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排序方式: 共有118条查询结果,搜索用时 15 毫秒
111.
The objective of this work was to investigate the efficacy of a prepackaged combined formulation, Companion (carbendazim 12% + mancozeb 63% WP), sole application of carbendazim 50% WP, manozeb 75% WP and methyl jasmonate (MeJA), an inducer of systemic acquired resistance on disease severity and their role in post-infectional defense responses in chilli seedlings against Sclerotium rolfsii. Seeds were treated for 8 h with MeJA (2.5 mM and 5.0 mM) and each of fungicides (500 ppm), and were sown in pots containing soil and fungal inocula (95:5 w/w). At 15 days after sowing maximum defense against fungal infection was exhibited by Companion comparably followed by the sole application of carbendazim and mancozeb. MeJA reduced percent mortality of S. rolfsii-infected chilli seedlings significantly as compared to the inoculated control. Assessment of peroxidase (POX) and esterase (EST) at 15 days after sowing revealed the increased activity under inoculated condition. Highest POX activity in MeJA treatments (5 mM > 2.5 mM) was followed by the Companion treatment. Highest EST activity was registered in Companion treatment. The zymogram of POX isozymes showed over-expression of POX 2 and POX 4 isoforms, and induction of POX 1 isoform in inoculated treatments. On the other hand, that of EST isozymes showed induction of EST 1 isoform in Companion, carbendazim and MeJA treatments. All EST isoforms were over-expressed in Companion-treated seedlings. Both fungicides and MeJA showed significant effects on disease severity, induction of defense enzymes and isozyme pattern in S. rolfsii-infected chilli seedlings. Contact and systemic fungicides under the experiment demonstrated differential responses. The combination formulation was superior in disease control to application of the fungicide components individually. They compared favourably with MeJA in induction of defense-related enzyme activities. All these findings are new with respect to the chilli-S. rolfsii host–pathogen interaction system, S. rolfsii representing the sclerotial basidiomycetes in particular. 相似文献
112.
Suman Bhusan Chakraborty Samir Banerjee Saibal Chatterjee 《Aquaculture International》2011,19(6):1119-1137
The aim of this study was to investigate the molecular mechanism behind androgen-induced sex reversal and growth increase
in Nile tilapia. Three-day-old mixed-sex tilapia juveniles were treated with differential dose (0, 5, 10, 20, 30 mg/kg diet)
and duration (0, 15, 30, 45, 60 days) regimes of 17α-methyltestosterone. Treatment regimes 10, 20, 30 mg/kg-30, 45, 60 days
showed ~95% males, while 0 mg/kg-0 days (control) showed ~50% males (P < 0.01). Next, tilapia was cultured for 6 months in cistern and pond culture systems with 17α-methyltestosterone-treated
diet (10 mg/kg) for three different durations: 0 days (control), 30 days (30-day-treated), and 180 days (throughout-treated).
Fish in pond culture showed significantly higher (P < 0.05) final weight compared with tilapia in cistern culture (235.76, 156.82 g, respectively). Both 30-day-treated and throughout-treated
fish showed significantly higher (P < 0.05) final weight, length, daily weight gain, specific growth rate, and muscle protein content compared with control fish.
The androgen receptor β mRNA and protein expression levels in both 30-day-treated and throughout-treated fish were significantly
higher (~twofolds, P < 0.05) compared with hormone-untreated control males. However, there was not much difference for all these parameters among
the two hormone-treated groups. This higher growth probably results from an androgen-induced increased ‘androgen-androgen
receptor’ mediated anabolic pathway. Serum testosterone concentration of 30-day-treated fish after 6 months was similar to
that of control males (0.9 ng/ml). Moreover, culture of 17α-methyltestosterone-treated monosex tilapia was found beneficial
than hormone-untreated mixed-sex tilapia culture for maintenance of natural fish diversity in indigenous water bodies. 相似文献
113.
Three rearranged phragmalin-type limonoids, khayanolide A, khayanolide B and 1-O-acetylkhayanolide B, and a mexicanolide-type limonoid, khayalactol, have been isolated from the stem bark of Khaya senegalensis (Desr) A Juss (Meliaceae). The antifeedant and growth-inhibitory activities of the isolated compounds were evaluated on Spodoptera littoralis (Boisduval). When added to an artificial diet, khayanolide A, khayanolide B and 1-O-acetylkhayanolide B showed antifeedant activity in a concentration-dependent manner. Khayalactol exhibited strong antifeedant activity without significant differences at all of the tested concentrations (7.5-100 mg kg(-1)). Khayanolide B was the most potent antifeedant with an ECso of 2.19 mg kg(-1). The results also revealed that the isolated compounds caused marked larval growth inhibition on S littoralis after 7 days of feeding on treated diet; this effect was concentration-dependent. Khayanolide B was the most active growth inhibitor among the isolated compounds, with an EC50 of 6.96 mg kg(-1). 相似文献
114.
Abdel-Moneim AM El-Saad AM Hussein HK Dekinesh SI 《Journal of aquatic animal health》2012,24(3):148-160
Various oxidative stress and histopathological biomarkers in gill tissues of Nile tilapia Oreochromis niloticus were investigated. Fish were collected from four sites that differ in their extent of pollution load, including heavy metals: the southeast basin (SEB), main basin (MB), and northwest basin (NWB) of Lake Mariut; and Boughaz El-Maadiya, a channel in Lake Edku. The oxidative stress biomarkers that were analyzed included lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), and glutathione redox cycle enzymes (glutathione peroxidase [GPx] and glutathione reductase [GR]). Levels of reduced glutathione (GSH) were also evaluated. Gill morphology was analyzed by light microscopy and scanning electron microscopy (SEM). Gill LPO was significantly higher in gill tissues of fish collected from the more heavily contaminated MB (40.0%) and NWB (51.4%) sites than in gill samples from the less-contaminated (reference) site, the SEB. Gill LPO in fish from Lake Edku was intermediate but was not significantly higher (17.1%) than the reference. The activities of antioxidant enzymes and the redox-sensitive thiol compound GSH were significantly lower in gill samples from the disturbed sites than in samples from the reference site. Specifically, SOD in MB, NWB, and Lake Edku samples; CAT and GPx in NWB samples; and GR activity and GSH content in MB and NWB samples were lower than those in SEB samples. In most cases, gill tissues from Lake Edku fish had intermediate levels of antioxidants. The main histopathological alterations observed in gills were epithelial lifting, hyperplasia and hypertrophy of the respiratory epithelium, lamellar fusion, and aneurysms. In addition, SEM results demonstrated transformation of the surface structure of epithelial pavement cells. Pathological reactions in the gills of Nile tilapia were most severe at the MB and NWB sites. Our findings suggest that Nile tilapia responded differently according to the environmental stress index in each sampling area. This study is the first to report gill oxidative stress and histopathologies in Nile tilapia from Egyptian aquatic environments. 相似文献
115.
Mohamed A. M. Alsafy Samir A. El-Gendy Basma Kamal 《Anatomia, histologia, embryologia》2021,50(1):108-113
The objective of the current study was to describe the structures of the pastern and coffin joints in dromedary camel using x-ray, bone and soft tissue windows computed tomography (CT) and three-dimensional volume rendering (3DVR) of CT imaging. 3DVR of CT was obtained at the slight flexed dorsal view, plantar view, dorsolateral view and lateral view which explained all the surfaces and structures of the digit bony parts even the parts of the articular surface. The processed images of 3DVR of CT showed different patterns of the cortical, cancellous, subchondral bones and medullary cavity of the bones of the digits. The present study showed clearly all the hard and soft tissues in the pastern and coffin joints of the camel in CT images; however, the plantar ligaments of the pastern joint and ligaments of the navicular cartilage identified on CT images. The CT soft tissue window visualized the joint cavity and their pouches and tendon sheath of the flexor tendons better than the bone window CT. The radiographic, CT and 3D images could be used as a normal reference for the interpretation of some clinical diseases in the pastern and coffin joints of the camel. 相似文献
116.
Igor Renan Honorato Gatto Daniel Correia Lima Linhares Henrique Meiroz de Souza Almeida Luis Antônio Mathias Andrea Souza Ramos de Medeiros Zvonimir Poljak Samir Issa Samara Luis Guilherme de Oliveira 《Tropical animal health and production》2018,50(4):773-778
Bovine viral diarrhea virus (BVDV) infects ruminants as primary hosts. However, other animals like pigs are susceptible. This study was conducted to investigate seroprevalence and risk factors associated with the detection of BVDV antibodies in pig herds. A total of 1.705 serum samples of 33 finisher herds, from seven Brazilian states, were collected in slaughterhouses. The samples were tested by virus neutralization (VN) test. In total, 5.35% (91/1.705) were positive and 64% (21/33) of the herds had positive animals. A significant association with “trucks are not cleaned and disinfected” and “visitors do not respect 72-h interval between visits to farms” (P?<?0.05) was found in association with detection of BVDV-2 antibodies. This study suggests that important biosecurity gaps are present in Brazilian pig farms, as the presence of BVDV antibodies in pigs suggests (direct or indirect) contact with population(s) of ruminant species. Closing biosecurity gaps prevents spread of BVDV and other pathogens such as foot-and-mouth disease virus (FMDV) between pig and ruminant farms. This data should be taken in account by CSF surveillance programs, once cross-reaction in serologic tests between classical swine fever virus (CSFV) and BVDV antibodies has been shown to occur. 相似文献
117.
The determination of emitted Biogenic Volatile Compounds (BioVOCs) profile via Field Air Analysis (FAA) — Solid Phase Micro Extraction (75 μm Carboxen/PDMS portable field sampler) was performed using GC-MS. The six sampling sites located in the Natural Park of Ampezzo Dolomites, part of the UNESCO’s World Heritage List, are characterized by different predominating vegetation. The ubiquitous compound hexanal was chosen as internal standard, in order to compare the amounts of the different compound in the different sites. The main terpenes identified were α-pinene, β-pinene, δ-3-carene and d-limonene, while 1,8 cineole was the highest abundant oxygenated terpene. In the site next the national road a higher amount of benzene derivatives (benzene, toluene, o-xylene, p-xylene and ethylbenzene) were observed. In the site relatively close to the road a marked decrease of benzene derivatives was observed. In the sites close to conifers (i.e. Fir, Pine and Larch) the terpenic content observed was higher than in the site close to the mixed forest (mainly large-leaf and some conifers). Some terpenes were observed also in the high-quote meadow site, although of lower abundance than in the other sites. The highest abundance of terpenes was observed in the Pinus cembra (Swiss Pine) site. 相似文献
118.
Samir Demdoum Fernando Muñoz Ignacio Delgado José Valderrábano Ana Wünsch 《Genetic Resources and Crop Evolution》2012,59(2):253-260
EST-SSR from Medicago truncatula Gaertn. and Glycine max (L.) Merr. were tested for transferability in various species of Onobrychis (O. pyrenaica Sennen, O. argentea Boiss. and O. viciifolia Scop.). Repeatable amplification was obtained for 81% of the microsatellites and 52% were polymorphic. Six selected SSRs
from M. truncatula were used to fingerprint and estimate the genetic similarity of a set of 23 accessions of O. viciifolia. PCA analysis discriminated among the different Onobrychis species and the sainfoin accessions were clustered in a single major group. This grouping is discussed in terms of the history
of cultivation of sainfoin in Spain. The selected SSRs will allow fingerprinting and genetic studies in Onobrychis species, solving the lack of available SSR markers in this species. 相似文献