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Tea production in North-East India hit a record loss due to the widespread severe outbreak of a mixed brood of three species of looper caterpillar pests of geometrid moths (Lepidoptera) in 2008-2010. In addition to Buzura suppressaria, two newly recorded geometrids, viz., Hyposidra infixaria and Hyposidra talaca have caused widespread severe damage in recent years. In the present study we report the nucleopolyhedroviruses (NPV) isolated from the tea looper caterpillar from North-East India. We identified and characterized the NPV by cloning and sequencing a partial segment of polyhedrin gene of virus infected larvae of B. suppressaria, H. talaca and H. infixaria. A comparison of deduced amino acids of polyhedrin gene among H. talaca, H. infixaria and B. suppressaria showed that same strain was found to infect all the three loopers in India, which show high sequence identity with B. suppressaria Chinese isolates. Based on the polyhedrin sequence homology, it is predicted that a variant of B. suppressaria Chinese isolate of NPV found to infect H. talaca, H. infixaria and B. suppressaria in India.  相似文献   

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Variations in leaf gas-exchange characteristics, leaf pigment content, and other important leaf traits were investigated in seven wild Oryza species, five hybrids, and five improved varieties. The significant variations were observed in photosynthetic pigment contents amongst different species of Oryza. The mean chlorophyll (Chl) content was higher in O. sativa (varieties and hybrids), while O. eichengeri showed the lowest Chl content. The mean carotenoid (Car) content in O. sativa (varieties and hybrids) was higher than in other wild rice species. O. eichengeri and O. barthii had significantly lower Car contents than other rice species. Significant differences were noticed in the rate of photosynthesis (P N), stomatal conductance (g s), transpiration rate (E), internal CO2 concentration (C i), specific leaf mass (SLM), and leaf thickness amongst different Oryza species. The mean P N was the highest in O. nivara followed by O. eichengeri. The mean P N was the lowest in O. glumaepatula, which was lower than that of cultivated varieties and hybrids of O. sativa. High rates of photosynthesis were observed in O. nivara (ACC. No. CR 100097), O. rufipogon (ACC.No. CR 100267), and O. nivara (ACC.No. CR 100008). The O. nivara and O. rufipogon genotypes with high P N might be used in rice improvement programmes for an increase of leaf photosynthesis in rice. Multiple correlations performed between different gas-exchange characteristics and other physiological traits revealed that the rate of photosynthesis was not dependent on the leaf pigment content or the leaf thickness. A strong positive correlation between P N and the P N/Ci ratio, which represents the carboxylation efficiency, indicated that the observed variation in P N was not based on pigment content or other leaf traits.  相似文献   

4.
The spatial and temporal dynamics of rotifers in relation to the physico-chemical parameters in Fish-Culture Research Station (Southern Tunisia) were studied monthly from February 2005 to January 2006. Thirteen rotifer species were found: Brachionus urceolaris, Brachionus calyciflorus, Brachionus sp., Lecane stichaea, Lecane rhytida, Lecane sp., Hexarthra mira, Rotaria tardigrada, Conochiloides natans, Trichocerca marina, Keratella quadrata, Keratella cochlearis and Notommata codonella. The most dominant rotifer was B. urceolaris (76% of total abundance). Rotifer density and water temperature were negatively correlated (r=−0.94, n=12, p=0.001). The highest abundance of rotifers was found in basin 4 (1.5×105 ind m−3, in June 2005).  相似文献   

5.
Insulin is an inducer of chondrocyte hypertrophy and growth plate chondrogenesis, although the specific molecular mechanisms behind these effects are mostly unknown. Our aim was to investigate whether insulin-induced chondrocyte hypertrophy occurs through a modification in the amount of O-linked N-acetylglucosamine (O-GlcNAc)-modified proteins and in the expression of the key enzymes of this pathway, O-GlcNAc transferase and O-GlcNAcase (OGA). We also studied if O-GlcNAc accumulation per se, induced by an OGA inhibitor, was able to induce pre-hypertrophic chondrocyte differentiation both in vitro and in vivo. Insulin-induced differentiation of ATDC5 pre-chondrocytes occurred alongside a gradual increase in the accumulation of O-GlcNac-modified proteins (O-GlcNAcylated proteins), as well as an increase in the expression of O-GlcNAc transferase and OGA. In the absence of insulin, O-GlcNAc accumulation induced by thiamet-G, a specific OGA inhibitor, was able to increase the gene expression of differentiation markers, as well as the activity of MMP-2 and -9. Thiamet-G also activated pERK, p-JNK, and p-p38 and the O-GlcNAcylation of Akt. Thiamet-G administration to C57/bl mice induced a significant expansion in the growth plate height and in the hypertrophic zone height. Therefore, our results show that O-GlcNAc glycosylation has chondromodulating activity.  相似文献   

6.
黑龙江省药用植物根际土壤真菌多样性   总被引:4,自引:1,他引:3  
为了解黑龙江省药用植物根际土壤真菌的种群结构和区系分布特点,于2010年7月份和10月份,在黑龙江省的伊春、铁力、绥化、哈尔滨、牡丹江和佳木斯6个中药材产区共采集土壤样品220份,所采集的药用植物种类主要有五味子、平贝母、刺五加、党参、防风、柴胡、桔梗、黄芩等14种.经稀释平板法和土壤颗粒平板法分离共获得1016株真菌,经形态鉴定归为35属86种,其中接合菌7属10种,占7.78%;子囊菌1属2种,占0.69%;无性型真菌27属74种,占70.76%,其余20.77%的菌株为不产孢真菌.试验结果表明,黑龙江省药用植物根际土壤真菌的种群多样性丰富,其中青霉属Penicillium、曲霉属Aspergillus、木霉属Trichoderma、镰孢菌属Fusarium是优势种群,粘帚霉属Gliocladium、金孢属Chrysosporium、毛霉属Mucor、枝孢属Cladosporium、枝顶孢属Acremonium、根霉属Rhizopus是亚优势种群.不同药用植物根际土壤真菌区系的结构和组成存在一定的差异.除无孢类群外,青霉属Penicillium、曲霉属Aspergillus、木霉属Trichoderma和镰孢菌属Fusarium是14种药用植物根际土壤真菌的优势菌群.五味子、平贝母和柴胡是黑龙江省种植的主要中药材,它们在6个采样地点间的真菌种群的多样性水平存在差异,其中伊春地区的多样性指数(H’=2.9574)和丰富度指数(R=5.6683)最高,而佳木斯地区的均匀度指数(J=0.9200)最高.不同地区的相似性水平也存在差异,其中牡丹江与绥化的药用植物根际土壤真菌种群组成之间的相似性系数最高(Cj=0.6315),牡丹江与哈尔滨的相似性最低(Cj=0.3704).  相似文献   

7.
Global climate change has led to rising temperatures and drought in boreal forests in Northeast China. In some areas, shrubs and trees coexist in high altitude and high latitude areas, and their differences with global warming may lead to significant changes in vegetation composition and distribution. Therefore, we compared the relationships between climate and growth for the most widely distributed dwarf shrub (Pinus pumila) and the two dominant tree species (Larix gmelinii and Pinus sylvestris var. mongolica) in boreal forests in the Daxing’an Mountains, China. A total of 340 tree-ring cores from 172 trees and 64 discs from shrubs were collected from four sites and compared the responses of shrub and tree growth to climate patterns using dendrochronological methods. The shrub and two tree species responded differently to interannual climate variance. The negative effect of growing season temperature was greater on growth of L.gmelinii and P. sylvestrisvar.mongolica than on P. pumila, and the promoting effect of winter and spring precipitation was greatest on P. pumila. Compared with the two tree species, P. pumila had a higher temperature threshold and grew over a shorter growing season. Our findings suggested that L. gmelinii and P. sylvestrisvar.mongolica are more susceptible to global warming than the shrubs that coexist with them. However, P.pumila should be studied from an individual perspective in the future due to the dwarf morphology of shrubs and their complex microenvironment.  相似文献   

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Insect (epi)cuticular lipids characterize sex and species and often play an important role in mating behavior. We previously revealed that two black-colored swallowtail butterflies, Papilio polytes and Papilio protenor, show sexual dimorphism and species specificity in cuticular lipid composition and that P. polytes males use specific monoene components for mate discrimination. These findings suggest that their closely related species may have different profiles of cuticular lipids. We examined the cuticular lipid compositions of five Papilio species (P. bianor, P. maackii, P. helenus, P. macilentus, and P. memnon), closely related and sympatric to P. polytes and P. protenor, and discussed whether it is possible to discriminate between sexes, and between species based on their chemical profiles. The cuticular lipids consist mainly of C23–C31 aliphatic hydrocarbons, in which n-tricosane, n-heptacosane, and n-nonacosane are predominant. Several aliphatic ketones, aliphatic acids, and oxygenated terpenoids were also identified as major components shared by several species. There were no components exclusive to a particular species. Conspecific males and females shared most of the components but were mostly distinguishable based on their composition. Moreover, P. helenus males, P. polytes females, and P. protenor females had two different phenotypes of lipid composition. Although unrelated to the genetic lineage, the seven species were classified into four clusters based on their lipid profiles. The first cluster was composed of only P. memnon. The other six species were broadly classified into three clusters consisting of subclusters for each species: 1) P. polytes, P. helenus, P. macilentus, and several P. protenor females; 2) P. bianor and P. protenor; and 3) P. maackii and several P. helenus males. These results indicate that cuticular lipid profiles characterize the species and sex of the Papilio species and may be responsible for mate discrimination among them.  相似文献   

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Without the proper information on pyrazinamide (PZA) susceptibility of Mycobacterium tuberculosis (MTB), PZA is inappropriately recommended for the treatment of both susceptible and multidrug-resistant tuberculosis (MDR-TB) in Nepal. This study aimed to collect information regarding PZA susceptibility in MTB isolates from Nepal by analyzing pncA and its upstream regulatory region (URR). A total of 211 MTB isolates were included in this study. Sequence analysis of pncA and its URR was performed to assess PZA resistance. First-line drug susceptibility testing, spoligotyping, and sequence analysis of rpoB, katG, the inhA regulatory region, gyrA, gyrB, and rrs were performed to assess their association with pncA mutation. Sequencing results reveal that 125 (59.2%) isolates harbored alterations in pncA and its URR. A total of 57 different mutation types (46 reported and 11 novel) were scattered throughout the whole length of the pncA gene. Eighty-seven isolates (41.2%) harbored mutations in pncA, causing PZA resistance in MTB. There was a more significant association of pncA alterations in MDR/pre-extensively drug-resistant (Pre-XDR) TB than in mono-resistant/pan-susceptible TB (p < 0.005). This first report on the increasing level of PZA resistance in DR-TB in Nepal highlights the importance of PZA susceptibility testing before DR-TB treatment.  相似文献   

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Biallelic mutations in the GJB2, GJB3, GJB6 and CLDN14 genes have been implicated in autosomal recessive non-syndromic hearing impairment (ARNSHI). Moreover, a large number of GJB2 heterozygous patients was reported. The phenotype was in partly justified by the occurrence of two deletions including GJB6. We analysed GJB2, GJB6, GJB3 and CLDN14 in 102 Tunisian patients with ARNSHI. The deletions del(GJB6-D13S1830) and del(GJB6-D13S1854) were also screened. The c.35delG in GJB2 was the most frequent mutation (21.57%). It was detected at heterozygous state in 2 patients. The del(GJB6-D13S1830) was identified in one case at heterozygous state. No other mutation in studied gap junction genes was detected in heterozygous patients. Several polymorphisms were identified in GJB3, GJB6 and CLDN14. Our study confirms the importance of GJB2 screening in ARNSHI and suggests that in consanguineous populations, a single DFNB1 mutant allele in individuals with HI is likely due to a coincidental carrier state.  相似文献   

12.
Ticks and tick-borne diseases are important in human and livestock health worldwide. In November 2012, ixodid ticks were collected and identified morphologically from cattle and wild animals in the Maswa district and Iringa urban, Tanzania. Amblyomma gemma, A. lepidum, and A. variegatum were identified from Maswa cattle, and A. variegatum was the predominant species. A. marmoreum, Hyalomma impeltatum, and Rhipicephalus pulchellus were identified from Iringa cattle in addition to the above 3 Amblyomma species, and A. gemma was the most abundant species. Total 4 Amblyomma and 6 Rhipicephalus species were identified from wild animals of the 2 areas. A. lepidum was predominant in Maswa buffaloes, whereas A. gemma was predominant in Iringa buffaloes. Overall, A. variegatum in cattle was predominant in the Maswa district and A. gemma was predominant in Iringa, Tanzania.  相似文献   

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吉林不同生境防风夏季光合特性   总被引:5,自引:0,他引:5  
采用LCpro+全自动便携式光合仪同时测定了长春、长岭和白城3个生境防风的光合作用及环境因子,研究不同生境防风净光合速率、蒸腾速率及水分利用效率等日变化特征及其与生态因子之间关系,并采用通径分析法分析各环境因子对防风净光合速率的直接和间接影响,探讨防风的光合生理规律,为进一步研究防风的光合生理提供依据。结果表明,各环境因子之间存在相互作用,在影响防风光合作用的环境因子中,光合有效辐射(PAR)是驱动因子,它的变化驱动了大气温度(Ta)、叶片温度(Tl)变化,Ta升高引起空气密度的变化是午间相对湿度(RH)和大气浓度CO2(Ca)降低的一个重要原因。环境因子中对Pn直接作用由大到小长春为TlTaPARCaRH,长岭为PARTlRHCaTa,白城为TaTlRHPARCa。长春、长岭PAR与Pn相关系数最大,而白城地区Ca与Pn相关系数最大,说明防风叶片对不同环境因子的反应有所不同。8月份3个地区防风净光合速率日变化均呈双峰型曲线,具有明显的光合"午休"现象。长春、长岭地区防风光合"午休"现象主要由气孔因素引起,白城地区防风光合"午休"现象主要由非气孔因素引起的。3个生境防风的Pn与Gs之间均呈显著的正相关关系,白城的Gs比长春、长岭地区的低44%左右,这是防风为适应高温干旱的环境而形成的生理反应。不同生境土壤含水量间差异显著,白城地区土壤水分含量很低,只有20.35%,仅是长春土壤含水量的56.50%,而空气温度较高,强辐射使气孔叶片蒸腾失水加剧,导致叶片含水量也很低,仅仅为56.60%,高温干旱使防风叶温升高,防风磷酸化、电子传递、酶活性等受到抑制,导致光合速率降低。因此,白城地区长期高温胁迫是限制防风Pn的主要原因。  相似文献   

14.
We investigated the abundance of total and pathogenic Vibrio parahaemolyticus in shellfish sampled from four provinces in China during May 2013 and March 2014 using the most probable number-polymerase chain reaction (MPN-PCR) method. Total V. parahaemolyticus was detected in 67.7% of 496 samples. A total of 38.1% and 10.1% of samples exceeded 1,000 MPN g-1 and 10,000 MPN g-1, respectively. V. parahaemolyticus densities followed a seasonal and geographical trend, with Guangxi and Sichuan shellfish possessing total V. parahaemolyticus levels that were 100-fold higher than those of the Liaoning and Shandong regions. Moreover, the levels of V. parahaemolyticus were at least 10-fold higher in the summer and autumn than in the cooler seasons. Pathogenic V. parahaemolyticus levels were generally lower than total V. parahaemolyticus levels by several log units and tended to be high in samples contaminated with high total V. parahaemolyticus levels. The aqua farms had a lower prevalence but higher abundance of total V. parahaemolyticus compared to retail markets. The catering markets showed the lowest levels of total V. parahaemolyticus, but 20.0% of samples exceeded 1,000 MPN g-1. The levels of both total and pathogenic V. parahaemolyticus in oysters were higher than in clams. The log-transformed abundance of V. parahaemolyticus was significantly correlated with both water temperature and air temperature but not water salinity. These results provide baseline contamination data of V. parahaemolyticus in shellfish in China, which can be applied to local risk assessments to prioritize risk control to key sectors and evaluate the effectiveness of future control measures.  相似文献   

15.
Plasmids in Listeria   总被引:14,自引:0,他引:14  
Thirty-two Listeria strains, including L. monocytogenes of the different Seeliger serovars, L. grayi and L. murrayi, have been analyzed for the presence of plasmids. A cryptic plasmid of 38.5 Md was found in seven strains: in four L. monocytogenes (serovars 12c, 4b, 4d, and Ivanov 1), and in both the L. grayi and the single L. murrayi strains. Restriction enzyme cleavage analysis with two restriction enzymes suggests that the plasmid is a single molecular species, pRYC16. Conjugation experiments between Streptococcus agalactiae BM6101 containing the resistance plasmid pIP501 and L. monocytogenes, L. grayi, or L. Murrayi demonstrated that pIP501 is transferred to Listeria at a mean frequency of 10?6. pIP501 is fully expressed in Listeria and promotes its own transfer between strains of Listeria and from Listeria back to Streptococcus. It is suggested that a circulation of plasmids can take place among members of the genera Listeria and Streptococcus.  相似文献   

16.
The plant-parasitic nematodes Criconemoides lobatum, Hoplolaimus tylenchiformis, and Tylenchorhynchus dubius were present in the top 7.5 cm of sod consisting of numerous stolons and fibrous roots. Phenamiphos and 1,2-dibromo-3-chloropropane (DBCP) controlled all three species, whereas ethoprop and oxamyl controlled H. tylenchiformis and T. dubius but not C. lobatum. Benomyl and carbofuran controlled H. tylenchiformis but had poor control of C. lobatum and T. dubius. The effectiveness of carbofuran varied with the type of formulation, being most effective as a quick-release formulation. C. lobatum was the most difficult to control with chemicals. No chemical treatment improved the growth of ''Astoria colonial'' bentgrass (A. tenuis Sibth.) or Kentucky bluegrass (Poa pratensis L.) under the moist condtions prevalent in these tests.  相似文献   

17.
Beaver J. P. and Dobson C. 1978. Acetylcholinesterase levels in Angiostrongylus cantonensis in relation to the immune response in rats. International Journal for Parasitology8: 9–13. Angiostrongylus cantonensis larvae and adult nematodes synthesize three acetylcholinesterase (AChE) isozymes. The Km of this isozyme complex changes with the development and migrations of the parasite in the rat host. The levels of parasite AChE changed as the development of A. cantonensis progressed; increasing quantities of AChE were found in young adult A. cantonensis from the brain of rats. After migration to the pulmonary arteries, the quantity of AChE in the parasite was reduced and continued to decline in the aging parasite. Anti-A. cantonensis antibody inhibited parasite AChE activity; this inhibition of the parasite AChE activity changed at stages during development of the parasite which suggested variation in parasite AChE isozyme levels. Haemagglutinating anti-A. cantonensis antibody appeared in the serum of infected rats when the parasites commenced to lay eggs and increased in titre thereafter until 103 days after infection.  相似文献   

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《Journal of Asia》2021,24(3):940-947
Wolbachia are maternally inherited endosymbiotic bacteria. These intracellular bacteria are common in arthropods and could manipulate host reproduction in diverse ways, such as feminization, parthenogenesis, male killing and cytoplasmic incompatibility. In spiders, infection by Wolbachia has been found in a total of 99 species belonging to 62 genera and 17 families. Furthermore, recent studies analyzed the phylogeny of Wolbachia in Hylyphantes graminicola, 2 cave spiders and Agelenopsis species using multilocus sequence typing (MLST) approach. However, the diversity of Wolbachia strains determined by MLST in spiders from China is still largely unknown.In this study, we collected 1153 spider individuals from Mangshan in China and screened for Wolbachia in 975 individuals representing 68 spider species belonging to 45 genera of 16 families. We analyzed the phylogenetic relationship between Wolbachia and their host spiders by MLST approach. We found novel infections of Wolbachia in 1 family, 9 genera and 20 species of spiders. We found 13 new Wolbachia strains and suggest that group A is more common than group B in Wolbachia that infect spiders. Our results revealed three recombination events of the concatenated multilocus sequences in Wolbachia that infect spiders. Furthermore, our results demonstrated the phylogenetic incongruence between Wolbachia and spiders, suggesting the horizontal transmission of Wolbachia in spiders.We suggest that recombination and horizontal transmission may play an important role in the diversity and evolution of Wolbachia in spiders.  相似文献   

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