Bacterial endosymbionts have enabled aphids to adapt to a range of stressors,but their effects in many aphid species remain to be established.The bird cherry-oat aphid,Rhopalosiphum padi(Linnaeus),is an important pest...Bacterial endosymbionts have enabled aphids to adapt to a range of stressors,but their effects in many aphid species remain to be established.The bird cherry-oat aphid,Rhopalosiphum padi(Linnaeus),is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type symbiont endobacteria,although the resulting aphid phenotype has not been described.This study presents the first report of R.padi infection with the facultative bacterial endosymbiont Hamiltonella defensa.Individuals of R.padi were sampled from populations in Eastern Scotland,UK,and shown to represent seven R.padi genotypes based on the size of polymorphic microsatellite markers;two of these genotypes harbored H.defensa.In parasitism assays,survival of H.defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani(Viereck)was 5 fold higher than for uninfected nymphs.Aphid genotype was a major determinant of aphid performance on two Hordeum species,a modern cultivar of barley H.vulgare and a wild relative H.spontaneum,although aphids infected with H.defensa showed 16%lower nymph mass gain on the partially resistant wild relative compared with uninfected individuals.These findings suggest that deploying resistance traits in barley will favor the fittest R.padi genotypes,but symbiontinfected individuals will be favored when parasitoids are abundant,although these aphids will not achieve optimal performance on a poor quality host plant.展开更多
To achieve the triple challenge of food security,reversing biodiversity declines plus mitigating and adapting to climate change,there is a drive to embed ecological principles into agricultural,value-chain practices a...To achieve the triple challenge of food security,reversing biodiversity declines plus mitigating and adapting to climate change,there is a drive to embed ecological principles into agricultural,value-chain practices and decisionmaking.By diversifying cropping systems at several scales there is potential to decrease reliance on inputs,provide resilience to abiotic and biotic stress,enhance plant,microbe and animal biodiversity,and mitigate against climate change.In this review we highlight the research performed in Scotland over the past 5 years into the impact of the use of ecological principles in agriculture on sustainability,resilience and provision of ecosystem functions.We demonstrate that diversification of the system can enhance ecosystem functions.Soil and plant management interventions,including nature-based solutions,can also enhance soil quality and utilization of legacy nutrients.Additionally,this is facilitated by greater reliance on soil biological processes and trophic interactions.We highlight the example of intercropping with legumes to deliver sustainability through ecological principles and use legumes as an exemplar of the innovation.We conclude that there are many effective interventions that can be made to deliver resilient,sustainable,and diverse agroecosystems for crop and food production,and these may be applicable in any agroecosystem.展开更多
文摘Bacterial endosymbionts have enabled aphids to adapt to a range of stressors,but their effects in many aphid species remain to be established.The bird cherry-oat aphid,Rhopalosiphum padi(Linnaeus),is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type symbiont endobacteria,although the resulting aphid phenotype has not been described.This study presents the first report of R.padi infection with the facultative bacterial endosymbiont Hamiltonella defensa.Individuals of R.padi were sampled from populations in Eastern Scotland,UK,and shown to represent seven R.padi genotypes based on the size of polymorphic microsatellite markers;two of these genotypes harbored H.defensa.In parasitism assays,survival of H.defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani(Viereck)was 5 fold higher than for uninfected nymphs.Aphid genotype was a major determinant of aphid performance on two Hordeum species,a modern cultivar of barley H.vulgare and a wild relative H.spontaneum,although aphids infected with H.defensa showed 16%lower nymph mass gain on the partially resistant wild relative compared with uninfected individuals.These findings suggest that deploying resistance traits in barley will favor the fittest R.padi genotypes,but symbiontinfected individuals will be favored when parasitoids are abundant,although these aphids will not achieve optimal performance on a poor quality host plant.
基金supported by the 2016–2021 strategic research program funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division。
文摘To achieve the triple challenge of food security,reversing biodiversity declines plus mitigating and adapting to climate change,there is a drive to embed ecological principles into agricultural,value-chain practices and decisionmaking.By diversifying cropping systems at several scales there is potential to decrease reliance on inputs,provide resilience to abiotic and biotic stress,enhance plant,microbe and animal biodiversity,and mitigate against climate change.In this review we highlight the research performed in Scotland over the past 5 years into the impact of the use of ecological principles in agriculture on sustainability,resilience and provision of ecosystem functions.We demonstrate that diversification of the system can enhance ecosystem functions.Soil and plant management interventions,including nature-based solutions,can also enhance soil quality and utilization of legacy nutrients.Additionally,this is facilitated by greater reliance on soil biological processes and trophic interactions.We highlight the example of intercropping with legumes to deliver sustainability through ecological principles and use legumes as an exemplar of the innovation.We conclude that there are many effective interventions that can be made to deliver resilient,sustainable,and diverse agroecosystems for crop and food production,and these may be applicable in any agroecosystem.
