中国烟蚜不同地理种群的核型多态性研究(英文)

对中国不同地区 (湖南郴州、吉林长春、河南宜阳和江苏南京 )取食烟草的不同生活史的烟蚜Myzuspersicae (Sulzer)核型研究结果表明 :在红色型和褐色型中发现 4种染色体组型 ,即 2n =12 ,A1 与A3易位 ;3n =18,A1 与A3易位 ;3n =18,正常 ;2n =11。在黄绿色型中仅发现 2种染色体组型 ,即 2n =12 ,正常和 2n =12 ,A1 与A3易位。在 2n =12核型中 ,不同地区不同体色的烟蚜其染色体相对长度差异不显著 (α =0 .0 5)。     

The inheritance of natural chromosomal polymorphisms in the aphid Myzus persicae (Sulzer)

Two types of chromosomal abnormality have been found in natural populations of Myzus persicae in Japan. One type is apparently due to an autosome 3 dissociation, giving a 2n=13 karyotype. The other is interpreted as a translocation between autosomes 1 and 3, resulting in a 2n=12 complement with marked structural heterozygosity. In laboratory crosses, both types of abnormality were inherited through the sexual phase. The proportions of each type in the F₁ agreed well with expectations, except that no forms homozygous for the translocation were obtained from crosses between translocation heterozygotes, and no karyotypes with both the translocation and the dissociation were obtained when translocated and dissociated forms were crossed. In the F₁ of one cross a triploid clone with the autosomal 1,3 translocation was obtained.     

风毛菊属6种植物的核型分析

采用常规压片技术对分布于横断山区菊科(Compositae)风毛菊属(Saussurea DC.)的6种植物进行染色体数目和核型分析。结果表明:尖苞雪莲（S.polycolea var.acutisquama）核型公式为:2n=2x=32=20m+12sm,属2B型;球花雪莲核（S.globosa）型公式为:2n=2x=34=16m+18sm,属2B型;重齿风毛菊(S.katochaete)核型公式为:2n=2x=32=8m+18sm+6st,属3B型;柱茎风毛菊(S.columnaris)核型公式为:2n=2x=32=24m+8sm,属2B型;禾叶风毛菊(S.graminea)核型公式为:2n=2x=28=8m+18sm+2st,属3B型;长毛风毛菊(S.hieracioides)核型公式为:2n=2x=32=12m+16sm+4st,属2B型。6个种染色体中均未发现随体。其中尖苞雪莲和柱茎风毛菊染色体为首次报道。     

The founder effect theory: quantitative variation and mdg-1 mobile element polymorphism in experimental populations of Drosophila melanogaster

The chromosomes of 14 specimens of the genus Reithrodon from three different localities of Argentina and two localities of Uruguay were studied using G-and C-banding techniques. Specimens of Uruguay showed a karyotype of 2n=28 chromosomes having a large metacentric X, and a telocentric Y chromosome. This karyotype is very similar to that recently described in a sample from southern Brazil, differing only in the nature of the Y chromosome, which is metacentric in the Brazilian form. All specimens from Argentina showed a 2n=34 karyotype, differing from the Brazilian karyotype by two centric fusions, an acquisition of chromosome material, and at least one pericentric inversion, and by the telocentric nature of both the X and the Y chromosomes. G-and C-banding suggest that the metacentric gonosomes in the Brazilian form resulted from a double autosomal-X-Y Robertsonian translocation. The Uruguayan cytotype is interpreted as derived from a hypothetical neo-X/Y₁Y₂ ancestral form by the secondary loss of the Y₁ chromosome. The karyotypic differences between the Brazilian-Uruguayan and the Argentinian forms afford evidence of species differentiation. It is proposed to assign the former to Reithrodon typicus, and the later to R. auritus.     

Chromosome banding and genome size differentiation inProspero (Hyacinthaceae): Diploids

Prospero is a Mediterranean autumn-flowering genus ofHyacinthaceae commonly classified inScilla asS. autumnalis andS. obtusifolia. Extensive dysploid and polyploid variation has been reported. In the present study 77 diploid accessions from the western to the eastern part of the area of distribution, the major part being from continental Greece and Crete, have been analysed for karyotype structure and, in part, for genome size. Methods employed were acetocarmine staining, Giemsa C-banding, fluorochrome staining mainly with chromomycin A₃/DAPI, silver impregnation, and Feulgen densitometry. Banded idiograms were established with a computer assisted karyotype analysis procedure. Chromosome numbers were 2n = 8 inP. obtusifolium, and 2n = 12 and 14 inP. autumnale s. l. Dispensable euchromatic chromosome segments and different types of B chromosomes occurred. Among the cytotypes with 2n = 14 two karyotypes from Turkey differed from each other and from the rest in form, position of the nucleolar constriction, and in genome size. The remaining accessions were similar in karyotype shape but three levels of genome size could be discerned, the highest (1C = 7.50 pg) being found on the Iberian Peninsula, an intermediate one on Corsica and Malta, and the lowest (4.27 pg) in the Aegean. The karyotype with 2n = 12 had an intermediate genome size, and that ofP. obtusifolium a relatively low one. Heterochromatin amount was generally low, but some karyotypes showed characteristic banding patterns. The relationship between the chromosome complements with 2n = 14, 12 and 8 is discussed on the basis of idiograms and DNA amounts.The authors respectfully dedicate this papers to emer. o. Prof. Dr.Elisabeth Tschermak-Woess on the occasion of her 80th birthday.     

Saussurea pseudograminea sp. nov. (Asteraceae) from the Qinghai–Tibetan plateau,China

Morphological characteristics, as well as ultrastructure of pollen grains, chromosome numbers and karyotype analysis have been used to establish a new species of Saussurea from the Qinghai–Tibetan plateau. The new species, Saussurea pseudograminea Y. F. Wang, G. Z. Du et Y. S. Lian is easily distinguished from the similar S. graminea Dunn by having 2–3 capitula, involucre 0.7–1.2 cm in diameter, smaller pollen grains, pollen surface with larger and denser spines, achenes 4.0–5.5 mm long, 32 chromosomes, and a karyotype formula 2n = 2x = 32 = 18m + 10sm + 4st, whereas S. graminea has solitary capitula, involucre 1.2–2.0 cm in diameter, larger pollen grains, pollen surface with smaller and sparser spines, achenes 3–4 mm long, 28 chromosomes and a karyotype formula 2n = 2x = 28 = 6m + 20sm + 2st. The new species is distributed in Dianzhangou, Awanchang, and Gamaliang mountain regions of Maqu county in Gansu province.     

Further survey of chromosomal polymorphisms in the freshwater planarian Polycelis auriculata

Although the chromosomal number of Polycelis (Seidlia) auriculata Ijima et Kaburaki is basically 2n = 6, this species shows remarkable chromosomal polymorphisms in different populations. Among worms collected at 30 stations in the central part of Japan's Main Island and in Hokkaido, we found five new karyotypes, considered to be variations of tetraploidy and diploidy: 4n?fis¹. + 1 = 3SM + 2A + 3T₁ + 2T₂ + 4M = 14, 4n?fis².(B) = 2SM + 2A + 4T₁ + 2T₂ + 4M + (0?2B) = 14 –16, 4n?fis². + 1 = 2SM + 2A + 4T₁ + 2T₂+5M= 15, 4n?fis².?2 = 2SM + 2A + 4T₁ + 4M = 12, and 2nM- = 2SM + 2A = 4 (where SM = submetacentric; A = acrocentric; T₁ and T₂ = telocentric; M = metacentric; B = B-chromosome; fis¹. and fis². = occurrence of one or two centric fissions, respectively; and M- = deletion of a metacentric chromosome). These karyotypes exist singly in one individual or as various mixoploids within the same individual. No individual having only karyotype 2nM- has yet been found. This brings the total number of known karyotypes in P. auriculata to 17; these can be arranged in an order that we believe reflects their evolution.     

凤仙花近缘种间核型分析与叶表皮微形态研究

为探究凤仙花近缘种植物的细胞学和微形态学方面的亲缘关系,该文选取荔波凤仙花(Impatiens liboensis)及近缘种赤水凤仙花(I.chishuiensis)和管茎凤仙花(I.tubulosa)的根尖和叶表皮为实验材料,采用体细胞染色体常规压片法和叶表皮光学显微镜观察法对凤仙花近缘种植物进行染色体及叶表皮特征研...     

THE EFFECT OF ESTRADIOL ON THE CELL KINETICS IN THE UTERINE AND CERVICAL EPITHELIUM OF NEONATAL MICE

The effect of estradiol-17β on the length of the various phases of the cell cycle was studied in the neonatal mouse uterine, and cervical epithelium. A double labelling method was used, and in addition labelled mitoses were counted. In the uterus proper, estradiol shortens the length of the total cell cycle, T_c, from 17-9 hr to 15-7 hr, and the duration of S phase, T_s, from 6–7 to 5-1 hr 6 hr after estradiol treatment. 12 hr after estradiol treatment, T_c is shortened to 7-4 hr and T_s to 4–5 hr. The shortening of T_c at 12 hr is mainly due to an effect on T_G1, which is shortened from 8–55 hr in untreated animals to 1–8 hr in estradiol treated animals. The T_c of cervix epithelium cells in untreated animals was found to be 21-8 hr. After treating the mice for 6 hr with estradiol the T_c was now increased to 47 hr and further to 61 -2 hr following 12 hr treatment with the hormone. T_s increases from 8-3 hr to 15-2 hr following 6 hr estradiol treatment, and to 15-4 hr after 12 hr treatment. The effect is most pronounced in T_G1, which is lengthened from 10–95 hr in untreated animals to 28-1 hr and 43 hr, respectively, in animals treated for either 6 or 12 hr with estradiol.     

High-resolution flow karyotyping and chromosome sorting in Vicia faba lines with standard and reconstructed karyotypes

Flow cytometric analysis has been performed on chromosomes isolated from formaldehyde-fixed root tips in a Vicia faba (2n = 12) line with a standard (wild-type) karyotype and in six V. faba translocation lines with reconstructed karyotypes. The resolution of individual chromosome types on histograms of chromosome fluorescence intensity (flow karyotypes) depended on the type of fluorochrome used for chromosome staining. The highest degree of resolution was achieved with 4,6-diamidino-2-phenylindole (DAPI). The lower resolution obtained after staining with mithramycin A (MIT) and propidium iodide (PI) was probably due to the sensitivity of these stains to changes in chromatin structure induced by formaldehyde fixation. After the staining with DAPI, only 1 chromosome type could be discriminated in the line with a standard karyotype. In the translocation lines, the number of chromosome types resolved on flow karyotypes ranged from 2 in the G and the ACB lines to all (6) chromosome types in the EFK and EF lines. Refined flow karyotyping permitted the sorting of a total of 15 different chromosome types from five of the translocation lines. It is expected that flow sorting of chromosomes from reconstructed karyotypes will become a powerful tool in the study of nuclear genome organisation in V. faba.     

Leggadas (Mus sp.) de Moundou (Tchad). Observation d'un caryotype aberrant chez une femelle

Pigmy mice (Mus sp.) from Moundou (Tchad), Aberrant karyotype in a female.In a sample of 12 pigmy-mice, one male had the karyotype 2n=36. N.F.=36, sex chromosomes PR, already known from five different taxa, but morphologically it does not belong to any of these. Ten specimens (7 , 3 ) present the karyotype previously described in a population from Ippy (Central African Republic) and for a male from Senegal: , 2n=19, sex chromosomes X/Y₁Y₂; , 2n=18, X/X. Probably we are dealing with a taxonomic entity derived from the superspecies minutoides/musculoides.An aberrant karyotype was found in one female: 2n=19, N.F.=37. The supernumerary is a small acrocentric, morphologically similar to the Y₂ of the male. Its origin could be explained through non-disjunction during the first moiotic division of a paternal spermatocyte, X and Y₃ having passed together to the same daughter cell. If Y₂ is homologous with a segment of the autosomal arm of the X/TR, the complement XXY₂ does not imply the intersexuality of its bearer, but should be considered as an autosomal duplication.     

Models for spring migration of two aphid species Sitobion avenae (F.) and Rhopalosiphum padi (L.) infesting cereals in areas where they are entirely holocyclic

1 Cereals can be attacked severely by the grain aphid, Sitobion avenae (F.), and the bird cherry‐oat aphid, Rhopalosiphum padi (L.). The time of migration from winter hosts in spring is important regarding input to decision support systems concerning insecticide treatment of aphids. 2 The present study aimed to construct two separate migration models, which could be used immediately for advisors and farmers but also be part of a decision support system for the chemical control of aphids in winter wheat and spring barley. 3 Winter wheat (Triticum sativum Lam.) and spring barley (Hordeum vulgare L.) fields were monitored from 1991–2005 for the occurrence of grain aphids and bird cherry‐oat aphids, and the data were used to construct migration models. 4 The models were constructed based on all 9 years data and subsequently validated by using all 9 years data, excluding 1 year at a time. 5 The migration model for the grain aphid producing the best forecast was obtained with migration date M (number of days from 1 June), degree‐days (DD) of April (T_a) and DD of May (T_m), with the model being M= 265.0 ? 10.2 log_e(T_a) ? 35.1 log_e(T_m). 6 The migration model for the bird cherry‐oat aphid producing the best forecast was obtained with migration date M (number of days from 15 May), DD of April (T_a) and DD from 1–15 May (T_m1), with the model being M= 294.4 ? 34.7 log_e(T_a) ? 22.5 log_e(T_m1). 7 The models only worked well in areas where the grain aphid and the bird cherry‐oat aphid are entirely holocyclic.     

Giemsa C-banded karyotypes of some diploidArtemisia species

Detailed C-banded karyotypes of eight diploidArtemisia species from three different sections are reported together with preliminary observations on three additional related diploid species. In the majority, the overall amount of banding is relatively low. Bands are mostly confined to distal chromosome regions; intercalary banding is virtually absent and centromeric heterochromatin is also scarce. With the exception ofA. judaica there is in general great uniformity in karyotype structure but considerable interspecific variation in total karyotype length (and hence DNA content) ranging from 44 µm inA. capillaris (2n = 18) to 99 µm inA. atrata (2n = 18).A. judaica (2n = 16; total karyotype length 97 µm) was distinguished by its karyomorphology, with one large non-banded metacentric chromosome pair and 7 pairs of smaller terminally banded meta- or submetacentric chromosomes.     

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.     

Cytogenetic studies on natural intergeneric hybridization inAster alliances

The karyotype and meiosis of the 12-ploid plants—one of the offspring of the natural F₁ hybrid (Aster ageratoides subsp.ovatus (2n=36) ×Kalimeris incisa (2n=72), 2n=72)—were examined. The 2n=108 chromosomes of the 12-ploids were found to consist of 18 large chromosomes and 90 small chromosomes. In meiosis of the PMCs of the 12-ploid, chromosome configurations of 3_III+46_II+7_I, 2_III+48_II+6_I and 3_III+47_II+5_I were observed. All the univalents and trivalents were small, and among the 46–48 bivalents nine were large and the remaining 37–39 were comparatively small. The large bivalents were found to represent autosyndetic pairings, and the small bivalents and trivalents were probably formed by autosyndetic pairings. The large chromosomes of the 12-ploids were found to coincide with the large chromosomes ofovatus, and the 90 small chromosomes to correspond to small chromosomes ofovatus andK. incisa. The 12-ploids were concluded to have been produced by a fusion of an unreduced gamete of the F₁ plant and a reduced gamete ofK. incisa which was growing in proximity to the F₁s. Thus the 12-ploids were regarded to be an amphidiploid having 36 chromosomes ofovatus and 72 chromosomes ofK. incisa.     

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。     

Phytoremediation potential of vetiver grass irrigated with wastewater for treatment of metal contaminated soil

A field experiment was conducted to understand the potential of vetiver grass (Vetiveria zizanioides) in heavy metal uptake from the soil and wastewater. Four main irrigation treatments including T₁ (treated industrial wastewater), T₂ (1:1 ratio of municipal:industrial wastewater), T₃ (treated municipal wastewater) and T₄ (fresh water) were applied. Moreover, the effect of arbuscular mycorrhizal fungus (AMF), Glomus mosseae, on plant growth and heavy metal concentration was evaluated. Three main criteria including bioconcentration factor (BCF), translocation factor (TF) and heavy metal uptake were applied to assess the potential of vetiver grass in accumulation and translocation of heavy metals to aerial parts. The highest concentration of heavy metals was found in plant and soil irrigated with T₁ treatment followed by T₂, T₃ and the lowest concentrations were found in T₄ treatment. Irrigation with treated municipal wastewater led to a significant increase in plant biomass and heavy metal uptake compared to other treatments. In T₁ treatment (industrial wastewater), vetiver grass caused a significant decrease in Zn, Fe, Cu, Cd and Pb concentrations in soil as compared to no-plant treatment (without planting vetiver grass). Therefore, vetiver grass, irrigated with treated industrial wastewater, is a promising method for the development of urban and industrial green space.     

Fast chromosomal evolution and karyotype instability: recurrent chromosomal rearrangements in the peach potato aphid Myzus persicae (Hemiptera: Aphididae)

The occurrence of karyotype variations with respect to both chromosome number and structure has been frequently reported in aphids. Here, we review recent data attesting to the presence of recurrent chromosomal changes in the karyotype of the peach potato aphid Myzus persicae, where clones presenting metaphases with different chromosome number (from 12 to 17) have been observed, also comparing plates obtained within the same embryo. According to the available data, M. persicae autosomes 3 and 1 are the chromosomes mostly involved in changes compared to other autosomes, suggesting that they could have sites more susceptible to fragmentation. Chromosomal fissions involving the X chromosomes have also been observed, suggesting that they may have fragile sites located at the termini opposite to the nucleolar organizer regions‐bearing telomere. The presence of holocentric chromosomes and reproduction by apomictic parthenogenesis, together with a constitutive expression of telomerase, could explain the inheritance of the observed chromosomal instability in aphids. Considering that chromosomal changes may affect the host choice and could also favour speciation, it would be intriguing to confirm whether the observed karyotype variants have effects over short temporal and spatial scales.     

Establishment of homozygous transgenic rice lines after elimination of unlinked albino traits from transgenic events through segregation

In an analysis of 339 independent T ₀ transgenic rice lines generated by Agrobacterium-mediated transformation, albino plants appeared in the T ₁ generation in two single-copy transgenic lines, O54 and O36 and in one double-copy transgenic line, C18. While the T ₀ plants of these three lines were green, albino and green plants emerged in a 1:3 ratio in the T ₁ generation. The albino phenotype segregated as a monogenic recessive trait. Southern blot analysis of the green and albino plants in the T ₁ generation confirmed that the albino trait and the T-DNA insertion events were unlinked. Segregation of the albino trait from the transgenic trait in the lines O54 and O36 was confirmed in T ₂ and T ₃ generations, respectively. Homozygous transgenic plants free from the albino trait were also identified. In the double-copy transgenic line C18, we genetically separated the two transgenic loci, out-segregated the albino locus from both transgene loci, and identified homozygous plants for each of the transgenic events by Southern blot analysis in the T ₁ generation itself. Thus, we demonstrate that when an albino trait appears in the T ₁ generation and is unlinked to a transgene locus, the albino locus can be segregated from the transgene locus and homozygous transgenic lines free from albinos can be established.