A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae)

KONDO, K. & LAVARACK, P. S., 1984. A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae). Karyomorphological comparisons of 15 species of Australian Drosera are presented along with 11 new chromosome counts. In Australia the genus forms an extensive aneuploid series. The species which have chromosome numbers from n =10 to n = 19 show large chromosomes, while those which have chromosome numbers more than 20 show small chromosomes. Drosera paleacca shows the lowest chromosome number in the genus, 2 n = 10, with 10 large chromosomes, indicating a new basic number, x = 5. The non-staining gap between the chromatids of each chromosome is rather wide and their centromeric region is not seen throughout prophase, prometaphase, and metaphase. The C-banding and silver-staining analyses in Drosera petiolaris chromosomes suggest that Drosera chromosomes could have diffuse centromeres and simplified C-segments. Some taxonomic implications are considered, notably the possible removal of Drosera banksii from Drosera section Ergaleium to Drosera section Lasiocephala and the reduction to synonymy of Drosera section Prolifera .     

国产８种蜘蛛抱属植物的核型研究

首次报道了８种蜘蛛抱属植物的核型,其中６种的染色体数目为首次报道,结果如下：峨边蜘蛛抱蛋Ａ.ebianensis,2n=2x=36=18m 2sm(2sat) 16st;盈江蜘蛛抱蛋Ａ．yingjiangensis,2n=2x=36=14m 6sm(2sat) 16st;海南蜘蛛抱蛋Ａ．hainensis,2n=2x=36=20m(2sat) 14st 2t;石山蜘蛛抱蛋Ａ.saxicola,2n=2x=36=16m 4sm(2sat) 16st;要蜘蛛抱蛋白Ａ.muricata,2n=2x=36=18m 2sm(2sat) 16st);啮边蛛抱蛋Ａ.marginella,2n=2x=38=22m 4sm(2sat) 12st;西林蜘蛛抱蛋Ａ.xillinensis,2n=4x=76=48m(4sat) 2sm 26st;十字蜘蛛抱蛋A.cruciformis,2n=4x=76=46m(4sat) 12sm 18st。核型类型都为２Ｃ型。首次在中国发现了Ａ.cruciformis和A.xilinensis的野生四倍体。根据外部形态性及已有的３８种植物的核型资料分析,认为该属染色体的原始基数可能为x=18,核型向对称性增强的方向演化,其主要表现在中部着丝粒染色体数目的增多,这种演化趋似与其花部结构的进化密切相关。     

国产8种蜘蛛抱蛋属植物的核型研究

首次报道了8种蜘蛛抱蛋属植物的核型,其中6种的染色体数目为首次报道。结果如下：峨边蜘蛛抱蛋A．ebianensis,2n=2x=36=18m+2sm(2sat)十16st;盈江蜘蛛抱蛋A．yingjiangensis,2n=2x=36=14m+6sm(2sat)十16st;海南蜘蛛抱蛋A．hainanensis,2n=2x=36=20m(2sat)十14st十2t;石山蜘蛛抱蛋A．saxicola,2n=2x=36=16m十4sm(2sat)十16st;糙果蜘蛛抱蛋A．muricata,2n=2x=36=18m+2sm(2sat)十16st;啮边蜘蛛抱蛋A．marginella,2n=2x=38=22m+4sm(2sat)十12st;西林蜘蛛抱蛋A．xilin-ensis,2n=4x=76=48m(4sat)十2sm+26st;十字蜘蛛抱蛋A．cruciformis,2n=4x=76=46m(4sat)十12sm十18st。核型类型都为2C型。首次在中国发现了A．cruciformis和A．xilinensis的野生四倍体。根据外部形态性状及已有的38种植物的核型资料分析,认为该属染色体的原始基数可能为x=18,核型向对称性增强的方向演化,其主要表现在中部着丝粒染色体数目的增多,这种演化趋势似与其花部结构的进化密切相关。关键词 蜘蛛抱蛋属;染色体数目;核型;进化     

醉鱼草属四个种的核型分析

报道了醉鱼草属（Btuldleja）4个种的染色体核型。云南醉鱼草（B.yunnanensis）的核型公式为2n=2x=38=22m＋16sm,皱叶醉鱼草（B．crispa）为2n=2x=38=26m＋10sm＋2st,密蒙花（B．officinalis）为2n=2x=38=20m＋16sm＋2st,口本醉鱼草（B．japonica）为2n=2x=38=20m＋16sm＋2st。日本醉鱼草的核型为2B型,其它3个种的核型为2A型。根据核型分析结果,结合形态学特征和已有的细胞学资料,初步讨论了醉鱼草组（Sect．Neemda）两个系（Series）可能的演化关系。     

Karyotype of Four Species in Buddleja ( Loganiaceae) *

The chromosome numbers and karyotypes of the 4 species in genus Buddleja were reported. The karyotype formulas are 2n= 2x= 38= 22m+ 16sm ( B1 yunnanensis) , 2n= 2x= 38= 26m+ 10sm+ 2st ( B1 crispa) , 2n= 2x= 38= 20m+ 16sm + 2st ( B1 off icinalis ) , and 2n= 2x= 38= 20m+ 16sm+ 2st ( B1japonica) . Karyotype of B1japonica belongs to Stebbins. s 2B type and other 3 species belong to Stebbins. s 2A type. Based on the cytological data ( karyotypes and the recorded chromosome numbers) and the species morphologies, the evolution trend of the two series in Sect1Neemda was briefly discussed.     

国产毛茛属植物五种一变种的核型

对国产6种毛茛属(Ranunculus)植物进行了核型研究。它们的核型公式分别为:扇叶毛茛2n=4x=32=12m 20sm,云生毛茛2n=4x=32=16m 10sm 6st,曲升毛茛2n=4x=32=14m 16sm 2st及2n=5x=40=18m 16sm 4st 2T,西南毛茛2n=2x=16=12m 2sm 2st,匍枝毛茛2n=2x=16=8m 8st及2n=4x=32=12m 4sm 14st 2t,棱喙毛茛2n=2x=16=6m 6sm 4st。并结合形态及孢粉的资料就毛茛属植物核型不对称系数对分类的意义进行分析。     

横断山区伞形科4种7个居群植物的核型研究

对横断山区伞形科棱子芹属2种植物(松潘棱子芹Pleurospermum franchetianumHemsl.和西藏棱子芹Pleurospermum hookeriC.B.Clarke var.thomsoniiC.B.Clarke)和茴芹属2种植物(异叶茴芹Pimpinella diversi-foliaDC.和锐叶茴芹Pimpinella argutaDiels)共7个居群进行体细胞染色体数目观察和核型比较分析,结果表明,棱子芹属和茴芹属植物属内种间染色体基数存在差异,其中松潘棱子芹为2n=2x=18=16sm 2st,西藏棱子芹为2n=2x=22=16m 6sm;茴芹属光果组中锐叶茴芹为2n=2x=22=22m,毛果组中异叶茴芹为2n=18=18st或2n=18=2sm 16st.松潘棱子芹、西藏棱子芹、锐叶茴芹的染色体数目和核型均为首次报道,从而为棱子芹属和茴芹属的分类和演化研究提供细胞学依据.     

Chromosome evolution in the genus Mikania (Compositae)

Karyotypic analysis of ten species of the genus Mikania was carried out using Feulgen staining. Species belonging to the following sections were analyzed: Section Thyrsigerae containing M. additicia (2n = 34), M. hemisphaerica, M. lanuginosa, and M. punctata (2n = 36), and Mikania sericea (2n = 42), which adds a new basic chromosome number (x = 21) to the genus and to the tribe Eupatorieae; Section Corymbosae with M. hastato-cordata (2n = 34) and M. involucrata and M. microptera with 2n = 36 chromosomes; Section Spicato-Racemosae with M. sessilifolia, with 2n = 108 chromosomes. One unidentified species with 2n = 34 chromosomes was also analyzed. All the species studied show one large pair of chromosomes with a secondary constriction in the middle region of the long arm. The morphology of this chromosome suggests that it can be considered as a cytological marker for the genus. Because of the distinctive inflorescence types found in the genus Mikania and the high frequency of species with x = 18, a correlation between morphological and chromosomal evolution is discussed. The present study suggests that the basic original chromosome number for the genus is x = 18, from which the others (x = 17, 19, 20, 21) have been derived by aneuploidy to form the observed aneuploid series.     

Variation in chromosome numbers, CMA bands and 45S rDNA sites in species of Selaginella (Pteridophyta)

BACKGROUND AND AIMS: Selaginella is the largest genus of heterosporous pteridophytes, but karyologically the genus is known only by the occurrence of a dysploid series of n=7-12, and a low frequency of polyploids. Aiming to contribute to a better understanding of the structural chromosomal variability of this genus, different staining methods were applied in species with different chromosome numbers. METHODS: The chromosome complements of seven species of Selaginella were analysed and, in four of them, the distribution of 45S rDNA sites was determined by fluorescent in situ hybridization. Additionally, CMA/DA/DAPI and silver nitrate staining were performed to investigate the correlation between the 45S rDNA sites, the heterochromatic bands and the number of active rDNA sites. KEY RESULTS: The chromosome numbers observed were 2n=18, 20 and 24. The species with 2n=20 exhibited chromosome complement sizes smaller and less variable than those with 2n=18. The only species with 2n=24, S. convoluta, had relatively large and asymmetrical chromosomes. The interphase nuclei in all species were of the chromocentric type. CMA/DA/DAPI staining showed only a weak chromosomal differentiation of heterochromatic bands. In S. willdenowii and S. convoluta eight and six CMA+ bands were observed, respectively, but no DAPI+ bands. The CMA+ bands corresponded in number, size and location to the rDNA sites. In general, the number of rDNA sites correlated with the maximum number of nucleoli per nucleus. Ten rDNA sites were found in S. plana (2n=20), eight in S. willdenowii (2n=18), six in S. convoluta (2n=24) and two in S. producta (2n=20). CONCLUSIONS: The remarkable variation in chromosome size and number and rDNA sites shows that dramatic karyological changes have occurred during the evolution of the genus at the diploid level. These data further suggest that the two putative basic numbers of the genus, x=9 and x=10, may have arisen two or more times independently.     

Karyotypes of eight species of Euphorbia L. (Euphorbiaceae) from China

In this paper, eight species of the genus Euphorbia L. were cytologically studied. The three species of the subgenus Chamaesyce Raf., E. hirta, E. humifusa and E. hypericifolia, had chromosome numbers of 2n = 18, 22 and 32, with their basic chromosome numbers being x = 9, 11 and 8 respectively. The two species of the subgenus Poinsettia (Grah.) House. E. dentata, with 2n=28, a tetraploid, and E. cyathophora, with 2n= 56, a octoploid, had both the basic chromosome number of x= 7. The three species of the subgenus Esula Pers, E. lathyris, E. helioscopia and E. hylonoma, had chromosome number of 2n= 20, 42 and 20, with their basic numbers being x= 10, 7 and 10 respectively. The basic chromosome number of x = 8 is new for E. hypericifolia, in which x = 7 was previously reported. This indicates that this species had both ploidy(2n = 4x = 28, 8x = 56) and dysploidy(x = 7, 8) variations. In E. dentata, there occurred also ploidy variation (2n = 2x, 4x and 8x). A tetraploid cytotype of E. esula was found in China, its diploid cytotype and hexaploid cytotype being previously reported in North America, the Iberian Peninsula and some other European areas. Based on our results and those previously reported, we support the viewpoint that x＝10 may be the original basic chromosome number of Euphorbiaand discuss the role of polyploidy and dysploidy in the speciation and evolution of this genus     

10种菊科花卉的染色体观察

作者对10种菊科花卉进行了染色体数目的观察,并对其中8种进行了核型分析。结果如下:翠菊(Callistephus chinensis Nees) 2n=18=18m (4SAT);麦秆菊(Helichrysum bracteatum Andr.)2n=24=18m+6sm;蛇目菊(Coreopsis tinctoria Nutt.) 2n=24=16m+8sm (2SAT);黑心菊(Rudbechia hirta L.) 2n=76;肿柄菊(Tithonia diversifolia A. Gray) 2n=34=24m(4SAT)+10sm (2SAT);大丽花(Dahlia pinnata Cav.) 2n=64;硫华菊(Cosmos sulphureus Cav.) 2n=24=2sm+22st;万寿菊(Tagetes erecta L.) 2n=24=6sm+16st(2SAT)+2t;天人菊(Gaillardia pulchella Foug.) 2n=34=22m+12sm;矢车菊(Centaurea cyanus L.) 2n=24=2sm+16st+6t(2SAT)。     

A cytological study ofPelargonium sect.Eumorpha (Geraniaceae)

The chromosome numbers of seven species ofPelargonium sect.Eumorpha have been determined from material of known wild origin, and karyotypic comparisons have been made. Within the section there is variation in basic chromosome number (x = 4, 8, 9, 11), variation in chromosome size, and two species have polyploid races. The three species with chromosome numbers based on x = 11 have the smallest chromosomes (1.0–1.5 µm); chromosomes are larger (1.0–3.0 µm) in the other species.P. elongatum has the lowest chromosome number in the genus (2n = 8).P. alchemilloides is exceptional in that it has four cytotypes, 2n = 16, 18, 34 and 36, and the form with 2n = 36 has large chromosomes (2.0–5.0 µm). Evidence from a synthesized hybrid suggests thatP. alchemilloides with 2n = 16 may be of polyploid origin. The three species based on x = 11 appear to be more closely related to species from other sections ofPelargonium that have the same basic chromosome number and small chromosome size, rather than to other species of sect.Eumorpha.     

新疆猪毛菜属4种植物核型分析及进化研究

采用常规压片法,对钠猪毛菜、准噶尔猪毛菜、小药猪毛菜和薄翅猪毛菜等4种新疆猪毛菜属植物的染色体核型进行了分析,并对已报道的12种新疆猪毛菜属植物核型进行了比较.结果表明:(1)钠猪毛菜体细胞染色体数2n=2x=18=12m+6sm,准噶尔猪毛菜、小药猪毛菜体细胞染色体数为2n=2x=18=18m,该3种均属于1A型;薄翅猪毛菜体细胞染色体数为2n=2x=54=50m+2sm+2st,属2A型;(2)12种新疆猪毛菜属植物核型比较结果证明,猪毛菜属植物的染色体基数为9,钠猪毛菜、准噶尔猪毛菜和小药猪毛菜均为二倍体,薄翅猪毛菜为六倍体,钠猪毛菜和准噶尔猪毛菜具有随体.准噶尔猪毛菜、小药猪毛菜、薄翅猪毛菜属植物的核型均属于首次报道.     

百合科开口箭属六个种的核型研究

本文报道了开口箭属(Tupistra)6个种的核型,发现6个种皆为二倍体,染色体数目为38。他们的核型公式是:弯蕊开口箭(T. wattii)为2n=2x=38=38m;长梗开口箭(T. longipeduncuJara)为2n=2x=38=28m 10sm;橙花开口箭(T. aurantiaca)为2n=2x=38=22m 16sm;开口箭(T. chinensis)和云南开口箭(T. yunnanensis)皆为2n=2x=38=24m 14sm,核型皆为2B型,但sm染色体的位置有所不同;伞柱开口箭(T. fungilliformis)为2n=2x=38=18m 2sm 12st 6t。前述5个种的核型由一型染色体组成,而伞柱开口箭的核型由二型染色体组成。开口箭属和蜘蛛抱蛋属(Aspisdistra)是亲缘关系接近的两个属,伞柱开口箭是开口箭属和蜘蛛抱蛋属之间的一个过渡类群。     

基于染色体计数和ITS序列初步探讨横断山区柴胡属植物(伞形科)的系统发育

横断山区是中国柴胡属Bupleurum植物的分布中心。本文对横断山区6个种2变种进行了染色体记数报道,其中4个种2变种是首次报道。对横断山区的10个种4个变种、中国北方（河北和黑龙江）的3个种的nrDNA ITS进行测序,同时从GenBank里面下载同属的来自非洲和地中海西部的16个nrDNA ITS序列数据,结合染色体数目变化结果,初步探讨了横断山区柴胡属植物的系统发育。结果表明横断山区可能是现代柴胡属植物的频度中心和多样分布中心之一。它们的祖先种可能是非洲北部的木本柴胡属植物B.fruticosum,或者是地中海西部的柴胡属植物,推测是通过中东和高加索扩散而形成的,其中与非洲南部特有种B.mundtii的亲缘关系也较近;染色体基数演化趋势是：8是较原始基数,6和7是次生基数,其染色体异基数变异和多倍化可能是物种形成、进化以及向外扩散的主要方式;在ITS系统发育树中,中国柴胡属植物染色体基数为8的种类聚为一支,染色体基数为6和7的种类聚为了一支,不支持舒璞等（1998）关于中国柴胡属的属下分类系统。结合已有的形态学、细胞学、孢粉学证据和ITS系统发育树,建议窄竹叶柴胡B.marginatum var.stenophyllum独立成种。     

Chromosome Numbers and Karyotypes of Six Oxytropis Species (Fabaceae) from the Qinghai Tibetan Plateau,China

Chromosome numbers and karyotypes of 13 populations of six Oxytropis species (Fabaceae) from the Qinghai Tibetan Plateau, China, were presented. The chromosome numbers and karyotypes in O.ochrocephala, O.tatarica, O.kansuensis and O.humifusa (2n=16) were reported for the first time. B chromosomes were found from O.stracheyana (2n=48). The basic chromosome number of x=8 is confirmed for the genus. The available chromosomal data indicate that polyploidy may have played an important role in the evolution of the genus, with the incidence of polyploidy in the genus reaching 58%. However, our results indicated that among the populations here examined only one was a hexaploid with 2n=48. Such a chromosomal pattern indicates that the karyotypic repatterning at the diploid level seems to be the predominant feature of chromosomal evolution in the Oxytropis species from the Qinghai Tibetan Plateau, and that sympatric speciation via hybridization and polyploidization has played a minor role in the species diversification of the genus from this area.     

10种菊属(Dendranthema)植物的细胞学研究

对菊属(Dendranthema)在中国分布的10种20个居群的材料进行了细胞学研究,首次报道了异色菊(2n＝18,36)、银背菊(2n＝56)、楔叶菊(2n＝18,72)的染色体数目和核型,以及蒙菊(2n＝18)的染色体数目新纪录,并结合前人的工作,分析了菊属的核型特征和演化趋势,及其与该属分类群的关系。     

国产十四种苋属植物的染色体数目

报道了国产14种苋属植物的染色体数目。部分种的染色体数目为2n=34,即反枝苋Amaranthus retroflexus,刺苋A．spinosus,红苋A．cruentus,腋花苋A．roxburghianus,合被苋A．polygonoides,皱果苋A． viridis,凹头苋A．lividus,苋A．tricolor。其他种的染色体数目为2n=32,即尾穗苋A．caudatus,绿穗苋A． hybridus,千穗谷A．hypochendriacus,繁穗苋A．paniculatus,北美苋A．blitoides,白苋A．albus。其中腋花 苋的染色体数目为首次报道。该属染色体基数为x=16,17。两种染色体基数在苋属2个组(sect．Ama- ranthus和sect．Blitopsis)中均存在。由于苋属植物染色体大多为小型染色体,因此对苋属植物目前尚不 能进行详尽的核型分析。     

锦鸡儿属3种植物的核型研究

以锦鸡儿属中间锦鸡儿、柠条锦鸡儿、狭叶锦鸡儿为材料,用光学显微镜观察了3种锦鸡儿的染色体,按全国第一次植物染色体学术讨论会建议的标准进行了核型分析。结果表明,3种锦鸡儿的体细胞染色体数目2n=16,核型公式分别为:中间锦鸡儿2n=2x=16=10m 6sm、柠条锦鸡儿2n=2x=16=12m 4sm、狭叶锦鸡儿2n=2x=16=14m 2sm,中间锦鸡儿和柠条锦鸡儿的核型属于2A型,狭叶锦鸡儿的核型属于2B型。狭叶锦鸡儿二倍体染色体核型为首次报道。     

Observations on chromosome numbers and biosystematics in Dahlia (Asteraceae, Heliantheae) with an account on the identity of D. pinnata, D. rosea, and D. coccinea

The chromosome numbers in Dahlia (Asteraceae, Heliantheae) are surveyed, and counts made on species grown in the Botanic Garden, University of Copenhagen, are given. Next a biosystematic study of species within Dahlia sect. Dahlia is presented. It is concluded that taxa with the same chromosome number can be brought to hybridize without specific barriers (some diploids possibly excepted). Based on this conclusion, it is demonstrated that the original European introduction of dahlias from Mexico consisted of two tetraploid (2n = 64) hybrids and a native, diploid (2n = 32) D. coccinea with scarlet rays. One of the hybrids was named D. pinnara which designation is consequently not applicable for the native species, currently known under that name. Instead, the new designation D. sorensenii is formally established. The other hybrid, D. rosea , is a synonym of D. pinnara .