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1.
M. T. Dumas 《Forest Pathology》1992,22(1):11-18
Pseudomonas fluorescens, Pseudomonas spp., Bacillus spp., Enterobacter spp., Serratia spp. and Agrobacterium radiobacter were isolated from root-free soils of the Boreal Mixedwood Forest of Ontario a, nd found to be capable of inhibiting the linear growth of Armillaria ostoyae in vitro. Isolates of P. fluorescens, Bacillus spp. and A. radiobacter were the most effective inhibitors of mycelial growth. To test the ability of the bacteria to suppress rhizomorph formation, A. gallica, which produces rhizomorphs in culture more consistently than does A. ostoyae, was used; only a small fraction of P. fluorescens and Bacillus spp. isolates were capable of preventing in vitro rhizomorph formation by A. gallica. 相似文献
2.
From the heartwood-free stemwood of Pinus densiflora, 7 compounds inhibitory to the linear growth of Fomes annosus were isolated. These were identified as pinosylvin, pinosylvin monomethyl ether, (3-sitosterol, a cembrol-like diterpene alcohol, and three isomeric diterpene acids belonging to the abietane group, one of which is probably palustric acid. Other antifungal fractions contained complex mixtures and were not characterized. 相似文献
3.
J. Bordes G. Charmet R. Dumas de Vaulx A. Lapierre M. Pollacsek M. Beckert A. Gallais 《Euphytica》2007,154(1-2):41-51
Progress made in the in situ gynogenesis technique since 1990 now allows production of a high number of maize (Zea mays L.) doubled-haploid (DH) lines. The aim of the study was to compare DH lines versus selfing lines for testcross performance.
DH and single-seed descent (SSD) lines were produced from random S1 progenies of a broad-base population. For grain yield, kernel moisture, plant height, ear height and leaf length, the three
population means were similar. Except for kernel moisture, the genetic variance of DH lines was nearly twice as high as the
genetic variance of S1 families, as expected. On the other hand, genetic variance among SSD lines was only 1.5 times higher than the genetic variance
of S1 families. This lower variance could be due to a selection bias in the method of production of SSD lines. However, for all
traits, heritability of SSD or DH lines was higher than heritability of S1 families. Epistasis effects in DH progenies were not significant. The consequence was a high correlation between S1 testcross progenies and DH or SSD testcross progenies, meaning that the S1 testcross value can be used to select the best families from which DH lines will be extracted. As a whole, the observed variation
in DH lines appeared to be more in accordance with the observed variation among S1 families than with the observed variation among SSD lines. 相似文献
4.
Riley MB Dumas JA Gbur EE Massey JH Mattice JD Mersie W Mueller TC Potter T Senseman SA Watson E 《Journal of agricultural and food chemistry》2005,53(13):5079-5083
An interlaboratory study was conducted to compare pesticide recovery from Empore C(18) and Speedisks C(18)XF solid phase extraction disks after shipping. Four pesticides were used for the comparison of the two disk extraction materials: atrazine, diazinon, metolachlor, and tebuconazole. These pesticides were chosen to provide a range of physiochemical properties. Water samples were extracted onto the disk types and shipped to a cooperating laboratory for elution and analysis. The mean recoveries from Empore disks were atrazine, 95%; diazinon, 91%; metolachlor, 92%; and tebuconazole, 83%. The recoveries from Speedisks C(18)XF were atrazine, 89%; diazinon, 87%; metolachlor, 86%; and tebuconazole, 79%. Means for each of the pesticides using the different disk types were not statistically different (alpha = 0.05), but results were more variable when using Speedisks C(18)XF as compared to Empore disks. Reasons for the increased variability are discussed, but overall results indicate that Speedisks C(18)XF could be used as an alternative to Empore disks. Speedisks C(18)XF are enclosed in a plastic housing, so they can be used more easily in remote sampling sites without the possibility of glassware breakage, no prefiltration of samples is needed, and there are realignment problems that can be associated with the Empore disks. 相似文献
5.
Spencer JR Stern SA Cheng AF Weaver HA Reuter DC Retherford K Lunsford A Moore JM Abramov O Lopes RM Perry JE Kamp L Showalter M Jessup KL Marchis F Schenk PM Dumas C 《Science (New York, N.Y.)》2007,318(5848):240-243
Jupiter's moon Io is known to host active volcanoes. In February and March 2007, the New Horizons spacecraft obtained a global snapshot of Io's volcanism. A 350-kilometer-high volcanic plume was seen to emanate from the Tvashtar volcano (62 degrees N, 122 degrees W), and its motion was observed. The plume's morphology and dynamics support nonballistic models of large Io plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source. In images taken in Jupiter eclipse, nonthermal visible-wavelength emission was seen from individual volcanoes near Io's sub-Jupiter and anti-Jupiter points. Near-infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150- to 1335-kelvin range, consistent with basaltic composition. 相似文献
6.
An in vitro system for adhesion and fusion of maize gametes 总被引:1,自引:0,他引:1
The development of in vitro fertilization systems in flowering plants is important for understanding and controlling the mechanisms of fertilization. Here a method is described in which isolated maize gametes fuse. In a medium containing 5 mM calcium chloride, sperm and egg cells adhere for several minutes and then fuse within 10 seconds. The method is specific to male-female gamete pairs and results in 80 percent fusion, whereas fusions with other combinations of gametic and mesophyllic cells are less frequent. Eggs fertilized in vitro do not fuse with additional male gametes, which suggests that a block to polyspermy exists. 相似文献
7.
8.
Rudolf I Golovchenko M Sikutová S Rudenko N Grubhoffer L Hubálek Z 《Folia parasitologica》2005,52(3):274-276
A total of 350 nymphs of the common tick Ixodes ricinus (Linnaeus, 1758) were collected in an endemic focus of Lyme borreliosis (South Moravia, Czech Republic) and examined for the presence of the protozoan Babesia microti (Fran?a, 1909) by polymerase chain reaction (PCR), using primers specific for the B. microti gene encoding small subunit rRNA. The assay revealed five positive pools (out of 70 pools examined); the corresponding prevalence rate was about 1.5%. Sequence analysis of the PCR products confirmed their 100% homology with that of B. microti. The study represents the first evidence of B. microti in ixodid ticks in the Czech Republic. 相似文献
9.
10.
Zdenek Hublek Martin Tomeek Marcel Kosina Silvie ikutov Petra Strakov Ivo Rudolf 《Zoonoses and public health》2019,66(8):978-981
West Nile virus lineage 2 (WNV‐2) was detected in the brain of 17 goshawks (Accipiter gentilis) that succumbed to neuroinvasive disease in the Czech Republic during 2018: twelve birds were captive and five wild. Furthermore, two wild sparrowhawks (Accipiter nisus) and three other captive birds of prey (golden eagle Aquila chrysaetos, hybrid saker falcon Falco cherrug × F. rusticolus and Harris's hawk Parabuteo unicinctus) also died due to WNV encephalitis. The 2018 outbreak in Czech raptors clearly reflects a new epidemiological situation and indicates an increasing risk of both raptor and human infection with WNV‐2 in the country. 相似文献