松墨天牛和光肩星天牛染色体核型

以松墨天牛Monochamus alternatus Hope和光肩星天牛Anoplophora glabripennis Motschulsky为研究对象,以各种天牛的最适条件和最佳材料进行染色体的制备和观察。试验结果如下:松墨天牛的最佳试验材料为7日龄蛹的精巢或卵巢,染色体数目2n=20,性别决定机制为Xyp,有大型染色体5对,中型染色体4对,性染色体在其大小排列中位于最末位,为中型染色体,染色体组式为5L+4M+Xyp;光肩星天牛的最佳试验材料为初羽化成虫的精巢或卵巢,染色体数目2n=20,性别决定机制为Xyp,有大型染色体6对,中型染色体3对,性染色体在其大小排列中位于最末位,但也为中型染色体,染色体组式:6L+3M+Xyp。     

雏蝗属黑翅亚属两种雏蝗染色体核型的比较研究

采用常规染色体制片方法,对雏蝗属黑翅亚属的黑翅雏蝗(Chorthippus(Megaulacobothrus)aethalinus(Zub.))和中华雏蝗(Ch.(M.)chinensis Tarb.)的染色体核型进行了分析比较,结果表明,两种雏蝗的染色体数目均为2n(♂)=17=16+XO;常染色体为中部着丝粒(m,6条)和端部着丝粒(t,10条)两种类型,性染色体类型为端部着丝粒,二者的相似性显示出该属的基本特征。但两种雏蝗的核型公式和染色体的相对长度组成则不相同,黑翅雏蝗K(2n,♂)=6m+11t=6L+6M+4S+XO;中华雏蝗K(2n,♂)=6m+11t=6L+8M+2S+XO。而且,二种雏蝗的性染色体位次及相对长度也有明显差异:黑翅雏蝗的性染色体位于第五位,相对长度为8.33%,而中华雏蝗的则位于第八位,相对长度为5.53%。由此看出,二种雏蝗不同物种间存在的不同遗传特征。     

桑属（Morus L.）3个种的核型分析

采用火焰干燥涂片法制备染色体标本。对桑属(Morus L.)的广东桑(M. atropurpurea Roxb.)、鲁桑(M. muticaulis Perr.)、瑞穗桑(M. mizuho Hotta.)进行了核型分析。结果表明,广东桑、鲁桑的核型公式是2n=2x=28=24m+4sm,瑞穗桑的核型公式是2n=2x=28=26m+2sm。广东桑与鲁桑的核型相近,可归为同一类,而瑞穗桑核型与之不同。     

条叶车前和小车前的核型报道

本文报道了车前属两种车前的核型。Plantago lessingii为2n＝12,核型属于“2A”,核型公式为K(2n)＝12＝10m+2sm;P. mmuta为2n＝12,核型仍属“2A”型,核型公式K(2n)＝12＝8m+2sm+2st。染色体相对长度组成,前者2n＝2L+4M2+4M1+2S1,后为2n＝6M2+6M1,染色体总长分别为30.60、29.80,由12条染色体组成,还测量了这两种车前的染色体体积。     

大戟科野桐属4种6个居群的核型研究

采用常规压片法对大戟科野桐属4种(含变种)6个居群进行了体细胞染色体数目和核型研究。研究结果显示其染色体数目为2n=22或2n=44,核型均为1A。核型公式分别为:绒毛野桐2n=4x=44m;白背叶2n=20m 2sm或2n=2x=22m或2n=20m(2sat) 2sm;广西白背叶2n=2x=22m;毛桐2n=2x=22m。其中白背叶[Mallotus apelta(Lour.)Muell.-Arg.]、广西白背叶[M.apelta(Lour.)Muell.-Arg.var.kwangsiensisMetic.]和毛桐[M.barbatus(Wall.)Muell.-Arg.]的染色体数目和核型均为首次报道。根据野桐属细胞分类学资料推测,多倍化和异基数变异是野桐属属内物种形成的重要方式。     

雏蝗属与异爪蝗属二个近缘属蝗虫的染色体核型比较（直翅目：网翅蝗科）

采用常规染色体制片方法,对雏蝗属的模式种白边雏蝗Chorthippus albomarginatus(De Geer)和异爪蝗属的模式种素色异爪蝗Euchorthippus unicolor(Ikonnikov)的染色体核型进行了分析比较。结果表明,两种蝗虫的染色体数目均为2n(♂)=17=16+XO;常染色体为中部着丝粒(m,6条)和端部着丝粒(t,10条)两种类型,性染色体类型为端部着丝粒。二者的相似性显示出2属具有较近的亲缘关系,并且在进化过程中处于较近的发展阶段。但2种蝗虫的核型公式和染色体的相对长度组成则不相同,白边雏蝗K(2n,♂)=6m+11t=8L+4M+4S+XO;素色异爪蝗K(2n,♂)=6m+11t=8L+6M+2S+XO;且2种蝗虫性染色体的位次也有明显差别,白边雏蝗的性染色体为第9位,而素色异爪蝗则为第8位。由此看出,该2属的蝗虫存在的不同遗传特征。     

绒毛白蜡的核型分析

应用根尖压片法对木樨科白蜡属绒毛白蜡(Fraxinus velutina)的染色体数目和核型进行了研究。结果表明:绒毛白蜡体细胞染色体数目为2n=22,核型公式为:K(2n)=22=20m+2 sm,属于"1A"类型。染色体相对长度组成为2n=22=4L+10M₂+8M₁。     

青海四种雏蝗染色体核型的比较分析

采用常规染色体制片方法对雏蝗属的褐色雏蝗Chorthippusbrunneus(Thunb .) ,异色雏蝗C .big uttulus(Linnaeus) ,小翅雏蝗C .fallax(Zub .) ,青藏雏蝗C .qingzangensis(Ying)的染色体核型进行分析 ,结果 :染色体数目均为 2n(♂ ) =1 7=1 6+XO ;常染色体类型为两类 ,中着丝点染色体 (m ,6条 )和端着丝点染色体 (T ,1 0条 ) ;性染色体类型为端着丝点。褐色雏蝗、异色雏蝗和青藏雏蝗的核型公式和染色体的相对长度组成为K( 2n ,♂ ) =1 7=6m +1 1T =6L +6M +4S +XO ,K( 2n ,♀ ) =1 8=6m +1 2T =6L +6M +4S +XX ;小翅雏蝗的为K( 2n,♂ ) =1 7=6m +1 1T =6L +4M +6S +XO ,K( 2n ,♀ ) =1 8=6m +1 2T =6L +4M +6S+XX。褐色雏蝗性染色体中部有次缢痕。染色体臂数 4种均为NF =2 3(♂ ) ,2 4 (♀ )。     

风毛菊属5种植物的核型分析

采用常规压片法,对风毛菊属(Saussurea)5种植物的染色体数目和核型类型进行分析。结果表明:大耳叶风毛菊(S.macrota)核型公式为2n=2x=26=10m+12sm+4st,属2A型;长梗风毛菊(S.dolichopoda)核型公式为2n=2x=26=14m+8sm+4st,属2A型;川陕风毛菊(S.licentiana)核型公式为2n=2x=28=12m+16sm,属2B型;杨叶风毛菊(S.populifolia)核型公式为2n=2x=28=6m+18sm+4st,属2B型;尾叶风毛菊(S.caudata)核型公式为2n=2x=30=14m+14sm+2st,属2A型。这5种风毛菊属植物中,除大耳叶风毛菊染色体数目和核型类型与前人报道的一致外,其余4种植物的染色体数目和核型类型均为首次报道,并在川陕风毛菊中发现1对B染色体。     

葱属粗根组5种材料的核型研究

本文分析了葱属Allium粗根组Sect．Bromatorrhiza Ekberg五群材料的核型。多星韭Allium wallichii Kunth有两个类型：第一类型是二倍体,染色体组公式为AA,核型公式为K(2n)=2X=14=2m(SAT)+2m+10sm,属2A型;第二类型是同源四倍体,染色体组公式为AAAA, 核型公式为K(2n)＝4X＝28＝2m(SAT)+6m十20sm,属2A型。宽叶韭Allium hookeri Thwaites有三个类型： 第一类型是双基数同源异源三倍体,染色体组公式为AAB1,核型公式为 K(2n)＝2X+ x'＝22＝(12sm+2t)十(1m十45m+1st+2t), 属3A型; 第二类型也是双基数同源异源三倍体,能配对的两个染色体组染色体大小和形态与第一类型大体相似,不能配对的一个染色体组染色体大小和形态与第一类型有明显区别,其中至少有两条染色体发生了罗伯逊易位,出现一条很大的染色体和一条很小的染色体,染色体组公式为AAB2,核型公式为K(2n)=2x+x'＝22=(12sm+2t)+ (3m+1sm十2st+2t),属3A型;第三类型相当于第一类型染色体的自然加倍,是双基数同源异源六倍体,染色体组公式为AAAAB1B1,核型公式为K(2n)=4X十2x'＝44＝(24sm+4t)十(2m+ 8sm十2st+4t),属3A型。     

臭鼩染色体的研究

本文采用骨髓染色体制片法,对捕自我国浙江萧山市的臭鼩进行了组型、G-带、C-带和核仁组织区银染的观察分析。结果表明,我国臭鼩染色体数目为2n=40,组型为8(m)+2(sm)+10(st)+18(t),性染色体为,(?):X(m或sm),Y(m或sm);♀:XX(m或sm)。G-带较为丰富,每一对染色体都有其特定的带型,较易于辨别与配对。在C-带方前,4对中间着丝粒染色体与5对亚端着丝粒染色体均具有不同程度的着丝粒带,1对亚中着丝粒染色体与9对端着丝粒染色体缺乏C-带物质,性染色体具丰富的远端带及中间带.银染的结果显示,第5、12和13对染色体具银染物质。     

Chromosomal polymorphism of Rattus rattus (Linnaeus, 1758) (rodentia: muridae) in Central Anatolia

In this study, conventionally stained, C- and Ag-NOR banded karyotypes of Rattus rattus from Central Anatolia are presented. The karyotype of the specimens from Ankara and (Cankiri provinces consist of 2n = 38, NF = 60 and NFa = 58 while the karyotype of Kirikkale specimens consist of 2n = 38 and NFa = 59 due to a heteromorphic autosome pair. The X is a large to medium sized acrocentric and the Y chromosome is a small acrocentric in all examined specimens. Constitutive heterochromatin is located in the centromeric regions of all pairs of autosomes and the X chromosome. Nucleolar organizer regions (NORs) are located only in 3 autosome pairs.     

Evolution of diploid chromosome number,sex‐determining systems,and heterochromatin in Western Mediterranean and Canarian species of the genus Pimelia (Coleoptera: Tenebrionidae)

A compilation of the diploid chromosome numbers and karyotype formulae of 30 species of the genus Pimelia from Morocco, Iberian Peninsula, Balearic and Canary Islands is presented. All species show a conservation of diploid numbers and karyotype formulae 2n = 18 (8 + Xy_p) except for Pimelia cribra, Pimelia elevata, and Pimelia interjecta 2n = 20 (9 + Xy_p) and Pimelia sparsa sparsa 2n = 18 (8 + neoXY). The ancestral state for the genus Pimelia is suggested to be 2n = 18 (8 + Xy_p) in accordance with a previously described phylogeny of these species based on mitochondrial and nuclear DNA. The derived state 2n = 20 (9 + Xy_p) is present in a monophyletic clade, which originated about 2.5–5 Mya. The male meiotic formula 8 + neoXY found in P. sparsa sparsa seems to have originated by the reorganization of the Xy_p pair resulting in two homomorphic sexual chromosomes and the lost of most of the heterochromatin from the former X chromosome. In all chromosomes C‐banding revealed conspicuous pericentromeric heterochromatic blocks, except in the Y chromosome in most of the species, and in situ hybridization of satellite DNA probes revealed the correspondence between heterochromatin and satellite DNA. Finally, the possible role of heterochromatin and satellite DNA is discussed in relation to the uniformity of the Tenebrionidae α‐karyology.     

中国刺猬的染色体研究

本文采用全血培养和骨髓染色体制片法,对分布于我国南京市郊和济南市郊的刺猬染色体进行了组型、C-带、G-带和银染色的观察分析,并与东欧、西欧两种刺猬比较,它们之间的核型及带型差异显著;又将南京、济南及金清波(1985)报道的河南新乡三地分布的刺猬进行比较,它们的核型及带型也显示出一定差异,这种多态性在分类和进化上有一定的意义。     

Comparative karyology of seven species of staphylinoid beetles (Polyphaga: Coleoptera)

The morphology of chromosomes of two species of Silphidae and five species of Staphylinidae and the behaviour of chromosomes in mitosis and meiosis were studied. These staphylinoid beetles did not exhibit a modal karyotype. However, Xy_p was found to be the most common male sex-chromosome mechanism althoughPhilonthus varius andQuedius fuliginosus possessed XO. Dicentric chromosomes were found inPhilonthus fuscipennis. Dicentrics were also found in both European and one East Siberian populations ofPhosphuga atrata.In the seven species, the diploid chromosome number ranged from 2n=24 to 2n=56. The evolution of karyotype and the interrelationships between species are dicussed.     

C-banding and non-homologous associations

A chromosome complement formed by 16 autosomes and an Xy_p sex chromosome system was found in Epilachna paenulata Germar (Coleoptera: Coccinellidae). All autosomes were metacentric except pair 1 which was submetacentric. The X and the Y chromosomes were also submetacentric but the Y was minute. The whole chromosome set carried large paracentric heterochromatic C-segments representing about 15% of the haploid complement length. Heterochromatic segments associated progressively during early meiotic stages forming a large single chromocenter. After C-banding, chromocenters revealed an inner networklike filamentous structure. Starlike chromosome configurations resulted from the attachment of bivalents to the chromocenters. These associations were followed until early diakinesis. Thin remnant filaments were also observed connecting metaphase I chromosomes. Evidence is presented that, in this species, the Xy_p bivalent resulted from an end-to-end association of the long arms of the sex chromosomes. The parachute Xy_p bivalent appeared to be composed of three distinct segments: two intensely heterochromatic C-banded corpuscles formed the canopy and a V-shaped euchromatic filament connecting them represented the parachutist component. The triple constitution of the sex bivalent was interpreted as follows: each heterochromatic corpuscle corresponded to the paracentric C-segment of the X and Y chromosomes; the euchromatic filament represented mainly the long arm of the X chromosome terminally associated with the long arm of the Y chromosome. The complete sequence of the formation of the Xy_p bivalent starting from nonassociated sex chromosomes in early meiotic stages, and progressing through pairing of heterochromatic segments, coiling of the euchromatic filament, and movement of the heterochromatic corpuscles to opposite poles is described. These findings suggest that in E. paenulata the Xy_p sex bivalent formation is different than in other coleopteran species and that constitutive heterochromatic segments play an important role not only in chromosome associations but also in the Xy_p formation.     

High chromosomal polymorphism and heterozygosity in Cyclocephala tridentata from Guadeloupe: chromosome comparison with some other species of Dynastinae (Coleoptera: Scarabaeidae)

Very distinct karyotypes have been observed in two Cyclocephala species from Guadeloupe, considered as very close and possibly vicariant: C. insulicola with only metacentric and C. tridentata tridentata with many acrocentric autosomes. This prompted us to study the karyotype of a few other neotropical Dynastinae belonging to four of the eight existing tribes, to find out which one of these two species had the most divergent chromosomes from their ancestral condition. In the four additional species studied, i.e., Cyclocephalamaffafa, Strategus syphax, Ligyrus cuniculus and Megasoma actaeon, a karyotype composed of 20 chromosomes, including 18 meta- or submetacentric autosomes was found, as it was in C. insulicola. Thus, the karyotype of C. t. tridentata, in which most of the 18 autosomes were acrocentric, is apomorphic. In addition, it was highly polymorphic, with six different karyotypes observed among the ten specimens studied. All had one to four heterozygous chromosome pairs formed by one acrocentric and one submetacentric carrying a large juxta-centromeric heterochromatic component. This heterozygosity did not seem to impair either meiotic synapsis or chiasma formation and chromosome segregation. Such high rates of chromosome heterozygosity and polymorphism are infrequent and never described in beetles. This suggests that C. t. tridentata undergoes an active process of chromosome evolution. A possible relationship with insularity and/or pesticide exposure is briefly discussed.     

Mauritius type black rats with peculiar karyotypes derived from robertsonian fission of small metacentrics

All seventeen black rats collected from Mauritius Island were characterized by having many extra small acrocentric autosomes. Their basic karyotype was of Oceanian type, because of the presence of the large metacentric M₁ and M₂ pairs, but chromosome numbers in 13 specimens among them were 42, those of 3 specimens 43, and those of the remaining one specimen 44. Although the Oceanian type rat had 2 small acrocentric autosomes (pair no. 13), 16 Mauritius rats had 10 small acrocentrics, and the remaining one had 8 small acrocentrics. Comparative karyotype analysis between Oceanian and Mauritius type rats showed that the extra small acrocentrics found in Mauritius rats were due to Robertsonian fission of small metacentric pairs no. 14 and 18 of the original Oceanian type rat. Only one rat with 8 small acrocentrics showed the heteromorphic pair no. 18 consisting of one metacentric and two acrocentrics. The large metacentric M₁ chromosome in 13 of 17 rats examined showed homologous pair, but two of them were heteromorphic by involving one metacentric M₁ and two acrocentrics. In the remaining two rats M₁ chromosome was not observed, but acrocentric pairs no. 4 and 7 were included. These acrocentrics were also suggested to be originated from Robertsonian fission of the large metacentric M₁ chromosome. Robertsonian fission seemed to be one of the important mechanism found in karyotype evolution.     

Report on Karyotypes of Smilacina tatsienensis and Ophiopogon japonicus

In the present paper the karyotypes of Smilacina tatsienensis (Franch.) Wang et Tang and Ophiopogon japonicus (L. f.) Ker.- Gawl. in Sichuan were analysed. The karyotypes of the two species are reported for the first time. The results are shown as follows. Smilacina tatsienensis (Franch.) Wang et Tang is a dipoiid. Its karyotype formula is 2n=2x=36=16m+10sm+10st(4SAT) (Plate 1: Fig. 1, 3). The karyotype is bimodal with ten large and eight small chromosome pairs and the length ratio of the tenth pair to the eleventh being 1.33. The length ratio of the largest chromosome and the smallest one is 4.33. Ophiopogon japonicus (L.f.) Ker.-Gawl. is a mixoploid, with diploid, triploid and tetraploid cells in a single plant. The karyotype formula of the diploid is 2n=2x=36=18m (4SAT)+18sm(Plate 1: Fig. 2, 4). The species is of a bimodal karyotype with eight large and ten small chromosome pairs and the length ratio to the eighth pair and the ninth being 1.10.There are nine metacentric pairs (two pairs of sat-chromosomes) and nine submetacentric pairs.