摘要：The brown planthopper, Nilaparvata lugens is a pest of cultivated rice through- out Asia and is controlled using insecticides and/or resistant rice varieties. This species has developed resistance to many classes of insecticide and biotypes have developed that are vir- ulent against formerly resistant rice cultivars. Insects use a suite of detoxification enzymes, including cytochrome P450s, glutathione S-transferases and carboxyl/cholinesterases to defend themselves against plant secondary metabolites and pesticides. Pyrosequencing on the Roche 454-FLX platform was used to produce a substantial expressed sequence tag （EST） dataset to complement the existing Sanger sequenced ESTs in GenBank. A total of 78 959 reads were combined with the 37 392 publically available Sanger ESTs; these assembled into 8 911 contigs and 10 620 singletons. Analysis of the distribution of tenta- tive unique genes （TUGs） with the gene ontology for biological processes and molecular functions suggests that the 454 and Sanger EST assembly is broadly representative of the N. lugens transcriptome. The brown planthopper transcriptome was found to contain 31 TUGs encoding P450s, nine encoding glutathione S-transferases and 26 encoding car- boxyl/cholinesterases and many of these are putatively involved in the detoxification of xenobiotics. The Agilent eArray platform was used to construct an oligonucleotide mi- croarray populated with probes for ~ 19 000 unigene sequences, including all those known to encode detoxification enzymes. The genomic resources developed in this study will be useful to the community studying this crop pest and will help elucidate the molecular mechanism underlying insecticide resistance and planthopper adaptation to resistant rice cultivars.

摘要：We describe a few mathematical tools which allow to investigate whether air-water interfaces exist(under prescribed conditions)and are mechanically stable and temporally *** terms of physics,air-water interfaces are governed by the Young-Laplace *** they are surfaces of constant mean curvature which represent solutions of a nonlinear elliptic partial differential *** explicit solutions of this equation can be obtained only in very special cases,it is -under moderately special circumstances-possible to establish the existence of a solution without actually solving the differential *** also derive criteria for mechanical stability and temporal persistence of an air *** we calculate the lifetime of a non-persistent air ***,we apply these tools to two examples which exhibit the symmetries of 2D *** examples can be viewed as abstractions of the biological model represented by the aquatic fern Salvinia.

摘要：Plants growing in nutrient-rich environment are predicted to be less defended than conspecifics under nutrient ***,less is known about the effects of nutrient levels on tolerance and induced resistance,and whether the effects differ between native and introduced populations of invasive *** performed a greenhouse experiment with introduced(the USA)and native(Argentina)genotypes of Alternanthera philoxeroides in order to study the effects of soil nitrogen levels on plant growth,constitutive and herbivore(Agasicles hygrophila)-induced chemical defense,and herbivory *** measured total biomass,elongation rate(as proxy of growth rate),carbon and nitrogen,and the concentration of triterpenoid saponins(defensive chemicals)in leaves and *** resistance(+33%higher leaf triterpenoid saponins in control treatment at low nitrogen level)and tolerance[less decreased total biomass after herbivory treatment(−24%and−15%for high and low nitrogen levels)]were favored at lower nitrogen level,while induced resistance was favored at higher nitrogen level(+24%increased leaf triterpenoid saponins after herbivory treatment at high nitrogen level).Constitutive resistance and tolerance exhibited trade-offs with growth rate,while induced resistance positively correlated with growth ***,the introduced genotypes had−6%lower content of leaf carbon in the presence of herbivores than the native genotypes at low nitrogen level,but such difference was absent at high nitrogen *** results indicate that soil nitrogen levels influence the preference of different defensive strategies of plant,and interweave with herbivory to determine the performance of introduced genotypes.

摘要：Aims Intensive land management practices can compromise soil biodiversity,thus jeopardizing long-term soil *** mycorrhizal fungi(AMF)play a pivotal role in promoting soil productivity through obligate symbiotic associations with ***,it is not clear how properties of plant communities,especially species richness and composition influence the viability of AMF populations in *** Here we test whether monocultures of eight plant species from different plant functional groups,or a diverse mixture of plant species,maintain more viable AMF *** address this question,we extracted AMF spores from 12-year old plant monocultures and mixtures and paired single AMF spores with single plants in a factorial design crossing AMF spore origin with plant species *** Findings AMF spores from diverse plant mixtures were more successful at colonizing multiple plant species and plant individuals than AMF spores from plant ***,we found evidence that AMF spores originating from diverse mixtures more strongly increased biomass than AMF from monocultures in the legume Trifolium repens *** viability and ability to interact with many plant species were greater when AMF spores originated from 12-year old mixtures than *** results show for the first time that diverse plant communities can sustain AMF viability in soils and demonstrate the potential of diverse plant communities to maintain viable AMF propagules that are a key component to soil health and productivity.

摘要：青藏高原东部的高山森林是长江上游的重要生态屏障。然而,由于近几十年来持续的高强度采伐,大量的人工种植,以及完全的禁伐等措施,导致树木种类与年龄结构变得相对单一,生物多样性和生态功能都有所下降。为设计有效的森林管理方案,以优化森林结构,提高森林碳汇能力,本研究以四川茂县为研究地点,利用LANDIS-II模型对6种不同强度的森林管理方案(采伐、种植)进行测试,模拟和比较了这些方案与当前管理方案在未来100年间森林地上固碳速率的差异。研究结果表明:(i)与目前的管理方案相比,不同强度的采伐和种植明显改变了森林地上固碳速率;(ii)不同群落对管理方案的反应不同,不同的管理方案对寒温带针叶林和温带针叶林的地上固碳速率有显著的影响(P<0.05),但对阔叶林影响较小;(iii)应综合物种、群落和景观3个层面全面考虑森林管理方案。这些结果说明,在研究地点实施较长的采伐和种植间隔(20年)可以最大限度地提高森林的地上固碳速率。该研究为评估森林管理方案在恢复森林生态和增加碳汇功能的能力,以及为在青藏高原东部地区选择有效的森林管理方案提供了重要参考。