芥蓝和结球甘蓝染色体组型及C-带带型的研究

本文用改进的染色体标本制片技术,研究了芥蓝和结球甘蓝的染色体组型和 C-带带型。两种植物的二倍体均由4对中着丝粒、5对亚中着丝粒染色体组成,其中一对为随体染色体。芥蓝和结球甘蓝具有统一的染色体组型公式:2n=18=8m+10sm(2SAT),但两者的某些染色体在编号顺序上有差异。在结球甘蓝中观察,到4种不同形态的随体。用 BSG C-带方法得到 C-带带型,带型公式,芥蓝为2n=18=CITS 型=10C+2CI_++4CT~++2CS;结球甘蓝为2n=18=CITS 型=8c+2CI_++6CT~++2CS。某些带纹具多态性和杂合性。本文从染色体水平上讨论了芥蓝与甘蓝的亲缘关系。     

Mitotic karyotypes of Brassica campestris and Brassica alboglabra and identification of the B. alboglabra chromosome in an addition line.

A Brassica campestris-alboglabra monosomic addition line (genome: AA + one chromosome from the C genome, 2n = 21) harbours the Brassica alboglabra (CC, 2n = 18) chromosome with the gene for erucic acid. In order to identify this chromosome, we have studied the mitotic prometaphase chromosomes of Brassica campestris (AA, 2n = 20), B. alboglabra, and the monosomic addition line. More pronounced differential staining and size differences of chromosomes were observed in B. campestris than in B. alboglabra. The karyotype of B. campestris was composed of four median (m), four submedian (sm), and two subterminal (st) chromosome pairs, while that of B. alboglabra was composed of three m, four sm, and two st chromosome pairs, provided that the length of the satellite was excluded when determining the arm ratio of the nucleolar chromosome. The alien chromosome from the C genome in the addition line was easily identified in the background B. campestris genome by its large size, its submedian centromere, and its differential staining pattern. When compared with the karyotype of B. alboglabra, the alien chromosome from the C genome in the monosomic addition line was revealed to be chromosome 4.     

Karyotypic characterization by mitosis, meiosis and C-banding of Eriopis connexa Mulsant (Coccinellidae: Coleoptera: Polyphaga), a predator of insect pests

Eriopis connexa presents a chromosome number of 2n = 18 + XX for most females analyzed and a meioformula of n = 9 + Xyp for all males. A small metacentric B chromosome restricted to females occurred in 10% of our sample and, when submitted to C-banding, it was shown to be almost completely euchromatic. Chromosome pairs 2 and 3 had satellites and probably contained the nucleolar organizer regions (NORs). C-band analysis also revealed that the constitutive heterochromatin was localized in the centromeres of all chromosomes in the complement.     

宜昌百合根尖染色体C-带分析

利用Giemsa C-带方法对宜昌百合（Lilium leucanthum(Baker) Baker）进行研究。结果表明：宜昌百合（L. leucanthum）的染色体数目为2n＝2x=24,单套染色体的条带总数目为21条。其带型公式为：2n＝24＝6C+2CI+2I+2CI⁺+2CI⁺+4I⁺+2I⁺+2T⁺+2I+S。宜昌百合（L. leucanthum）每条染色体上都显示出显著的特征带,且带纹的深浅差异明显。宜昌百合（L. leucanthum）的强带主要集中在着丝点及附近区域。通过Giemsa C-带方法可以将宜昌百合（L. leucanthum）的每条染色体区分开。     

Studies on the Karyotypes and Pollen Morphology of Brassica oleracea L.and B. alboglabra Bailey

The karyotypes and pollen morphology of Brassica oleracea L. and B. alboglabra Bailey were studied by preparing mitotic chromosome specimens and scanning electron microscope. The results are as follows: 1. the karyotypes of the 4 varieties in B. oleracea L. and of B. alboglabra Bailey are similar, all with the same chromosome number (2n=18) satellite number (one pair) and a type of karyotype, but different in respect to satellite position and karyotype symmetry 2. The pollengrains of 2 varieties of B. oleracea L. are 3-colporate and reticulate, distinctly different from those in B. alboglabra, which are pantoporate with smaller lumina. Based on the results we tend to regard that B. alboglabra Bailey is an independent species.     

Cytogenetic analysis of the neotropical spider Nephilengys cruentata (Araneomorphae, Tetragnathidae): standard staining nors, C-bands and base-specific fluorochromes.

The aim of this work is to characterize Nephilengys cruentata in relation to the diploid number, chromosome morphology, type of sex determination chromosome system, chromosomes bearing the Nucleolar Organizer Regions (NORs), C-banding pattern, and AT or GC repetitive sequences. The chromosome preparations were submitted to standard staining (Giemsa), NOR silver impregnation, C-banding technique, and base-specific fluorochrome staining. The analysis of the cells showed 2n = 24 and 2n = 26 chromosomes in the embryos, and 2n = 26 in the ovarian cells, being all the chromosomes acrocentric. The long arm of the pairs 1, 2 and 3 showed an extensive negative heteropycnotic area when the mitotic metaphases were stained with Giemsa. The sexual chromosomes did not show differential characteristics that allowed to distinguish them from the other chromosomes of the complement. Considering the diploid numbers found in N. cruentata and the prevalence of X1X2 sex determination chromosome system in Tetragnathidae, N. cruentata seems to possess 2n = 24 = 22 + X1X2 in the males, and 2n = 26 = 22 + X1X1X2X2 in the females. The pairs 1, 2 and 3 showed NORs which are coincident with the negative heteropycnotic patterns. Using the C-banding technique, the pericentromeric region of the chromosomes revealed small quantity or even absence of constitutive heterochromatin, differing of the C-banding pattern described in other species of spiders. In N. cruentata the fluorochromes DAPI/DA, DAPI/MM and CMA3/DA revealed that the constitutive heterochromatin is rich in AT bases and the NORs possess repetitive sequences of GC bases.     

Karyological Studies in Cunninchamia unicanaliculata and var. pyramidalis

Cunnighamia unicanaliculata D. Y. Wang et H. L. Liu and var. pyramidalis D. Y. Wang et H. L. Lin, two new taxa recently found in south-western Sichuan Province of China, have both a very restricted yet sympatric geographical distribution, including Dechang and Miyi districts.[7] There is a debate as regards the specific status of C. unicanaliculata. A comparative karyological investigation, including chromosome numbers, karyotype analyses and measurements of nuclear volume and DNA contents, was under- taken in order to shed some light on the phylogenetic relationships between these taxa and C. lanceolata (Lamb.) Hook. The kaxyotype formulas of the above two taxa and C. lanceolata are as follows: C.unicanaliculata; K(2n) = 22 =L8m+ S12m+S2sm; C. unicanaliculata var. pyramidalis: K(2n)= 22= L8m +S10m+S4sm; C. lanceolata (Type A): K(2n) =22 = Lsm+ S14m S2sm; C. lanceolata(TypeB): K(2n) = 22 = L8m + S14m . Frown the above karyotypes, we have found that C. unicanaliculata and var. pyrami- dalis, which are very similar to each other, are closely related to C. lanceolata (Type B), but seem more strongly differentiated in the following respects: (1) the former posses- sing 1--2 pairs of chromosomes with submedian primary constrictions each, while the latter with all chromosomes possessing median primary constrictions; (2) the satellites of the former being always located on the 4th pair of chromosomes, whereas the position of satellites of the latter varying with geographical distribution, being usually on the 1st and 4th pairs of chromosomes; (3) B-chromosomes being present in the latter (predominantly in the geographical races of southwestern China) but not seen in the former; (4) the average chromosome volume of C. unicanaliculata var. pyramidalis being 623.44, while those of the four geographical races of C. lanceolata being 667.2–796.0; (5) the comparative DNA amount of C. unicanaliculata var. pyramidalis being 5.54, while those of the various geographical races of C. lanceolata being 6.20–7.67. Upon an overall comparison of the data with regard to karyology, geographical distribution, ecology, morphology and isoenzymic patterns of the taxa in question, we come to the following conclusions. Cunninghamia unicanaliculata and var. pyramidalis are most likely taxa originated from natural populations of C. lanceolata. The extreme environmental conditions of the habitats axe thought to have played an important role in the production of these two new taxa. An elevation of over 2000 meters and the periodical aridity of climate of the habitat, which differed remarkably from those of C. lanceolata, made possible the isolation of alternative populations, accompanied by selection for adaptation to extreme environments. But the differences between these two newly found taxa and C. lanceolata are karyologically minor and morphologically quantitative and tend to display a more or less continuous variation pattern. It is, therefore, suggested that they are probably geographical races or ecotypes of C. lanceolata, and are not distinct enough from the latter to warrant specific status. It seems best to treat both C. unicanaliculata and var. pyramidalis as infraspecific catorories of C. lanceolata.     

大白菜与紫甘蓝种间杂种的获得与鉴定

以不同类型的大白菜与紫甘蓝为材料,运用蕾期授粉结合胚挽救技术获得大白菜与紫甘蓝的种间杂种,并对其进行细胞学鉴定.结果表明,大白菜与紫甘蓝杂交,获得了57株F1代幼苗;对根尖染色体数量进行观察和杂种花粉特性调查发现,其中47株具有预期的染色体数目,2n =19,鉴定为真杂种,其花粉败育;另有6株具有38条染色体,鉴定为种间异源双二倍体,应该是发生了染色体自然加倍,其花粉可育.可育的杂种F1代与大白菜回交,获得了大白菜-紫甘蓝BC1代材料.田间观测结果显示,杂种F1代植株综合性状均介于双亲之间,BC1代植株包球明显,综合性状偏向母本大白菜.     

Report on Karyotypes of 10 Species of Liliaceae (s. l.) From Qinling Range

The karyotypes of 10 species of the Liliaceae from the Qinling Range are reported as follows. I. Polygonatum Mill. (1) P. odoratum ( Mill. ) Druce was found to have the karyotype 2n=20=12m+8sm ( Plate 3, Fig. I), which belongs to Stebbins’ (1971) karyotype classification 2B. The chromosomes range from 3.88 to 11.26μm in size. Table 2 shows the karyotypes and number fundamentals (N.F.) of 13 materials from 12 different localities. The N. F. of these materials can be classified into two groups: N.F. =36 and N.F.=40, besides one (N.F. =38) from Beijing. N. F. =36 covers all the materials with 2n= 18 which have relatively symmetrical karyotypes ( all consisting of m and sm chromosomes), one with 2n=20 (10m+6sm+4st) and one with 2n=22 (14m+8st). N.F. =40 include four materials with 2n= 20 (all of m and sm chromosomes ) and 3 with 2n= 22 (10m+ 8sm+ 4st). ￥ It is considered that there are two original karyotypes, 2n= 18 with N. F. = 36 and 2n= 20 with N.F. =40, which are relatively symmetrical. All the more asymmetrical karyotypes with some st chromosomes have probably evolved from the symmetrical karyotypes without st chromosomes by centric fission. (2) P. zanlanscianense Pamp. has the karyotype 2n=30=18m(2SAT) + 4sm+ 6st+ 2t (Plate 1, Fig. 1) which belongs to 2C. The chromosomes range from 2.16 to 9.76μm. ￥ II. Asparagus filicinus Buch.-Ham. ex D.Don. The karyotype of this species is 2n = 16= 8m(2SAT )+ 6sm + 2st (Plate 1, Fig. 1 and Table 3 ) , which belongs to 2B. The chromosomes range from 2.33 to 5.30μm. Most species in Asparagus, including A.Filicinus, are reported to have basic number x= 10, and therefore 2n= 16 is a new chromosome number for A.filicinus. EL-Saded et.al.(1972) gave a report of n=8 for A. stipularis from Egypt, while Delay (1947) reported 2n = 24 for A. trichophyllus and A. verticillatus, Sinla(1972 ) gave a report of 2n=48 for A.racemosus. It is certain that there are two basic numbers in the genus Asparagus. III. Cardiocrinum giganteum (Wall.) Makino was found to have the karyotype 2n=24=4m+8st+12t (Plate 1, Fig. 1 ), which belongs to 3B. The chromosomes range from 8.71 to 20.24μm. IV. Smilax discotis Warb. was shown to have the karyotype 2n=32=4m+22sm+4st (2SAT)+2t (Plate 1, Fig. 1 and Table 3), which belongs to 3C. The first pair is much longer than others. The chromosomes range from 1.79 to 9.21μm. The chromosome number and karyotype of S. discotis are both reported for the first time. V. Reineckia carnea (Andr.) Kunth is of the karyotype 2n=38=28m+10sm (Plate 2, Fig. 1 ), which belongs to 2B. The chromosomes range from 5.65 to 12.75μm. VI. Tupistra chinensis Baker was found to have the karyotype 2n=38=25m+ 13sm (Plate 2, Fig. 1), which belongs to 2B. The chromosomes range from 8.11 to 23.82μm. A pair of heterozygous chromosomes is arranged at the end of the idiogram. The eighth pair possesses an intercalary satellite. Huang et al. (1989) reported the karyotype of T. chinensis from Yunnan as 2n = 38 = 24m+ 14sm without any intercalary satellite. Nagamatsu and Noda (1970) gave a report on the karyotype of T. nutans from Bhutan, which consists of 18 pairs of median to submedian chromosomes and one pair of subterminal chromosomes. And one pair of submedian chromosomes possess intercalary satellites on their short arms. VII. Rohdea japonica (Thunb) Roth. was found to have the karyotype 2n=38=30m+6sm+2st ( Plate 2, Fig. 1), which belongs to 2B. The chromosomes range from 7.94 to 18.29μm. Nagamatsu and Noda (1970) reported that the karyotype of R.japonica from Japan was the same as that of Tupistra nutans from Bhutan. But we have not discov ered any chromosome with an intercalary satellite. VIII. Hosta Tratt. (1) H. plantaginea (Lam.) Aschers was shown to have 2n=60. The 60 chromosomes are in 30 pairs,which can be classified into 4 pairs of large chromosomes (7.32- 8.72μm ), 3 pairs of medium-sized ones (4.72-5.60μm), and 23 pairs of small ones (1.40-3.64μm), (Plate 3 ,Table 4 ). The karyotype of H. plantaginea is reported for the first time. (2) H. ventricosa (Salisb.) Stearn was counted to have 2n=120, The 120 chromosomes are in 60 pairs, which can be classified into 8 pairs of large chromosomes (7.00- 8.40μm ), 6 pairs of medium-sized ones(4.40- 6.15um ), 46 pairs of small ones (1.20- 3.85μm), (Plate 3, Table 4). Based on the karyotypes of H. plantaginea and H. ventricosa, the latter is probably a tetraploid in the genus Hosta. Kaneko (1968b) gave a report on the karyotype of H. ventricosa, which is of8 pairs of large chromosomes, 4 pairs of medium-sized and 48 pairs of small ones.     

A karyological study of the spirurid nematode Mastophorus muris (Nematoda: Spirocercidae)

The karyotype of Mastophorus muris (Gmelin, 1790) comprises four pairs of small autosomal chromosomes and two larger sex X chromosomes in females or one X chromosome in males (2n = 8 + XX/XO). All pairs of chromosomes possess rather uniform morphology without distinct primary or secondary constrictions. No heterochromatin bands were found by C-banding analysis. The absolute chromosome length ranges from 4.02 to 2.24 microns. The mean total length of the haploid complement is 14.34 microns. The course of gametogenesis represents a typical pattern common in the order Spirurida. The recently available karyotypes of spirurid nematodes have been reviewed.     

Cytotaxonomical Studies on Liliaceae (s.l.): (2) Report on Chromosome Numbers and Karyotypes of 8 Species of 8 Genera from Zhejiang,China

Eight species in eight genera of Liliaceae from Zhejiang were cytotaxonomically studied in this work. The karyotypes of Chinese materials of these species are mostly reported for the first time. The results are shown as follows (see Table 2-4 for chromosome parameters of them): 1. Disporum sessile D. Don Sixteen chromosomes are counted at metaphase of roottip cells.The Karyotype formula is 2n=16=2lm+2sm+4st+2sm+3sm+ 1sm(SAT)+2st (Plate 1: 2-3, see Fig. 1:1 for its idiogram). The Karyotype belongs to 3B in Stebbins’ (1971) karyotype classification, and consists of four pairs of larger chromosomes (1-4) and four pairs of smaller chromosomes (5-8). One SAT-chromosome is situated at the sixth pair. The chromosomes range between 4.85-16.63μm. The karyotypic constitution is similar to that of Japanese material reported by Noguchi (1974). Chang and Hsu (1974) reported 2n=14=13st+1sm and 2n= 16=2m + 13st + 1sm for the material from Taiwan under the name of D. shimadai Hay. (=D. sessile D. Don). Compared with our result of D. sessile, the differences are obvious. 2. Polygonatum odoratum (Mill.) Druce PMCs diakinesis shows eleven bivalents, n = 11, 5 large and 6 small (Plate 2:5). The meiosis is normal. The majority of reports of this species are 2n=20, with a few 2n=22 and 30 (see Table 1). The materials from southen Siberia and the Far East in USSR are all of 2n= 20. Our result is the same as recorded by Jinno (1966) in the Japanese material and by Li (1980) from Beijing. Ge (1987) reported 2n=20 in the cultivated individuals of Shandong, China, showing that both 2n=20 and 22 exist in China. 3. Scilla scilloides (Lindl.) Druce This species has the somatic chromosome number 2n=18 (Plate 1: 4-6, see Fig. 1:2 for its idiogram), of which two groups of chromosomes can be recognized, i.e. the 1 st -5 th pairs of large and the 6 th-9th pairs of small chromosomes. A distinct character of the karyotype is that two satellites are attached to the short arms of the 1st pair of chromosomes. The degree of asymmetry is of 3C. The karyotype formula is 2n = 18 = 2sm (SAT) + 6st + 2t+ 6m + 2sm. The chromosomes range from 2.02 to 11.93 μm. The Previous counts on the species are 2n = 16, 18, 26, 34, 35, 36 and 43 (see Table 1). The present investigation confirms Noda’s and Haga’s results. The species is considered to be of two genomes, namely A(x = 8) and B(x = 9). Our result shows a genome composition of BB, having a pair of large SAT-chromosomes. Chang and Hsu (1974) reported 2n = 34 from a population of Taiwan, an amphidiploid (AABB), Karyotypes of other Chinese populations are worth further researches. 4. Tricyrtis macropoda Miq. The chromosome number of somatic cells is 2n= 26, and PMCs MII shows 13 bivalents (n= 13) (Plate 3:1-3, see Fig. 1:3 for its idiogram). The karyotype formula is 2n= 26= 6m + 10sm + 6st + 4st (or t), which is composed of chromosomes: 4L + 22S in size. The degree of asymmetry is of 3B. No centromeres of the 12th and 13th pairs of chromosomes were observed at metaphase, and the chromosomes may be of st or t. Nakamura (1968) reported 2n= 26(4L+ 22S)= 2sm+ 2sm-st+ 14st-sm+ 8st for T. macropoda Miq. and 2n= 26(4L+ 22S)= 8m+ 2sm+2sm-st+ 2st-sm+ 12st for its ssp. affinis, both from Japan. It is clear that the major character of their karyotypes, i. e. 4L + 22S, is consistent with that reported here. Based on the previous and present reports, all Tricyrtis species studied are remarkably uniform in the basic karyotype, i. e. 4L + 22S. 5. Allium macrostemon Bunge. The present observation on the root-tip cells of the species shows 2n = 32 (Plate 3: 4-5, see Fig. 1:4 for its idiogram). The karyotype formula is 2n (4x)= 32= 26m + 6sm, which belongs to 2B, being of high symmetry. Except the 6th, 10th and 13th pairs of chromosomes all the are metacentric. Chromosomes of this species are large, ranging from 5.94 to 18.06 μm. Our result agrees with Kawano’s (1975) report under the name of A. grayi Regel ( = A. macrostemon, Wang and Tang 1980). 6. Asparagus cochinchinensis (Lour.) Merr. Ten bivalents were observed in PMCs MI, n=10 (Plate 1: 1). The present result confirms the number of a population of Taiwan recorded by Hsu (1971). 7. Ophiopogon japonicus (L. f.) Ker-Gawl. The species from Mt. Taogui, Hangzhou, is found to have 2n (2x)=36=22m + 14sm (Plate 2: 1,5, see Fig. 1:5 for its idiogram) which belongs to 2B. The karyotype is composed of 2 medium-sized chromosomes with metacentric centromeres and 34 small chromosomes, ranging from 1.34 to 4.92 μm. The populations from Mt. Tianzhu and Mt. Yuling, Zhejiang, are found to be aneuploids at tetraploid level (2n=64-70). It is interesting that Nagamatsu (1971) found the karyotypes of Japanese materials to be 2n= 67 and 68, also showing unsteady 4x karyotypes of this species. In the previous. reports (see Table 1), the chromosome numbers of this species are mainly 2n = 72, besides 2n = 36 recorded by Sato (1942) from Japan. 8. Liriope platyphylla Wang et Tang The somatic complement of the species collected from Mt. Tianzhu, Hangzhou, is 2n = 36 (Plate 2: 3-4, see Fig. 1:6 for its idiogram). The karyotype is 2n(2x) = 36 = 16m + 20sm, belonging to 2B type. The chromosomes are small except the medium-sized, 1st pair and the range is from 1.27 to 5.19μm. The material from Mt. Yuling, Zhejiang, is found to have a variety of chromosome numbers (2n= 60-71), as observed in Ophiopogon japonicus. Hasegawa (1968) reported the karyotype of 2n = 72 (4x) from Japan The 2x karyotype is first recorded. This genus is closely related to Ophiopogon. Based on the Hasegawa’s and present studies, all the species in these two genera are remarkably uniform in karyo-type. Therefore, the taxonomy of the two genera is worth further researches.     

Meiotic studies on a Brassica campestris-alboglabra monosomic addition line and derived B. campestris primary trisomics.

Diakinesis chromosomes were studied in pollen mother cells of Brassica campestris (2n = 20, genome AA), B. alboglabra (2n = 18, genome CC), a B. campestris-alboglabra monosomic addition line (AA + 1 chromosome from the C genome), and four derived B. campestris primary trisomics. The nucleolar chromosomes of B. campestris were distinguishable by their morphology at diakinesis. The alien C-genome chromosome in the addition line paired preferentially with the nucleolar chromosome of the A genome. Very rarely, it paired with another pair of the A genome. Thus, it was concluded that the alien C-genome chromosome of the addition line is primarily homoeologous to the nucleolar chromosome and secondarily to another chromosome of the A genome. Three of the four derived B. campestris trisomic plants were identified as B campestris nucleolar trisomics. Trisomy in the fourth plant involved another chromosome. The cytological mechanism underlying the origin of trisomics in the addition line and chromosome homoeology relationships between B. campestris and B. alboglabra are envisaged.     

C-banded chromosomes of the genus Bembidion Latr. (Coleoptera, Carabidae)

The C-banding pattern of Bembidion punctulatum, B. varium, B. varicolor, B. ascedens, B. tibiale, B. ustulatum, B. decorum, and B. modestum are presented. All examined species have a symmetrical karyotype with meta- and submentacentric chromosomes and meioformula n=11+XY. All of them have an achiasmatic spermatogenesis in common. The present data confirm earlier studies indicating a considerable morphological and numerical stability of the Bembidiini karyotype. The C-banding showed the existence of heterochromatin in the paracentric regions of chromosomes, and also 2-3 intercalar C-positive segments were observed. The Y chromosome is entrely euchromatic. The C-banded karyotype of the analysed species in genus Bembidion has large heterochromatin segments on chromosomes, an exception in Coleoptera.     

黄牡丹八个居群的Giemsa C-带比较研究

应用ＢＳＧ方法对黄牡丹（Ｐａｅｏｎｉａ ｄｅｌａｖａｙｉ ｖａｒ．ｌｕｔｅａ）８个居群的Ｇｉｅｍｓａ Ｃ－带进行了比较研究。８个居群的所有染色体都在着丝点附近显示出了Ｃ－带,所有染色体的长臂上都没有显示Ｃ－带,而短臂上的Ｃ－带数量和位置在居群之间表现出了一定的差异。花甸凡居群手第二、第三、第四和第五对染色体显示端带;卓干山居群的第一、第三、第四和第五对染色体的短臂上没有显示Ｃ－带。在所研究的８个居     

Cytogenetic studies on Bacillus grandii grandii and B. grandii benazzii (Insecta,Phasmatodea): karyotype description,constitutive heterochromatin and nucleolus organizer regions

The karyotype of the new Sicilian subspecies Bacillus grandii benazzii is described and compared to that of B. g. grandii. Both taxa share constant, very similar chromosome sets with 2n=34, XX, female and 2n=33, XO, male, the sex chromosomes being the third element of the complement. C-banding reveals that a centromeric heterochromatin mass is present on all chromosomes, but no interstitial bands are observed. Differences between karyotypes reside in the satellites which are located on pairs 13 and 16 in B. g. benazzii and only on pair 16 in B. g. grandii, in contracted metaphases larger satellites are positively C-banded. Furthermore, Ag-detected NORs are seen on pair 13 in B. g. benazzii and on pair 16 in B. g. grandii. Relationships between constitutive heterochromatin and NORs, NOR heteromorphism and the position of the 34-chromosome taxa within the genus are discussed.     

Assigning Brassica microsatellite markers to the nine C-genome chromosomes using Brassica rapa var. trilocularis–B. oleracea var. alboglabra monosomic alien addition lines

Brassica rapa var. trilocularis-B. oleracea var. alboglabra monosomic alien addition lines (MAALs) were used to assign simple sequence repeat (SSR) markers to the nine C-genome chromosomes. A total of 64 SSR markers specific to single C-chromosomes were identified. The number of specific markers for each chromosome varied from two (C3) to ten (C4, C7 and C9), where the designation of the chromosomes was according to Cheng et al. (Genome 38:313-319, 1995). Seventeen additional SSRs, which were duplicated on 2-5 C-chromosomes, were also identified. Using the SSR markers assigned to the previously developed eight MAALs and recently obtained aneuploid plants, a new Brassica rapa-B. oleracea var. alboglabra MAAL carrying the alien chromosome C7 was identified and developed. The application of reported genetically mapped SSR markers on the nine MAALs contributed to the determination of the correspondence between numerical C-genome cytological (Cheng et al. in Genome 38:313-319, 1995) and linkage group designations. This correspondence facilitates the integration of C-genome genetic information that has been generated based on the two designation systems and accordingly increases our knowledge about each chromosome. The present study is a significant contribution to genetic linkage analysis of SSR markers and important agronomic traits in B. oleracea and to the potential use of the MAALs in plant breeding.     

Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes

Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA(3) ) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO (3) staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent.     

Karyotypes of the Genus Fritillaria from South Anhui

This paper reports chromosome numbers and karyotypes of five species of the genus Fritillaria from south Anhui. The origin of the material used in this work is provided in Table 1, micrographs of mitotic metaphase in Plate 1,2, and the parameters of chromosomes in Table 2. Except F. thunbergii Miq., the karyotypes and chromosome numbers of all the species in this paper were studied for the first time. The results are shown as follows: 1. Fritillaria qimenensis D. C. Zhang et J. Z. Shao Collected from Qimen, Anhui, it has the karyotype formula 2n = 24+4Bs = 3m+lsm+8st (2sc)+12t (2sc)+4Bs (Plate 1:1, 2). The chromosomes range in length 8.72-19.13μm, with the ratio of the longest to the shortest 2.19. Therefore, the karyotype belongs to Stebbins’ (1971) 3B. The secondary constrictions are found on the long arms of 7th and 10th pairs. All the five B-chromosomes are of terminal centromeres. The two chromosomes of the second pair show heteromorphy (Fig. 1, E) with arm ratios 1.86 and 1.56 respectively. 2. Fritillaria monantha Miq. var. tonglingensis S. C. Chen et S. F. Yin Collected from Tongling, Anhui, this species is shown to have three chromosome numbers, 2n =24+5Bs, 2n=24+2Bs and 2n=24. This paper reports 2 cytotypes: Type I: 2n = 24+5Bs = 4m+8st (2sc) +12t (2sc) +5Bs (Plate 1: 3, 4). The chromosomes range in length from 10.40 to 22.19μm, with the ratio of the longest to the shortest 2.13. It belongs to 3B of stebbins’(1971) karyotypic symmetry. The secondary constrictions are found on the short arms of 7th and the long arms of 9th chromosome pairs. The metacentric B-chromosomes and the small satellites located on the short arms are major characters of this cytotype. Type II: 2n=24=2m+2sm+8st(2sc)+12t(2sc) (Plate 1:5, 6). The chromosomes range in length from 13.84 to 29.81μm, with the ratio of the longest to the shortest 2.15. The karyotype belongs to Stebbins’3B. The secondary constrictions are found on the long arms of 5th and 10th pairs. No B-chromosomes are found. 3. Fritillaria xiaobeimu Y. K. Yang, J. Z. Shao et M. M. Fang Collected from Ningguo, Anhui, it has karyotype formula 2n = 24 = 2m+2sm+10st (4sc) + 10t (Plate 2:7, 8). The chromosomes range in length from 13.86 to 26.27μm, with the ratio of the longest to the shortest 1.89. The karyotype belongs to stebbins’3A. The secondary constrictions are found on the long arms of 7th and 9th pairs. 4. Fritillaria ningguoensis S. C. Chen et S. F. Yin Collected from Ningguo, Anhui, it is of karyotype formula 2n = 24 = 2m+2sm+8st (2sc) +12t (Plate 2: 9, 10). The chromosomes range in length from 9.11 to 23.23μm, with the ratio of the longest to the shortest 2.55. The karyotype belongs to Stebbins’3B. The secondary constrictions are only found on the long arms of the 10 th pair. 5. Fritillaria thunbergii Miq. Collected from Ningguo, Anhui, it is of karyotype formula 2n = 24 = 2m+2sm+8st(2sc) +12t(2sc)(Plate 2:11, 12). The chromosomes range in length from 8.83 to 19.85μm, with the ratio of the longest to the shortest 2.25. The karyotype belongs to stebbins’3B. There are secondary constrictions on the long arms of 5th and 7th pairs. The karyotype of the Ningguo material is similar to that of the Huoqiu (Anhui) material reported by Xu Jin-lin et al. (1987), but it is obviously different from 2n=2m(sc)+2sm+4st(2sc)+16t (2sc) reported byZhai et al. (1985) for the material from Xingjiang, Northwest China.     

Standard Giemsa C-banded karyotype of Russian wildrye (Psathyrostachys juncea) and its use in identification of a deletion-translocation heterozygote.

Ten accessions of Russian wildrye, Psathyrostachys juncea (Fisch.) Nevski (2n = 2x = 14; NsNs), collected from different geographical regions were analyzed using the C-banding technique. C-banding pattern polymorphisms were observed at all levels, i.e., within homologous chromosome pairs of the same plant, among different individuals within accessions, between different accessions of the same geographic area, and among accessions of different origins. The seven homologous groups varied in the level of C-banding pattern polymorphism; chromosomes A, B, E, and F were more variable than chromosomes C, D, and G. The polymorphisms did not hamper chromosome identification in Ps. juncea, because each chromosome pair of the Ns genome had a different basic C-banding pattern and karyotypic character. A standard C-banded karyotype of Ps. juncea is proposed based on the overall karyotypes and C-bands in the 10 accessions. The C-bands on the Ns-genome chromosomes were designated according to the rules of nomenclature used in wheat. A deletion-translocation heterozygote of Russian wildrye was identified based on the karyotype and C-banding patterns established. The chromosome F pair consisted of a chromosome having the distal segment in the long arm deleted and a translocated chromosome having the distal segment of long arm replaced by the distal segment of the long arm of chromosome E. The chromosome E pair had a normal chromosome E and a translocated chromosome having the short arm and the proximal segment of the long arm of chromosome E and the distal segment of the long arm of chromosome F.     

黄芪复合体（豆科）核型研究补充材料

本文首次报道了民和黄芪的染色体数目及核型。发现该种与黄芪复合体其它类群的染色体数目相同,但核型有别,其核型公式为２ｎ＝１６＝８ｍ（２ＳＡＴ）＋８ｓｍ。这种核型变异与它的形态变异一致。在黄芪复合体内,每一类群的染色体至少具１对随体,且附着在最后１对染色体的短臂上（除蒙古黄芪具２对随体外）,而Ｔｏｈ（１９７１）报道采自Ｋｙｕｎｇｉ和Ｍｔ．Ｈａｒｌａ膜荚黄芪和高山膜荚黄芪（新拟）的染色体不具随体,可能观察有误。