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1.
Abstract.  1. Australia has a unique and speciose gall-inducing scale insect fauna that is primarily associated with Myrtaceae. Much of the diversity is currently undescribed or uncharacterised.
2. This study concerns Apiomorpha munita (Hemiptera), a scale insect that induces characteristic four-horned galls on eucalypts of subgenus Symphyomyrtus and exhibits extraordinary karyotypic diversity (2n = 6 – 2n > 100). The three described subspecies of A. munita are each confined to hosts in different sections of Eucalyptus . Previous chromosomal data, however, cast doubt on the validity of the groupings, as two of the subspecies share multiple, different karyotypes (2n = 6, 20, 22, and 24).
3. Allozyme data were used to examine species delimitation, chromosome evolution, host associations and population structure in A. munita .
4. A cryptic-species radiation was revealed, with at least five taxa each restricted to a discrete set of host eucalypt species. This is consistent with host-associated speciation.
5. Karyotypic variation within A. munita partially fits the five distinct genetic groups, but there are additional chromosomal changes that are not accompanied by detected genetic differentiation.
6. The population structure of taxa within the A. munita species complex suggests that there are high levels of inbreeding, as would be expected for scale insects in which adult females are sessile. Some genotypes, however, are found over great distances (up to 1100 km). This is an unusual population structure because it combines low mobility and local differentiation with occasional long-distance dispersal, probably mediated by wind-dispersal of first-instar nymphs.  相似文献   

2.
L G Cook 《Génome》2000,43(2):255-263
Chromosome number reflects strong constraints on karyotype evolution, unescaped by the majority of animal taxa. Although there is commonly chromosomal polymorphism among closely related taxa, very large differences in chromosome number are rare. This study reports one of the most extensive chromosomal ranges yet reported for an animal genus. Apiomorpha Rübsaamen (Hemiptera: Coccoidea: Eriococcidae), an endemic Australian gall-inducing scale insect genus, exhibits an extraordinary 48-fold variation in chromosome number with diploid numbers ranging from 4 to about 192. Diploid complements of all other eriococcids examined to date range only from 6 to 28. Closely related species of Apiomorpha usually have very different karyotypes, to the extent that the variation within some species-groups is as great as that across the entire genus. There is extensive chromosomal variation among populations within 17 of the morphologically defined species of Apiomorpha indicating the existence of cryptic species-complexes. The extent and pattern of karyotypic variation suggests rapid chromosomal evolution via fissions and (or) fusions. It is hypothesized that chromosomal rearrangements in Apiomorpha species may be associated with these insects' tracking the radiation of their speciose host genus, Eucalyptus.  相似文献   

3.
Abstract  Scale insects of the genus Apiomorpha Rübsaamen (Hemiptera: Coccoidea: Eriococcidae) induce sexually dimorphic galls on Eucalyptus, but the Apiomorpha pharetrata species-group is unusual in that nymphal males aggregate on the surface of the maternal gall where they induce a compound structure. Although originally described as distinct species on the basis of differences in gall morphology, A. pharetrata (Schrader) and A. thorntoni (Froggatt) were subsequently synonymised, primarily because the adult females of the two are morphologically indistinguishable. The two gall types of A. pharetrata sensu lato are allopatric and found on different host eucalypt species. To test the hypothesis that gall morphology may be determined by the host species on which the female feeds, we reared crawlers of field-collected females from both gall types on eucalypts in a glasshouse. Both gall types were induced on the same eucalypt species, with the gall type matching that of the maternal gall from which the crawlers had emerged. This indicates that it is the insect, not the host, that determines the gall morphology in these taxa. In addition, insects from the two gall types were different chromosomally and could be distinguished by one fixed allozyme difference. Thus, Brachyscelis (=  Apiomorpha ) thorntoni (Froggatt) revised status is removed from synonymy with Brachyscelis (=  Apiomorpha ) pharetrata (Schrader), and recognised as a distinct biological species. However, the extent of chromosomal variation among the populations of both A. pharetrata and A. thorntoni suggests that there may be further cryptic species present.  相似文献   

4.
A taxometric analysis of 153 colonies of the agamospermous Limonium binervosum aggregate in the British Isles has revealed an ordered hierarchy of variation. A taxonomic treatment of the group describes five new species, redefines four others and describes other infraspecific variants as subspecies or varieties. Each species is morphologically distinct and has a defined geographic range. There are four widespread and morphologically variable species and five geographically restricted species (four monotypic). Limonium recurvum , previously described as a microspecies endemic to a small area of the Dorset Coast, has been widened to include all triploid (2 n = 27) L. binervosum agg. variants found also in W and N Ireland, SW Scotland and Cumbria. All other taxa are tetraploid, usually with 2 n = 35.  相似文献   

5.
6.
African killifishes of the genus Chromaphyosemion show a high degree of phenotypic and karyotypic diversity. The latter is especially pronounced in C. riggenbachi, a morphologically defined species restricted to a small distribution area in Cameroon. This study presents a detailed reconstruction of karyotype differentiation within C. riggenbachi using conventional Giemsa staining and sequential chromosome banding as well as a phylogenetic analysis based on part of the mitochondrial (mt) cytochrome b gene from eleven populations. The cytogenetic analysis revealed differences in chromosome morphology, banding patterns and/or diploid chromosome number (2n) among all populations examined. Diploid number ranged from 2n = 20 to 2n = 36 and varied mainly among populations, while C-banding patterns and NOR phenotypes showed fixed differences among populations as well as some variability within populations. The mtDNA analysis disclosed five clearly differentiated haplotype groups. Mapping the karyotype data onto the mtDNA dendrogram revealed a decrease in 2n from the most basal to the most derived groups, thus demonstrating a reduction of 2n during their evolutionary history. Our results indicate that karyotype differentiation involved Robertsonian fusions as well as non-Robertsonian processes. Causes of the high karyotypic variability may include an elevated chromosomal mutation rate as well as certain features of the ecology and mating system that could facilitate the fixation of chromosomal rearrangements. The pattern of karyotype and haplotype differentiation and the results of previous crossing experiments suggest incipient speciation in C. riggenbachi.  相似文献   

7.
Abstract An unusual new species of the gall-inducing scale insect genus Apiomorpha Rübsaamen is described from Queensland. The adult female, its gall, and the first-instar nymph (crawler) are illustrated, and relationships of the new species are estimated using mitochondrial COII data. Adult females induce cigar-shaped galls on leaves of several eucalypts in section Adnataria of subgenus Symphyomyrtus . The bilobed anal lobes of the adult female differ from those of all other Apiomorpha species (single lobe) and the first-instar nymph possesses features, such as broad frontal tubercles and dorsal stripes, that are not present in crawlers of other Apiomorpha species. However, DNA sequence data confirm that the new species falls within Apiomorpha , rather than representing a sister group, and indicate that the new species is not closely related to the A. pharetrata (Schrader) species-group, the only other group within Apiomorpha that induces cigar-shaped galls on leaves. The systematic affiliations of A. gullanae sp. n. are currently not known. Females only are known and there is some indication that reproduction in the new taxon is parthenogenetic. This represents the first putative case of parthenogenesis in Apiomorpha .  相似文献   

8.
Hardy NB  Gullan PJ 《ZooKeys》2010,(58):1-74
We revise the genus Opisthoscelis Schrader, and erect the genus Tanyscelisgen. n. with Opisthoscelis pisiformis Froggatt as its type species. Species of both genera induce sexually dimorphic galls on Eucalyptus (Myrtaceae) in Australia, with Opisthoscelis subrotunda Schrader also in Papua New Guinea. We synonymise the following taxa (junior synonym with senior synonym): Opisthoscelis fibularis Froggatt, syn. n. with Opisthoscelis spinosa Froggatt; Opisthoscelis recurva Froggatt, syn. n. with Opisthoscelis maculata Froggatt; Opisthoscelis globosa Froggatt, syn. n. (= Opisthoscelis ruebsaameni Lindinger) with Opisthoscelis convexa Froggatt; and Opisthoscelis mammularis Froggatt, syn. n. with Opisthoscelis verrucula Froggatt. We transfer seven Opisthoscelis species to Tanyscelis as Tanyscelis conica (Fuller), comb. n., Tanyscelis convexa (Froggatt), comb. n., Tanyscelis maculata (Froggatt), comb. n., Tanyscelis maskelli (Froggatt), comb. n., Tanyscelis pisiformis (Froggatt), comb. n., Tanyscelis spinosa (Froggatt), comb. n., and Tanyscelis verrucula (Froggatt), comb. n. We redescribe and illustrate the adult female of each named species of Opisthoscelis for which the type material is known, as well as the first-instar nymph of the type species of Opisthoscelis (Opisthoscelis subrotunda) and Tanyscelis (Opisthoscelis pisiformis). We describe four new species of Opisthoscelis: Opisthoscelis beardsleyi Hardy & Gullan, sp. n., Opisthoscelis thurgoona Hardy & Gullan, sp. n., Opisthoscelis tuberculataHardy & Gullan, sp. n., and Opisthoscelis ungulifinis Hardy & Gullan, sp. n., and five new species of Tanyscelis: Tanyscelis grallator Hardy & Gullan, sp. n., Tanuscelis megagibba Hardy & Gullan, sp. n., Tanyscelis mollicornuta Hardy & Gullan, sp. n., Tanyscelis tripocula Hardy & Gullan, sp. n., and Tanyscelis villosigibba Hardy & Gullan, sp. n. We designate lectotypes for Opisthoscelis convexa, Opisthoscelis fibularis, Opisthoscelis globosa Froggatt, Opisthoscelis maculata, Opisthoscelis mammularis, Opisthoscelis maskelli, Opisthoscelis pisiformis, Opisthoscelis recurva, Opisthoscelis serrata, Opisthoscelis spinosa, and Opisthoscelis verrucula. As a result of our taxonomic revision, Opisthoscelis has six species and Tanyscelis has 12 species. We describe the galls of females for all 18 species and galls of males for 10 species of Opisthoscelis and Tanyscelis, and provide photographs of the galls for most species. A key to the adult females of the species of both genera is included.  相似文献   

9.
Nearly 32 species of Angelica occur in China, taking up one third of total species number of the genus in the world, with 12 species in Sichuan. In the present paper karyotypes of 8 species from Sichuan are first reported with x = 11. The parameters of chromosomes of 8 species are given in Table 1 and the karyotypes are shown in Plate 1, 2. The karyotype formulae are as follows: A. valida Diels K(2n) =22=20m+2sm (Wulong Xian, alt. 1900m); A. dielsii Boiss. K(2n) =22= 18m+2smsat+2sm (Songpan Xian, alt. 3000m); A. laxifoliata Diels has 2 kinds of karyotypes in 3 populations: K(2n) =22= 18m+4sm (Hanyuan Xian, alt. 1900m) and K(2n) =22= 16m+6sm (Songpan Xian, alt. 2500m and Baoji in Shaanxi, alt. = 1500m); A. setchuensis Diels K (2n) = 22 = 16m+2smsat+4sm (Songpan Xian, alt. 2800m); A. maowenensis Yuan et Shan K(2n) =22= 16m+ 6sm (Songpan Xian, alt. 2800); A. chinghaiensis Shan ex K.T.Fu K (2n) = 4x= 44 = 36m+8sm (Songpan Xian, alt. 3500m); A. Sinensis (Oliv.)Diels K(2n) =22= 14M+8sm (Songpan Xian, alt. 2900m); A. omeiensis Yuan et Shan K (2n) = 22 = 10m+2sm+ 10st (Mt. Omei, alt. 2100m). The karyotypes of A. valida and 2 populations of A. laxifoliata belong to “1A” and those of one population of A. laxifoliata and the rest 6 species “2A”. By analysing the correlation between the karyotypic symmetry and vertical distribution of A. laxifoliata and A. chinghaiensis, it is considered that as altitude rises, the karyotypic asymmetry and ploidy increases. Comparing with the karyotypes of other species distributed in Northeastern China and Japan previously reported, the karyotype of A. valida with oblong-ovoid fruits and 1-2-pinnate leaves is most primitive and that of A. omeiensis with nearly rounded fruits and 3-ternate-pinnate leaves is most advanced in Angelica. Based on the fact that many species including the most primitive and the most advanced species are concentrated in Sichuan, it may be suggested that the center of origin and diversity of Angelica be inSichuan characterized.  相似文献   

10.
八个四倍体鹅观草属物种的核型研究   总被引:1,自引:0,他引:1  
康厚扬  周永红  张海琴  邓小锋  曹刚   《广西植物》2006,26(4):360-365
对8个鹅观草属物种的核型进行了研究。核型公式如下:纤穗鹅观草2n=4x=28=20m+8sm(2sat);紫穗鹅观草2n=4x=28=22m(2sat)+6sm;假花鳞草2n=4x=28=24m(2sat)+4sm;肃草2n=4x=28=22m+6sm(2sat);小颖鹅观草2n=4x=28=22m+6sm(2sat);纤瘦鹅观草2n=4x=28=24m(4sat)+4sm;变颖鹅观草2n=4x=28=20m+8sm(2sat);毛花鹅观草2n=4x=28=24m(2sat)+4sm。它们的核型属1A或2A型。其中后5个物种的核型为首次报道。  相似文献   

11.
三种东亚冷杉植物的核型研究   总被引:4,自引:0,他引:4  
首次报道了急尖长苞冷杉AbiesgeorgeiOrrvar.smithii(ViguieetGaussen)Chenget.L.K.Fu,臭冷杉A.nephrolepis(Traurv.)Maxim和杉松,A.holophyllamaxim等3种东亚冷杉植物的核型,它们的核型公式分别是K(2n)=24=18m(2SC)+6sm,18m(6SC)+6sm和14m(6SC)+10sm,染色体相对长度组  相似文献   

12.
对澳大利亚特产的Callitris属植物C.preissii,C.verrucosa,C.endlicheri(柏科)的核型进行了分析,后2种的为首次报道。它们的核型公式分别为K(2n)=22=22m(2SAT),22m(2SAT)和22m(6SAT),均属1A核型类型。染色体相对长度组成同是2n=22=10M_2+12M_1该3种及其他8种Calltris属植物一致的核型K(2n)=22m和1A类型的通常被认为是最对称和原始的。因此该属在柏科的系统发育上也许处于相当原始的地位。  相似文献   

13.
高成芝  邹畸丽   《广西植物》1995,15(2):166-171
本文分析了广义山蚂蝗属6种1变种的核型,并报道了9种1亚种的染色体数目。假地豆Desmodiumheterocarpon(L.)DC.,伏毛假地豆D.heterocorpo。(L.)DC.var.strigosumvanMeeuwen,单叶假地豆D.rubrum(Lour.)DC..金钱草D.styracifolium(Osbeck.)Merr.及假木豆Dendrolobiumtriangulare(Retz.)Schindl.的核型均为K(2n)=22=22m,属1A类型.但它们的染色体相对长度变化范围有一定的差异,假木豆的较大,假地豆的较小。舞草Codoriocalyxmotorius(Houtt.)Ohashi和圆叶舞草C.gyroides(Roxb.exLink.)Hassk.的核型为K(2n)=22=22m,有的细胞可见随体染色体,属1B类型.根据核型资料比较.作者发现狭义的舞草属比狭义的山蚂螟属和假木豆属较为进化。本文还报道大叶山蚂蝗DesmodiumlaxiflorumDC,波叶山蚂蝗D.sequaxWall.绒毛山蚂蝗D.velutinum(Willd.)DC,异叶山绿豆D.heteroph?  相似文献   

14.
The present paper deals with the karyotypic analysis of Taxodium ascendens Brongn. The somatic chromosomes in root-tip cells of the plant are found to be 2n =22, all with median and submedian constrictions. A character of the karyotype is that the chromosome 10 has a long kinetochore region (Plate 1:1). According to the terminology defined by Levan et al.[18], the karyotype formula is k(2n)=22=20m+2sm, which is different to Huang et Hsu’s[8] K(2n)=24=22m+2B(m). The karyotype belongs to “lA” of Stebbins’[24] karyotypic symmetry and is generally regarded as a relatively primitive one. The species’ chromosome complement is 2n=22=2L+8M2+12M1 according to I.R.L.difined by Kuo et al.[15] based on relative length. The lengths, arm ratios and types of chromosomes of the species are given in Table 1-I. The morphology of the chromosomes and the karyotype, are given in Plate 1:1. In the light of the works of Schlarbaum et al.[21] and Mehra et al.[17], K(2n)=22=20m (2SAT)+2sm and 2n=22=2L+6M2+14M1 are for T. distichum (L.) Rich. (see Table 1-II), K(2n)=20m+2sm and 2n=22=4L+4M2+12M1+2S for T. mucronatum Tenore (see Table 1-III, Plate 1:2), which belong to “lA” and “2A” respectively. The differences between three species in the ratio of the longest to the shortest chromosome, I.R.L. and the proportion of chromosomes with arm ratio >2 show that the karyotype of T. mucronatum is the most advanced and that of T. distichum the most primitive. The present author suggests that the sequence of evolutionary advance be T. distichum, T. ascendens, T. mucronatum. Based on the evidence from the karyotype analyses, ecology and geographical distribution (including fossil), the secondary center of genetic diversity (Fig. 1) and the probable evolu-tionary pattern (Fig. 2) of Taxodium are discussed.  相似文献   

15.
本文首次报道3种北美冷杉Abies amabilis、A.grandis和A.lasiocarpa的根尖体细胞核型、染色体参数及核型模式图。核型公式分别是K(2n)=24=16m(4SC)+8sm、14m(2SC)+10sm和18m(4SC)+6sm,染色体相对长度组成为2n=24=2L+12M2+6M1+4S、2L+12M2+8M1+2S和2L+8M2+12M1+2S。均为2A核型类型。文中还讨  相似文献   

16.
四种云杉的核型分析   总被引:5,自引:0,他引:5  
李林初  王刚  苏苏  徐阿生 《广西植物》2001,21(1):43-46,T001,T002
首次报道了中国珍稀濒危保护植物长叶云杉 ( P. smithiana ( Wall.) Boiss.)和康定云杉 ( P. likian-gensis( Franch.) Pritz.var.montigena( Mast.) Cheng ex Chen)及我国特产的青海云杉 ( P.crassif oliaKom.)和林芝云杉 ( P.likiangensis( Franch.) Pritz.var.linzhiensis Cheng et L.K.Fu)的核型。它们的核型公式都是 K( 2 n) =2 4 =2 2 m+2 sm (林芝云杉有 1条 B染色体 ) ,染色体相对长度组成分别为 2 n=1 4 M2 +8M1 +2 S,2 L+1 2 M2 +6M1 +4S,2 L +1 0 M2 +1 0 M1 +2 S,和 2 L+1 2 M2 +6M1 +4S.均为 2 A (除青海云杉 1 A外 )核型类型。  相似文献   

17.
We give the haploid chromosome numbers of 173 species or subspecies of Riodinidae as well as of 17 species or subspecies of neotropical Lycaenidae for comparison. The chromosome numbers of riodinids have thus far been very poorly known. We find that their range of variation extends from n =?9 to n =?110 but numbers above n =?31 are rare. While lepidopterans in general have stable chromosome numbers, or variation is limited at most a subfamily or genus, the entire family Riodinidae shows variation within genera, tribes and subfamilies with no single modal number. In particular, a stepwise pattern with chromosome numbers that are about even multiples is seen in several unrelated genera. We propose that this variation is attributable to the small population sizes, fragmented populations with little migration, and the behavior of these butterflies. Small and isolated riodinid populations would allow for inbreeding to take place. Newly arisen chromosomal variants could become fixed and contribute to reproductive isolation and speciation. In contrast to the riodinids, the neotropical Lycaenidae (Theclinae and Polyommatinae) conform to the modal n =?24 that characterizes the family.  相似文献   

18.
Karyotypes of 6 species in Angelica L . from Sichuan are studied at population level and the karyotype of A. pseudoselinum is firstly reported . It is found that the number of chromosomes are invariably 2n = 2x =22 , with most of them are median and submedian centromeric chromosomes, while subterminal centromeric chromosomes exist in A. omeiensis . The majority of karyotypes belong to 2A, and Shihuiyao population of A. laxifoliata has 1A types . As for karyotypic formula , A. omeiensis is 2n =22 = 10m+ 2sm+ 10st , A. maowenensis is 2n =22= 16m+ 4sm+ 2sm (SAT) , A. sinensis is 2n = 22 = 14m+ 8sm, A. apaensis is 2n = 22 = 14m+8sm, and A. pseudoselinum is 2n =22 = 12m+ 8sm+2sm (SAT ) . However, different populations of A. laxiforliata don’t have the same karyotypic formulae, and there are some variations between the caryotypes more or less . According to Stebbins, A. omeiensis’s evolution status was showed by the highest index of asymmetry among six species studied in this paper , while A. laxiforliata is a little primitive because of its lower index of asymmetry and its 1A caryotypes . However , the morphological, anatomic , karyotypic characters and that of pollen grains are evolving asynchronously , suggesting that, Sichuan as one of the frequency centers of Angelica L . in China , is also one of thedifferentiation centers of Angelica L .  相似文献   

19.
四川当归属六种植物的核型   总被引:3,自引:0,他引:3  
从居群水平对四川当归属(AngelicaL.)6种植物的核型进行了研究,其中管鞘当归核型为首次报道。6个种的染色体均为2n=2x=22,多为中部和近中部着丝粒染色体,核型多为2A型,仅疏叶当归石灰窑居群为1A型;峨眉当归核型为2n=22=10m 2sm 10st,茂汶当归核型为2n=22=16m 4sm 2sm(SAT),当归核型为2n=22=14m 8sm,阿坝当归核型为2n=22=14m 8sm,管鞘当归核型为2n=22=12m 8sm 2sm(SAT),而疏叶当归不同居群的核型或多或少发生了不同程度的变异。参照Stebbins的观点,峨眉当归以核型不对称系数最高而在6个种中显示一定的核型进化性,疏叶当归不对称系数较低,且出现1A型核型因而体现出一定的原始性。但是,综合形态解剖、花粉性状以及核型特征可以看出,四川当归属植物各性状间具有进化的不同步性,这也表明,作为当归属分布频度中心之一的四川地区,同时也是当归属的分化中心之一。  相似文献   

20.
A new species of lac insect, Paratachardina javanensis Kondo and Gullan, sp. nov. (Hemiptera: Coccoidea: Kerriidae), is described and illustrated from a collection on Myrica rubra Siebold and Zucc. (also called Morella rubra Lour., Myricaceae) in West Java, Indonesia. This lac insect species is most similar morphologically to the pestiferous lobate lac scale, Paratachardina pseudolobata Kondo and Gullan. A comparison of the two species and an updated taxonomic key to all named Paratachardina species are provided.  相似文献   

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