 1992), countsof chromosomenumbers in Eupatorieae,to and molecularphylogenetic works (Jansen et al., comparethem with numbers reported previously, to 1991; Watsonet al., 1991; Kim et al., 1992) have analyze karyotypesof selected representativespe- stimulatedus to studythe originand evolutionof cies, and to apply the resultsto a betterunder- Eupatorieae.A broad range of base chromosome standingof the origin, phylogeny, and chromosomal numbers,from n = 4 to 25, has been reported(Fig. evolutionin the tribe. 1). The remarkableconstancy of chromosomemor- MATERIALS AND METHODS phologyand numberwithin genera has been in- valuable in the studyof plant systematics.In ad- Cytologicalobservations were made primarilyon dition,many of the groupsthat have distinctive mitoticcells of roottips obtainedfrom seedlings 'We thankThomas B. Croatof the MissouriBotanical Garden in St. Louis, Missouri,Gerald R. Carrof the University of Hawaii,J. Rzedowskiof the Institutode Ecologfain Mexico,and David B. Lellingerof the SmithsonianInstitution in Washington,D.C., forcollecting viable seeds forthis study.We also thankVictor Castro of the Universityof Costa Rica, San Jose,for his help in collectingplant material in Costa Rica and Harold Robinsonfor his help withidenti- fications.This studyis supportedby a Grantin Aid forOverseas Researchfrom the Ministryof Education,Culture and ScientificResearch, Japan, No. 03041028. 2 Departmentof Biology,Faculty of Science, Kobe University,Tsurukabuto 1-2-1, Kobe, 657, Japan. 3Department of Botany,National Museum of NaturalHistory, Smithsonian Institution, Washington, D.C. 20560, U.S.A. 4Department of Biology,Faculty of Science, KyushuUniversity, Fukuoka, 812, Japan. 5Department of Biology,Faculty of Science, Chiba University,Yayoi-cho, Inage-ku, Chiba, 260, Japan. 6 BotanicalGardens, University of Tokyo, Hakusan, Bunkyo-ku, Tokyo, 112, Japan. 7Museum of Natureand HumanActivities, Hyogo, 6 Yayoigaoka,Sanda, 669-13, Japan. 8 Departmentof Plant Biology,Ohio StateUniversity, Columbus, Ohio 54321, U.S.A. ANN. MISSOURi BOT. GARD. 82: 581-592. 1995. 582 Annals of the MissouriBotanical Garden 15 somaticchromosomes of eightrepresentative spe- Basic chromosome number In Eupatorleae cies. Chromosomenumber determinationsfrom 68 .0 populationsattributed to 53 species from25 genera of Eupatorieaeare reported.First reports are given forAcanthostyles buniifolius (2n = 20), Adenostem- 0 ma cuatrecasalsii(2n = 20), AgeratinaisoleJ)is (2n E2 34), Decachaeta thieleana (2n = 32), Fleisch- z mannia sideritides(n = 10, 2n = 20), Lepidesmia squarrosa(2n = 20), Koanophyllonlongifioium (2n 30), Mikaniacongesta (2n = 34+0 to 3B), Neo- mirandeaarthodes (n = 17+0 to 5B), N. guevarii (2n = 50+2 to 12B), N. parasitica(2n = 34+1 to 2B), N. standleyi(2n = 50+1 to 4B), Stevia con- nata (2n = 44), and S. suaveolens(2n = 33+0 to 2B), and new reportsare givenfor Ageratina roth- 50 rockii(2n = 51 and 68), Chromo/aenalaevigata (2n = 50), Mikania scandens(2n = 34 + 0 to I B), Praxelisclematidea (2n = 30), Steviaeupatoria (2n = 36 and 48), S. monardaefilia(2n = 33). S. pilosa (2n = 22), and S. tomentosa(2n = 33). Remaining countsconfirm the chromosome numbers of all pre- viousreports in somespecies or are consistentwith one ofvariable numbers reported by several authors 0 in otherspecies. Of the 68 accessions in which chromosomenumber determinations were made, 53 I} I (78%) are diploids and 15 (22%) are polyploids. The presence of B chromosomesis reportedfor 0 100| Bartlettinasordida, Mikania congesta, M. scandens, Neomirandeaangularis, N. arthodes,N. bIifora,N. guevarii,N. parasitica,N. standleyi,Stevia salici- folia, S. serrata,an(1 S. suaveolens.The B chro- mosomes are distinctlysmaller than autosomies (Fig. 3), except in Mikania an(1 Stevia,anr( show 4 9 10 11 12 15 16i17 15 19 20 25 Baslc chromosome number the early con(lensationtypical of the centromieric regionsof autosomes at prometaphase.Both Mikan- FIGURE 1. Distributionsof base chromosome numbers ia and Steviahave severalsmall autosomes in the species, genera,and subtribesof Eupatorieae. nearly the same size as B chromosomes(Fig. 7). grown from fruits of known provenance in the greenhouse of Kobe University.For the cultivation KARYOTYPE of specimens and the preparation of materials for Figures10-30 are haploidkaryotypic idiogramns. cytological work, the procedures of Watanabe et al. Drawingsare based on the means of ten measure- (1975) and Watanabe et al. (1990) were followed. mentsfor each. Each idiogramis arrangedin de- The measurements of karyotypiclength were made scendingorder of chromosomenumber within Eu- on root tip mitoses, and each measurement is the patorieae next to helianthoil Podachaenium mean of measurements of five metaphase plates. eminens(Lag.) Sch. Bip. Voucher specimens have been deposited in US and MAK. In Table 2, we reportthe mean totalkaryotypic lengthswith their standard errors, the rangesfrom RESULTS the longestto shortestchromosome amidi their ratio foreach karyotype,arid the mean arm ratio(total CHROMOSOME NUMBER long arm length/totalshort arm length).The two All chromosome number determinationsare pre- lattermeasurements indicate the degreeof karyo- sented in Table 1. Figures 2-9 are photographs of typic asymmetry.Significance of differencesbe- Volume 82, Number4 Watanabe et al. 583 1995 ChromosomalCytology in Eupatorieae Table 1. Chromosomenumber determinations in Eupatorieae(Asteraceae). n countsare frompollen mothercells (PMCs) and 2n countsare fromroot tips. Chromosomenumber Species n 2n Collectiondata or reference Acanthostylesbuniifolius (Hook. & 20 Argentina.Buenos Aires:Parana Delta at Ti- Arn.)R. M. King & H. Rob. gre,King 10288 (US) Adenostemmacuatrecasasii R. M. 20 Venezuela.Merida: 4.1-6.3 kmE of Santo King & H. Rob. Domingo,King 10538 (US) A. viscosumJ. R. & G. Forst. 20 U.S.A. Hawaii: KawaihauDist., Makaleha Mtns.,SSW of Puu Eu, Flynn5461 (US) Ageratinaanisochroma (Klatt) R. 34 Costa Rica. 10 km W of San Ramon,15 M. King & H. Rob. Aug. 1991, Yaharaet al. s.n. (MAK) A. bustamenta(DC.) R. M. King & 1711 -Costa Rica. 27 km N of San Isidro,Yahara H. Rob. et al. 39 (MAK) A. havanensisR. M. King & H. 34 Mexico.Coahuila: near the Universityin Rob. Saltillo,King 10379 (US) A. herbacea(A. Gray)R. M. King 34 U.S.A. Texas: BrewsterCo., Chisos Mts.,Mt. & H. Rob. Emory,Yahara et al. 13 (MAK) A. isolepis(B. Rob.) R. M. King & 34 Mexico.Hidalgo: 13 km fromPachuca to El H. Rob. Chico on Hwy.105, 17 Oct. 1993, Yahara & Ito s.n. (MAK) A. rothrockii(A. Gray)R. M. King 51 U.S.A. Texas: JeffDavis Co., Old FortDavis, & H. Rob. Yaharaet al. 7 (MAK) 68 U.S.A. Texas: BrewsterCo., Chisos Mts.,Mt. Emory,9 Aug. 1991, Yaharaet al. s.n. (MAK) A. scorodonioides(A. Gray)R. M. 34 Mexico.Coahuila: