oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Metabolic and Proteomic Profiling of Diapause in the Aphid Parasitoid Praon volucre  [PDF]
Hervé Colinet, David Renault, Blandine Charoy-Guével, Emmanuelle Com
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032606
Abstract: Background Diapause, a condition of developmental arrest and metabolic depression exhibited by a wide range of animals is accompanied by complex physiological and biochemical changes that generally enhance environmental stress tolerance and synchronize reproduction. Even though some aspects of diapause have been well characterized, very little is known about the full range of molecular and biochemical modifications underlying diapause in non-model organisms. Methodology/Principal Findings In this study we focused on the parasitic wasp, Praon volucre that exhibits a pupal diapause in response to environmental signals. System-wide metabolic changes occurring during diapause were investigated using GC-MS metabolic fingerprinting. Moreover, proteomic changes were studied in diapausing versus non-diapausing phenotypes using a combination of two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry. We found a reduction of Krebs cycle intermediates which most likely resulted from the metabolic depression. Glycolysis was galvanized, probably to favor polyols biosynthesis. Diapausing parasitoids accumulated high levels of cryoprotective polyols, especially sorbitol. A large set of proteins were modulated during diapause and these were involved in various functions such as remodeling of cytoskeleton and cuticle, stress tolerance, protein turnover, lipid metabolism and various metabolic enzymes. Conclusions/Significance The results presented here provide some first clues about the molecular and biochemical events that characterize the diapause syndrome in aphid parasitoids. These data are useful for probing potential commonality of parasitoids diapause with other taxa and they will help creating a general understanding of diapause underpinnings and a background for future interpretations.
Probing behaviors of Sitobion avenae (Hemiptera: Aphididae) on enhanced UV-B irradiated plants
Hu Zu-Qing,Zhao Hui-Yan,Thieme Thomas
Archives of Biological Sciences , 2013, DOI: 10.2298/abs1301247h
Abstract: UV-B induced changes in plants can influence sap-feeding insects through mechanisms that have not been studied. Herein the grain aphid, Sitobion avenae (Fabricius) (Hemiptera: Aphididae), was monitored on barley plants under the treatments of control [0 kJ/ (m2.d)], ambient UV-B [60 kJ/ (m2.d)], and enhanced UV-B [120 kJ/ (m2.d)] irradiation. Electrical penetration graph (EPG) techniques were used to record aphid probing behaviors. Enhanced UV-B irradiated plants negatively affected probing behaviors of S. avenae compared with control plants. In particular, phloem factors that could diminish sieve element acceptance appeared to be involved, as reflected by smaller number of phloem phase, shorter phloem ingestion, and fewer aphids reaching the sustained phloem ingestion phase (E2>10min). On the other hand, factors from leaf surface, epidermis, and mesophyll cannot be excluded, as reflected by higher number of non-probing, longer non-probing and pathway phase, and later the time to first probe.
Effect of static magnetic fields (SMF) on the viability and fecundity of aphid Sitobion avenae (Homoptera: Aphididae) under laboratory conditions
He Juan,Gao Huan-Huan,Zhao Hui-Yan,Monika Walter
Archives of Biological Sciences , 2012, DOI: 10.2298/abs1202693h
Abstract: The present study examines the effect of static magnetic fields (SMF) on aphids. The effect of a field of moderateintensity (1 mT-1 T) SMF on the life of Sitobion avenae was estimated using the age-stage, two-sex life table. Static magnetic fields were 0.065 T and 0.176 T and exposure was for 0, 15, 30, 60, and 120 min. The results show that the development, mortality, and fecundity of S. avenae were significantly affected by SMF in the second generation after exposure to 0.176 T for 30 min and to 0.065 T for 60 min in comparison to the control group. We concluded that SMF affects the development and reproduction of Sitobion avenae.
Chromosome studies in southern Brazilian wheat pest aphids Sitobion avenae, Schizaphis graminum, and Methopolophium dirhodum (Homoptera: Aphididae)
Celis, Verónica E. Rubín de;Gassen, Dirceu N.;Santos-Colares, Marisa C.;Oliveira, Alice K.;Valente, Vera L.S.;
Brazilian Journal of Genetics , 1997, DOI: 10.1590/S0100-84551997000300010
Abstract: we examined the chromosome set of the aphid species sitobion avenae, schizaphis graminum and methopolophium dirhodum by means of conventional staining and c, nor, alui and haeiii banding methods. these species are considered important pests to several plants of economic interest in brazil. no variation was observed in the number of chromosomes of s. avenae, whereas there was intraspecific variation in the other two species. interspecific differences in the response to the banding treatments were observed. whereas these techniques allowed the identification of several s. graminum chromosome pairs, only the alui treatment was capable of inducing differential staining in the m. dirhodum chromosomes and no clear patterns emerged when the s. avenae preparations were treated
Deciphering the Mechanism of β-Aminobutyric Acid-Induced Resistance in Wheat to the Grain Aphid, Sitobion avenae  [PDF]
He-He Cao, Meng Zhang, Hui Zhao, Yi Zhang, Xing-Xing Wang, Shan-Shan Guo, Zhan-Feng Zhang, Tong-Xian Liu
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0091768
Abstract: The non-protein amino acid β-aminobutyric acid (BABA) can induce plant resistance to a broad spectrum of biotic and abiotic stresses. However, BABA-induced plant resistance to insects is less well-studied, especially its underlying mechanism. In this research, we applied BABA to wheat seedlings and tested its effects on Sitobion avenae (F.). When applied as a soil drench, BABA significantly reduced weights of S. avenae, whereas foliar spray and seed treatment had no such effects. BABA-mediated suppression of S. avenae growth was dose dependent and lasted at least for 7 days. The aminobutyric acid concentration in phloem sap of BABA-treated plants was higher and increased with BABA concentrations applied. Moreover, after 10 days of treatment, the aminobutyric acid content in BABA-treated plants was still higher than that in control treatment. Sitobion avenae could not discriminate artificial diet containing BABA from standard diet, indicating that BABA itself is not a deterrent to this aphid. Also S. avenae did not show preference for control plants or BABA-treated plants. Consistent with choice test results, S. avenae had similar feeding activities on control and BABA-treated plants, suggesting that BABA did not induce antifeedants in wheat seedlings. In addition, aminobutyric acid concentration in S. avenae feeding on BABA-treated plants was significantly higher than those feeding on control plants. Sitobion avenae growth rate was reduced on the artificial diet containing BABA, indicating that BABA had direct toxic effects on this aphid species. These results suggest that BABA application reduced S. avenae performance on wheat seedlings and the mechanism is possibly due to direct toxicity of high BABA contents in plant phloem.
Development and Fecundity of Sitobion avenae (F.) (Hom.: Aphididae) on Some Wheat Cultivars in Laboratory Conditions
Nihal ?zder
Plant Pathology Journal , 2002,
Abstract: Nymphal development time and fecundity of Sitobion avenae (F.) were determined on nine widespread wheat varieties cultivated in Tekirdag Region in Turkey. Tests were carried out in controlled environment chambers (25 1oC, 65 5 % R.H. and 16:8 light and dark cycle). Developmental time ranged from 5.75 0.25 to 7.20 0.20 day. Fecundity was found the highest (12.87 1.50) on cv. Sana. Cv. MV-17, cv. Miryana, cv. Pehlivan and cv. Saraybosna were found particular resistant wheat varieties against S. avenae.
Ecological aspects of Aphidius colemani Viereck (Hymenoptera: Aphidiidae) on the Sitobion avenae (Fabricius) (Hemiptera: Aphididae) population in wheat culture in Medianeira, PR./ Aspectos ecológicos de Aphidius colemani Viereck (Hymenoptera: Aphidiidae) sobre a popula o de Sitobion avenae (Fabricius) (Hemiptera: Aphidiidae) na cultura de trigo em Medianeira, PR  [cached]
Agostinho Zanini,Luis F.A. Alves,Ayres de Oliveira Menezes Júnior,Tania Mari Vicentini Prestes
Semina : Ciências Agrárias , 2006,
Abstract: Aphids were the main winter-cereal problem in the 70’s in southern Brazil and it was necessary to use chemical control to avoid losses. Based in the weak performance of native parasites, 14 species of exotic parasites were introduced in 1978, and in 1984 the West of Paranà’s Biological Control Program was implanted. This program propitiated the reduction of the Aphid population as well as chemical applications in the field. However, no bibliographic study was found referring to the ecological aspects of the parasites nor about Aphid’s biological control in Western Paraná′s region wheat production motivating the development of this study. Week evaluations in 25 parcel of 25 m2 were performed where 100 wheat plants were collected, from which aphid and bugs were taken out. It was observed the presence of an Aphid specie, Sitobion avenae (Fabricius) (Hemyptera: Aphididae), the primary parasite Aphidius colemani Viereck (Hymenoptera: Aphidiidae), and hyper parasitoids, and also the presence of predators. S. avenae population zenith occurred in the beginning of budding and bugs appeared a week after the aphids. Aphid control was considered efficient at 95% total parasitism. Population zenith of A. colemani occurred in the beginning of August, while hyper parasitoids zenith occurred the following week. Aphid population growth was significantly influenced by the air relative humidity, whereas parasite population was influenced by temperature and aphid population density. Os afídeos foram o principal problema dos cereais de inverno na década de 70, no Sul do Brasil, havendo necessidade de controle químico para evitar as perdas. Com base no fraco desempenho dos parasitóides nativos, em 1978 foram introduzidas 14 espécies de parasitóides exóticos no Brasil e em 1984, implantou-se o Programa de Controle Biológico no Oeste do Estado do Paraná, que proporcionou redu o das popula es de afídeos e da aplica o de produtos químicos. No entanto, n o foram encontrados na bibliografia estudos referentes aos aspectos ecológicos dos parasitóides e de controle biológico de afídeos na regi o Oeste do Paraná, na cultura de trigo, motivo pelo qual se desenvolveu este estudo. Foram realizadas avalia es semanais em 25 parcelas com 25m2, coletando-se 100 plantas de trigo, retirando-se das mesmas os afídeos e as múmias. Verificou-se a presen a de uma única espécie de afídeo, Sitobion avenae (Fabricius) (Hemyptera: Aphididae), o parasitóide primário Aphidius colemani Viereck (Hymenoptera: Aphidiidae) e hiperparasitóides, verificando-se também a presen a de predadores. O pico popula
Impact of intercropping aphid-resistant wheat cultivars withoilseed rape on wheat aphid (Sitobion avenae) and its natural enemies

Wanlei Wang,Yong Liu,Julian Chen,Xianglong Ji,Haibo Zhou,Guang Wang,

生态学报 , 2009,
Abstract: The effects of intercropping of wheat cultivars and oilseed rape on the densities of wheat aphid, Sitobion avenae, and their arthropod natural enemies were evaluated. Three winter wheat cultivars with different resistant levels to S. avenae were used: ‘KOK’ (high resistance), ‘Xiaobaidongmai’ (low resistance) and ‘Hongmanghong’ (susceptible). The results showed that the densities of S. avenae were significantly higher on the monoculture pattern than on either the 8-2 intercropping pattern (eight rows of wheat with two rows of oilseed rape) or the 8-4 intercropping pattern (eight rows of wheat with four rows of oilseed rape). The mean number of predators and the mummy rates of S. avenae were significantly higher in two intercropping patterns than those in the monoculture pattern. The densities of S. avenae, ladybeetles, and mummy rate of S. avenae were significantly different among different wheat cultivars. The highest densities of S. avenae and ladybeetles were found on wheat cultivar Hongmanghong. The lowest densities of S. avenae associated with high mummy rate of S. avenae were found on wheat cultivar Xiaobaidongmai. The results showed that wheat-oilseed rape intercropping conserved more predators and parasitoids than in wheat monoculture fields, and partial resistance of wheat cultivar Xiaobaidongmai had complementary or even synergistic effects on parasitoid of S. avenae.
Relationship between Water Soluble Carbohydrate Content, Aphid Endosymbionts and Clonal Performance of Sitobion avenae on Cocksfoot Cultivars  [PDF]
Hussein Alkhedir, Petr Karlovsky, Stefan Vidal
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054327
Abstract: Aphids feed on plant phloem sap, rich in sugars but poor in essential amino acids. However, sugars cause osmotic regulation problems for aphids, which they overcome by hydrolysing the sugars in their gut and polymerising the hydrolysis products into oligosaccharides, excreted with honeydew. Aphids harbour primary bacterial endosymbionts, which supply them with essential amino acids necessary for survival. They also harbour secondary (facultative) endosymbionts (sfS), some of which have a positive impact on life history traits, although it is not yet known whether they also play a role in providing effective tolerance to differing levels of water soluble carbohydrates (WSCs). We investigated the relationship between WSC content of cocksfoot cultivars and performance of clones of the English grain aphid Sitobion avenae F. We evaluated how clone genotype and their sfS modulate performance on these different cultivars. We therefore examined the performance of genetically defined clones of S. avenae, collected from different host plants, harbouring different sfS. The performance was tested on 10 Dactylis glomerata L. cultivars with varying WSC content. D. glomerata is known as a wild host plant for S. avenae and is also commercially planted. We found that high WSCs levels are responsible for the resistance of D. glomerata cultivars to specific S. avenae clones. The minimum level of WSCs conferring resistance to D. glomerata cultivars was 1.7% dw. Cultivars with a WSC content of 2.2% or higher were resistant to S. avenae and did not allow reproduction. Our results further indicate that sfS modulate to some extend host plant cultivar adaptation in S. avenae. This is the first study revealing the importance of WSCs for aphid performance. Cocksfoot cultivars with a high content of WSCs might be therefore considered for aphid control or used for resistance breeding in this and other grass species, including cereals.
Effect of UV\|B radiation on biological characteristics of two body color biotypes of Sitobion avenae (Fab.) offspring
同紫外(UV\|B)辐射时间对两种体色型麦长管蚜后代生物学特征的影响

Hu Zuqing and,
胡祖庆
,亢菊侠,赵惠燕,汤兴春,胡想顺

生态学报 , 2010,
Abstract: The objective of the study was to examine the influence of ultraviolet radiation on the offspring of two body-color biotypes(i.e.,red and green)of Sitobion avenae(Fab.),and to elucidate the role of ultraviolet radiation in the body color differentiation of aphids.Under controlled conditions in artificial bioclimatic chambers,adult aphids of red and green biotypes of Sitobion avenae were placed on two wheat varieties('Astron' and 'Xiaoyan-22')and treated under 30W lamp of UV-B for different durations respect...
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.