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1.
Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is the most recent of four tephritid fruit fly species accidentally introduced into Hawaii. Although parasitoids have been released against other tephritid fruit fly species and have shown partial success in Hawaii, no parasitoids were released until 2004 to suppress populations of B. latifrons. The present study was conducted to document the parasitoid complex that has naturally established against B. latifrons in Hawaii and to assess whether there is a need for improving the biological control of this species. Based on ripe turkeyberry (Solanum torvum Sw) fruit collections over three consecutive years B. latifrons was the dominant tephritid fruit fly infestating turkeyberry at all four sites surveyed, across three major islands in Hawaii. The overall percentage parasitism of B. latifrons ranged from a low of 0.8% (Hana, Maui) to a high of 8.8% (Kahaluu, Oahu). Five primary parasitoid species were recovered from individually held B. latifrons puparia: Fopius arisanus (Sonan), Psyttalia incisi (Silvestri), Diachasmimorpha longicaudata (Ashmead), D. tryoni (Cameron), and Tetrastichus giffardianus Silvestri. F. arisanus was the predominant parasitoid at three of the four sites. Low levels of parasitism suggest that there is a need to improve biological control of B. latifrons, to minimize chances of this species causing economic impacts on crop production in Hawaii. We discuss the possibility of improving biological control of B. latifrons through augmentative releases of F. arisanus or introduction and release of specific and efficient new parasitoid species.  相似文献   

2.
Random Amplified Polymorphic DNA (RAPD) showed a high degree of polymorphism in nine species of bamboo, Dendrocalamus giganteus Wall ex Munro, D. asper Becker ex K. Heyn, D. longispathus (Kurz) Kurz, Bambusa vulgaris `Striata', B. ventricosa, B. bambos (L.) A. Voss, B. atra Lindley, Gigantochloa atroviolacea Wdjaja and Arundinaria hindsii, in Sri Lanka. The lowest mean genetic distance of 0.143 was between B. vulgaris and B. ventricosa. They could however be distinguished morphologically. The genetic distances separating D. longispathus from D. giganteus and D. asper were both greater than that between the latter two species, which had a value of 0.313. Although the genetic distances between Bambusa vulgaris, B. ventricosa and B. bambos were relatively small, B. atra separated from them at greater distances. The smaller genetic distances between G. atroviolacea and B. vulgaris, B. ventricosa and B. bambos indicated that G. atroviolacea had a closer affinity to these three Bambusa species than B. atra. A. hindsii with the greatest genetic distances from all other species in the study, was not related to any of them. RAPD analysis was useful in determining the genetic diversity and relationships and in detecting problematic generic assignments.  相似文献   

3.
TheNor-loci of polyploid wheats and their putative diploid progenitor species were assayed by probing isolated nuclear DNA with ribosomal DNA spacer sequences (spacer rDNA sequences, isolated by cloning), from theNor-loci of genomes B (Triticum aestivum), G (T. timopheevi), B (syn. S,T. speltoides), A (T. monococcum) and V (Dasypyrum villosum). DNA samples for analysis were digested with the restriction endonuclease Taq 1 and assayed by DNA-DNA hybridization under standard (37°C) and high stringency (64°C) conditions. The assay procedure emphasized differences between the divergent spacer sequences of the polyploid species and allowed relative homologies to the respective sequences in diploid species to be established. — The studies indicated thatT. timopheevi andT. speltoides contain different sets of spacer rDNA sequences which were readily distinguishable and, in the case ofT. timopheevi, assigned toNor-loci on different chromosomes. This contrast with the spacer rDNA sequences of the majorNor-loci on chromosomes 1 B and 6 B inT. aestivum, which were difficult to distinguish and were deduced to contain very similar sequences. Among the diploid progenitor species only the spacer rDNA fromT. speltoides shared close homology with polyploid wheat species. OneNor-locus inT. timopheevi (on chromosome 6 G) did not show close homology with any of the rDNA spacer probes available. — The data suggestsT. speltoides was the origin of someNor-loci for both theT. timopheevi andT. turgidum lines of tetraploid wheats. The possibility that the 6GNor-locus inT. timopheevi may have derived from an unknown diploid species by introgressive hybridization is discussed. The spacer rDNA sequence probe fromT. monococcum shared good homology with some accessions ofD. villosum and a line ofT. dicoccoides; the implications of this finding for evolution of present-day wheats are discussed.  相似文献   

4.
In contrast to the well-known blue-green algal containing lichens several green algal containing lichens, belonging to very different genera, show regular connections to free-living or ± lichenized blue-green algae, mainlyStigonema. Most of these lichens have squamulose thalli. This lichen-algal relationship, regarded as cyanotrophy, may be either facultative or obligate. Some of the species occur only on very poor, acidic rocks onStigonema, while they occur independent ofStigonema in high nutrient biotops. Obligate species cover the blue-green algae with hyphae and some of these species cover the algae so extensively that one can call these connections paracephalodia. — Two species and one variety are new to science from the mainly Himalayan genusBryonora. They occur in high elevations in Nepal and are cyanotrophic.Bryonora selenospora has thick, halfmoon-shaped to slightly twisted ascospores. The other two new taxa areB. reducta andB. rhypariza var.cyanotropha. There are several other cyanotrophic lichen taxa besides the ones described here. They will be introduced at a later occasion.
Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.  相似文献   

5.
Deneke  Rainer 《Hydrobiologia》2000,433(1-3):167-172
A review of the literature on rotifers and crustacean zooplankton in highly acidic environments revealed that data from eleven aquatic environments on three continents (America, Europe, Japan) with a pH 3 are available. Seven sites are influenced by volcanism or weathering processes in the catchment area, four others originated from human mining activities. Species richness was generally low. Only 16 species are found and 1–11 species are reported for each area. These studies clearly show that small littoral or benthic rotifers predominate over crustaceans under highly acidic conditions. In the Lusatian mining area (Germany), all lakes are colonized by zooplankton, even the most acidic one with a pH of 2.3. The core community consists of the rotifers Cephalodella hoodi, C. gibba, Elosa worallii and Rotaria rotatoria, with C. hoodi and E. worallii the most abundant. Larger species, such as the rotifer Brachionus sericus or the cladoceran Chydorus sphaericus, occur at a pH close to 3. A similar pattern is reported from acidic mining lakes in Illinois, U.S.A. Many of these species can also be found in less acidic softwater or even alkaline environments due to the tolerance of a broad range of pH values. Elosa worallii and Brachionus sericus are probably the most acidophilic rotifer species, though at least the latter can also grow at neutral pH in the laboratory. Clear understanding of the pH limits of B. sericus in nature may also have been complicated by the fact that it has probably in the past been wrongly named as B. urceolaris (phenotype `sericus'). The typical B. urceolaris cannot tolerate extremely low pH. Overall, generalist species with a worldwide distribution seem to play the major role in the colonization of anthropogenic highly acidic lakes.  相似文献   

6.
This first study of the whole genusAgathis makes use of recent local revisions of the New Caledonian and Australian species which are all maintained. The male cone is shown to have most of the taxonomically useful variation, and this confirms the findings of two partial revisions centred on Indonesian species. Thirteen species are recognized, two of which have two subspecies. New Caledonia has five, and Australia three, sympatric species. Otherwise the species are allopatric except for a few populations of central MalesianA. dammara within the range of west MalesianA. borneensis. One of these montane populations is the distinctiveA. dammara subsp.flavescens of Malaya, formerly a full species.Two groups and three individually distinctive species can be recognized on microsporophyll characters. The larger, group B, comprizes eight species,A. australis (New Zealand),A. corbassonii, A. lanceolata andA. montana (New Caledonia),A. macrophylla (Melanesian islands and includingA. obtusa andA. vitiensis),A. atropurpurea (Australia),A. dammara (mainly central Malesia) andA. borneensis (west Malesia); both the last have long synonymies. The smaller species, group (A), comprizesA. microstachya (Australia) andA. labillardieri (west New Guinea and the Sepik basin). The individually distinctive species areA. moorei andA. ovata of New Caledonia andA. robusta of Australia with its new subspeciesnesophila, described here, of eastern New Guinea and New Britain.  相似文献   

7.
SixBrassica species, known as the triangle of U, and four species from related genera were characterized by DNA fingerprinting with simple repetitive oligonucleotide probes. Our results show that CT-, TCC-, and GTG-repeat motifs are equally abundant in the genomes of the sixBrassica species. In contrast, GATA-, GGAT-, and GACA-multimers are unevenly distributed among different species. As judged from the number and strength of hybridization signals, the highest copy number of all three motifs occurs inBrassica nigra, while the lowest is observed inB. oleracea. The abundance of GATA-and GACA-repeats varies in a coordinate way. The amphidiploid genomes ofB. juncea, B. carinata, andB. napus each harbour intermediate amounts of (GATA)4 and (GACA)4-detected repeats as compared to their diploid progenitors, thus supporting the concept of the U triangle. GATA-, GACA-, and GGAT-repeats were also abundant inEruca sativa andSinapis arvensis, but not inRaphanus sativus andSinapis alba. These results support the idea thatBrassica nigra is more closely related toSinapis arvensis than to otherBrassica species such asB. rapa andB. oleracea.  相似文献   

8.
The sequences of the Internal Transcribed Spacer regions (ITS1 and ITS2) within the genes coding for cytoplasmic ribosomal (r) RNAs on the A chromosome complement of 34 members of the higher plant genus Brachycome (synonym Brachyscome) have been compared. The ITS1 sequence of species within the B. lineariloba complex contains a 56 bp tract that is absent from at least 12 Brachycome species but is present in other species within Brachycome as well as other Asteraceae. Phylogenetic data support the suggestion that the number of chromosomes reduced in several independent Brachycome lineages during speciation. Comparisons with the B chromosome ITS2 of B. dichromosomatica cytodeme A1 suggests an origin of the B chromosome at a time prior to the divergence of the four cytodemes of B. dichromosomatica.  相似文献   

9.
We tested the hypothesis that populations of the parthenogenetic parasitic wasp Encarsia formosa Gahan (Hymenoptera: Aphelinidae) differed in their ability to use two different host species, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae). Of the three wasp populations tested, two populations had been reared for many generations on B. tabaci and one population had been reared for many years on T. vaporariorum. Performance was measured by the number of whitefly nymphs that were successfully parasitized by individual wasps, and performance on either host was measured in separate experiments. There was variation between wasp populations in their performance on the host B. tabaci, with one wasp population reared for many years on this host performing considerably better than the other two populations. There were no significant differences between populations in their use of the preferred host, T. vaporariorum. The experiments were conducted in such a way that we could distinguish heritable differences between populations from environmentally-induced conditioning differences due to the immediate host from which an individual wasp enclosed. In either experiment there were no significant effects of conditioning, although there was a trend within each population for wasps conditioned on T. vaporariorum to have higher performance than those conditioned on B. tabaci. Thirdly, we conducted a selection experiment, initiated with wasps from a single population historically reared on T. vaporariorum, to measure the effect of laboratory rearing on different hosts for 17 generations. We did not see any difference in the performance of wasps on B. tabaci after this period of rearing on either of the two hosts. In summary, populations of E. formosa do differ in their relative performance on B. tabaci. The one population that was tested further did not show any response to selection by rearing, but the ability to respond to selection on performance may not be equal for all populations. The possibility that wasp populations have differential performance on particular hosts may affect the use of this species as a biological control agent.  相似文献   

10.
Ludwig Tent 《Hydrobiologia》1987,154(1):189-199
The effects of food density on competition between Bosmina longirostris and Bosmina fatalis from Lake Kasumigaura were examined in the laboratory. When the animals were reared with a high concentration of Chlorella, B. fatalis, which is slightly larger than B. longirostris in body length, had larger brood sizes and a higher rate of population growth than B. longirostris. When the species were reared together at high food density, B. fatalis overcame B. longirostris. But B. longirostris won the competition at low food density.The effects of Microcystis on the competition were also examined. When the two species of Bosmina were reared in a mixture of Chlorella and Microcystis, the populations of both species hardly increased, although individual B fatalis showed slightly better individual growth and reproduction than B. longirostris. Decomposed Microcystis, however, was utilized well by both species.In Lake Kasumigaura, the decomposition of abundant Microcystis seemed to raise the food level, favouring B. fatalis over B. longirostris.  相似文献   

11.
廖苗  曾思金  唐光大 《广西植物》2022,42(10):1717-1729
秦岭藤属(Biondia Schltr.)是中国特有属,约13种,驼峰藤属(Merrillanthus Chun&Tsiang)是仅在我国与柬埔寨分布的单种属,目前两个属均被归并到白前属(Vincetoxicum Wolf),由于取样和系统发育分析尚存一些欠缺,因此其系统位置和归属尚需进一步确认。该文使用2个核糖体基因序列片段(ITS、ETS)、5个叶绿体基因序列片段(psbA-trnH、trnG、trnL、trnL-F、trnT-L),以及二者的合并数据,重建娃儿藤亚族(Tylophorinae)(包含属的模式秦岭藤[B.chinensis Schltr.=V.shaanxiense(Schltr.) Meve&Liede]与驼峰藤[M.hainanensis Chun&Tsiang=V.hainanense(Chun&Tsiang) Meve, H. H. Kong&Liede])的系统发育树。结果表明:秦岭藤属与驼峰藤属均包含在白前属中,秦岭藤与青龙藤[B.henryi(Warb.) Tsiang&Li=V.henryi(Warb....  相似文献   

12.
We undertook a preliminary investigation of the cuticular extracts of five common mantid species in the eastern United States: Tenodera sinensis (Saussure), T. angustipennis (Saussure) and Mantis religiosa (Linnaeus) introduced from the Old World and Stagmomantis carolina (Johannson) and Bruneria borealis (Scudder), which are New World species. The major components of these mixtures were normal alkanes, predominately hentriacontane, or in the case of the parthenogenic species B. borealis, tritriacontane. Tricontanal was detected in the extracts of all five species, and smaller amounts of other aldehydes and n-tricontanol were detected in some species. Complex mixtures of methyl and dimethylalkanes also were present in these extracts. The composition of the cuticular hydrocarbons of these mantids may be an adaptation for reduction of evaporative water loss in these insects that inhabit open fields.  相似文献   

13.
The family Sordariaceae incorporates a number of fungi that are excellent model organisms for various biological, biochemical, ecological, genetic and evolutionary studies. To determine the evolutionary relationships within this group and their respective phylogenetic placements, multiple-gene sequences (partial nuclear 28S ribosomal DNA, nuclear ITS ribosomal DNA and partial nuclear β-tubulin) were analysed using maximum parsimony and Bayesian analyses. Analyses of different gene datasets were performed individually and then combined to generate phylogenies. We report that Sordariaceae, with the exclusion Apodus and Diplogelasinospora, is a monophyletic group. Apodus and Diplogelasinospora are related to Lasiosphaeriaceae. Multiple gene analyses suggest that the spore sheath is not a phylogenetically significant character to segregate Asordaria from Sordaria. Smooth-spored Sordaria species (including so-called Asordaria species) constitute a natural group. Asordaria is therefore congeneric with Sordaria. Anixiella species nested among Gelasinospora species, providing further evidence that non-ostiolate ascomata have evolved from ostiolate ascomata on several independent occasions. This study agrees with previous studies that show heterothallic Neurospora species to be monophyletic, but that homothallic ones may have a multiple origins. Although Gelasinospora and Neurospora are closely related and not resolved as monophyletic groups, there is insufficient evidence to place currently accepted Gelasinospora and Neurospora species into the same genus.  相似文献   

14.
A loop-mediated isothermal amplification (LAMP) assay system was employed for detecting Bacillus anthracis spores in pure cultures as well as in various simulated powder samples. The specificity of the designed LAMP primer sets was validated by assaying 13 B. anthracis strains and 33 non-B. anthracis species. The detection limits of the LAMP assay were 10 spores/tube for pure cultures and 100 spores/2 mg powder for simulated powder samples. The results show that the LAMP protocol is a promising method for detecting B. anthracis.  相似文献   

15.
A low-copy, non-coding chromosome-specific DNA sequence, isolated from common wheat, was physically mapped to the distal 19% region of the long arm of chromosome 3B (3BL) of common wheat. This sequence, designated WPG118, was then characterized by Southern hybridization, PCR amplification and sequence comparison using a large collection of polyploid wheats and diploid Triticum and Aegilops species. The data show that the sequence exists in all polyploid wheats containing the B genome and absent from those containing the G genome. At the diploid level, it exists only in Ae. searsii, a diploid species of section Sitopsis, and not in other diploids including Ae. speltoides, the closest extant relative to the donor of the B genome of polyploid wheat. This finding may support the hypothesis that the B-genome of polyploid wheat is of a polyphyletic origin, i.e. it is a recombined genome derived from two or more diploid Aegilops species.  相似文献   

16.
Summary Chloroplast DNA (cpDNA) restriction endonuclease patterns are used to examine phylogenetic relationships between Bromus subgenera Festucaria and Ceratochloa. Festucaria is considered monophyletic based on the L genome, while Ceratochloa encompasses two species complexes: the B. catharticus complex, which evolved by combining three different genomes, and the B. carinatus complex, which is thought to have originated from hybridization between polyploid species of B. catharticus and diploid members of Festucaria. All species of subgenus Ceratochloa (hexaploids and octoploids) were identical in chloroplast DNA sequences. Similarly, polyploid species of subgenus Festucaria, except for B. auleticus, were identical in cpDNA sequences. In contrast, diploid species of subgenus Festucaria showed various degrees of nucleotide sequence divergence. Species of subgenus Ceratochloa appeared monophyletic and phylogenetically closely related to the diploid B. anomalus and B. auleticus of subgenus Festucaria. The remaining diploid and polyploid species of subgenus Festucaria appeared in a distinct grouping. The study suggests that the B. catharticus complex must have been the maternal parent in the proposed hybrid origin of B. carinatus complex. Although there is no direct evidence for the paternal parent of the latter complex, the cpDNA study shows the complex to be phylogenetically very related to the diploid B. anomalus of subgenus Festucaria.  相似文献   

17.
18.
A comparison of karyotypes ofBrachyscome breviscapis (2n = 8),B. lineariloba cytodemes E (2n = 10), B (2n = 12) and C (2n = 16) suggests that these species have a homoelogous basic set of four chromosome pairs, two large pairs and two small, and that theB. lineariloba cytodemes E, B and C are related toB. breviscapis by successive additions of small chromosomes. A pronounced asynchrony of chromosome condensation between these large and small chromosomes has been observed. In the artificial hybrids betweenB. dichromosomatica (2n = 4) ×B. breviscapis, and theB. lineariloba cytodemes, theB. dichromosomatica chromosomes are similar in size and condensation behaviour to the small chromosomes ofB. breviscapis and ofB. lineariloba cytodemes E, B and C. Meiotic pairing in these hybrids also demonstrates the strong affinities between these chromosomes. It is suggested thatB. breviscapis may be of amphidiploid origin between a species with two large early condensing chromosome pairs and another,B. dichromosomatica-like species with two small late condensing pairs. It seems most likely that the additional small and late condensing chromosomes inB. lineariloba cytodemes E, B and C are derived from theB. dichromosomatica-like parent, and that each addition increases vigour, fecundity and drought tolerance, allowing these cytodemes to colonize more open and arid environments. Transmission of the univalents in the quasidiploidB. lineariloba cytodeme E was verified as being via the pollen, and not via the embryo sacs.The cytology ofBrachyscome lineariloba (Compositae, Asteroidae), 10.  相似文献   

19.
Twenty isolates of four species of entomopathogenic hypocrealean fungi (Beauveria bassiana, Beauveria brongniartii, Isaria farinosa, and Metarhizium anisopliae) were found to be pathogenic to adults of the Asian longhorned beetle, Anoplophora glabripennis. Survival times for 50% of the beetles tested (ST50) ranged from 5.0 (M. anisopliae ARSEF 7234 and B. brongniartii ARSEF 6827) to 24.5 (I. farinosa ARSEF 8411) days. Screening studies initially included strains of B. brongniartii, which is registered as a microbial control agent in Europe, Asia and South America but not in North America. At that time, we could not confirm that this fungal species is native to North America which added uncertainty regarding future registration of this species for pest control in the USA. Therefore, subsequent bioassays documented median survival times for three M. anisopliae isolates (5–6 days to death) and two of these isolates are suggested for further development because they are already registered for pest control in the USA. An erratum to this article can be found at  相似文献   

20.
Summary This study used the microsatellite locus B10 to determine the frequency of colonies with multiple patrilines in a previously unexamined group, the North American bumble bees (Bombus). The effective mating frequency (me) was greater than 1 in six of 28 colonies. Five of 11 species tested showed at least one incidence of polyandry: four species from the subgenus Pyrobombus (B. bimaculatus, B. impatiens, B. mixtus, B. ternarius) and one species from the parasitic subgenus Psithyrus (B. citrinus). The B10 locus showed high cross-species amplification success for North American Bombus.  相似文献   

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