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11.
Willows (Salix spp.) are beneficial as a potential source of renewable energy, riparian barriers and riverbank control, yet are considered
invasive weeds when they clog watercourses and lead to erosion and flooding. Interactions between willow rustMelampsora epitea (Thüm.) (Uredinales: Melampsoraceae) and leaf beetlePhratora spp. (Coleoptera: Chrysomelidae) feeding damage have an impact on effective pest management and biological control. The present
study investigated the effects of(a) prior mechanical leaf damage on rust development, and(b) rust infection on beetle feeding under laboratory conditions for different time intervals and levels of damage. Willow rust
infection significantly reduced the amount of leaf area consumed by beetles. The result was similar when a compatible or an
incompatible rust pathotype was sprayed ontoSalix viminalis (L.) ‘Mullatin’ plants. There were no overall significant effects of mechanical damage on rust development, although the
lowest level of rust infection was found with the incremental damage treatment. There were, however, differences of significance
for leaf position and damage status, with damaged leaves at all positions having fewer pustules and a smaller pustule area
than the corresponding undamaged leaves. There was no detectable effect of possible volatile emissions from crushed willow
leaves on rust infection and development, although the volatile compoundcis-3-hexenyl acetate significantly reduced pustule diameter and overall pustule area. The results are discussed in terms of
the implications for pest management and biological control.
Corresponding author
http://www.phytoparasitica.org posting April 6, 2003. 相似文献
12.
Cudworth DP Hegde VB Yap MC Guenthenspberger KA Hamilton CT Pechacek JT Johnson PL Bis SJ Tisdell FE Dripps JE Bruce TJ Dintenfass LP Gifford JM Karr LL Kempe MK McCormick DC Schoonover JR 《Journal of agricultural and food chemistry》2007,55(18):7517-7526
An extended lipophilic system that incorporated some key elements of first-generation 2,6-dihaloaryl actives, such as 1, demonstrated desirable efficacy against chewing insects as well as sap-feeding insects. These four-ring systems, based on 2, were accessed primarily via Suzuki couplings of halothiophene derivatives with appropriately substituted boronic acids. In particular, phenylthiophene systems that incorporated haloxyether groups, such as those in 3, 4, and 5, had the broadest spectrum of activity across chewing and sap-feeding insect pests. Expansion of this structure-activity relationship to include compounds with differing substitution patterns on the thiophene-C-ring and aryl-D-rings was undertaken. The synthesis and insecticidal activity of 3-aryl-5-(thiophen-2-yl)-1-methyl-1H-[1,2,4]triazoles will be described. 相似文献
13.
Meteorological analyses of precipitation and air quality data for the period 1976 to 1983 have been undertaken to infer potential source regions of acidity in Ontario. Techniques such as air parcel trajectory modelling and synoptic weather classification have been utilized. A meteorological data acquisition system has been implemented to provide historical and real-time trajectory statistics. This paper provides an overview of these studies. For areas of South and Central Ontario, precipitation events most commonly occur with pre-warm front and cyclonic situations, and trajectories from the south and southwest octants. Furthermore, most of the reported wet deposition of S and N is associated with trajectories from these octants, the direction of the Ohio Valley industrial source region and industrialized SW Ontario. High air concentrations of S and N are also associated with trajectories from these octants. 相似文献
14.
Dryobalanops aromatica Gaertn. f. is a major tropical canopy species in lowland tropical rain forests in Peninsular Malaysia. Diurnal changes in net photosynthetic rate (A) and stomatal conductance to water vapor (g(s)) were measured in fully expanded young and old leaves in the uppermost canopy (35 m above ground). Maximum A was 12 and 10 micro mol m(-2) s(-1) in young and old leaves, respectively; however, because of large variation in A among leaves, mean maximum A in young and old leaves was only 6.6 and 5.5 micro mol m(-2) s(-1), respectively. Both g(s) and A declined in young leaves when T(leaf) exceeded 34 degrees C and leaf-to-air vapor pressure deficit (DeltaW) exceeded 0.025, whereas in old leaves, g(s) and A did not start to decline until T(leaf) and DeltaW exceeded 36 degrees C and 0.035, respectively. Under saturating light conditions, A was linearly related to g(s). The coefficient of variation (CV) for the difference between the CO(2) concentrations of ambient air and the leaf intercellular air space (C(a) - C(i)) was smaller than the CV for A or g(s), suggesting that maximum g(s) was mainly controlled by mesophyll assimilation (A/C(i)). Minimum C(i)/C(a) ratios were relatively high (0.72-0.73), indicating a small drought-induced stomatal limitation to A and non-conservative water use in the uppermost canopy leaves. 相似文献
15.
A new method for assessing coastal environments using the reproduction potential of corals has been developed and examined
in situ. Six assessment racks were deployed before the full moon of May 2006 at three sites located around a river outlet
in Nagura Bay, Ishigaki Is. and at one control location in Sekisei Lagoon. Each rack was equipped with two marine blocks (MB)
containing 378 holes, two cases of coral settlement devices (CSDs), each containing 120 CSDs, and a water temperature logger.
Assessment was based on recruitment of Acropora due to mass spawning. After 4 months of deployment, the surface of assessment racks showed apparent biofouling depending
on sites mainly by algal settlement on the surfaces. Almost all the holes of the MBs were partly occupied, mainly by turf
algae. Nagura Bay was thought likely to be an “unhealthy” coral reef due to runoff from land. However, our assessment showed
that there were 0.85 corals per CSD in the Bay, compared with 0.51 in Sekisei Lagoon, indicating that coral larvae supply
is not the cause of the unhealthy condition of corals in the Nagura Bay. 相似文献
16.
Schaeffer EM Debnath J Yap G McVicar D Liao XC Littman DR Sher A Varmus HE Lenardo MJ Schwartzberg PL 《Science (New York, N.Y.)》1999,284(5414):638-641
T cell receptor (TCR) signaling requires activation of Zap-70 and Src family tyrosine kinases, but requirements for other tyrosine kinases are less clear. Combined deletion in mice of two Tec kinases, Rlk and Itk, caused marked defects in TCR responses including proliferation, cytokine production, and apoptosis in vitro and adaptive immune responses to Toxoplasma gondii in vivo. Molecular events immediately downstream from the TCR were intact in rlk-/-itk-/- cells, but intermediate events including inositol trisphosphate production, calcium mobilization, and mitogen-activated protein kinase activation were impaired, establishing Tec kinases as critical regulators of TCR signaling required for phospholipase C-gamma activation. 相似文献
17.
Antisense transcription in the mammalian transcriptome 总被引：2，自引：0，他引：2
Katayama S Tomaru Y Kasukawa T Waki K Nakanishi M Nakamura M Nishida H Yap CC Suzuki M Kawai J Suzuki H Carninci P Hayashizaki Y Wells C Frith M Ravasi T Pang KC Hallinan J Mattick J Hume DA Lipovich L Batalov S Engström PG Mizuno Y Faghihi MA Sandelin A Chalk AM Mottagui-Tabar S Liang Z Lenhard B Wahlestedt C;RIKEN Genome Exploration Research Group;Genome Science Group 《Science (New York, N.Y.)》2005,309(5740):1564-1566
18.
Water, Air, & Soil Pollution - Biocrude oil generation from microalgae and cyanobacteria through hydrothermal liquefaction generates an aqueous by-product (post-hydrothermal liquefaction... 相似文献
19.
Leila Shafea Julia Yap Nicolas Beriot Vincent J. M. N. L. Felde Elvis D. Okoffo Christian Ebere Enyoh Stephan Peth 《植物养料与土壤学杂志》2023,186(1):5-22
Contamination of soils in agroecosystems with microplastics (MPs) is of increasing concern. The contamination of the environment/farmland soils with MPs (1 µm to 5 mm sized particles) and nanoplastics (NPs; <1 µm sized particles) is causing numerous effects on ecological soil functions and human health. MPs enter the soil via several sources, either from intentional plastic use (e.g., plastic mulch, plastic greenhouses, plastic-coated products) or indirectly from the input of sewage sludge, compost, or irrigation water that is contaminated with plastic. Once in the soil, plastic debris can have various impacts such as changes in soil functions and physicochemical properties and it affects soil organisms due to its toxic behavior. This review paper describes the different effects of plastic waste to understand the consequences for agricultural productivity. Furthermore, we identify knowledge gaps and highlight the required approaches, indicating future research directions on sources, transport, and fate of MPs in soils to improve our understanding of various unspecified abiotic and biotic impacts of MP pollution in agroecosystems. 相似文献
20.
Gary E. Glass John A. Sorensen Kent W. Schmidt George R. Rapp Jr. David Yap Duncan Fraser 《Water, air, and soil pollution》1991,56(1):235-249
Mercury concentrations and depositions for northeastern Minnesota were measured in precipitation to investigate depositional
trends, relationships with major cations and anions, and possible source emission regions. Results for 1987–1990 showed that
environmentally significant amounts of Hg are present in precipitation and air and are subsequently deposited to remote lake
watersheds. Volume-weighted concentrations of total Hg in precipitation averaged about 18 ng Hg L−1 with calculated annual depositions near 15 μg Hg m−2. Mercury concentrations in precipitation are positively correlated with the major ions, conductivity, and pH, and are negatively
correlated with precipitation volume. The best predictor equation from stepwise regression has an r2 of 0.65 with Mg and chloride concentrations as predictor variables. From measurements of Hg in rain concentrations as a function
of time within events, scavenging ratios for “washable” Hg were calculated to be 140 ± 80 (mass based at a 1 mm hr −1 precipitation rate). Up to about 10% of the total Hg in air is subject to washout by precipitation for a given event. Air
parcel back-trajectories indicate that possible source regions within 72-hr travel time were located mostly to the south,
southeast, and southwest, up to 2500 km distance away but local sources may also be important. 相似文献