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1.
Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae) is an indigenous parasitoid of Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae) from southern China; the effects of constant temperatures on the life history of E. sp. nr. furuhashii were examined in the laboratory. The developmental period ranged from 39.2 days at 20°C to 12.40 days at 32°C. A total of
263.4 degree-days were required to complete development with a lower developmental threshold temperature of 11.1°C. Of the
eggs produced, 59.3% completed development at 20°C with completion increasing to 71.5% at 26°C. Adult female longevity was
10.8 days at 20°C and 5.2 days at 32°C while the mean daily offspring reproduced per female was highest at 29°C with 5.9 offspring.
Adult oviposition peaked three days after emergence at 26, 29 and 32°C, and four days post-emergence at 20°C and 23°C. The
total numbers of offspring produced per female ranged from 25.7 individuals at 32°C to 41.1 individuals at 20°C. The sex ratio
had a female bias and ranged from 0.72 at 17°C to 0.51 at 35°C. The intrinsic rate of increase was 0.1727 at 29°C followed
with 0.1606 at 32°C. Results indicated that E. sp. nr. furuhashii reaches its maximum biological potential at temperatures ranging from 26°C to 32°C. 相似文献
2.
The potential for using the entomopathogenic fungus Lecanicillium muscarium to control the sweetpotato whitefly, Bemisia tabaci has been established in the laboratory by other studies. Laboratory studies however frequently overestimate the level of
control achieved by biological control agents in the glasshouse. Before full-scale commercial or field development is considered,
glasshouse trials are required to confirm laboratory results. Under both controlled laboratory and glasshouse conditions high
mortality of second instar B. tabaci was recorded after application of L. muscarium. The potential of incorporating L. muscarium into integrated pest management strategies for the control of B. tabaci is discussed. 相似文献
3.
Lecanicillium muscarium is a widely occurring entomopathogenic fungus. Laboratory studies were conducted to determine the efficacy of L. muscarium against different instars of Bemisia tabaci on tomato and verbena foliage after two incubation times (3 and 7 days). Significant reduction in B. tabaci numbers were recorded on fungus treated plants (p < 0.001). Second instar B. tabaci proved most susceptible to L. muscarium infection. There was no significant difference in mortality of B. tabaci second instars after either 3 or 7 days exposure to L. muscarium on either host plant. The importance of the speed of pest mortality following treatment and the potential of L. muscarium to be incorporated into an integrated pest management strategy for the biocontrol of B. tabaci on tomato and verbena plants are discussed. 相似文献
4.
del Rosario Abraham-Juárez M del Carmen Rocha-Granados M López MG Rivera-Bustamante RF Ochoa-Alejo N 《Planta》2008,227(3):681-695
Capsaicinoids are responsible for the pungent taste of chili pepper fruits of Capsicum species. Capsaicinoids are biosynthesized through both the phenylpropanoid and the branched-fatty acids pathways. Fragments
of Comt (encoding a caffeic acid O-methyltransferase), pAmt (a putative aminotransferase), and Kas (a β-keto-acyl-[acyl-carrier-protein] synthase) genes, that are differentially expressed in placenta tissue of pungent chili
pepper, were individually inserted into a Pepper huasteco yellow veins virus (PHYVV)-derived vector to determine, by virus-induced gene silencing, irrespective of whether these genes are involved in
the biosynthesis of capsaicinoids. Reduction of the respective mRNA levels as well as the presence of related siRNAs confirmed
the silencing of these three genes. Morphological alterations were evident in plants inoculated with PHYVV::Comt and PHYVV::Kas constructs; however, plants inoculated with PHYVV::pAmt showed no evident alterations. On the other hand, fruit setting was normal in all cases. Biochemical analysis of placenta
tissues showed that, indeed, independent silencing of all three genes led to a dramatic reduction in capsaicinoid content
in the fruits demonstrating the participation of these genes in capsaicinoid biosynthesis. Using this approach it was possible
to generate non-pungent chili peppers at high efficiency. 相似文献
5.
Van Immerseel F Eeckhaut V Boyen F Pasmans F Haesebrouck F Ducatelle R 《Antonie van Leeuwenhoek》2008,94(3):455-461
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7.
Hippophae rhamnoides ssp. sinensis occurs mainly in the arid regions of northwest China. The wood stands of this subspecies play an important role in maintaining
the local ecosystems in these regions. In addition, the genetic characteristics are essential to understand the historical
range changes of this subspecies and its morphological differentiation with other subspecies. In this study, we developed
nine microsatellite loci for this subspecies for the first time. We used the combining biotin capture method to enrich AG/CT/AC/GT/CG/GTG/CCA
microsatellites. Twenty-six microsatellites were isolated from the enriching library and nine of them were found to be polymorphic
through screening 12 distantly distributed individuals. The number of alleles per locus ranged from three to twelve and expected
heterozygosity from 0.2659 to 0.4767, respectively. We further performed cross-priming tests in another subspecies and two
congeneric species. These firstly isolated loci will provide a useful tool to investigate the genetic structure of this subspecies
and its morphological differentiation from the other subspecies. 相似文献
8.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
9.
10.
Transmission of tomato leaf curl geminiviruses by Bemisia tabaci: effects of virus isolate and vector biotype 总被引:1,自引:0,他引:1
Cultures of Bemisia tabaci from Ivory Coast (IC), Pakistan (PK) and USA (US B-type) were compared for the frequency with which they transmitted three tomato geminivirus isolates: Indian tomato leaf curl virus from Bangalore (ITmLCV), and tomato yellow leaf curl viruses from Nigeria (TYLCV-Nig) and Senegal (TYLCV-Sen). Frequency of transmission from tomato to tomato depended both on the whitefly culture and the virus isolate. US B-type and IC whiteflies transmitted TYLCV-Sen more frequently than ITmLCV whereas PK whiteflies transmitted ITmLCV more frequently than TYLCV-Sen. US B-type whiteflies transmitted both viruses four to nine times more frequently than IC whiteflies. TYLCV-Nig was transmitted rarely by US B-type and not at all by IC whiteflies. Previous work indicates that the geminivirus coat protein controls vector transmissibility. The differential adaptation of TYLCV-Sen to transmission by US B-type whiteflies and of ITmLCV to PK whiteflies was associated with a large difference in epitope profile of the coat proteins of the two viruses. Also, the readily transmissible TYLCV-Sen differed appreciably in epitope profile from the poorly transmissible TYLCV-Nig, which reached a consistently greater concentration in source tissues but lacked epitope 18. However, the lack of epitope 18 in ITmLCV did not prevent its transmission by US B-type whiteflies. Differences in frequency and specificity of geminivirus transmission by whitefly cultures from different countries therefore were associated with differences among epitope profiles of the coat proteins of the viruses, but the structural features of the proteins that control transmission remain to be determined. 相似文献
11.
Host-handling behavior is an important aspect of parasitoid foraging behavior. When a parasitoid encounters a potential host, the handling behavior starts with the evaluation of the host and continues if the host has been judged acceptable. Host handling is usually terminated after egg laying or host feeding and host marking. Host-handling behavior of an arrhenotokous population of two Eretmocerus species, E. mundus Mercet and E. eremicus Rose and Zolnerowich, along with a thelytokous population of E. mundus were compared under laboratory conditions. Several elements of host-handling behavior, including encountering, ascending, turning on host, descending, preening, egg laying, and host feeding were recorded. There were no correlations among the durations of these phases across parasitoid populations/species or host nymphal instars. Duration of different phases of host-handling behavior showed only slight and sometimes significant differences between different Eretmoceruspopulations/species. The actual laying of the egg had the longest duration of all host-handling behaviors, and was longer on third nymphal instars than on younger ones. Females of the three populations/species accepted the first three nymphal stages either for egg laying or for host feeding. Females spent a lot of time to make wounds in the host when preparing for host feeding, and eventually killed the host. The implications of these findings for the use of the different Eretmoceruspopulations/species in biological control are discussed. 相似文献
12.
A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
13.
Sarawood Sungkaew Atchara Teerawatananon John A. N. Parnell Chris M. A. Stapleton Trevor R. Hodkinson 《Kew Bulletin》2008,63(4):669-673
Summary A new monotypic bamboo genus Phuphanochloa (Poaceae: Bambusoideae) from north-eastern Thailand is described, together with a new species, P. speciosa. 相似文献
14.
Conidia of two morphologically different types, one with a basal appendage only and the other with appendage at both ends, were isolated from the stems of Paeonia suffruticosa. Single conidial isolates of both types of conidia yield identical colonies, which then produced both types of conidia on agar media depending on temperature, thus showing that both types of conidia belong to the same fungus. Seimatosporium botan is described based on its morphological characteristics. The teleomorph of the fungus was first found on sterilized P. suffruticosa stems placed on water agar, when grown at 5°C for 2 months in 12-h photoperiod. Discostroma botan is described for this fungus. The teleomorph is also found on the same host in the field. 相似文献
15.
D. J. Goyder 《Kew Bulletin》2008,63(2):331-333
Summary
Funastrum rupicola Goyder, a new species of Apocynaceae: Asclepiadoideae from Bolivia, is described and illustrated. The conservation status of this species is assessed. 相似文献
16.
Spiromesifen is a novel insecticide/acaricide belonging to the new chemical class of spirocyclic phenyl-substituted tetronic
acids, and it is especially active against whiteflies and tetranychid spider mite species. In the biologically based integrated
pest management (IPM) programs in vegetable crops in southeastern Spain, the key natural enemies include the parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) for sweetpotato whitefly control, and the minute pirate bug, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) for western flower thrips control. Side effects of spiromesifen on E. mundus and O. laevigatus, were evaluated by laboratory studies and field trials in commercial greenhouses under IPM programs. Results indicate that
spiromesifen had favourable selectivity to O. laevigatus and E. mundus and would complement biological control of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) by E. mundus.
Handling editor: Patrick De Clercq 相似文献
17.
Domenico Fulgione Valeria Maselli Giuseppe Pavarese Daniela Rippa Rakesh K. Rastogi 《European Journal of Wildlife Research》2009,55(4):385-396
During the last years, the population of Italian hare decreased significantly in central and south Italy. This is imputable
to harvest, poaching, habitat fragmentation, and the probable competition with congeneric European hare introduced in the
last decades by man for hunt. The goal of our work is to define the ecological characteristics of the two aforementioned species
in order to understand how landscape facilitates or impedes movement. Spatially explicit models are used to identify a species
ecological niche and to build a landscape model of suitability. To validate ecological modeling of landscape, we performed
a population genetic analysis. Results suggest that the Italian hare shows an ecological requirement close to average of available
resources in the considered landscape. The genetic structure of this autochthonous species validates the habitat suitability
model and highlights the differences with European hare. This work analyzes for the first time the ecological relationship
between those two sympatric species. 相似文献
18.
The flagfish (Jordanella floridae) is commonly used in studies of wetlands ecology. Here we describe the isolation of ten microsatellite loci, six of which
were polymorphic. The observed number of alleles ranged from 4 to 24 and observed heterozygosities ranged from 0.59 to 0.81
for the polymorphic loci. The isolation of these markers will enable estimations of genetic diversity in natural populations. 相似文献
19.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献
20.
Stefanie Kimbacher Ingrid Gerstl Branko Velimirov Sylvia Hagemann 《Molecular genetics and genomics : MGG》2009,282(2):165-172
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding
region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献