1,721,001 research outputs found
Development of the wing buds in Megoura viciae: a morphological study
No full textThis study describes the initial phases of wing morphogenesis of Megoura viciae. We evaluated the development of wing buds in males (winged) and parthenogenetic females (presumed to become wingless) of M. viciae from birth to IV instar. Wing bud epithelium in males is initially simple, becoming bistratified and then progressing to stratify. Mitotic activity is more intense in the proximal region of bud, and its behaviour seems to be synchronous. In parthenogenetic females, from birth to I instar, the buds resemble those of males at the same stages, but subsequently the epithelium returns to the simple state, and from the III instar stage, it cannot be distinguished from the adjacent epithelium.This study moreover defines distinctive wing bud features that can be used to identify these buds during development in other aphid species
Survival and feeding activity of Protaphorura armata in different composts
No full textInteractions between the collembolan Protaphorura armata and different compost products enriched or not enriched with the mycoparasitic fungus Trichoderma atroviride or Ca-Lignosulphonate, a by-product of pulping process, were investigated by survival tests performed in controlled conditions. The gut content of animals was examined at the end of the experiments and the viability of T. atroviride conidia after the gut transit was also tested.
All compost products enriched or not enriched with the mycoparasitic fungus or Ca-Ls did not affect the survival of the collembolans. In addition to adults live juveniles were also observed in all products. In a few cases conidia were observed into the gut of collembola and the majority of these conidia were not damaged during the gut transit. These results suggest compatibility between collembola, T. atroviride and Ca-Lignosulphonate
Cytogenetic analysis of the holocentric chromosomes of the aphid Schizaphis graminum
Full text linkChromatin organization in the holocentric chromosomes of the aphid Schizaphis graminum has been investigated at a cytological level after C-banding, NOR, Giemsa, DAPI and CMA(3) staining. C-banding technique showed the presence of numerous C bands on the two X chromosomes both in telomeric and intercalary regions, whereas autosomes show a small number of heterochromatic bands. Contrary to the results with other aphid species, in S. graminum the C-banding pattern is peculiar to each chromosome pair, thus allowing the identification of homologues and the reliable reconstruction of a karyotype. These cytogenetic data could be useful for the identification of chromosomal rearrangement eventually occurred between different S. graminum biotypes. Moreover, silver staining and fluorescent in situ hybridization (FISH) with a 28S rDNA probe localized rDNA genes on one telomere of each X chromosome; these are the only brightly fluorescent C-positive regions revealed after CMA(3) staining, whereas all other heterochromatic bands are DAPI positive
Interazione collemboli -funghi del suolo: effetto sulla salute delle piante in diverse condizioni di umidità del substrato di crescita
No full textInteractions among Collembola (Protaphorura armata)- plant pathogenic fungus (Gaeumannomyces graminis tritici) and wheat plants under different soil moisture (dryl and wet conditions) were studied in mesocosms under controlled conditions. The wet soil moisture condition, even if more favourable to G. graminis tritici growth, did not decrease the beneficial effect of collembola on plant health
Do substrate water content influence the effect of Collembola-pathogenic fungus interaction on plant health?
No full textThe effect of interaction between the springtail Protaphorura armata (Tullberg) (Collembola Onychiuridae), and the foot and root
pathogenic fungus Gaeumannomyces graminis Von Arx et Olivier var. tritici Walker on number, dry biomass and health of wheat
seedlings under two substrate water content levels was studied in a mesocosm experiment. Adult specimens of P. armata were added
to each container consisting in metallic frame enveloped by a wrap to prevent the passage of animals, filled with sand previously inoculated
with G. graminis var. tritici propagules, where, immediately before the springtails addition, wheat kernels were sown. Containers
were placed in plastic boxes (mesocosms) provided by a system of watering regime regulation. The sand moisture content was
set up at 5 or 15%, which are the lowest and the highest level respectively of available water for plants in a 100% sandy substrate.
Mesocosms were maintained in a growth chamber at 12 hours light, 22 °C temperature, and 60% RH for three weeks. Then wheat
seedlings were collected, counted, and disease index and dry biomass determined. At 15% water content, in presence of P. armata the
disease severity was lower than that of plants grown in presence of the pathogenic fungus and in absence of animals. At 5% water
content, no differences between plant parameters in presence or absence of Collembola were found
Response of plant growth to Collembola, arbuscular mycorrhizal and plant pathogenic fungi interactions
No full textEffects of interactions of the collembolan Protaphorura armata, the arbuscular mycorrhizal fungus Glomus intraradices and the foot and root pathogenic fungus Fusarium culmorum on growth and health of wheat plants were studied in modified Leonard bottle-jars containing sterile sand and peat. The mycorrhizal colonisation, the root and shoot dry weight and the disease index were determined. Also the number of adult Collembola was determined and their gut content analysed. The presence of Collembola did not decrease the positive effect of the arbuscular mycorrhizal fungus Glomus intraradices on the plant biomass and did not reduce the biocontrol capacity of this fungus
Interazioni collemboli-funghi terricoli: quale effetto sulla salute delle piante?
No full textviene studiata l'interazione fra collemboli della specie Protaphorura armata e funghi antagonisti dei patogeni (Trichoderma harzianum) e simbionti mutualistici (MA; Glomus intraradices) in presenza di funghi patogeni per le piante (Fusarium culmorum o Gaeumannomyces graminis tritici) per verificarne l'effetto sulla salute delle painte. Sono state utilizzate come piante modello semenzali di frumento duro cv Creso. Le prove sono state svolte in ambiente controllato. Gli animali animali ed i funghi sono risultati compatibili con una situazione di sanità delle piante
Trophic interactions between soil fungi and Collembola
No full textInteractions between different species of soil borne fungi and different species of euedaphic Collembola were studied in experiments carried out in Petri dishes and microcosmos in absence/ presence of plants
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