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1.
A multiplex PCR method has been developed to detect, differentiate, and confirm the morphological identification of three root infecting Olpidium spp.: O. bornovanus, O. brassicae, and O. virulentus. Of the 132 root samples examined, 101 samples were infected by Olpidium spp.. Based on the morphology of resting spores, the presence of O. bornovanus was confirmed in 20.5 % of the samples, whereas species identity could not be determined for the remaining samples because they failed to reproduce sexually. With multiplex PCR, it was possible to determine the Olpidium identity of all the infected samples, even when resting spores were not formed. This method was also effective for detecting Olpidium spp. in water samples. In addition, the specificity and sensitivity of multiplex PCR were evaluated. The multiplex PCR method was validated with samples of 9 different crops from 11 countries of America, Europe, and Africa.  相似文献   

2.
Reaction of the Schiff base ligands 2-Br-4,5-(OCH2O)C6H2C(H)NCH2CH2NMe2 (a) and 4,5-(OCH2CH2)C6H3C(H)NCH2CH2NMe2 (b) with Pd(OAc)2 or K2[PdCl4] leads to the mononuclear cyclometallated compounds [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(OCOMe)] (1a) and [Pd{4,5-(OCH2CH2)C6H2C(H)NCH2CH2NMe2-C6,N,N}(Cl)] (1b), derived from C-H activation at the C6 carbon. Treatment of a with Pd2(dba)3 gave [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N,N}(Br)] (2a), via C-Br activation.The metathesis reaction of 1a with aqueous sodium chloride gave [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(Cl)] (3a), with exchange of the acetate group by a chloride ligand. Treatment of the cyclometallated monomers 1a-3a with PPh3 in a 1:1 molar ratio yielded the mononuclear complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N}(L)(PPh3)] (L: OAc, 4a; Cl, 5a) and [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N}(Br)(PPh3)] (6a), with Pd-NMe2 bond cleavage. However, treatment of a solution of 3a or 2a with silver trifluoromethanesulfonate, followed by reaction with PPh3 in acetone yielded the cyclometallated complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(PPh3)][CF3SO3] (7a) and [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N,N}(PPh3)][CF3SO3] (8a), respectively, where the Pd-NMe2 bond was retained.The reaction of the ligands 2-Br-4,5-(OCH2O)C6H2C(H)N(2′-OH-5′-tBuC6H3) (c) and 4,5-(OCH2CH2)C6H3C(H)N(2′-OH-5′-tBuC6H3) (d) with Pd(OAc)2 gave the tetranuclear complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(2′-O-5′-tBuC6H3)-C6,N,O}]4 (1c) and [Pd{4,5-(OCH2CH2)C6H2C(H)N(2′-O-5′-tBuC6H3)-C6,N,O}]4 (1d), respectively. Treatment of 1c with PPh3 in 1:4 molar ratio, gave the mononuclear species [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(2′-(O)-5′-tBuC6H3)-C6,N,O}(PPh3)] (2c) with opening of the polynuclear structure after P-Obridging bond cleavage.The structure of compounds 2a, 1c and 1d has been determined by X-ray diffraction analysis.  相似文献   

3.
Interactions between Oesophagostomum columbianum and Oesophagostomum venulosum were studied by comparing the establishment, development and distribution of each species in single and mixed infections in sheep. The establishment of O. venulosum was reduced by 90 % in sheep previously infected with O. columbianum and by a mean of 50 % in sheep given a simultaneous concurrent infection with O. columbianum. Prior or simultaneous infection with O. venulosum had little or no effect on the establishment of O. columbianum. It is concluded that the increase in incidence of O. venulosum in sheep on the Northern Tablelands of New South Wales has been consequent upon but not the cause of the decline in incidence of O. columbianum. The decline in O. columbianum has probably occurred because of a combination of factors including the failure of infective larvae to overwinter on pasture, the use of efficient anthelmintics and changes in pasture composition.  相似文献   

4.
The structures of isoflavidinin and iso-oxoflavidinin, two new modified 9, 10-dihydrophenanthrenes of the orchids Pholidota articulata, Otochilus porecta and O. fusca have been established. 13C NMR spectral analysis of isoflavidinin acetate was made to confirm its structure.  相似文献   

5.
Thiourea, PhNHC(S)NHP(O)(OPri)2 (LH) chelates of CoII, NiII, and PdII ions have been obtained and investigated by single-crystal X-ray diffraction, UV, IR, NMR spectroscopy, and EI mass-spectrometry. The unusual 1,3-N,S-coordination via sulfur and NP(O) nitrogen atoms has been found in the trans-square-planar NiL2 and PdL2 complexes, whereas the 1,5-O,S-coordination is realized in the tetrahedral CoL2 complex. DFT calculations have revealed significant stabilization of the 1,3-N,S-structures due to stronger crystal field and the NH-OP hydrogen bonds.  相似文献   

6.
Invasion of the Mediterranean Sea by the two world-wide famous exotic algae species, Caulerpa taxifolia and Caulerpa racemosa, is still a problem and has adverse effects on the Mediterranean sublittoral ecosystem. Biological control studies revealed that the two native Sacoglossans, Oxynoe olivacea and Lobiger serradifalci, may have an effect on the expansion of invasive Caulerpa spp. in the Mediterranean. In the framework of this study, antioxidant enzyme activities, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), lipid peroxidation (LPO) and oxidized glutathione (GSSG) levels, as oxidative stress markers in L. serradifalci and O. olivacea were determined at two different temperature conditions (20 and 27 °C). In both species, SOD, CAT and GSH-Px activities were found to be positively correlated with temperature. The SOD activities in L. serradifalci were higher than those in O. olivacea at both temperatures, whereas the CAT and GSH-Px activities were significantly (p<0.05) higher in O. olivacea, compared to L. serradifalci. As expected, both species showed decreased LPO levels at 27 °C compared to 20 °C. GSSG level at 27 °C in O.olivacea was significantly (p<0.05) higher than that of 20 °C. On the other hand, no statistical (p>0.05) difference in L.serradifalci existed between GSSG levels at two temperatures. But, despite the variations in the antioxidant enzyme activities, there was no significant difference in LPO levels between the species, suggesting that the oxidative consequences of a given environmental condition may vary among different species. Inasmuch as the GSSG levels were in accordance with antioxidant enzyme activities, GSH might have acted as a cofactor of GSH-Px and an individual antioxidant in these sea slugs.  相似文献   

7.
Floral initiation and development of Hedysarum varium, Onobrychis melanotricha and Alhagi persarum was studied using epi-illumination light-microscopy techniques. The studied species belong to the tribe Hedysareae of the inverted repeat loss clade (IRLC clade), which is characterized by missing the large inverted repeat in the chloroplast genome. The main aim of our study was to determine developmental bases for similarities and differences among the three taxa and to verify the position of Alhagi relative to other genera of the IRLC clade. According to our observations, bracteoles are missing in Onobrychis melanotricha, but are present in the other two species. All three species share unidirectional sepal initiation starting with a median abaxial sepal and bidirectional petal initiation. Stamen initiation is unidirectional in all except in the outer stamen whorl of Hedysarum varium, where it is bidirectional. An important ontogenetic feature in O. melanotricha is the existence of five common primordia, which give rise to petal and stamen primordia. Although in H. varium and O. melanotricha common primordia are observed at some stages in floral organ initiations, in Alhagi all organs are initiated separately. Moreover, overlap in time of floral organs initiation occurs in H. varium and O. melanotricha, but not in A. persarum. The carpel initiates concurrently with the petal primordia in all. It might be presumed that Alhagi is primitive in relation to the other studied Hedysareae taxa, due to the presence of bracteoles, the absence of common primordia, and the lack of overlap in time of different organ initiations.  相似文献   

8.
2012年6月23日,在重庆市城口县大巴山国家级自然保护区综合科考过程中采集到臭蛙属(Odorrana)标本5号,经鉴定为光雾臭蛙(O.kuangwuensis)3号、南江臭蛙(O.nanjiangensis)2号,均为重庆市两栖类新纪录.  相似文献   

9.
O-Polysaccharides (O-antigens) were isolated from Escherichia coli O13, O129, and O135 and studied by chemical analyses along with 2D 1H and 13C NMR spectroscopy. They were found to possess a common →2)-l-Rha-(α1→2)-l-Rha-(α1→3)-l-Rha-(α1→3)-d-GlcNAc-(β1→ backbone, which is a characteristic structural motif of the O-polysaccharides of Shigella flexneri types 1-5. In both the bacterial species, the backbone is decorated with lateral glucose residues or/and O-acetyl groups. In E. coli O13, a new site of glycosylation on 3-substituted Rha was revealed and the following O-polysaccharide structure was established:The structure of the E. coli O129 antigen was found to be identical to the O-antigen structure of S. flexneri type 5a specified in this work and that of E. coli O135 to S. flexneri type 4b reported earlier.  相似文献   

10.
Orthosiphon stamineus (Java tea) has been widely used as traditional herb and several bioactive compounds against animal cells have been isolated. However, no bioactive compound against plants has been reported. Therefore, we investigated possible allelopathic properties and substances in O. stamineus. Aqueous methanol extracts of O. stamineus inhibited root and hypocotyl growth of cress (Lepidium sativum) and lettuce (Lactuca sativa) seedlings. Increasing the extract concentration increased the inhibition, which suggests that O. stamineus may have allelopathic properties. When the extract was divided into an ethyl acetate and an aqueous fraction, the ethyl acetate fraction showed the stronger inhibitory effect. Thus, the ethyl acetate phase was further purified, and the main allelopathic substance was isolated and identified as 13-epi-orthosiphol N, a novel compound, by spectral data. 13-epi-Orthosiphol N inhibited root and hypocotyl growth of cress and lettuce at concentrations greater than 10 μmol/L. The concentrations required for 50% inhibition ranged from 41 to 102 μmol/L. These results suggest that 13-epi-orthosiphol N may be an allelochemical and main contributor to the growth inhibitory effect of O. stamineus and may have potential as a template for the development of new plant control substances.  相似文献   

11.
斑膜合垫盲蝽Orthotylus(O.)sophorae Josifov是近年来临夏地区国槐Sophora japonica Linnaeus上严重发生的害虫之一。应用6种分布型指数法分析判定了斑膜合垫盲蝽若虫在国槐上的空间分布型,利用Taylor幂法则和Iwao回归方程分析聚集原因,结果表明,斑膜合垫盲蝽若虫在国槐上呈聚集分布,公共k c值为0.6169,且符合负二项分布;其种群聚集是由某些环境作用引起的。在此基础上,采用Iwao的方法确定了斑膜合垫盲蝽若虫的田间最适抽样数和序贯抽样表;并根据Gerrard的零频率模型建立了估计该种群平均密度的零频率公式:x=1.7457(-lnP0)1.1119。  相似文献   

12.
13.
Two sporozoan parasites, Gregarina hylobii and Ophryocystis hylobii n. sp., parasitizing the adults of natural populations of Hylobius abietis are described. The gregarine G. hylobii, a parasite of the gut of H. abietis, has been reexamined and its complete life cycle, including the solitary gamonts, gametocysts, and sporoducts is described. The life cycle of the neogregarine O. hylobii infecting the Malpighian tubules of host animals examined at light and electron microscope levels is discussed. Some data on the prevalence of infections and host-parasite relationships are also discussed.  相似文献   

14.
Acanthamoeba is a genus of free-living amoebae found to be able to host many bacterial species living in the environment. Acanthamoebae and Vibrio cholerae are found in the aquatic environments of cholera endemic areas. Previously it has been shown that V. cholerae O1 and O139 can survive and grow in Acanthamoeba castellanii. The aim of this study was to examine the ability of Acanthamoeba polyphaga to host V. cholerae O1 and O139. The interaction between A. polyphaga and V. cholerae strains was studied by means of viable amoeba cell counts and viable count of the bacteria in the absence and presence of amoebae. The viable count of intracellularly growing bacteria was estimated by utilizing gentamicin assay. Electron microscopy was used to determine the localization of V. cholerae inside A. polyphaga. The results showed that A. polyphaga enhanced growth and survival of V. cholerae, which grew and survived inside the amoeba cells for 2 weeks. The electron microscopy showed that A. polyphaga hosted intracellular V. cholerae localized in the vacuoles of amoeba cell. Neither the presence of V. cholerae together with A. polyphaga nor the intracellular localization of the bacteria inhibited growth and survival of A. polyphaga. The outcome of the interaction between these microorganisms may support strongly the role of A. polyphaga as host for V. cholerae O1 and O139.  相似文献   

15.
16.
研究了菊科向日葵族鳢肠亚族蟛蜞菊属(Sphagneticola O. Hoffm.)和孪花菊属(Wollastonia DC. ex Decne.)各2种植物的染色体数目和染色体形态。蟛蜞菊[S. calendulacea (L.) Pruski]的染色体数目为2n=50, 核型公式为2n=18m+30sm+2st,南美蟛蜞菊[S. trilobata (L.) Pruski]的染色体数目为2n=56, 核型公式为2n=24m+28sm+4st, 孪花菊[W. biflora (L.) DC.]的染色体数目为2n=30,核型公式为2n=24m+4sm+2st,山孪花菊[W. montana (Blume) DC.]的染色体数目为2n=74, 核型公式为2n=37m+31sm+6st。根据上述结果并结合以前的有关资料,推测蟛蜞菊属的染色体基数可能为x=14和x=25,而不应是x=15。该属的3个新世界热带种[S. brachycarpa (Baker) Pruski、S. gracilis (Richard) Pruski和南美蟛蜞菊]可能都基于x=14, 其中S. gracilis为二倍体(2n=2x=28), S. brachycarpa和南美蟛蜞菊为四倍体(2n=4x=56); 唯一的亚洲种(蟛蜞菊)可能是基于x=25的二倍体(2n=2x=50)。染色体资料不支持将山孪花菊(x=37)这一植物置于孪花菊属(x=15)中。  相似文献   

17.
Following exposure to short wavelength (254 nm) ultra-violet light, the detached leaflets of Passaea (Ononis) ornithopodioides and 31 species and subspecies of Ononis have been found to accumulate substantial quantities of the isoflavonoid (pterocarpan) phytoalexin, medicarpin. Apart from P. (Ononis) ornithopodioides, O. cristata, O. fruticosa, O. pubescens and O. rotundifolia, leaf tissues of all the species investigated similarly contained small amounts of the related fungitoxic pterocarpan, maackiain. Isoflavan phytoalexins common in genera such as Medicago and Trifolium (tribe Trifolieae) were absent from both Ononis and Passaea. The phytoalexin data suggest that Passaea should probably be combined with Ononis and, in conjunction with information on constitutive isoflavonoids, that Ononis itself should be assigned to the Trifolieae rather than to the distinct tribe Ononideae. Chemical evidence for and against an especially close taxonomic association between Ononis and Cicer (tribe Cicereae) is also briefly discussed.  相似文献   

18.
Chiu J.-K., Ong S.-J., Yu J.-C., Kao C.-Y. and Iuima T. 1981. Susceptibility of Oncomelania hupensis formosana recombinants and hybrids with Oncomelania hupensis nosophora to infection with Schistosoma japonicum. International Journal for Parasitology11: 391–397. Three generations of Oncomelania hupensis formosana recombinants were produced by mating the Kaohsiung race with the Ilan and Changhua races of the snails. F2 and F3 recombinants were produced by back-crossing F1 and F2 with Kaohsiung O. h. formosana. Subsequently, susceptibility of recombinants to infection with the original strain of Schistosoma japonicum, Ilan or Changhua strain, was investigated. Results indicated that susceptibility of recombinants declined steadily generation by generation. Marked decline of infectivity was observed for Kaohsiung-Ilan recombinants as compared with Kaohsiung-Changhua recombinants. For example, the overall infection rate of Kaohsiung-Ilan F1 recombinants was 7.3 % with a 51.4 % of control snails. The same figures for F2 were 4.2 and 52.6%, and 1 and 40.3 % for F3. On the other hand, the overall infection rate of Kaohsiung-Changhua F1 recombinants was 21.9% with a 46.9% of control snails; and 11.9 and 50.3 % for F2; and 7.6 and 33.2% for F3. The F3 hybrids of Oncomelania hupensis nosophora from Japan and O. h. formosana from Kaohsiung and Ilan were also produced, and susceptibility with the Japanese strain of S. japonicum was studied. A highly significant decline of susceptibility was observed among hybrids (4.4%) in contrast with control snails (85.6 %).Feasibility of applying O. h. formosana in biological control of S. japonicum was discussed. One must determine in the laboratory, prior to application, which race of O. h. formosana should be used depending on the Oncomelania snails of an endemic area. For S. japonicum prevalent in Yamanashi, Japan, the Ilan race of O. h. formosana was found to be better choice than the Kaohsiung race of the snails.  相似文献   

19.
Trophozoites and cysts of free-living Acanthamoeba castellanii present a serious risk to human health as causative agents of human diseases such as fatal granulomatous amoebic encephalitis and Acanthamoeba keratitis that is reported from various part of the world, also in Poland, with increasing frequency, particularly in the contact lens wearers. The amphizoic amoebae are generally extremely resistant to different chemical agents, however, several strains/isolates within A. castellanii may differ in virulence. Among the features considered as associated with the amoeba pathogenicity, temperature tolerance and resistance to different environmental conditions are reported. In the present study, A. castellanii strain cultured in 26 °C after several year passages were tested for sensibility/tolerance to instant temperature changes as well as exposition to deuterium oxide, D2O. Significant decrease of number of viable amoebae during in vitro exposition to D2O occurred, but no changes in trophozoites/cysts ratio. The ability of the strain examined to develop in higher temperature may indicate a wide adaptation reserve and its pathogenic potential.  相似文献   

20.
Daily observations were made of the maternal and paternal behaviour of Onychomys torridus and Peromyscus leucopus in laboratory cages. In both species, the females spent more time in the nest area with the young and groomed the young more frequently than their male partners, but the males played a surprisingly active role in nest attendance. Paternal nest attendance was more frequent in O. torridus males than in P. leucopus males. Onychomys males were also more active in grooming the young than Peromyscus males. These species-specific patterns of parental care are discussed in relation to the behavioural and ecological characteristics of Onychomys and Peromyscus.  相似文献   

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