ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1570-7458
    Keywords: Aphids ; Sitobion avenae ; cereals ; monoecy ; clones ; sexual morphs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The production of sexual morphs was compared for French clones of S. avenae. Sal was collected in the Rennes basin (West of France), Sa2 by the seaside in the Pas de Calais (North of France) and Sa3 near Angoulême in the south-western part of the country. 1): aphids of Sal and Sa2 were reared at three constant temperature-photoperiod conditions: 10°C/12 L; 15°C/12 L and 20°C/16 L. Males were produced by both clones at 10°C/12 L and 15°C/12 L. More of them were produced at 15°C than at 10°C with some interclonal differences. The clones differed mainly by their ability to produce gynoparae and oviparae. Sal produced them only at 15°C/12 L and Sa2 only at 10°C/12 L. Gynoparae of Sa2 produced only oviparae whereas those of Sal produced a mixture of oviparae and virginoparae specially at the end of the reproducing sequence. A large part of both clonal populations did not turn into sexual morphs and remained parthenogenetic until the 3rd generation. 2): aphids of Sal, Sa2 and Sa3 were exposed to decreasing photoperiods and temperatures simulating two summer-autumn climatic sequences, only different by cumulated temperatures. Starting mid October males were produced by the three clones under both climatic sequences, but more under the warmer than under the colder sequence. When produced, oviparae occured at the same period than males did. For Sa2 oviparae were produced under both climatic sequences and in reduced quantities. For Sal and Sa3 oviparae were only produced under the warmer climatic sequence but in large number for Sal and in reduced number for Sa3. It was shown that the three clones were genetically holocyclic and probably able to produce some sexual morphs outside normal autumn conditions. The differences between these results and some others obtained with British clones were discussed. They may be due to clonal differences in the degree of evolution of S. avenae from heteroecy to monoecy.
    Notes: Abstract On a comparé les modalités de la production de formes sexuées par deux ou trois clônes de Sitobion avenae F. originaires de régions océaniques de la France. Deux expérimentations ont été faites, l'une en conditions climatiques constantes et l'autre en conditions simulant un climat d'automne. Les trois clônes sont génétiquement holocycliques et deux d'entre eux, étudiés plus en détail, diffèrent par certaines modalités de leur production de sexués, l'un formant en particulier des femelles ovipares à 10°C/12 h de photophase et l'autre à 15°C/12 h de photophase. Au contraire, ces clônes conservent des caractères généraux identiques, ils forment des andropares aptères et des gynopares ailés. Ils paraissent ainsi moins dégradés par rapport au type primitif hétéroécique qu'un autre clône étudié en Grande-Bretagne. Les limits d'extrapolation de ces résultats à ce qui se passe dans la nature sont discutées.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1570-7458
    Keywords: Cereal aphids ; Rhopalosiphum padi ; Sitobion avenae ; rate of increase ; fecundity ; alate ; apterous ; clone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Cette étude a eu pour but d'évaluer l'importance de facteurs intrinsèques (clone et morphe) sur les paramètres du taux d'accroissement de Sitobion avenae (F.) et Rhopalosiphum padi (L.). Pour chaque espèce, trois clones originaires de régions océaniques françaises ont été comparés à 20 °C pour les morphes exules ailés et exules aptères. L'effet du clone est significatif sur l'âge reproducteur (durée comprise entre la naissance du puceron et le début de sa phase de reproduction) et sur le taux intrinsèque d'accroissement naturel. Il est plus faible que celui du morphe avec lequel il intéragit dans le cas de R. padi. Les différences interspécifiques relevées mettent en évidence les capacités d'accroissement supérieures de R. padi par rapport à celles de S. avenae, dans le cas des ailés comme dans celui des aptères. Enfin, différents modèles ont été appliqués aux données de reproduction journalière des pucerons. Le type et la qualité des ajustements varient essentiellement en fonction du morphe.
    Notes: Abstract This study aimed at evaluating the influence of intrinsic factors (clone, morph) on the parameters of the intrinsic rate of increase of Sitobion avenae (F.) and Rhopalosiphum padi (L.). For each species, apterous and alate exules of three clones originating from French oceanic regions were compared at 20 °C. The clonal factor had a significant effect on both time from birth until onset of reproduction (TBR) and intrinsic rate of increase (r). This effect was lower than that of the morph. Moreover, in the case of R. padi, a strong clone-morph interaction was observed. Both apterous and alate morphs were shown to have a higher rate of increase in R. padi than in S. avenae. Various models were fitted to aphid daily rate of reproduction. Both types of model and quality of fit depended mainly on the morph.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...