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AM真菌对紫花苜蓿茎点霉叶斑病及豌豆蚜为害的影响 总被引：1，自引：0，他引：1
苜蓿茎点霉(Phoma medicaginis)叶斑病和豌豆蚜(Acyrthosiphon pisum)是紫花苜蓿(Medicago sativa)生产中重要的病虫害,在自然条件下常混合发生.本研究以紫花苜蓿为植物材料,探究接种AM真菌后,紫花苜蓿被苜蓿茎点霉侵染时,植物自身的防御机制,以及对后续豌豆蚜为害的影响,以期... 相似文献
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Andrew H. Smith Piotr Łukasik Michael P. O'Connor Amanda Lee Garrett Mayo Milton T. Drott Steven Doll Robert Tuttle Rachael A. Disciullo Andrea Messina Kerry M. Oliver Jacob A. Russell 《Molecular ecology》2015,24(5):1135-1149
The microbiome can significantly impact host phenotypes and serve as an additional source of heritable genetic variation. While patterns across eukaryotes are consistent with a role for symbiotic microbes in host macroevolution, few studies have examined symbiont‐driven host evolution or the ecological implications of a dynamic microbiome across temporal, spatial or ecological scales. The pea aphid, Acyrthosiphon pisum, and its eight heritable bacterial endosymbionts have served as a model for studies on symbiosis and its potential contributions to host ecology and evolution. But we know little about the natural dynamics or ecological impacts of the heritable microbiome of this cosmopolitan insect pest. Here we report seasonal shifts in the frequencies of heritable defensive bacteria from natural pea aphid populations across two host races and geographic regions. Microbiome dynamics were consistent with symbiont responses to host‐level selection and findings from one population suggested symbiont‐driven adaptation to seasonally changing parasitoid pressures. Conversely, symbiont levels were negatively correlated with enemy‐driven mortality when measured across host races, suggesting important ecological impacts of host race microbiome divergence. Rapid drops in symbiont frequencies following seasonal peaks suggest microbiome instability in several populations, with potentially large costs of ‘superinfection’ under certain environmental conditions. In summary, the realization of several laboratory‐derived, a priori expectations suggests important natural impacts of defensive symbionts in host‐enemy eco‐evolutionary feedbacks. Yet negative findings and unanticipated correlations suggest complexities within this system may limit or obscure symbiont‐driven contemporary evolution, a finding of broad significance given the widespread nature of defensive microbes across plants and animals. 相似文献
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- 1 Aphids are the major group of insects that vector plant viruses, and they often display a preference for foliage showing disease symptoms. Although this behaviour will increase the numbers of vectors acquiring the pathogen, it will not in itself result in a greater spread of the disease.
- 2 The present study examined how infection of Vicia faba by the nonpersistently transmitted virus bean yellow mosaic virus (BYMV) affected colonization by pea aphids Acyrthosiphon pisum. We then examined how foraging by the hymenopterous parasitoid Aphidius ervi affected aphid settling/movement behaviour and the consequences for dissemination of the virus.
- 3 In Petri dish arenas, aphids colonized discs from BYMV‐infected leaves more rapidly than discs from uninfected plants. Reflectance from infected foliage was approximately 20% higher than from uninfected leaves in the green–yellow wavelengths, indicating that aphids might be responding to visual cues from the brighter foliage. Settling was reduced by A. ervi, with the foraging wasps preventing the aphids reaching and/or remaining on the leaf tissue.
- 4 In multiple plant arenas, A. ervi caused a reduction in aphid numbers but also a nine‐fold increase in BYMV infection. It is hypothesized that disturbance by the parasitoids resulted in more aphid movement as well as more cases of aphids probing on a BYMV‐infected plant and then a new host within the critical time period for successful inoculation to occur. This effect of parasitoids on virus dispersal should be considered in epidemiological models of insect‐vectored plant diseases, and also when evaluating the use of natural enemies in biocontrol strategies of insect herbivore/vector pests.
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The examination of the compatibility between agricultural practices and biocontrol activities is crucial for establishing an efficient, eco-friendly, and sustainable pest management program. In this study, we examined the population dynamics of two specialist aphids, the English grain aphid (Sitobion avenae) on potted wheat and the pea aphid (Acyrthosiphon pisum) on potted alfalfa, as well as the biocontrol activity of a generalist predator, the harlequin ladybird beetle (Harmonia axyridis). We investigated their responses to the presence of the intercropping partner plant species (alfalfa and wheat, respectively) through plant volatiles or visual cues at three nitrogen fertilizer levels in a greenhouse. In the absence of the predator, the English grain aphid population growth rate increased significantly with increasing nitrogen levels, whereas the pea aphid population increased significantly more slowly in response to high nitrogen levels. The English grain aphid and pea aphid population dynamics were unaffected by the presence of the intercropping partner. However, the presence of the intercropping partner enhanced the control of both aphid populations by the harlequin ladybird beetle. Increasing nitrogen fertilizer levels decreased the predation rates, which were otherwise increased by the intercropping partner. The beneficial effects of the intercropping partner were eventually non-existent at the highest nitrogen level tested. These results imply that the interaction between the presence of intercropping partner and the nitrogen fertilizer application affects the biocontrol activity of the natural enemies of insect pests. Thus, the compatibility between agricultural intensification and biocontrol strategies in integrated pest management programs need to be investigated. 相似文献
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Heather J. Henter 《Evolution; international journal of organic evolution》1995,49(3):439-445
Much of the study of coevolution has focused on the adaptations that have resulted from interactions between species. For reciprocal evolution to occur, there must be genetic variation in each species for traits that directly affect their interaction. Here I report evidence of significant additive genetic variance within a population of parasitic wasps in the ability to successfully parasitize an aphid host. These data, combined with companion work documenting clonal variation in a population of aphids from the same site, provide evidence that within the same population both a host and its parasitoid have the potential for specific and reciprocal genetic interactions. 相似文献
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Heather J. Henter Sara Via 《Evolution; international journal of organic evolution》1995,49(3):427-438
For coevolution to occur, there must be genetic variation in each species for traits relevant to their interaction. Here, statistically significant variation in susceptibility to a parasitic wasp was found among pea-aphid clones collected from a single population. In a subset of clones that was tested further, wasps were found to oviposit in aphids from both resistant and susceptible lines, but eggs failed to develop in resistant hosts. Significant genetic variance in susceptibility provides evidence that this aphid population has the potential to evolve resistance in response to selection by one of its major natural enemies. Predictions of an expected response to selection based on the experimental measures of variation and field parasitism rates suggested that there should be a detectable change in susceptibility over the course of a season. However, an experimental comparison of mean susceptibility of clones collected early and late in the summer, a period of several generations, revealed no response to selection by the wasps. Aphids collected late in the season were as susceptible, on the average, as those collected early in the summer. Possible constraints on the response of the aphids to selection by this natural enemy are considered. 相似文献
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Aphids are attacked by a large guild of natural enemies including many primary parasitoids which mummify their hosts. These mummies are themselves attacked by a guild of mummy parasitoids which are potentially important in regulating primary parasitoids at densities below which they can exert biological control. The response of mummy parasitoids to mummy densities was investigated in an experiment in which mummy densities of the pea aphid (Acyrthosiphon pisum) attacked by the parasitoid Aphidius ervi were manipulated across host plant patches. Overall, the risk of parasitism was density independent, though with very high inter-patch variability which may allow probabilistic refuges from secondary parasitism. Six species of four genera of mummy parasitoids were recorded. Of the responses of the individual genera, Coruna were reared most frequently from patches of high host density while amongst patches from which Syrphophagus was reared parasitism was inversely density dependent. 相似文献
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1. Predator–prey interactions have traditionally focused on the consumptive effects that predators have on prey. However, predators can also reduce the abundance of prey through behaviourally‐mediated non‐consumptive effects. For example, pea aphids (Acyrthosiphon pisum Harris) drop from their host plants in response to the risk of attack, reducing population sizes as a consequence of lost feeding opportunities. 2. The objective of the present study was to determine whether the non‐consumptive effects of predators could extend to non‐prey herbivore populations as a result of non‐lethal incidental interactions between herbivores and foraging natural enemies. 3. Polyculture habitats consisting of green peach aphids (Myzus persicae Sulzer) feeding on collards and pea aphids feeding on fava beans were established in greenhouse cages. Aphidius colemani Viereck, a generalist parasitoid that attacks green peach aphids but not pea aphids, was released into half of the cages and the abundance of the non‐host pea aphid was assessed. 4. Parasitoids reduced the population growth of the non‐host pea aphid by increasing the frequency of defensive drops; but this effect was dependent on the presence of green peach aphids. 5. Parasitoids probably elicited the pea aphid dropping behaviour through physical contact with pea aphids while foraging for green peach aphids. It is unlikely that pea aphids were responding to volatile alarm chemicals emitted by green peach aphids in the presence of the parasitoid. 6. In conclusion, the escape response of the pea aphid provided the opportunity for a parasitoid to have non‐target effects on an herbivore with which it did not engage in a trophic interaction. The implication is that natural enemies with narrow diet breadths have the potential to influence the abundance of a broad range of prey and non‐prey species via non‐consumptive effects. 相似文献
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Julia Ferrari Alistair C. Darby Tim J. Daniell H. Charles J. Godfray Angela E. Douglas 《Ecological Entomology》2004,29(1):60-65
Abstract. 1. Pea aphids, Acyrthosiphon pisum , harbour a range of facultative accessory bacteria (secondary symbionts), including those informally known as PASS (R-type), PAR, PABS (T-type), and PAUS (U-type).
2. To explore the relationship between possession of these bacteria and ecologically important traits of A. pisum , correlations between the accessory bacteria found in 47 parthenogenetic clones of A. pisum and the host plant on which each clone was collected and its susceptibility to natural enemies were surveyed.
3. The bacterial complement varied with plant of collection. PAUS (U) was present in all of 12 clones affiliated to Trifolium but was otherwise rare, while PABS (T) and PASS (R) occurred at significantly higher frequency in clones from Lotus and Vicia , respectively, than clones from other plants.
4. Possession of PABS (T) was associated strongly with resistance to the parasitoid Aphidius eadyi and weakly with resistance to Aphidius ervi . Aphids carrying PAUS (U) were more resistant to the fungal pathogen Pandora ( Erynia ) neoaphidis , although this correlation was complicated by a strong association with host-plant use. 相似文献
2. To explore the relationship between possession of these bacteria and ecologically important traits of A. pisum , correlations between the accessory bacteria found in 47 parthenogenetic clones of A. pisum and the host plant on which each clone was collected and its susceptibility to natural enemies were surveyed.
3. The bacterial complement varied with plant of collection. PAUS (U) was present in all of 12 clones affiliated to Trifolium but was otherwise rare, while PABS (T) and PASS (R) occurred at significantly higher frequency in clones from Lotus and Vicia , respectively, than clones from other plants.
4. Possession of PABS (T) was associated strongly with resistance to the parasitoid Aphidius eadyi and weakly with resistance to Aphidius ervi . Aphids carrying PAUS (U) were more resistant to the fungal pathogen Pandora ( Erynia ) neoaphidis , although this correlation was complicated by a strong association with host-plant use. 相似文献
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Piotr Łukasik Huifang Guo Margriet van Asch Lee M. Henry H. Charles J. Godfray Julia Ferrari 《Evolution; international journal of organic evolution》2015,69(10):2757-2766
Heritable microbial symbionts can have important effects on many aspects of their hosts’ biology. Acquisition of a novel symbiont strain can provide fitness benefits to the host, with significant ecological and evolutionary consequences. We measured barriers to horizontal transmission by artificially transferring facultative symbionts from the grain aphid, Sitobion avenae, and five other aphid species into two clonal genotypes of S. avenae. We found the symbiont Hamiltonella defensa establishes infections more easily following a transfer from the same host species and that such infections are more stable. Infection success was also higher when the introduced symbiont strain was more closely related to the strain that was originally present in the host (but which had previously been removed). There were no differences among successfully established symbiont strains in their effect on aphid fecundity. Hamiltonella defensa did not confer protection against parasitoids in our S. avenae clones, although it often does in other aphid hosts. However, strains of the symbiont Regiella insecticola originating from two host species protected grain aphids against the pathogenic fungus Pandora neoaphidis. This study helps describe the extent to which facultative symbionts can act as a pool of adaptations that can be sampled by their eukaryote hosts. 相似文献
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Penmetsa RV Uribe P Anderson J Lichtenzveig J Gish JC Nam YW Engstrom E Xu K Sckisel G Pereira M Baek JM Lopez-Meyer M Long SR Harrison MJ Singh KB Kiss GB Cook DR 《The Plant journal : for cell and molecular biology》2008,55(4):580-595
The plant hormone ethylene negatively regulates bacterial infection and nodule formation in legumes in response to symbiotic rhizobia, but the molecular mechanism(s) of ethylene action in symbiosis remain obscure. We have identified and characterized multiple mutant alleles of the MtSkl1 gene, which controls both ethylene sensitivity and nodule numbers. We show that this locus encodes the Medicago truncatula ortholog of the Arabidopsis ethylene signaling protein EIN2. In addition to the well-characterized role of MtSkl1 in rhizobial symbiosis, we show that MtSkl1 is involved in regulating early phases of the symbiotic interaction with mycorrhizal fungi, and in mediating root responses to cytokinin. MtSkl1 also functions in the defense against Rhizoctonia solani and Phytophthora medicaginis , with the latter interaction likely to involve positive feedback amplification of ethylene biosynthesis. Overexpression of the C-terminal domain of MtEIN2 is sufficient to block nodulation responses, consistent with previous reports in Arabidopsis on the activation of ethylene signaling. This same C-terminal region is uniquely conserved throughout the EIN2 homologs of angiosperms, which is consistent with its role as a higher plant-specific innovation essential to EIN2 function. 相似文献
14.
Henry LM Roitberg BD Gillespie DR 《Evolution; international journal of organic evolution》2008,62(3):689-699
The diversity of parasitic insects remains one of the most conspicuous patterns on the planet. The principal factor thought to contribute to differentiation of populations and ultimately speciation is the intimate relationship parasites share with hosts and the potential for disruptive selection associated with using different host species. Traits that generate this diversity have been an intensely debated topic of central importance to the evolution of specialization and maintenance of ecological diversity. A fundamental hypothesis surrounding the evolution of specialization is that no single genotype is uniformly superior in all environments. This \"trade-off\" hypothesis suggests that negative fitness correlations can lead to specialization on different hosts as alternative stable strategies. In this study we demonstrate a trade-off in the ability of the parasitoid, Aphidius ervi, to maintain a high level of fitness on an ancestral and novel host, which suggests a genetic basis for host utilization that may limit host-range expansion in parasitoids. Furthermore, behavioral evidence suggests mechanisms that could promote specialization through induced host fidelity. Results are discussed in the context of host-affiliated ecological selection as a potential source driving diversification in parasitoid communities and the influence of host species heterogeneity on population differentiation and local adaptation. 相似文献
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PIOTR ŁUKASIK EMILY L. HANCOCK JULIA FERRARI H. CHARLES J. GODFRAY 《Ecological Entomology》2011,36(6):790-793
1. Facultative endosymbiotic bacteria of insects are known to affect life‐history traits of their hosts, and can provide important fitness benefits under certain environmental conditions. While several distinct endosymbiont‐induced effects have been reported, there is no data on whether heritable facultative endosymbionts in any species affect their hosts' performance at low temperatures, something that could have a major effect on insect physiology and survival, and thus population structure and distribution. 2. The original facultative endosymbionts were experimentally removed from five clonal genotypes of the grain aphid, Sitobion avenae Fab., which were then exposed to frost. 3. Aphid genotypes differed considerably in survival following the exposure and in fecundity of the survivors. However, the presence of the facultative symbionts had no overall effect on the studied traits. 4. The results suggest that the facultative symbionts have limited effects on the cold hardiness of their grain aphid hosts. 相似文献
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Jianjun Mao Changyan Liu Fanrong Zeng 《Archives of insect biochemistry and physiology》2013,84(4):209-221
Aphid, a short germband insect, displays an embryogenesis different from that of long germband insect species. Furthermore, the development of its parthenogenetic and viviparous embryo is different from that of the embryo resulting from sexual reproduction. To better understand the genetic regulation of this type of embryogenesis, the functions of hunchback in asexual Acyrthosiphon pisum were investigated by parental RNAi. Microinjection of Aphb double‐stranded RNA yielded several defective phenotypes. Quantitative real‐time PCR analysis revealed that these defects resulted from reduction of Aphb mRNA level in injected aphids. All these results suggested that the hb gene in parthenogenetic and viviparous Acyrthosiphon pisum was involved in abdominal identity suppression and germband growth as its homologue does in sexual insects. 相似文献
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Stomata help plants regulate CO2 absorption and water vapor release in response to various environmental changes, and plants decrease their stomatal apertures and enhance their water status under elevated CO2. Although the bottom‐up effect of elevated CO2 on insect performance has been extensively studied, few reports have considered how insect fitness is altered by elevated CO2‐induced changes in host plant water status. We tested the hypothesis that aphids induce stomatal closure and increase host water potential, which facilitates their passive feeding, and that this induction can be enhanced by elevated CO2. Our results showed that aphid infestation triggered the abscisic acid (ABA) signaling pathway to decrease the stomatal apertures of Medicago truncatula, which consequently decreased leaf transpiration and helped maintain leaf water potential. These effects increased xylem‐feeding time and decreased hemolymph osmolarity, which thereby enhanced phloem‐feeding time and increased aphid abundance. Furthermore, elevated CO2 up‐regulated an ABA‐independent enzyme, carbonic anhydrase, which led to further decrease in stomatal aperture for aphid‐infested plants. Thus, the effects of elevated CO2 and aphid infestation on stomatal closure synergistically improved the water status of the host plant. The results indicate that aphid infestation enhances aphid feeding under ambient CO2 and that this enhancement is increased under elevated CO2. 相似文献
18.
Sylwia Go&#;awska Iwona &#;ukasik & Bogumi&#; Leszczy&#;ski 《Entomologia Experimentalis et Applicata》2008,128(1):147-153
We studied the development and feeding behaviour of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on the Radius and Sapko alfalfa ( Medicago sativa L.) (Fabaceae) cultivars. Three saponins and flavones were identified in the alfalfa cultivars after thin layer chromatography separation. Cultivar Radius differed from Sapko in that it had a higher level of saponins, including zanhic acid tridesmoside and 3-GlcA,28-AraRhaXyl medicagenic acid glycoside. The flavones identified, including 7- O -β-D-glucuronopyranosyl-4'- O- [2'- O- E-feruloyl- O -β-D-glucuronopyranosyl(1→2)- O -β-D-glucuronopyranoside] apigenin, 7- O -{2- O- E-feruloyl-[β-D-glucuronopyranosyl(1→3)]- O -β-D-glucuronopyranosyl(1→2)- O -β-D-glucuronopyranoside} apigenin, and 4'- O- [2'- O -E-feruloyl- O -β-D-glucuronopyranosyl(1→2)- O -β-D-glucuronopyranoside] apigenin, occurred in tissues of both alfalfa cultivars. However, cv. Radius had very low mean flavonoid concentrations in comparison to cv. Sapko. Pea aphids that fed on cv. Radius plants showed a reduction in reproduction and survival. The aphid pre-reproductive period on cv. Radius was prolonged and the reproductive and post-reproductive periods on cv. Radius were reduced, compared to those on cv. Sapko. Cultivar Radius also negatively influenced aphid probing behaviour. This was especially the case during the initial period of the pathway phase. The results suggested that alfalfa cv. Radius, which had a higher level of saponins and a lower level of flavonoids, was less accepted by the pea aphid. 相似文献
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The effects of elevated CO2 (550 and 750 µL/L vs. ambient CO2) on the third trophic level, a predator Harmonia axyridis (Pallas) and a parasitoid Aphidius picipes (Nees), were studied in open-top chambers. The impact of elevated CO2 on the growth and development of H. axyridis was either weak or nonexistent, whereas the abundance of the parasitized aphid (Sitobion avenae Fabricius) by A. picipes showed a significant increase in 550 (12.5%) and 750 (19.6%) µL/L CO2 compared to ambient CO2, respectively. In addition, there was a significant decrease (10%) in the emergence rate of A. picipes under 750 µL/L CO2 compared to ambient CO2 (P<0.05). The predator and the parasitoid both substantially suppressed aphid abundance, especially in elevated CO2 for A. picipes. Moreover, H. axyridis and A. picipes preferred to prey on/parasitize more aphids, S. avenae, infested on 550 (9.1 and 16.9%) and 750 (23 and 25.7%) µL/L CO2-grown wheat plants than those fed ambient CO2-grown wheat plants. These initial results indicate that elevated CO2 markedly changes the predation/parasitization preference by the predator/parasitoid for wheat aphids. The biocontrol efficiency of A. picipes against S. avenae can be enhanced in elevated CO2; simultaneously, elevated CO2 has adverse effects on the growth and development of A. picipes-parasitized S. avenae. 相似文献
20.
James C. Carolan Dr. Carol I. J. Fitzroy Peter D. Ashton Angela E. Douglas Thomas L. Wilkinson 《Proteomics》2009,9(9):2457-2467
Nine proteins secreted in the saliva of the pea aphid Acyrthosiphon pisum were identified by a proteomics approach using GE‐LC‐MS/MS and LC‐MS/MS, with reference to EST and genomic sequence data for A. pisum. Four proteins were identified by their sequences: a homolog of angiotensin‐converting enzyme (an M2 metalloprotease), an M1 zinc‐dependant metalloprotease, a glucose‐methanol‐choline (GMC)‐oxidoreductase and a homolog to regucalcin (also known as senescence marker protein 30). The other five proteins are not homologous to any previously described sequence and included an abundant salivary protein (represented by ACYPI009881), with a predicted length of 1161 amino acids and high serine, tyrosine and cysteine content. A. pisum feeds on plant phloem sap and the metalloproteases and regucalcin (a putative calcium‐binding protein) are predicted determinants of sustained feeding, by inactivation of plant protein defences and inhibition of calcium‐mediated occlusion of phloem sieve elements, respectively. The amino acid composition of ACYPI009881 suggests a role in the aphid salivary sheath that protects the aphid mouthparts from plant defences, and the oxidoreductase may promote gelling of the sheath protein or mediate oxidative detoxification of plant allelochemicals. Further salivary proteins are expected to be identified as more sensitive MS technologies are developed. 相似文献