排序方式： 共有71条查询结果，搜索用时 15 毫秒
61.
Journal of Plant Diseases and Protection - Fusarium oxysporum f. sp. capsici (Foc) induces wilt disease in chilli and affects its yield. Implementing microorganisms and plant extracts for plant... 相似文献
62.
Rauf Iqra Wajid Abdul Hussain Irshad Ather Safa Ali Muhammad Asad 《Tropical animal health and production》2019,51(6):1357-1365
The first objective of the present study was to evaluate if the antibodies induced by the live LaSota and killed Newcastle disease (sub-genotype VIIi) vaccines protect the chickens against exposure with pathogenic avian avulavirus-1 (AAvV-1) of chicken and/or pigeon origins. The second objective was to study the effect of vaccines on stressed birds (dexamethasone, aflatoxin, and heat stressed) with respect to antibody production and protection against pathogenic AAvV-1 challenge. Sixty-one-day-old Hubbard chickens were divided into six groups (gA–gF) with ten animals each. All the groups received LaSota (105 EID50, 0.1 ml per chick) on days 7 and 27 via eye drop and one intramuscular injection of a killed vaccine (sub-genotype VIIi) (107.5 EID50, 1 ml) on day 18, except the control birds received the PBS only. Moreover, group gC-DEX received dexamethasone intramuscularly at a dose rate of 1-mg/kg body weight daily; gD-AFLA had received aflatoxin as oral gavage at a dose rate of 30 ppb daily, and gE-HEAT was kept under heat stressed (38 °C) till challenged. All the groups were challenged with AAvV-1 strain of chicken origin of sub-genotype VIIi, except the group gA-pigeon was challenged with pigeon-origin strain (sub-genotype VIm). The result showed that the gA-pigeon and gB-chicken vaccinate showed 100% and 80% protection. The immunosuppressive birds produced low pre-challenge HI titer, and protection was observed at 40%, 50%, and 70% in gC-DEX, gD-AFLA, and gE-HEAT, respectively. Our findings suggest the stress factors such as aflatoxin in the feed and dexamethasone are immunosuppressive in nature and suppress the immune response and its associated protective role during infection.
相似文献63.
The foraging technique and prey‐handling time of the black‐necked stork (Ephippiorhynchus asiaticus) was studied in Dudhwa National Park, India, from January 1996 to June 1997. The habitat in which the storks foraged played an important role in selecting a particular technique to procure food. Black‐necked storks mostly foraged using a tactile technique (>90%), but sometimes foraged visually. When the water level was estimated to be less than 60 cm, the storks foraged using tactile techniques. There was no difference in the feeding techniques of male and female storks. Foraging attempt rates varied between the sexes in summer (May) and during late winter (February) in 1997. The search time for prey increased when the water level was high and fish were widely distributed. Decreases in water level resulted in concentration offish in certain areas and this contributed to high fish‐catching rates by black‐necked storks. Males had a higher success rate offish capture than females. However, females captured longer fish than males. Prey‐handling time increased in both sexes as fish length increased. Fish 4–6 cm long were most frequently taken by the foraging storks. 相似文献
64.
Masoud Zolfaghari Gheshlaghi Kayvan Shams Asad Rokhzadi Khosro Mohammadi 《Journal of plant nutrition》2013,36(20):2715-2730
AbstractThis experiment carried out as split plot factorial based on a randomized complete block design with three replications during two consecutive years (2015–2016). The main plot consisted of drought stress: complete irrigation, irrigation withholding at R1 stage, irrigation withholding at R2 stage and subplots included foliar application of micronutrients: distilled water (control), zinc sulfate, manganese sulfate and zinc sulfate?+?manganese sulfate and cultivar as: Williams and Zan elite. The results showed that proline and linoleic acid were increased significantly, but chlorophyll a and b, seed yield, protein percentage, oleic and linolenic acids were decreased significantly by irrigation withholding. Also, the maximum values of chlorophyll b, protein percentage and linolenic acid were achieved by Williams. The significant increasing effect of zinc was found on the maximum root and stem proline, chlorophyll b, and oleic, linolenic and linoleic unsaturated fatty acids, meanwhile the maximum leaf proline was obtained by manganese sulfate. 相似文献
65.
Muhammad Azam KhanCheng Zhihui Xiao XuemeiAbdul Rehman Khan Shahjahan Shabbir Ahmed 《Crop Protection》2011,30(9):1149-1155
The overreliance on and overuse of fungicides is not only a health hazard but also induces natural resistance in plant pathogens, resulting in an economic burden on agricultural producers and a potential threat to natural systems across the globe. It is therefore necessary to identify natural substitutes of fungicides. This study was designed to evaluate the inhibitory effect of the root exudates of two different garlic cultivars, cv. Gailiang (G064) and Cangshan (G025), against Phytophthora capsici, a pepper fungus. All treatments (T1 to T4, i.e., 25%, 50%, 75% and 100% root exudate concentrations) of garlic cultivar G025 showed lower inhibition effects than cultivar G064. An intervarietal inhibition effect comparison at 100% concentration (T4) exhibited a 69.24% decline in hyphal growth for G064 compared with 49.06% for G025. The mycelial growth measured in the control was found to be significantly greater compared with the garlic treatments. The results of high performance liquid chromatography (HPLC) revealed that G064 possessed a large amount of allicin compared with G025. Scanning and transmission electron microscopy showed that, compared with the controls and hyphae treated with G025, the fungal hyphae treated with G064 exudates were misshaped, fragmented and had a smaller diameter, as well as empty cytoplasmic contents in the cell wall. Thus, the root exudates of the G064 cultivar had a significant fungicidal effect on P. capsici. 相似文献
66.
Abdonnaser Mohebbi Amin Nematollahi Eisa Ebrahimi Dorcheh Farnaz Goodarzian Asad 《Aquaculture Research》2012,43(8):1184-1193
Oxidative damage by free radicals has been implicated in the pathogenesis of several diseases. In this study, the antioxidative effect of dietary garlic on rainbow trout was examined. Trout fingerlings were fed on diets containing 10, 20, 30, 40 and 50 g garlic powder kg?1 diet. Serum lipid peroxides and activities of antioxidant enzymes were measured. Serum thiobarbituric acid reactive substances (TBARS) assay showed that garlic consumption that resulted in a significant decrease in lipid peroxidation. The lowest levels of TBARS were observed in fish fed diet supplemented with 30 g kg?1 garlic. However, higher doses of garlic (40 and 50 g kg?1 diet) caused no further reduction in serum TBARS. The results showed a significant increase in superoxide dismutase in all of the garlic‐treated groups compared with the control. Ingestion of 10, 20 and 30 g kg?1 dietary garlic resulted in a significant reduction in the catalase activity compared with all but the 10 g kg?1 group. There was no significant difference in glutathione peroxidase activity among the different groups. Serum alanine aminotransferase and aspartate aminotransferase levels increased significantly in trout‐fed diets containing 40 and 50 g kg?1 garlic powder. These results suggest that dietary garlic may improve the antioxidant status of rainbow trout. However, undesirable effects of higher doses of garlic should be considered. 相似文献
67.
Asad Mohammadi Zarejabad Mohammad Sudagar Mohammad Reza Imanpour Valiolah Jaafari 《Journal Of Applied Aquaculture》2013,25(3):207-211
We examined the influence of different hatching times on growth and survival of beluga, Huso huso, over a 28-day period. Larvae from a single pair of beluga, Huso huso, were divided according to hatching time into four groups: early, mid (between 6–9 h after the first group), late (23–26 h after the first group), and a mixture of first to last hatched larvae. At hatching time, there was no statistical difference (P > 0.05) in size and length among the four groups. Prior to the onset of exogenous feeding, groups A and D exhibited slightly earlier onset of aggregation behavior and began exogenous feeding 18 h sooner than the other groups (P < 0.05). Mortality after the onset of the endogenous feeding phase was not significantly different among groups (A: 8.15% ± 0.47%; B: 8.55% ± 0.41%; C: 6.63% ± 0.53% and C: 8.23% ± 0.43%) (P > 0.05). Results showed that hatching time has no effect on the growth and overall mortality of larval beluga. 相似文献
68.
In seed priming, seeds are soaked in a solution of low water potential and dried back to their original weight. This study was conducted to evaluate the comparative performance of different seed priming treatments and to investigate whether re-drying is essential or not? Seeds of fine grain aromatic rice (Oryza sativa L.) cultivar Super-Basmati were subjected to hardening, osmohardening with CaCl2 and KCl (ψ s ?1.25 MPa) each for 24 h (one cycle), and hydropriming and ascorbate priming (10 mg L?1) for 48 h. Seeds were primed in two sets. In one set after each treatment, seeds were given three surface washings with distilled water and dried back near to original moisture contents with forced air. In the other case, after surface washings with distilled water, seeds were surface dried using blotting paper and sown immediately. All the priming treatments improved the emergence, seedling growth and reserve metabolism. Use of surface drying was more effective for rice seed invigoration, as evident from earlier and synchronized seedling emergence. Moreover, shoot and root length, seedling dry weight, root score, α-amylase activity, soluble sugars and dehydrogenase activity were also improved, although germination percentage and leaf score were similar from both strategies. Results suggested that surface drying, rather than re-drying close to original weight, was more effective, while among the treatments, osmohardening with CaCl2 was the most effective. Increasing rice production with judicious use of water is need of the day, and aerobic rice cultivation is an attractive alternative for this purpose. However, poor and erratic stand establishment is one of the major hindrances in its wide scale adoption. In this regard, seed priming techniques are pragmatic approaches to achieve proper stand establishment in the new rice culture. They help in improving seedling density per unit area under optimal and adverse soil conditions and may be opted to improve the performance of aerobic rice. 相似文献
69.
A total of 100 poultry farms in northern and middle areas of Jordan were sampled to investigate the bacteria associated with airsacculitis in broiler chickens. Of 170 bacterial isolates, 88.2% were identified as Escherichia coli, 8.8% as Ornithobacterium rhinotracheale, and 3% as Bordetella avium. Fourteen serotypes of E. coli were identified among 66 typeable isolates and the remainder were untypeable. The most prevalent serotypes were O1, O8, and O78. The main serotype of O. rhinotracheale was serotype A. Experimental inoculation of O. rhinotracheale via intravenous, intratracheal, and intra-air sac routes resulted in growth retardation, thickening in the air sacs, arthritis, and liver necrosis. Reisolation of O. rhinotracheale from the air sacs, liver, trachea, heart, and spleen at day 7 postinoculation confirmed its role. In vitro susceptibility testing revealed that E. coli isolates were sensitive to gentamicin and colistin, O. rhinotracheale to tetracyline, and B. avium to most of the nine antibiotics examined. 相似文献
70.
【目的】以十字花科蔬菜害虫小菜蛾（Plutella xylostella）为研究对象,筛选参与小菜蛾代谢氯虫苯甲酰胺的主要细胞色素P450解毒基因,为阐明不同抗性水平小菜蛾对氯虫苯甲酰胺的抗性机理提供依据。【方法】利用叶片药膜法测定不同小菜蛾种群3龄幼虫对氯虫苯甲酰的抗性水平,通过转录组测序、insectbase数据库和小菜蛾基因组数据库筛选得到52个细胞色素P450基因。应用MEGA5.10软件对52个细胞色素P450基因进行进化分析,获得与抗药性密切相关的CYP3和CYP4家族P450基因。利用实时荧光定量PCR方法分析目的基因在小菜蛾室内筛选种群（HZY）和田间抗性种群惠州种群（HZ）、连州种群（LZ）、东升种群（DS）、钟落潭种群（ZLT）中的表达量,选用RNA干扰技术,采用注射法,验证在抗性种群中显著上调表达的CYP6BF1V4在小菜蛾抗氯虫苯甲酰胺中的功能。【结果】抗药性测定结果表明,LZ和HZ小菜蛾种群为中等水平抗性,ZLT、DS和HZY小菜蛾种群为高水平抗性。对52个细胞色素P450基因的系统发育树分析发现,小菜蛾拥有10个CYP4家族基因,28个CYP3家族基因,其中2个CYP4家族基因在HZ和HZY种群中的表达量显著高于敏感种群,4个CYP3家族基因表达量与小菜蛾抗性呈正相关,8个基因在中等水平抗性小菜蛾体内的表达量高于在高水平抗性小菜蛾体内的表达量。对田间种群进一步筛选得到6个与小菜蛾抗氯虫苯甲酰胺密切相关,在不同抗性种群中均上调表达的细胞色素P450基因,其中4个为CYP6家族基因（CYP6BF1V4、CYP6BF1V3、CYP6f1和CYP6B6）,2个为CYP9家族基因（CYP9G2.1和CYP9G2.2）,以CYP6BF1V4的表达量最高,其在抗性种群中的表达量是在敏感种群中表达量的3.5—6.3倍。RNA干扰结果显示,沉默CYP6BF1V4能够显著提高小菜蛾对氯虫苯甲酰胺的敏感性。【结论】CYP6BF1V4、CYP6BF1V3、CYP6f1、CYP6B6、CYP9G2.1和CYP9G2.2可能在小菜蛾体内协同调控多功能氧化酶的表达,从而加快小菜蛾代谢氯虫苯甲酰胺的速度,提高小菜蛾对氯虫苯甲酰胺的抗性。 相似文献