Antimicrobial activity of Lithocarpus celebicus.     

M R Khan  M Kihara  A D Omoloso 《Fitoterapia》2001,72(6):703-705

The methanol extracts of leaves, stem and root barks of Lithocarpus celebicus showed a broad spectrum of antibacterial activity which was increased on fractionation (petrol, dichloromethane, ethylacetate), particularly in the ethyl acetate fraction of the stem bark and petrol fraction of the root bark. None of the extractives was active against tested moulds.  相似文献   

Antimicrobial activity of Psychotria microlabastra.   总被引：2，自引：0，他引：2  

M R Khan  M Kihara  A D Omoloso 《Fitoterapia》2001,72(7):818-821

The methanol extracts of leaves, root and stem barks of Psychotria microlabastra showed a broad spectrum of antibacterial activity, that was increased on fractionation (petrol, dichloromethane, ethyl acetate), particularly in the ethyl acetate fractions. None of the extractives showed activity against the tested moulds.  相似文献   

Effect of different levels of dietary sweet orange (Citrus sinensis) peel extract on humoral immune system responses in broiler chickens          下载免费PDF全文

Zohreh Pourhossein  Ali Ahmad Alaw Qotbi  Alireza Seidavi  Vito Laudadio  Gerardo Centoducati  Vincenzo Tufarelli 《Animal Science Journal》2015,86(1):105-110

This experiment was conducted to evaluate the effects of different levels of sweet orange (Citrus sinensis) peel extract (SOPE) on humoral immune system responses in broiler chickens. Three hundred 1‐day broilers (Ross‐308) were randomly allocated to treatments varying in supplemental SOPE added in the drinking water. The experimental groups consisted of three treatments fed for 42 days as follows: a control treatment without feed extract, a treatment containing 1000 ppm of SOPE and a treatment containing 1250 ppm of SOPE. All treatments were isocaloric and isonitrogenous. Broilers were vaccinated with Newcastle disease virus (NDV), avian influenza (AI), infectious bursal disease (IBD) and infectious bronchitis virus (IBV) vaccines. Antibody titer response to sheep red blood cells (SRBC) was higher in the group fed 1250 ppm of SOPE (P < 0.05) as well as for immunoglobulin G (IgG) and IgM. Similarly, antibody titer responses to all vaccines were constantly elevated (P < 0.05) by SOPE enrichment in a dose‐dependent manner. Relative weights of spleen and bursa of Fabricius were unaffected by treatments. Dietary SOPE supplementation may improve the immune response and diseases resistance, indicating that it can constitute a useful additive in broiler feeding. Thus, supplying SOPE in rations may help to improve relative immune response in broiler chickens.  相似文献   

Isolation of two anti-inflammatory and one pro-inflammatory polyunsaturated fatty acids from the brown seaweed Undaria pinnatifida     

Khan MN  Cho JY  Lee MC  Kang JY  Park NG  Fujii H  Hong YK 《Journal of agricultural and food chemistry》2007,55(17):6984-6988

Two anti-inflammatory omega-3 polyunsaturated fatty acids (PUFAs) of stearidonic acid (SA) and eicosapentaenoic acid (EPA) and one pro-inflammatory omega-6 PUFA of arachidonic acid (AA) were isolated from the edible brown seaweed Undaria pinnatifida. SA was active against mouse ear inflammation induced by phorbol myristate acetate, with IC50 values of 160, 314, and 235 microg per ear for edema, erythema, and blood flow, respectively. EPA was also active against edema, erythema, and blood flow, with IC50 values of 230, 462, and 236 microg per ear, respectively. Although AA at low concentrations showed anti-inflammatory activities when measured 10 h later, AA doses of more than 243 microg per ear induced inflammatory symptoms 1 h later. Mature thalli generally had larger amounts of PUFAs than young thalli. The algal blade contained more omega-3 PUFAs than were found in other parts, while the holdfast contained extremely high amounts of AA. Late-season thalli showed increased amounts of PUFAs, especially AA.  相似文献   

Genetics and mechanism of resistance to deltamethrin in a field population of Spodoptera litura (Lepidoptera: Noctuidae)   总被引：2，自引：0，他引：2  

Ahmad M  Sayyed AH  Crickmore N  Saleem MA 《Pest management science》2007,63(10):1002-1010

BACKGROUND: Spodoptera litura (F.) causes enormous losses in many economically important crops. The genetics of insecticide resistance has been extensively studied in several insect pests, but there is a lack of information on S. litura. Therefore, the genetics and mechanisms of the resistance of S. litura to deltamethrin were investigated. RESULTS: Bioassays at generation G1 gave resistance ratios of 9, 5, 41, 52 and 49 for deltamethrin, cypermethrin, profenofos, chlorpyrifos and triazofos respectively, when compared with the susceptible Lab-PK strain. Bioassays at G4 with a deltamethrin-selected population (Delta-SEL) showed that selection gave resistance ratios of 63 and 7 for deltamethrin when compared with the Lab-PK and UNSEL strains respectively. Cross-resistance to other insecticides tested was observed in the selected population. A notable feature of the Delta-SEL strain was that resistance to deltamethrin, cypermethrin, profenofos and chlorpyrifos did not decline over the course of five generations. Synergism tests with microsomal oxidase (MO) and esterase-specific inhibitors indicated that the deltamethrin resistance was associated with MO and, possibly, esterase activity. Reciprocal crosses between the Delta-SEL and Lab-PK strains indicated that resistance was autosomal and incompletely dominant. A direct test of monogenic inheritance suggested that resistance to deltamethrin was controlled by more than one locus. CONCLUSION: Stability and dominance of resistance and cross-resistance suggest that insecticides with different modes of action should be recommended to reduce pyrethroid selection pressure.  相似文献   

Expression profiling of transgenes (Cry1Ac and Cry2A) in cotton genotypes under different genetic backgrounds          下载免费PDF全文

Kashif NOOR  Hafiza Masooma Naseer CHEEMA  Asif Ali KHAN  Rao Sohail Ahmad KHAN 《农业科学学报》2022,21(10):2818-2832

Transgenic cotton carrying the Cry1Ac gene has revolutionized insect pest control since its adoption, although the development of resistance in insect pests has reduced its efficacy.  After 10 years of cultivating Bacillus thuringiensis (Bt) cotton with a single Cry1Ac gene, growers are on the verge of adopting Bt cotton that carries the double gene (Cry1Ac+Cry2A) due to its better effectiveness against insect pests.  Thus, the current study was designed to evaluate the role of each gene in the effectiveness of Bt cotton carrying the double gene.  The expression levels of the Cry1Ac and Cry2A genes were evaluated in the leaves of 10 genotypes (2 parents and 8 F₁ hybrids) at 30 days after sowing (DAS), while samples of leaves, bolls and flowers were taken from the upper and lower canopies at 70 and 110 DAS.  The F₁ hybrids were developed through reciprocal crosses between two Bt (CKC-1, CKC-2) and two non-Bt (MNH-786, FH-942) parents.  The differential expression of transgenes was evaluated through Enzyme Linked Immuno-Sorbent Assay (ELISA).  The results showed that the MNH786×CKC-1 hybrid had the highest concentrations of Cry1Ac gene at 30 DAS (3.08 µg g^–1) and 110 DAS (1.01 µg g^–1) in leaves.  In contrast, the CKC-2×MNH-786 hybrid showed the lowest concentrations of Cry1Ac gene at 30 DAS (2.30 µg g^–1) and 110 DAS (0.86 µg g^–1).  The F₁ hybrid FH-942×CKC-2 showed the highest concentrations of Cry2A gene at 30 DAS (8.39 µg g^–1) and 110 DAS (7.74 µg g^–1) in leaves, while the CKC-1×MNH-786 hybrid expressed the lowest concentrations of Cry2A gene at 30 DAS (7.10 µg g^–1) and 110 DAS (8.31 µg g^–1).  A comparison between the two stages of plant growth showed that leaves had the highest concentrations at 30 DAS, whereas the lowest concentrations were observed at 110 DAS for both genes in leaves.  When the expression pattern was compared between various plant parts in genotype CKC-2, it was found that leaves had higher concentrations of Cry1Ac (3.12 µg g^–1) and Cry2A (8.31 µg g^–1) at 70 DAS, followed by bolls (Cry1Ac (1.66 µg g^–1) and Cry2A (8.15 µg g^–1)) and flowers (Cry1Ac (1.07 µg g^–1) and Cry2A (7.99 µg g^–1)).  The genotype CKC-2 had higher concentrations of Cry1Ac (3.12 µg g^–1) and Cry2A (8.31 µg g^–1) in the upper canopy but less accumulation (2.66 µg g^–1 of Cry1Ac, 8.09 µg g^–1 of Cry2A) in the lower canopy at 70 DAS.  Similarly, at 110 DAS, the expression levels of Cry1Ac and Cry2A in upper and lower canopy leaves were 1.52 and 7.92 µg g^–1, and 0.99 and 7.54 µg g^–1, respectively.  Hence, the current study demonstrates that different genotypes showed variable expression for both of the Cry1Ac and Cry2A genes during plant growth due to different genetic backgrounds.  The Cry2A gene had three-fold higher expression than Cry1Ac with significant differences in expression in different plant parts.  The findings of this study will be helpful for breeding insect-resistant double-gene genotypes with better gene expression levels of Cry1Ac and Cry2A for sustainable cotton production worldwide.  相似文献   

Dynamics of organic carbon and nitrogen in deep soil profile and crop yields under long-term fertilization in wheat-maize cropping system          下载免费PDF全文

Muhammad QASWAR  LI Dong-chu  HUANG Jing  HAN Tian-fu  Waqas AHMED  Sehrish ALI  Muhammad Numan KHAN  Zulqarnain Haider KHAN  XU Yong-mei  LI Qian  ZHANG Hui-min  WANG Bo-ren  Ahmad TAUQEER 《农业科学学报》2022,21(3):826-839

Soil organic carbon (SOC) and nitrogen (N) are two of the most important indicators for agricultural productivity. The primary objective of this study was to investigate the changes in SOC and N in the deep soil profile (up to 100 cm) and their relationships with crop productivity under the influence of long-term (since 1990) fertilization in the wheat-maize cropping system. Treatments included CK (control), NP (inorganic N and phosphorus (P) fertilizers), NPK (inorganic N, P and potassium fertilizers), NPKM (NPK plus manure), and M (manure). Crop yield and the properties of topsoil were measured yearly from 2001 to 2009. C and N contents were measured at five different depths in 2001 and 2009. The results showed that wheat and maize yields decreased between 2001 and 2009 under the inorganic fertilizer (NP and NPK) treatments. The average yield between 2001 and 2009 under the NP, NPK, NPKM, and M treatments (compared with the CK treatment) increased by 38, 115, 383, and 381%, respectively, for wheat and 348, 891, 2 738, and 1 845%, respectively, for maize. Different long-term fertilization treatments significantly changed coarse free particulate (cfPOC), fine free particulate (ffPOC), intramicroaggregate particulate (iPOC), and mineral-associated (mSOC) organic carbon fractions. In the experimental years of 2001 and 2009, soil fractions occurred in the following order for all treatments: mSOC>cfPOC>iPOC>ffPOC. All fractions were higher under the manure application treatments than under the inorganic fertilization treatments. Compared to the inorganic fertilization treatments, manure input enhanced the stocks of SOC and total N in the surface layer (0–20 cm) but decreased SOC and N in the deep soil layer (80–100 cm). This reveals the efficiency of manure in increasing yield productivity and decreasing risk of vertical loss of nutrients, especially N, compared to inorganic fertilization treatments. The findings provide opportunities for understanding deep soil C and N dynamics, which could help mitigate climate change impact on agricultural production and maintain soil health.  相似文献   

Commercial cash crop production and households’ economic welfare: Evidence from the pulse farmers in rural China          下载免费PDF全文

MA Ji-liang  LI Fan  ZHANG Hui-jie  Khan NAWAB 《农业科学学报》2022,21(11):3395-3407

Whether promoting cash crop production can increase household welfare has long been the focus of the food policy debate. This study first investigated the determinants of household behavior in commercial pulse farming. It then examined how households’ commercial pulse production improves their economic welfare. We used a dataset of 848 households collected from 2018 to 2019 to estimate the determinants of household behavior in commercial pulse farming by the Heckman two-step model. The endogenous treatment regression (ETR) method was employed to examine the impact of commercial pulse farming on household economic welfare. The results showed that factors such as market purchase prices, agricultural technology services, farmers’ access to loans, and government subsidies promoted smallholders’ commercial pulse farming; production costs and perceptions of climate change risks constrained smallholders’ commercial pulse production. Overall, commercial pulse production has increased household farm income but there was a limited impact on household off-farm income. Our findings suggest that policies aiming to increase households’ cash crop production and market access could significantly improve the economic welfare of pulse farmers.  相似文献   

Effects of the addition of Calanopia elliptica,Artemia franciscana,and Brachionus rotundiformis in a nursery biofloc system on water quality,growth, gut morphology,health indices,and transcriptional response of immune and antioxidant-related genes in Penaeus vannamei     

Abbaszadeh  Akbar  Mozanzadeh  Mansour Torfi  Qasemi  Ahmad  Oujifard  Amin  Nafisi Bahabadi  Mahmod 《Aquaculture International》2022,30(2):653-676

Aquaculture International - A 56-day study was carried out to examine the addition of live foods a biofloc technology (BFT) system on Penaeus vannamei postlarvae performance (PL25, initial weight:...  相似文献   

Effects of feeding rates on growth and production of Nile tilapia, common carp and silver carp polycultured in fertilized ponds     

Ali E Abdelghany  & Mohammed H Ahmad 《Aquaculture Research》2002,33(6):415-423

Abstract In an attempt to identify appropriate feeding rates for multispecies of fish raised in fertilized earthen ponds, the present work was conducted over a 19‐week experimental period to establish the growth performance, production and body composition of Nile tilapia, common carp and silver carp fed 0.0%, 0.5%, 1.0%, 3.0%, 5.0% biomass and to apparent satiation (treatments). Twelve ponds were stocked with a similar number and weight of each fish species. Two ponds were assigned to each of the treatments, and a 25% protein pelleted fish feed was used to feed fish at the specified rate of feeding. At the end of the experiment, growth, weight gain, survival, yield and body composition of fish groups were affected by the treatments. The economic effectiveness also varied among treatments. The most conspicuous attribute of the feeding rates was its lack of influence on growth (g day^?1), weight gain (g per fish), yield (kg ha^?1) or body composition of silver carp. The results of whole‐body proximate analysis indicated that various feeding rates had either an irregular pattern or no effects on the protein and ash gain per 100 g of fish body weight (bw) gain. The most notable exceptions were significant (P < 0.05) increases in body fat and gross energy gains in Nile tilapia, common carp and silver carp accompanied by decreases in percentages of moisture (but not in silver carp) as feeding rate increased. Among the six different feeding levels, feeding to apparent satiation (feed amount was equivalent to 2.67% of fish bw day^?1) appeared to be optimal, as it significantly (P < 0.05) supported the highest fish production, income and net profit compared with all other treatments except for the 3% feeding level, for which the differences in those measurements were comparable.  相似文献