斜纹夜蛾抗性种群中酶抑制剂对杀虫剂的增效作用(英文)

采用浸液生测法研究了斜纹夜蛾Spodoptera litura巴基斯坦抗性种群中酶抑制剂[胡椒基丁醚(PBO)和脱叶膦(DEF)]对丙溴磷、灭多威、硫双灭多威、氯氰菊酯、氯氟氰菊酯、联苯菊酯、茚虫威和多杀菌素等杀虫剂的增效作用。结果表明:PPO和DEF对氨基甲酸酯杀虫剂灭多威和硫双灭多威均具有增效作用,但对有机磷杀虫剂丙溴磷不具有增效作用。两种抑制剂对氯氰菊酯均产生增效作用,但对联苯菊酯没有增效作用。PPO和DEF增加了氯氟氰菊酯对Multan种群的毒性,但没有增加其对Mailsi种群的毒性。DEF对多杀菌素具有增效作用,但PBO对其没有增效作用。PBO和DEF对氨基甲酸酯杀虫剂、拟除虫菊酯杀虫剂、茚虫威和多杀菌素具有明显的增效作用,这说明细胞色素P450单加氧酶和酯酶的解毒作用至少部分参与了斜纹夜蛾对这些杀虫剂的抗性过程。不过,两种增效剂对杀虫剂增效作用范围有限,暗示对于斜纹夜蛾巴基斯坦种群而言,其他的机制(如靶位点不敏感、表皮穿透作用降低)可能是更重要的抗性机制。

Nanosuspension enhances dissolution rate and oral bioavailability of Terminalia arjuna bark extract in vivo and in vitro

Objective:To enhance the dissolution rate and oral bioavailability of Terminalia arjuna bark extract by formulating its nanosuspension.Methods:Nanoprecipitation approach was used for the formulation of nanosuspension using polysorbate-80 as a stabilizer.The formulated nanosuspension was assessed for particle size,polydispersity index,zeta potential value and for in vitro dissolution study.Oral bioavailability studies were carried out in Wistar male albino rats by administering a single dose(50 mg/kg.b.wt)of the formulated nanosuspension and coarse suspension.The storage stability of the formulated nanosuspension was determined after three months of storage at room temperature and under the refrigerated condition.Mutagenicity assay was carried out to evaluate the toxicity of the formulated nanosuspension using two mutant strains(Salmonella typhimurium TA100 and Salmonella typhimurium TA98).Results:The mean particle size of the formulated nanosuspension was 90.53 nm with polydispersity index and zeta potential values of 0.175 and-15.7 m V,respectively.Terminalia arjuna nanosuspension showed improved dissolution rate and 1.33-fold higher oral bioavailability than its coarse suspension.The formulated nanosuspension also showed better stability under the refrigerated condition and was non-mutagenic against both strains.Conclusions:Our study demonstrates that nanosuspension technology can effectively enhance the dissolution rate and oral bioavailability of Terminalia arjuna bark extract.

The mycobiota of discoloured needles of the Swiss stone pine(Pinus cembra L.) in the Tatra Mountains(Poland)

The Swiss stone Pine(Pinus cembra L.) is an alpine species, fairly commonly occurring in the Alps and the Carpathians, close to the timberline. Natural sites of the Swiss stone pine in Poland are found exclusively in the Tatra Mountains, within the area of the Tatra National Park(TNP). In 2017, the health status of the needles of P. cembra was determined and their mycological analysis was carried out. As a result, 11 species of fungi were isolated from the needles showing disease symptoms, manifested by various shades of discoloration. The most frequently observed species was Fusarium oxysporum. It probably does not bring on disease symptoms, but may affect the development of other frequently isolated species(such as Sydowia polyspora, Lophodermium sp. and Lophodermium conigenum) that are pathogenic to Pinus spp.

Diapause development in early and late emerging phenotypes of Delia floralis

The turnip fly, Delia floralis Fall6n （Diptera： Anthomyiidae） is an important insect pest of brassica vegetable crops in the holarctic region. Different populations have strongly varying temperature requirements for fly emergence, a challenge for accurate prediction of activity. This study focused on diapause development in one early and one late emerging phenotype. The physiological state after various treatments was deduced from emergence data. Our results showed a slow diapause progression at chilling conditions for both populations and diapause ended about 7 months after pupae were formed for the early population. For the late population held at 4℃ diapause did not end, no matter how long the duration of chilling. These pupae required a period with elevated temperatures above 6~C to continue development. At constant non-chilling conditions （18℃） from the time pupae were formed both populations completed diapause most rapidly. These results indicate that chilling delayed, rather than accelerated development and was not a prerequisite for diapause development. For post-diapause, results indicated a linear relationship between rate of development and temperature within the range of 6-18℃and a theoretical base temperature for development of about 2℃ for both populations. In conclusion, D. floralis pupae are in diapause throughout a long winter period, and delayed emergence of the late population appears to be caused by prolonged diapause regulated by a developmental temperature threshold. The study has added information on the biology of turnip fly populations, a prerequisite for improved pest control.

One stop shopⅢ:taxonomic update with molecular phylogeny for important phytopathogenic genera:51–75(2019)

This is a continuation of a series focused on providing a stable platform for the taxonomy of phytopathogenic fungi and organisms.This paper focuses on 25 phytopathogenic genera:Alternaria,Capnodium,Chaetothyrina,Cytospora,Cyphellophora,Cyttaria,Dactylonectria,Diplodia,Dothiorella,Entoleuca,Eutiarosporella,Fusarium,Ilyonectria,Lasiodiplodia,Macrophomina,Medeolaria,Neonectria,Neopestalotiopsis,Pestalotiopsis,Plasmopara,Pseudopestalotiopsis,Rosellinia,Sphaeropsis,Stagonosporopsis and Verticillium.Each genus is provided with a taxonomic background,distribution,hosts,disease symptoms,and updated backbone trees.A new database(Onestopshopfungi)is established to enhance the current understanding of plant pathogenic genera among plant pathologists.

Interactions between rodents and weeds in a lowland rice agro-ecosystem:the need for an integrated approach to management

Rodents and weeds are important pests to rice crops in Southeast Asia.The interaction between these 2 major pests is poorly documented.In temperate cereal systems,seeds of grass weeds can be an important food source for rodents and weed cover along crop margins provides important refuge for rodents.In 2012 and 2013,a rep­licated study(n=4)in Bago,Myanmar compared 4 treatments(rodents and weeds;no rodents and weeds;ro­dents and no weeds;no rodents and no weeds)each of 0.25 ha in transplanted rice.Weeds were managed with hand weeding in the wet season,and hand weeding and herbicides in the dry season.Plastic fences were in­stalled to exclude rodents.We examined the weed cover and relative abundance of weed species,rodent dam­age,rodent population dynamics and rice yield loss caused by rodents and weeds.The dominant rodent species was Bandicota bengalensis.In the dry season,Cyperus difformis was dominant at the tillering stage and Echi­nochloa crus-galli was the dominant weed species at the booting stage.In the wet season E.crus-galli was a dominant weed throughout the season.Damage by rodents was higher in the dry season.There were larger eco­nomic benefits for best weed management and effective rodent control in the dry season(258 US$/ha)than in the wet season(30 US$/ha).Concurrent control of weeds in and around rice fields combined with coordinated community trapping of rodents during the early tillering stage and ripening stage of rice are recommended man­agement options.

Point-of-need molecular processing of biosamples using portable instrumentation to reduce turnaround time

Infectious agents,both standard and emerging or engineered,might initiate outbreaks with global impact and/or existential-level threat potential.Such agents might infect human,livestock,exploitable plant cultures or the environment at large.Instead of responding by sampling teams which may also carry out prolonged surveillance,a more effective concept is to pre-process the samples,possibly to nucleic acid extract so as to transport them without biological risks by standard channels,or to process them up to a point and return the results,leaving the samples which only need specialized tests and dedicated equipment.In this context a portable device,allowing multiple routine and crisis-management applications due to its inherent flexibility,is scrutinized against alternatives and possible needs so as to develop a novel standard of surveillance and intervention,meant to facilitate containment by providing faster much more reliable laboratory results at a fraction of older generation mobile nucleic acids analyzers.Additional steps,such as agarose in pills and buffers pre-packaged in expendable syringes with pistons locked by improvised safety features may improve the Complexity Level of the whole system so as to make it appealing to intervention/crisis management personnel,while the instrument proper may double as backup for respective benchtop devices.