Effects of microbial,organically acceptable,and reduced risk insecticides on Anthonomus signatus (Curculionidae: Coleoptera) in strawberries (Fragaria × ananassa)

Anthonomus signatus, the strawberry bud weevil, is active in early spring coinciding with the bloom period of host plants and when managed and unmanaged pollinators are active. Female A. signatus cause injury to the host plant during egg laying when they deposit a single egg inside an unopened flower bud and then girdle or “clip” the bud at the pedicel. Past efforts to control A. signatus populations have relied on the use of broad spectrum insecticides. Fields are either treated at the first signs of damage, or precautionary treatments may be applied prophylactically in fields with a history of damage. Because A. signatus damage occurs during bloom, there is concern about the potential harm to pollinators caused by these treatments. In order to identify materials more compatible for use during bloom, the efficacy of reduced risk pesticides against A. signatus was tested in semi-field bioassays over two years. Beauveria bassiana, cyantraniliprole, novaluron, and pyrethrins were assessed in the first year, and none caused significant A. signatus mortality. Acetamiprid, flonicamid, and spinosad were compared in the second year, acetamiprid and spinosad had higher A. signatus mortality than an untreated control, and exposure to spinosad resulted in similar mortality to bifenthrin, an industry standard material.     

Effect of fungal to bacterial biomass ratio on the relationship between CO2 evolution and total soil microbial biomass

The relationship between the fungal: bacterial biomass ratio and the metabolic quotient (qCO₂) was studied in three different soils. In addition, the effect of the fungal: bacterial biomass ratio on the relationship between CO₂ evolution and the size of the soil microbial biomass was examined. Soil samples were collected from three experimental fields amended with various organic materials (Yatsugatake, Ibaraki, and Tochigi fields). The range of the fungal:bacterial biomass ratio in the Yatsugatake and Ibaraki fields was small (1.54–2.24 and 1.11–1.71, respectively), but it was large in the Tochigi field (1.18–3.75). We found a high negative correlation between this ratio and the metabolic quotient (qCO₂=2.10–0.361 (fungal:bacterial biomass ratio), R=–0.851, P<0.01) in the Tochigi field. Therefore, we suggest tha qCO₂ decreases with an increase in the fungal:bacterial biomass ratio, which may be due to a higher efficiency of substrate C use by fungal flora in comparison with bacterial flora. In the Yatsugatake and Ibaraki fields, there was a high positive correlation between CO₂ evolution and total microbial biomass. In contrast, no correlation was observed between these two parameters in the Tochigi field, probably reflecting the wide range of values for the fungal:bacterial biomass ratio. From the results obtained, we suggest that the fungal: bacterial biomass ratio is an important factor regulating the relationship between CO₂ evolution and the size of the microbial biomass.     

Remediating sulfadimethoxine-contaminated aquaculture wastewater using ZVI-activated persulfate in a flow-through system

Antibiotic resistant bacteria can result from the improper discharge of water from the aquaculture farming industry. This calls for the development of a low-cost remediation technology. Our research verified the use of ZVI-activated persulfate (PS) to treat antibiotic-contaminated aquaculture discharge water in a flow-through system. We selected sulfadimethoxine (SDM) as a representative antibiotic residual and tested SDM degradation under varying parameters: activator dose, initial pH, chloride concentration, activator dose and timing. The results demonstrated that increasing the ZVI dosage significantly decreased SDM degradation due to the scavenging effects for the persulfate radical (SO₄⁻). SDM decomposition occurred when SO₄⁻ attacked the aniline moiety via electron transfer prior to undergoing hydrogen abstraction/addition on the sulfonamide. A high pH produced the fastest degradation with reaction rates following the order pH 11 > > pH 9 > pH 3 > pH 5. A high Cl⁻ concentration (>100 mM) enhanced SDM degradation because of the production of chlorine radicals. The experiment results from ZVI sequential addition indicated that only a small continual input of ZVI was sufficient to generate SO₄⁻ to react with SDM. We used a flow-through concept for the real discharge water that was spiked with SDM prior to treating with PS/ZVI. The results showed that our system was able to remove approximately 68% of SDM from filtered and 74% from unfiltered discharge water. These results provide proof-of-concept that our PS/ZVI system could potentially be developed to remediate antibiotic-contaminated aquaculture wastewater.     

Hatching envelope formation in the egg of the black tiger shrimp,Penaeus monodon (Decapoda,Penaeidae)

The aim of this study was to reveal the process of hatching envelope (HE) formation in eggs of the black tiger shrimp Penaeus monodon, using fluorocytochemistry with fluorescein isothiocyanate (FITC)‐labelled lectins and transmission electron microscopy (TEM) with mouse monoclonal anti‐FITC‐conjugated gold‐lectin labelling. Following lectin binding screening tests, Concanavalin A (Con A) and wheat germ agglutinin (WGA) were chosen to trace movements of specific sugar‐associated components of the HE. This revealed that both Con A and WGA‐binding components migrated from the ooplasm to the HE. Using TEM, it was revealed that membranous materials in the ooplasm were released at the time of spawning, that these became associated with granular structures outside the oocyte and that they together developed into an outer layer of the HE. Contents of flocculent vesicles and dense vesicles in the ooplasm were exocytosed and formed the inner layer of the HE. The TEM with gold‐labelled Con A and WGA revealed that the dense and flocculent vesicles and the inner layer of the HE contained components associated with mannose (sugar affinity to Con A) and N‐acetyl‐β‐d ‐glucosamine (sugar affinity to WGA).     

Microbial biomass and mineralization-immobilization of nitrogen in some agricultural soils

Summary The chloroform fumigation-incubation method (CFIM) was used to measure the microbial biomass of 17 agricultural soils from Punjab Pakistan which represented different agricultural soil series. The biomass C was used to calculate biomass N and the changes occurring in NH₄ ⁺-N and NO₃ ^–-N content of soils were studied during the turnover of microbial biomass or added C source. Mineral N released in fumigated-incubated soils and biomass N calculated from biomass C was correlated with some N availability indexes.The soils contained 427–1240 kg C as biomass which represented 1.2%–6.9% of the total organic C in the soils studied. Calculations based on biomass C showed that the soils contained 64–186 kg N ha^–1 as microbial biomass. Immobilization of NCO₃ ^–-N was observed in different soils during the turnover of microbial biomass and any net increase in mineral N content of fumigated incubated soils was attributed entirely to NH₄ ⁺-N.Biomass N calculated from biomass C showed non-significant correlation with different N availability indexes whereas mineral N accumulated in fumigated-incubated soils showed highly significant correlations with other indexes including N uptake by plants.     

5种不同作用机理除草剂对青海高原农田土壤微生物的影响研究

研究了5种不同作用机理除草剂对青海高原土壤微生物生物量的影响。结果表明：土壤微生物类群对不同除草剂具有各自不同的反应。从影响时间看,影响大小依次为：百草枯〉氟磺胺草醚〉溴苯腈〉氟乐灵〉精喹禾灵;从影响程度看,精喹禾灵对土壤微生物生物量的影响是这5种除草剂中最小的;氟乐灵、百草枯、溴苯腈、精喹禾灵对土壤微生物生物量的影响表现为“抑制-恢复”;氟磺胺草醚对土壤微生物生物量的影响表现为“抑制-激活-恢复”。     

生物碳对灰漠土有机碳及其组分的影响

土壤有机碳是影响土壤肥力和作物产量高低的决定性因子。以棉花秸秆为原料,在高温厌氧条件下热解制备生物碳,通过盆栽试验探讨了生物碳对新疆灰漠土有机碳及其组分的影响。试验设置3种生物碳:棉花秸秆分别在450℃、600℃和750℃下热解制备(以BC450、BC600和BC750表示);每种生物碳的施用量分别为5 g·kg-1、10 g·kg-1和20 g·kg-1(占土壤重量的比例);同时,以空白土壤为对照(CK)。结果表明:施用生物碳可促进小麦生长,两茬小麦的地上部干物质重均显著高于对照。施用生物碳可显著提高土壤总有机碳,且生物碳热解温度越高,施用量越大,提高作用越明显。各生物碳处理土壤易氧化碳含量均显著高于对照;生物碳低、中施用量处理(5 g·kg-1、10 g·kg-1)土壤水溶性有机碳含量显著高于对照,但高施用量处理(20 g·kg-1)与对照无显著差异;除BC750低施用量处理(5 g·kg1)外,其余各生物碳处理土壤微生物量碳含量也均显著高于对照。生物碳不同热解温度对土壤易氧化碳和微生物量碳含量的影响表现为BC450>BC600>BC750;但对土壤水溶性有机碳含量无显著影响。生物碳不同施用量对土壤易氧化碳的影响表现为10 g·kg-1≈20 g·kg-1>5 g·kg-1,水溶性有机碳含量为5 g·kg1≈10 g·kg-1>20 g·kg-1。生物碳对土壤微生物商的影响总体表现为:生物碳的热解温度越高,施用量越大,土壤微生物商越低。因此,合理的施用棉花秸秆生物碳可显著增加灰漠土有机碳储量,改变土壤有机碳组分,提高土壤生产力。     

土壤中微生物对多环芳烃的降解及其生物修复的研究进展

多环芳烃是一类在环境中普遍存在的有机污染物,微生物降解是多环芳烃（PAHs）降解的主要途径。文中主要介绍PAHs的降解菌,降解机理和PAHs的生物修复方面的研究进展。这些进展可为降解菌株的分子及遗传机制研究提供理论依据,将促进通过基因工程优化降解菌、更有效地检测PAHs环境污染及实现PAHs污染的生物修复。     

长期施用有机肥对瘠薄红壤有效碳库及碳库管理指数的影响

主要分析了长期施用有机肥对瘠薄红壤有效碳库(微生物量碳,易氧化碳,矿化碳)及碳库管理指数(CPMI)的影响.结果表明:长期施用有机肥对土壤有效碳库和碳素有效率有很大影响,绿肥,稻草秸秆肥和厩肥处理的土壤有机碳,微生物量碳、易氧化碳、矿化碳的数量、碳素有效率明显高于对照处理的土壤。施肥对全碳、矿化碳的影响为:厩肥>绿肥>秸秆稻草肥>本田还田>对照,对微生物量碳的影响为:绿肥>厩肥>稻草秸秆肥>本田还田>对照,对活性碳(CA)、CPMI,碳素有效率A、B、C的影响为:绿肥>稻草秸秆肥>厩肥>本田还田>对照。在提高CA、CPMI方面,绿肥和稻草秸秆肥优于厩肥。相关分析表明:土壤有效碳库和碳素有效率与土壤化学性质相关或极相关,CPMI与土壤养分因子相关或极相关,反映了农业生产措施对土壤碳库的影响,可以运用CPMI来评估土壤碳库的变化。     

Assessing the severity of canine pancreatitis

The objective of this study was to determine whether laboratory testing currently available is able to provide prognostic information in canine pancreatitis. A prospective study of dogs with naturally occurring pancreatitis was undertaken. Twenty-two cases with histologically confirmed pancreatic inflammation were included in the study. Each dog had routine haematology parameters, serum biochemistry (including lipase and amylase), serum trypsin-like immunoreactivity and trypsinogen activation peptides (TAP) in urine and plasma measured. Twelve of the dogs were classified as having severe disease. These dogs had statistically significant increases in urinary TAP-creatinine ratio (UTCR) measurement, serum lipase, serum phosphate and serum creatinine concentrations. Additionally dogs with severe pancreatitis had significantly decreased urine specific gravity levels. The most sensitive and specific test to assess the severity of pancreatitis was the measurement of UTCR.