The Chinese seabass(Lateolabrax maculatus)is one of the most popular and valuable aquaculture species in China.Recently,the disease caused by Vibrio anguillarum has brought huge economic losses in the L.maculatus indu...The Chinese seabass(Lateolabrax maculatus)is one of the most popular and valuable aquaculture species in China.Recently,the disease caused by Vibrio anguillarum has brought huge economic losses in the L.maculatus industry.However,the immune response of L.maculatus after V.anguillarum infection remains unknown.In this study,the blood homeostasis,gut microbiota and transcriptomic profiling of L.maculatus after V.anguillarum infection were investigated.Our results indicated that the levels of superoxide dismutase(SOD),alanine aminotransferase(ALT)and total bilirubin(TBIL)increased,while the levels of blood glucose(BG),total protein(TP)and albumin(ALB)decreased after V.anguillarum infection.The analysis of the gut microbiota composition revealed that the dominant phyla was Firmicutes and Proteobacteria,and the relative abundance of genus Vibrio increased after V.anguillarum infection.Subsequently,the differentially expressed genes(DEGs)in the kidney and spleen after V.anguillarum infection were analyzed by transcriptome sequencing.The results indicated that immunity-related genes like TLR5,TLR8,TLR9,IL-1β,CCL3,IFNγ,CXCL11 and TNFαwere affected and the NOD-like receptor signaling pathway,cytokine-cytokine receptor interaction and Toll-like receptor signaling were activated.Thus,an effective immune and pro-flammatory response can help resist V.anguillarum infection.Our results provide a theoretical support for improving the disease resistance ability of L.maculatus.展开更多
The Na^+/K^+/2Cl^-cotransporter(NKCC)and the cystic fibrosis transmembrane conductance regulator(CFTR)proteins play crucial roles in the transportation of Na^+and Cl^-.In this study,we identified cftr,nkcc1 a,nkcc1 b ...The Na^+/K^+/2Cl^-cotransporter(NKCC)and the cystic fibrosis transmembrane conductance regulator(CFTR)proteins play crucial roles in the transportation of Na^+and Cl^-.In this study,we identified cftr,nkcc1 a,nkcc1 b and nkcc2 in spotted sea bass(Lateolabrax maculatus)genomic and transcriptomic databases.We also characterized these genes via phylogenetic and structural analyses.The results showed that both cftr and nkcc were highly conservative in L.maculatus.Quantitative real-time polymerase chain reaction(qRT-PCR)analysis in ten tissues showed that cftr,nkcc1 a and nkcc2 highly express in osmoregulatory organs such as gill,kidney and intestine.Furthermore,the expressions of cftr and nkcc1 a in gill as well as nkcc2 in intestine were up-regulated by high salinity,indicating that these genes function potentially in osmoregulation.Our findings provided the insights into the cftr and nkcc functions in euryhaline teleost.展开更多
In this study, three cDNA sequences corresponding to cytochrome P450 C17(CYP17 Ⅰ), 3β-hydroxysteroid dehydrogenase(3β-HSD) and androgen receptor(AR) were isolated from spotted sea bass(Lateolabrax maculatus). The m...In this study, three cDNA sequences corresponding to cytochrome P450 C17(CYP17 Ⅰ), 3β-hydroxysteroid dehydrogenase(3β-HSD) and androgen receptor(AR) were isolated from spotted sea bass(Lateolabrax maculatus). The mRNA abundances of CYP17 Ⅰ and 3β-HSD increased from stage Ⅱ to stage V with a significant increase at stage Ⅴ, and the highest abundance of AR mRNA was detected at stage Ⅲ in testicular development cycle. CYP17 I, 3β-HSD and AR transcripts were obviously abundant in steroidogenesis tissues such as testis, brain, head kidney among others. Strong and positive signals were observed mainly in interstitial cell regions of L. maculatus testis as were measured with in situ hybridization method. Significant increases of CYP17 Ⅰ and3β-HSD transcripts were detected after 12-48 h hCG(human chorionic gonadotropin) and GnRHa(gonadotropin-releasing hormone analogue) treatments. However, an opposite relationship was found for AR in testis at the same time. In addition, decreasing trends of CYP17 Ⅰ and 3β-HSD mRNA were observed in testis of L. maculatus in freshwater group(FW) from day 2 to day 6, and mRNA abundance of AR increased in brackish water(BW) group from day 4 to day 8. These findings revealed that these three steroid synthesis genes are import for testicular development, hormone and salinity treatment, and provided also an insight into the mechanism of reproductive endocrine of L. maculatus.展开更多
The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowp...The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus (Fab.) were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly (P<0.05) reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs.展开更多
Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none o...Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%-100% whereas in S. zeamais, the mortality ranged from 87.5%-100% and 70%-100% in concentrations of 1 g extract＋3 ml methanol and 1 g extract＋5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract＋l 5 ml methanol had no significant lethal effect on Sitophilus zeamais.展开更多
Bambara groundnut, Vigna subterranea is an important legume crop that is adaptable to the dry regions of Africa. It is a major source of protein to people in many parts of Africa. One major constraint to increased pro...Bambara groundnut, Vigna subterranea is an important legume crop that is adaptable to the dry regions of Africa. It is a major source of protein to people in many parts of Africa. One major constraint to increased production of the crop is the incidence of the storage pest Callosobruchus maculatus which causes significant weight loss to seeds in storage. The preference of the cowpea beetle C. maculatus for a particular seed coat colour was determined using four different colour types of bambara groundnut in an arena. The olfactory attractiveness of testa against cotyledon and cotyledon against whole grain was carried out in an olfactometer. Oviposition preference of C. maculatus on the different seed colours was determined. In the arena experiment significantly more of the beetles showed preference for cream and mottled seeds than red and black seeds. Significantly more beetles chose seeds with testa over decorticated seeds as well as whole grain over decorticated seeds. Colour significantly affected the seeds as oviposition sites. Significantly fewer eggs were laid on red and black seeds than cream seeds in both the choice and no choice tests (P < 0.0001). Thus for the purpose of reducing losses of seeds in storage it is advisable to cultivate red- and black-coloured seeds which showed lower acceptability to C. maculatus as oviposition site.展开更多
Essential oil （EO） of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry （GCMS） and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Si...Essential oil （EO） of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry （GCMS） and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Sixteen compounds predominated by monoterpenes were identified. The major compounds were Eucalyptol （28.36%）, α-Terpineol （25.99%）, γ-Terpinene （15.24%）, α-Pinene （5.08%）, 1H-Cyclopropa[a]naphthalene （4.25%） and 1, 3, 6, 10-Dodeeatetraene （3.74%）. Percentage mortality due to fumigant toxicity was dose- and exposure period-dependent. One hour after treatment （HAT）, application of L. adoensis leaf EO at 107 μL· L^-1 air caused significantly （p〈0.05） higher mortality （50.00%） than 0.00% mortality observed at 0-53 μL· L^-1 air, but not significantly （p〉0.05） different from 22.50% observed in 80 μL· L^-1 air. At 3 HAT, application ofL. adoensis EO at 80 μL· L^-1 air caused significantly higher mortality （90.00 %） than mortality observed at 0 μL· L^-1 air. At 6 HAT, application of L. adoensis EO at 53-107 μL· L^-1 air caused significantly higher mortality （100.00 %） than that was observed in the control. The same trend was observed at 12 HAT where 100 % mortality observed in 27-107 μL· L^-1 air was significantly greater than 13.33 % observed in the control. At 3 HAT, percentage repellence was significantly （p〈0.05） affected by doses. Application of EO at 10-30 μL· cm^2 caused class V repellence （86.67%-100%） compared with the control which caused class I repellence （0-20%）.展开更多
A consensus sequence, encoding a putative DNA polymerase type B derived from a Polinton transposon, was assembled from the sex determination region of Xiphophorus maculatus. This predicted protein, which is 1,158 aa i...A consensus sequence, encoding a putative DNA polymerase type B derived from a Polinton transposon, was assembled from the sex determination region of Xiphophorus maculatus. This predicted protein, which is 1,158 aa in length, contains a DNAA_pol_B_2 domain and a DTDS motif. The DNA polymerase type B gene has about 10 copies in the haploid X. maculatus genome with one Y-specific copy. Interestingly, it has specific copies on the W chromosome in the X. maculatus Usumacinta strain （sex determination with female het- erogamety）, which represent new markers for this type of sex chromosome in platyfish. This marker with W- and Y-specific copies suggests relationship between different types of gonosomes and allows comparing male and female heterogameties in the platyfish. Further molecular analysis of the DNA polymerase type B gene in X. maculatus will shed new light on the evolution of sex chromosomes in platyfish.展开更多
To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （...To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （PgEO） with cowpea varietal resistance in the control of cowpea seed beetle, Callosobruehus maculatus Fabricius. Four cowpea varieties （Sokoto, Drum, Oloyin and Gwallam） were studied. Data collected included oviposition, progeny emergence, Reproductive Efficiency （RE） and Percentage Seed Damage （PSD）. At first filial generation, numbers of eggs laid on Oloyin variety treated with 25 μL PgEO per 25 g cowpea seeds （2.15） were significantly （p〈0.05） lower than the values obtained in untreated cowpea （3.61） and hexane-treated seeds （3.07）. C. maculatus RE on Oloyin （33.73） was significantly （p〈0.05） lower than values obtained on other varieties （47.34-54.67） for seeds without PgEO; and were significantly greater than 0.00 observed on Oloyin seeds treated with 50 pL PgEO. PSD on Oloyin （6.63%） was significantly （p〈0.05） lower than the values obtained on Sokoto （10.04%） and Drum （9.79%） for seeds without PgEO, while there was no damage in Oloyin treated with 50 pL PgEO. Significantly （p〈0.05） lower F2 progeny emergence occurred on Oloyin （4.02） and Sokoto （4.71） compared with Drum （9.03） and Gwallam （6.07） from the untreated cowpea seeds. The results implied that application of PgEO to Oloyin gave better protection from infestation of C. maculatus than other varieties. Hence, combination of varietal resistance with PgEO for management ofbruchid could be an effective mean of improving cowpea food security.展开更多
This study determined the effects of initial infestation of cowpea seeds （Ife brown variety） with different insect densities （0, 2, 4 and 6 pairs per 50 g seeds） of Callosobruchus maculatus （F.） and evaluated th...This study determined the effects of initial infestation of cowpea seeds （Ife brown variety） with different insect densities （0, 2, 4 and 6 pairs per 50 g seeds） of Callosobruchus maculatus （F.） and evaluated the effects of aqueous leaf extract of Nicotiana tabacum L. on C. maculatus in the laboratory. It was observed that adult beetle population increased significantly （p〈0.05） with increase in insect density. The increase in population of beetles and corresponding weight loss of the seeds in different levels of infestation showed that the cowpea variety was susceptible to beetle infestation, emergence and survival of progeny. Significantly more adults emerged on higher infestation compared to lower and no infestation. In Nigeria, Nicotiana tabacum L. is a locally available plant, with known insecticidal properties. The plant leaf extract was easily extracted with water and confirmed its effectiveness as a protective agent for stored cowpea seeds. Experiment was conducted to assess the effects of aqueous extracts ofN. tabacum at 0, 0.1, 0.2 and 0.3 mL＂ 50 g-1 cowpea seeds on C. maculatus. Data was recorded and showed varying levels of effectiveness against C. maculatus. Result showed that seed appearance was dependent on levels of insect population, while N. tabacum aqueous extract exerted effects on survival of C. maculatus. Aqueous leaf extract of N. tabacum probably contained some insecticidal properties which might have significantly conferred beetle mortality and reduced beetle emergence leading to a decrease in seed weight loss.展开更多
Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus ma...Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus maculatus. The commonly used control strategy is essentially based on chemicals whose use is toxic, expensive and restrictive. In the search for alternatives to chemical control, this work was undertaken to evaluate the insecticidal potential of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots. Powder toxicity and insecticidal efficacy tests were performed separately on groups of 20 Callosobruchus maculatus using 3 doses of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots in jars each containing 100 g cowpea. The mortality of Callosobruchus maculatus and the impact of powders were noted respectively for 96 h and 4 months after infestation. The germination capacity of the treated seeds was assessed at the start of the study. Doses of 1 and 8 g of Ageratum conyzoides leaf powders and Securidaca longepedunculata roots were applied respectively to every 100 g of cowpea and led to 100% mortality of Callosobruchus maculatus. At these same doses, more than half of the treated seeds were attacked during the 4 months of storage. Germination tests have shown that powders of Ageratum conyzoides leaves and roots of Securidaca longepedunculata have no negative effect on the germination power of cowpea seeds. Therefore, they could be considered as excellent bio-insecticides that socio-professional strata (farmers and warehouse workers) can use in the fight against cowpea insects intended for storage.展开更多
Intensive aquaculture-induced oxidative stress is detrimental to fish health and yield.Medicinal plants show promise as natural health boosters and antioxidants in the aquaculture industry.Therefore,this work investig...Intensive aquaculture-induced oxidative stress is detrimental to fish health and yield.Medicinal plants show promise as natural health boosters and antioxidants in the aquaculture industry.Therefore,this work investigated the effects of turmeric aqueous extract(TAE)on the growth performance,antioxidant status,and hydrogen peroxide(H2O2)-induced oxidative stress in spotted seabass(Lateolabrax maculatus).Fish were fed diets supplemented with 0(Con),2(TAE2),or 4(TAE4)g/kg TAE for eight weeks,then were injected with H2O2.The results showed that dietary supplementation of TAE did not affect fish growth,feed utilization,or body composition.TAE treatment increased liver antioxidant enzyme activities and decreased liver malondialdehyde content and serum levels of glutamate oxalate transaminase,glutamate pyruvate transaminase,and lactate dehydrogenase.Furthermore,the increases in mortality,liver malondialdehyde content,and serum biomarkers of liver injury in the H2O2-treated fish were inhibited as a consequence of the TAE treatment.In addition,TAE treatment activated the Nrf2/Keap1 pathway in the liver,supported by the up-regulated expression of nrf2,ho-1,and gclc,and down-regulated keap1 expression.Overall,dietary incorporation of TAE protected against H2O2-induced oxidative stress in spotted seabass probably by enhancing antioxidant capacity through the Nrf2/Keap1 pathway.展开更多
A 10-week feeding trial,followed by 24-h nitrite stress,was performed to evaluate the effects of dietary selenium-L-methionine(Se-Met)on growth,Se accumulation,antioxidant capacity,transcripts of selenoproteins and hi...A 10-week feeding trial,followed by 24-h nitrite stress,was performed to evaluate the effects of dietary selenium-L-methionine(Se-Met)on growth,Se accumulation,antioxidant capacity,transcripts of selenoproteins and histological changes of muscle as well as resistance to nitrite stress in spotted seabass(Lateolabrax maculatus)reared at optimal(27℃)and high(33℃)temperatures.Five experimental diets were formulated to contain Se-Met at 0,0.9,1.8,3.5,and 7.0 mg/kg.Each diet was fed to fish(2.60±0.2 g)in two parallel treatments at 27 or 33℃.The results showed that elevated temperature(33℃)induced thermal stress in fish,and fish under thermal stress exhibited lower weight gain and hepatosomatic index but a higher condition factor compared to those reared at 27℃.However,the growth and feed utilisation were promoted in L.maculatus with 0.9 to 3.5 mg/kg Se-Met treatments.The protein and lipid content in the muscle increased with the dietary Se-Met level,and the total Se level in the whole body and muscle showed a linear increase with dietary Se-Met supplementation.Thermal stress changed the histology of the muscle,leading to raised levels of malondialdehyde(MDA),reduced antioxidant parameters in the serum and liver,and a decrease in the transcripts of selenoprotein genes in the muscle.Meanwhile,increased antioxidant capacity of serum and liver and up-regulated transcripts of selenoprotein of muscle were observed in L.maculatus reaching a maximum with 3.5 mg Se-Met/kg treatment.After 24 h of nitrite stress,thermal stress exacerbated oxidative damage caused by nitrite stress in L.maculatus.In contrast,dietary Se-Met enhanced the resistance to nitrite stress of L.maculatus fed with Se-Met enriched diets containing 0.9 to 1.8 mg Se-Met/kg.Based on the effects of dietary Se-Met on the growth,antioxidant capacity and resistance to nitrite stress of L.maculatus,this study suggests that the optimal range of Se-Met supplementation in L.maculatus diets is 1.80 to 2.39 mg Se-Met/kg of diet at 27℃ and 1.80 to 4.46 mg Se-Met/kg of diet at 33℃.展开更多
An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted s...An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted seabass(Lateolabrax maculatus).Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil(n-3)and linoleic acid-enriched oil(n-6)leading to n-3/n-6 PUFA ratios of 0.04,0.35,0.66,1.35,2.45 and16.17.Each diet was fed to triplicate groups of juvenile L.maculatus(11.06±0.20 g,30 fish/tank).Final body weight(FBW),weight gain(WG),specific growth rates(SGR),protein efficiency ratio(PER)and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level,and then decreased thereafter.Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW,WG,SGR and PER and the lowest feed conversion ratio.Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes(fas,acc2 and srebp-1c)and down-regulated expression of lipolysis related genes(atgl,ppara,cpt-1 and aox).Higher expression of lipolysis-related genes(atgl,ppara and cpt-1)was recorded at moderate n-3/n-6 PUFA ratios(0.66 to 1.35).Moreover,inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes(il-6 and tnf-a)and down-regulation of antiinflammatory genes(il-4 and il-10)in the intestine.The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation,improved intestinal flora richness,increased the abundance of beneficial bacteria such as Lactobacillus,Alloprevotella and Ruminococcus,and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus.In summary,it could be suggested that a dietary n-3/n-6PUFA ratio of 0.66 can improve growth performance and feed utilization in L.maculatus,as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.展开更多
Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle C...Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.展开更多
The present study was conducted to determine the effects of dietary phosphorus(P)levels on growth performance,body composition,liver histology and enzymatic activity,and expression of lipid metabolism-related genes in...The present study was conducted to determine the effects of dietary phosphorus(P)levels on growth performance,body composition,liver histology and enzymatic activity,and expression of lipid metabolism-related genes in spotted seabass(Lateolabrax maculatus).Seven diets were prepared to contain available P levels of 0.48%(the control group),0.69%,0.89%,1.10%,1.28%,1.51%and 1.77%and feed fish(4.26±0.03 g)to satiety twice daily for 10 weeks.Significantly higher weight gain and specific growth rate were recorded at P levels of 0.69%-1.51%compared to the control group.Feed conversion ratio decreased with increasing P levels up to 0.89%and increased thereafter.The lowest liver lipid content,viscerosomatic index and lipid content of whole-body were obtained in the 0.89%-P group among dietary treatments.P and calcium(Ca)contents in whole body were increased,while liver triglyceride and cholesterol contents were decreased with increasing dietary P levels from 0.48%to 1.77%.The highest activity of hepatic lipase was recorded in the 1.10%-P group among dietary treatments.Compared to the control group,1.10%P enhanced the proportion of HUFA and reduced the proportion of SFA and MUFA.The histological observations showed that P deficiency(0.48%)led to the vacuolization of hepatocytes and increased number of lipid droplets.Meanwhile,overall liver tissue structure was improved when P level increased to 1.28%.Compared to the control group,expression of lipid metabolism-related genes such as FAS,ACC-2 and SREBP-1 was decreased at 0.89%-1.10%P group while an opposite trend was observed in the expression of PPARa2 and CPT-1 genes.The current study showed that 0.89%dietary P levels could promote growth performance of spotted seabass and reduce lipid accumulation in the liver.A broken-line regression analysis based on weight gain showed that the optimum dietary P level(available P)for juvenile spotted seabass reared in freshwater was 0.72%.展开更多
Chinese sea perch(Lateolabrax Maculatus)is one of the main marine fish culture species in China,its green development has received increasing attention and its ecological economic study is rare.Based on field survey,t...Chinese sea perch(Lateolabrax Maculatus)is one of the main marine fish culture species in China,its green development has received increasing attention and its ecological economic study is rare.Based on field survey,this paper takes water pollution tax of China as conversion indicator for aquaculture eutrophication to simulate aquaculture waste fee for further analyzing the ecological impact of Chinese sea perch’s aquaculture.For data analysis,data envelopment analysis model has been used.The comparison for Chinese sea perch’s economic performance and ecological economic performance under its main aquaculture systems has been done.The results show that:1.The simulated waste fee has no significant impact for the comparison.2.Ranking for ecological economic performance’s ecological economic,technical and scale efficiency is as follow:pond farming,offshore cage culture and cage culture.3.Offshore cage culture is the only system presenting positive increase for ecological economic performance,which makes its aquaculture activity more sustainable than other systems.4.The key point of green development is to maximize the ecological economic efficiency of main aquaculture systems.Thus,offshore cage culture is the most sustainable aquaculture system among China’s current marine fish culture systems,and other systems need innovation for achieving the green development of China’s aquaculture.展开更多
Objectives:Three medicinal plants:Zingiber officinale rhizome,Allium sativum bulb,and Moringa oleifera seeds,were evaluated for progeny inhibition in fish beetle,Dermestes maculatus,and incidence of bacteria and fungi...Objectives:Three medicinal plants:Zingiber officinale rhizome,Allium sativum bulb,and Moringa oleifera seeds,were evaluated for progeny inhibition in fish beetle,Dermestes maculatus,and incidence of bacteria and fungi in smoked-dried Clarias gariepinus.Materials and Methods:Cleaned C.gariepinus were separately soaked in extracts of these selected plants(50 g/1000 ml)for 60 min before smoke-drying in a mud kiln at 105℃ and later divided into lots.Sensory evaluation was conducted on uninfested fishes in lot A while fishes in lot B was artificially infested with five pairs of newly emerged adult D.maculatus for 10 days.Number of emerged larva,adult insects,and incidence of microorganisms before and following 90 days in storage after infestation were used as indices of potency of the extracts.Results:Results obtained showed that all the treated uninfested smoked-dried C.gariepinus retained high scores for taste,texture,aroma,and appearance within the first 5 weeks of storage after smoking when compared with the control.This implied that the tested extracts had no negative effect in terms of sensory attributes on the treated fish during storage and can therefore be used for fish preservation.Meanwhile,A.sativum among all the selected extracts had the least number of larvae(17.67±1.45),adult(21.00±1.53),fungi(9.00×10^(2)±0.53 sfu/ml)and bacteria counts(11.33×10^(2)±0.33 cfu/ml)following 90 days in storage after infestation.Conclusion:Allium sativum among the tested extracts proved to be most effective and could be recommended for control of D.maculatus and microorganisms in smoked C.gariepinus.展开更多
Objectives:The possibility that bone charcoal dusts of some species of mammal will control the major insect pest of stored cowpea seeds and the implications on seed viability(after pest control process)were investigat...Objectives:The possibility that bone charcoal dusts of some species of mammal will control the major insect pest of stored cowpea seeds and the implications on seed viability(after pest control process)were investigated in the laboratory at ambient temperature(30±3°C)and relative humidity(70±5%)and in field.Materials and Methods:Standard entomological and agronomical techniques were used.Results:The results showed that at 1.0%w/w dosage,the bone charcoal dusts of Ovis aries and Bos taurus were more effective than permethrin standard insecticide in killing adult Callosobruchus maculatus Fab.infesting cowpea seeds in storage.Bos taurus had a faster action speed than permethrin at 1.0%w/w.At 1.5%w/w of dust,all the species of mammal investigated deterred oviposition considerably in C.maculatus females,whereas only the bone charcoal dusts of O.aries and Sus scrofa were comparable with permethrin in suppressing adult emergence and seed damage;S.scrofa only was comparable with permethrin in reducing larval density.Bone charcoal dusts of O.aries and S.scrofa require chemical and olfactory analyses to know if they might have caused irritation to the insects and disrupted insect circadian rhythm,affecting behaviour and mating activities,adversely.The bone charcoal dusts of the six species of mammal at a highest test dose of 1.5%w/w allowed high seed viability in both laboratory and field.Conclusion:The study recommends the use of bone charcoal dusts of O.aries and S.scrofa at economical-and quality-favourable dose 1.5%w/w for managers seeking to control C.maculatus insect attacking cowpea seeds in storage.The transitive components of the bones,abrasion of the insect epicuticle lipid layer by the charcoal dust,and combustion-related toxic factors were responsible for the insecticidal activities of the bone charcoal dusts of the mammals.展开更多
Toxicity of bruchid-resistant cultivars MIT04K-399-1 and MIT07K-299-92 powders as cowpea protectants against Callosobruchus maculatus(Fab.)was investigated at an ambient temperature of 28±2°C and a relative ...Toxicity of bruchid-resistant cultivars MIT04K-399-1 and MIT07K-299-92 powders as cowpea protectants against Callosobruchus maculatus(Fab.)was investigated at an ambient temperature of 28±2°C and a relative humidity of 75±5%.Their efficacy was tested at dosage,0.5,1.0,1.5,2.0,2.5,and 3.0 g/20 g of cowpea seeds on adult mortality,oviposition,adult emergence,progeny development,seed damage,weight loss,and Beetle Perforation Index(BPI)by cowpea bruchid.The result showed that toxicity of the bruchid-resistant cowpea cultivar powders on adult bruchid is dosage-and time-dependent.At a dosage of 3.0 g/20 g,cultivars MIT04K-399-1 and MIT07K-299-92 powders achieved 70%and 72.5%lethal effect on adult C.maculatus after 4 days of treatment,respectively.Oviposition and percentage adult emergence of C.maculatus decrease with an increase in powder dosage.Conversely,reduction in progeny development of C.maculatus increases with an increase in powder dosage.The mean number of adult emergence decreased at 2 g/20 g,2.5 g/20 g and 3 g/20 g.The MIT04K-399-1 and MIT07K-299-92 powders significantly affected egg development.The MIT07K-299-92 powder was more effective against oviposition and adult emergence at higher concentrations than MIT04K-399-1 powder,an effect that was not significantly different(P>0.05)from each other.The BPI of 9.1 and 6.2 was recorded on cowpea seeds treated with MIT04K-399-1 and MIT07K-299-92 powders at a dosage of 3 g/20 g,respectively.The fear of residual toxicity on nontargeted organisms is not associated with the use of resistant cowpea cultivars as seed protectant.Subsistence farmers are familiar with the technology involved in the preparation and application of powders as protectants.Integration of bruchid-resistant cowpea cultivars MIT04K-399-1 and MIT07K-299-92 powders into the management of coleopteran pests will ensure availability of viable seeds for future farming in developing nations such as Nigeria.展开更多
基金received funding from the Natural Science Foundation of Shandong Province(No.ZR2023MC141)the Innovation and Entrepreneurship Training Program for College Students(No.202210435003)financial support was also provided by the‘First Class Fishery Discipline’Program and the Special Talent Program‘One Thing One Decision(Yishi Yiyi)’in Shandong Province,China。
文摘The Chinese seabass(Lateolabrax maculatus)is one of the most popular and valuable aquaculture species in China.Recently,the disease caused by Vibrio anguillarum has brought huge economic losses in the L.maculatus industry.However,the immune response of L.maculatus after V.anguillarum infection remains unknown.In this study,the blood homeostasis,gut microbiota and transcriptomic profiling of L.maculatus after V.anguillarum infection were investigated.Our results indicated that the levels of superoxide dismutase(SOD),alanine aminotransferase(ALT)and total bilirubin(TBIL)increased,while the levels of blood glucose(BG),total protein(TP)and albumin(ALB)decreased after V.anguillarum infection.The analysis of the gut microbiota composition revealed that the dominant phyla was Firmicutes and Proteobacteria,and the relative abundance of genus Vibrio increased after V.anguillarum infection.Subsequently,the differentially expressed genes(DEGs)in the kidney and spleen after V.anguillarum infection were analyzed by transcriptome sequencing.The results indicated that immunity-related genes like TLR5,TLR8,TLR9,IL-1β,CCL3,IFNγ,CXCL11 and TNFαwere affected and the NOD-like receptor signaling pathway,cytokine-cytokine receptor interaction and Toll-like receptor signaling were activated.Thus,an effective immune and pro-flammatory response can help resist V.anguillarum infection.Our results provide a theoretical support for improving the disease resistance ability of L.maculatus.
基金supported by the China Agriculture Research System (No. CARS-47)the National Natural Science Foundation of China (No. 31602147)
文摘The Na^+/K^+/2Cl^-cotransporter(NKCC)and the cystic fibrosis transmembrane conductance regulator(CFTR)proteins play crucial roles in the transportation of Na^+and Cl^-.In this study,we identified cftr,nkcc1 a,nkcc1 b and nkcc2 in spotted sea bass(Lateolabrax maculatus)genomic and transcriptomic databases.We also characterized these genes via phylogenetic and structural analyses.The results showed that both cftr and nkcc were highly conservative in L.maculatus.Quantitative real-time polymerase chain reaction(qRT-PCR)analysis in ten tissues showed that cftr,nkcc1 a and nkcc2 highly express in osmoregulatory organs such as gill,kidney and intestine.Furthermore,the expressions of cftr and nkcc1 a in gill as well as nkcc2 in intestine were up-regulated by high salinity,indicating that these genes function potentially in osmoregulation.Our findings provided the insights into the cftr and nkcc functions in euryhaline teleost.
基金supported by the Chinese Agriculture Research System (No. CARS-47)Shandong Provincial Natural Science Foundation (No. ZR2016CQ21)the Key Laboratory of Mariculture (Ocean University of China), Ministry of Education (No. 2018008)
文摘In this study, three cDNA sequences corresponding to cytochrome P450 C17(CYP17 Ⅰ), 3β-hydroxysteroid dehydrogenase(3β-HSD) and androgen receptor(AR) were isolated from spotted sea bass(Lateolabrax maculatus). The mRNA abundances of CYP17 Ⅰ and 3β-HSD increased from stage Ⅱ to stage V with a significant increase at stage Ⅴ, and the highest abundance of AR mRNA was detected at stage Ⅲ in testicular development cycle. CYP17 I, 3β-HSD and AR transcripts were obviously abundant in steroidogenesis tissues such as testis, brain, head kidney among others. Strong and positive signals were observed mainly in interstitial cell regions of L. maculatus testis as were measured with in situ hybridization method. Significant increases of CYP17 Ⅰ and3β-HSD transcripts were detected after 12-48 h hCG(human chorionic gonadotropin) and GnRHa(gonadotropin-releasing hormone analogue) treatments. However, an opposite relationship was found for AR in testis at the same time. In addition, decreasing trends of CYP17 Ⅰ and 3β-HSD mRNA were observed in testis of L. maculatus in freshwater group(FW) from day 2 to day 6, and mRNA abundance of AR increased in brackish water(BW) group from day 4 to day 8. These findings revealed that these three steroid synthesis genes are import for testicular development, hormone and salinity treatment, and provided also an insight into the mechanism of reproductive endocrine of L. maculatus.
文摘The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus (Fab.) were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly (P<0.05) reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs.
文摘Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%-100% whereas in S. zeamais, the mortality ranged from 87.5%-100% and 70%-100% in concentrations of 1 g extract＋3 ml methanol and 1 g extract＋5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract＋l 5 ml methanol had no significant lethal effect on Sitophilus zeamais.
文摘Bambara groundnut, Vigna subterranea is an important legume crop that is adaptable to the dry regions of Africa. It is a major source of protein to people in many parts of Africa. One major constraint to increased production of the crop is the incidence of the storage pest Callosobruchus maculatus which causes significant weight loss to seeds in storage. The preference of the cowpea beetle C. maculatus for a particular seed coat colour was determined using four different colour types of bambara groundnut in an arena. The olfactory attractiveness of testa against cotyledon and cotyledon against whole grain was carried out in an olfactometer. Oviposition preference of C. maculatus on the different seed colours was determined. In the arena experiment significantly more of the beetles showed preference for cream and mottled seeds than red and black seeds. Significantly more beetles chose seeds with testa over decorticated seeds as well as whole grain over decorticated seeds. Colour significantly affected the seeds as oviposition sites. Significantly fewer eggs were laid on red and black seeds than cream seeds in both the choice and no choice tests (P < 0.0001). Thus for the purpose of reducing losses of seeds in storage it is advisable to cultivate red- and black-coloured seeds which showed lower acceptability to C. maculatus as oviposition site.
基金Supported by the Senate of Ladoke Akintola University of Technology(LAUTECH)Ogbomoso,Nigeria Under the University Senate Research(LAU/SRG/13/045)
文摘Essential oil （EO） of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry （GCMS） and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Sixteen compounds predominated by monoterpenes were identified. The major compounds were Eucalyptol （28.36%）, α-Terpineol （25.99%）, γ-Terpinene （15.24%）, α-Pinene （5.08%）, 1H-Cyclopropa[a]naphthalene （4.25%） and 1, 3, 6, 10-Dodeeatetraene （3.74%）. Percentage mortality due to fumigant toxicity was dose- and exposure period-dependent. One hour after treatment （HAT）, application of L. adoensis leaf EO at 107 μL· L^-1 air caused significantly （p〈0.05） higher mortality （50.00%） than 0.00% mortality observed at 0-53 μL· L^-1 air, but not significantly （p〉0.05） different from 22.50% observed in 80 μL· L^-1 air. At 3 HAT, application ofL. adoensis EO at 80 μL· L^-1 air caused significantly higher mortality （90.00 %） than mortality observed at 0 μL· L^-1 air. At 6 HAT, application of L. adoensis EO at 53-107 μL· L^-1 air caused significantly higher mortality （100.00 %） than that was observed in the control. The same trend was observed at 12 HAT where 100 % mortality observed in 27-107 μL· L^-1 air was significantly greater than 13.33 % observed in the control. At 3 HAT, percentage repellence was significantly （p〈0.05） affected by doses. Application of EO at 10-30 μL· cm^2 caused class V repellence （86.67%-100%） compared with the control which caused class I repellence （0-20%）.
基金supported by the grants from the Biofuture Programme of the German Federal Ministry for Education and Research (BMBF,to JNV),the French Research Agency (ANR to JNV)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the Ministry of Education of China (to QZ)
文摘A consensus sequence, encoding a putative DNA polymerase type B derived from a Polinton transposon, was assembled from the sex determination region of Xiphophorus maculatus. This predicted protein, which is 1,158 aa in length, contains a DNAA_pol_B_2 domain and a DTDS motif. The DNA polymerase type B gene has about 10 copies in the haploid X. maculatus genome with one Y-specific copy. Interestingly, it has specific copies on the W chromosome in the X. maculatus Usumacinta strain （sex determination with female het- erogamety）, which represent new markers for this type of sex chromosome in platyfish. This marker with W- and Y-specific copies suggests relationship between different types of gonosomes and allows comparing male and female heterogameties in the platyfish. Further molecular analysis of the DNA polymerase type B gene in X. maculatus will shed new light on the evolution of sex chromosomes in platyfish.
文摘To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （PgEO） with cowpea varietal resistance in the control of cowpea seed beetle, Callosobruehus maculatus Fabricius. Four cowpea varieties （Sokoto, Drum, Oloyin and Gwallam） were studied. Data collected included oviposition, progeny emergence, Reproductive Efficiency （RE） and Percentage Seed Damage （PSD）. At first filial generation, numbers of eggs laid on Oloyin variety treated with 25 μL PgEO per 25 g cowpea seeds （2.15） were significantly （p〈0.05） lower than the values obtained in untreated cowpea （3.61） and hexane-treated seeds （3.07）. C. maculatus RE on Oloyin （33.73） was significantly （p〈0.05） lower than values obtained on other varieties （47.34-54.67） for seeds without PgEO; and were significantly greater than 0.00 observed on Oloyin seeds treated with 50 pL PgEO. PSD on Oloyin （6.63%） was significantly （p〈0.05） lower than the values obtained on Sokoto （10.04%） and Drum （9.79%） for seeds without PgEO, while there was no damage in Oloyin treated with 50 pL PgEO. Significantly （p〈0.05） lower F2 progeny emergence occurred on Oloyin （4.02） and Sokoto （4.71） compared with Drum （9.03） and Gwallam （6.07） from the untreated cowpea seeds. The results implied that application of PgEO to Oloyin gave better protection from infestation of C. maculatus than other varieties. Hence, combination of varietal resistance with PgEO for management ofbruchid could be an effective mean of improving cowpea food security.
文摘This study determined the effects of initial infestation of cowpea seeds （Ife brown variety） with different insect densities （0, 2, 4 and 6 pairs per 50 g seeds） of Callosobruchus maculatus （F.） and evaluated the effects of aqueous leaf extract of Nicotiana tabacum L. on C. maculatus in the laboratory. It was observed that adult beetle population increased significantly （p〈0.05） with increase in insect density. The increase in population of beetles and corresponding weight loss of the seeds in different levels of infestation showed that the cowpea variety was susceptible to beetle infestation, emergence and survival of progeny. Significantly more adults emerged on higher infestation compared to lower and no infestation. In Nigeria, Nicotiana tabacum L. is a locally available plant, with known insecticidal properties. The plant leaf extract was easily extracted with water and confirmed its effectiveness as a protective agent for stored cowpea seeds. Experiment was conducted to assess the effects of aqueous extracts ofN. tabacum at 0, 0.1, 0.2 and 0.3 mL＂ 50 g-1 cowpea seeds on C. maculatus. Data was recorded and showed varying levels of effectiveness against C. maculatus. Result showed that seed appearance was dependent on levels of insect population, while N. tabacum aqueous extract exerted effects on survival of C. maculatus. Aqueous leaf extract of N. tabacum probably contained some insecticidal properties which might have significantly conferred beetle mortality and reduced beetle emergence leading to a decrease in seed weight loss.
文摘Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus maculatus. The commonly used control strategy is essentially based on chemicals whose use is toxic, expensive and restrictive. In the search for alternatives to chemical control, this work was undertaken to evaluate the insecticidal potential of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots. Powder toxicity and insecticidal efficacy tests were performed separately on groups of 20 Callosobruchus maculatus using 3 doses of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots in jars each containing 100 g cowpea. The mortality of Callosobruchus maculatus and the impact of powders were noted respectively for 96 h and 4 months after infestation. The germination capacity of the treated seeds was assessed at the start of the study. Doses of 1 and 8 g of Ageratum conyzoides leaf powders and Securidaca longepedunculata roots were applied respectively to every 100 g of cowpea and led to 100% mortality of Callosobruchus maculatus. At these same doses, more than half of the treated seeds were attacked during the 4 months of storage. Germination tests have shown that powders of Ageratum conyzoides leaves and roots of Securidaca longepedunculata have no negative effect on the germination power of cowpea seeds. Therefore, they could be considered as excellent bio-insecticides that socio-professional strata (farmers and warehouse workers) can use in the fight against cowpea insects intended for storage.
基金supported by China Agriculture Research System (CARS-47)the Natural Science Foundation of Fujian Province of China (grant number:2019J01060380).
文摘Intensive aquaculture-induced oxidative stress is detrimental to fish health and yield.Medicinal plants show promise as natural health boosters and antioxidants in the aquaculture industry.Therefore,this work investigated the effects of turmeric aqueous extract(TAE)on the growth performance,antioxidant status,and hydrogen peroxide(H2O2)-induced oxidative stress in spotted seabass(Lateolabrax maculatus).Fish were fed diets supplemented with 0(Con),2(TAE2),or 4(TAE4)g/kg TAE for eight weeks,then were injected with H2O2.The results showed that dietary supplementation of TAE did not affect fish growth,feed utilization,or body composition.TAE treatment increased liver antioxidant enzyme activities and decreased liver malondialdehyde content and serum levels of glutamate oxalate transaminase,glutamate pyruvate transaminase,and lactate dehydrogenase.Furthermore,the increases in mortality,liver malondialdehyde content,and serum biomarkers of liver injury in the H2O2-treated fish were inhibited as a consequence of the TAE treatment.In addition,TAE treatment activated the Nrf2/Keap1 pathway in the liver,supported by the up-regulated expression of nrf2,ho-1,and gclc,and down-regulated keap1 expression.Overall,dietary incorporation of TAE protected against H2O2-induced oxidative stress in spotted seabass probably by enhancing antioxidant capacity through the Nrf2/Keap1 pathway.
基金supported by the Agriculture Research System of China(CARS-47)the Natural Science Foundation of Fujian Province of China(grant number:2020J01665,2023J01766).
文摘A 10-week feeding trial,followed by 24-h nitrite stress,was performed to evaluate the effects of dietary selenium-L-methionine(Se-Met)on growth,Se accumulation,antioxidant capacity,transcripts of selenoproteins and histological changes of muscle as well as resistance to nitrite stress in spotted seabass(Lateolabrax maculatus)reared at optimal(27℃)and high(33℃)temperatures.Five experimental diets were formulated to contain Se-Met at 0,0.9,1.8,3.5,and 7.0 mg/kg.Each diet was fed to fish(2.60±0.2 g)in two parallel treatments at 27 or 33℃.The results showed that elevated temperature(33℃)induced thermal stress in fish,and fish under thermal stress exhibited lower weight gain and hepatosomatic index but a higher condition factor compared to those reared at 27℃.However,the growth and feed utilisation were promoted in L.maculatus with 0.9 to 3.5 mg/kg Se-Met treatments.The protein and lipid content in the muscle increased with the dietary Se-Met level,and the total Se level in the whole body and muscle showed a linear increase with dietary Se-Met supplementation.Thermal stress changed the histology of the muscle,leading to raised levels of malondialdehyde(MDA),reduced antioxidant parameters in the serum and liver,and a decrease in the transcripts of selenoprotein genes in the muscle.Meanwhile,increased antioxidant capacity of serum and liver and up-regulated transcripts of selenoprotein of muscle were observed in L.maculatus reaching a maximum with 3.5 mg Se-Met/kg treatment.After 24 h of nitrite stress,thermal stress exacerbated oxidative damage caused by nitrite stress in L.maculatus.In contrast,dietary Se-Met enhanced the resistance to nitrite stress of L.maculatus fed with Se-Met enriched diets containing 0.9 to 1.8 mg Se-Met/kg.Based on the effects of dietary Se-Met on the growth,antioxidant capacity and resistance to nitrite stress of L.maculatus,this study suggests that the optimal range of Se-Met supplementation in L.maculatus diets is 1.80 to 2.39 mg Se-Met/kg of diet at 27℃ and 1.80 to 4.46 mg Se-Met/kg of diet at 33℃.
基金funded by the National Natural Science Foundation of China(32072984)the Natural Science Foundation of Fujian Province(2020J01664)China Agricultural Research System(CARS-47)。
文摘An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted seabass(Lateolabrax maculatus).Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil(n-3)and linoleic acid-enriched oil(n-6)leading to n-3/n-6 PUFA ratios of 0.04,0.35,0.66,1.35,2.45 and16.17.Each diet was fed to triplicate groups of juvenile L.maculatus(11.06±0.20 g,30 fish/tank).Final body weight(FBW),weight gain(WG),specific growth rates(SGR),protein efficiency ratio(PER)and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level,and then decreased thereafter.Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW,WG,SGR and PER and the lowest feed conversion ratio.Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes(fas,acc2 and srebp-1c)and down-regulated expression of lipolysis related genes(atgl,ppara,cpt-1 and aox).Higher expression of lipolysis-related genes(atgl,ppara and cpt-1)was recorded at moderate n-3/n-6 PUFA ratios(0.66 to 1.35).Moreover,inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes(il-6 and tnf-a)and down-regulation of antiinflammatory genes(il-4 and il-10)in the intestine.The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation,improved intestinal flora richness,increased the abundance of beneficial bacteria such as Lactobacillus,Alloprevotella and Ruminococcus,and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus.In summary,it could be suggested that a dietary n-3/n-6PUFA ratio of 0.66 can improve growth performance and feed utilization in L.maculatus,as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.
文摘Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.
基金This study was supported by National Natural Science Foundation of China(grant number:31972804)the China Agricultural Research System(grant number:CARS47-14).
文摘The present study was conducted to determine the effects of dietary phosphorus(P)levels on growth performance,body composition,liver histology and enzymatic activity,and expression of lipid metabolism-related genes in spotted seabass(Lateolabrax maculatus).Seven diets were prepared to contain available P levels of 0.48%(the control group),0.69%,0.89%,1.10%,1.28%,1.51%and 1.77%and feed fish(4.26±0.03 g)to satiety twice daily for 10 weeks.Significantly higher weight gain and specific growth rate were recorded at P levels of 0.69%-1.51%compared to the control group.Feed conversion ratio decreased with increasing P levels up to 0.89%and increased thereafter.The lowest liver lipid content,viscerosomatic index and lipid content of whole-body were obtained in the 0.89%-P group among dietary treatments.P and calcium(Ca)contents in whole body were increased,while liver triglyceride and cholesterol contents were decreased with increasing dietary P levels from 0.48%to 1.77%.The highest activity of hepatic lipase was recorded in the 1.10%-P group among dietary treatments.Compared to the control group,1.10%P enhanced the proportion of HUFA and reduced the proportion of SFA and MUFA.The histological observations showed that P deficiency(0.48%)led to the vacuolization of hepatocytes and increased number of lipid droplets.Meanwhile,overall liver tissue structure was improved when P level increased to 1.28%.Compared to the control group,expression of lipid metabolism-related genes such as FAS,ACC-2 and SREBP-1 was decreased at 0.89%-1.10%P group while an opposite trend was observed in the expression of PPARa2 and CPT-1 genes.The current study showed that 0.89%dietary P levels could promote growth performance of spotted seabass and reduce lipid accumulation in the liver.A broken-line regression analysis based on weight gain showed that the optimum dietary P level(available P)for juvenile spotted seabass reared in freshwater was 0.72%.
文摘Chinese sea perch(Lateolabrax Maculatus)is one of the main marine fish culture species in China,its green development has received increasing attention and its ecological economic study is rare.Based on field survey,this paper takes water pollution tax of China as conversion indicator for aquaculture eutrophication to simulate aquaculture waste fee for further analyzing the ecological impact of Chinese sea perch’s aquaculture.For data analysis,data envelopment analysis model has been used.The comparison for Chinese sea perch’s economic performance and ecological economic performance under its main aquaculture systems has been done.The results show that:1.The simulated waste fee has no significant impact for the comparison.2.Ranking for ecological economic performance’s ecological economic,technical and scale efficiency is as follow:pond farming,offshore cage culture and cage culture.3.Offshore cage culture is the only system presenting positive increase for ecological economic performance,which makes its aquaculture activity more sustainable than other systems.4.The key point of green development is to maximize the ecological economic efficiency of main aquaculture systems.Thus,offshore cage culture is the most sustainable aquaculture system among China’s current marine fish culture systems,and other systems need innovation for achieving the green development of China’s aquaculture.
文摘Objectives:Three medicinal plants:Zingiber officinale rhizome,Allium sativum bulb,and Moringa oleifera seeds,were evaluated for progeny inhibition in fish beetle,Dermestes maculatus,and incidence of bacteria and fungi in smoked-dried Clarias gariepinus.Materials and Methods:Cleaned C.gariepinus were separately soaked in extracts of these selected plants(50 g/1000 ml)for 60 min before smoke-drying in a mud kiln at 105℃ and later divided into lots.Sensory evaluation was conducted on uninfested fishes in lot A while fishes in lot B was artificially infested with five pairs of newly emerged adult D.maculatus for 10 days.Number of emerged larva,adult insects,and incidence of microorganisms before and following 90 days in storage after infestation were used as indices of potency of the extracts.Results:Results obtained showed that all the treated uninfested smoked-dried C.gariepinus retained high scores for taste,texture,aroma,and appearance within the first 5 weeks of storage after smoking when compared with the control.This implied that the tested extracts had no negative effect in terms of sensory attributes on the treated fish during storage and can therefore be used for fish preservation.Meanwhile,A.sativum among all the selected extracts had the least number of larvae(17.67±1.45),adult(21.00±1.53),fungi(9.00×10^(2)±0.53 sfu/ml)and bacteria counts(11.33×10^(2)±0.33 cfu/ml)following 90 days in storage after infestation.Conclusion:Allium sativum among the tested extracts proved to be most effective and could be recommended for control of D.maculatus and microorganisms in smoked C.gariepinus.
文摘Objectives:The possibility that bone charcoal dusts of some species of mammal will control the major insect pest of stored cowpea seeds and the implications on seed viability(after pest control process)were investigated in the laboratory at ambient temperature(30±3°C)and relative humidity(70±5%)and in field.Materials and Methods:Standard entomological and agronomical techniques were used.Results:The results showed that at 1.0%w/w dosage,the bone charcoal dusts of Ovis aries and Bos taurus were more effective than permethrin standard insecticide in killing adult Callosobruchus maculatus Fab.infesting cowpea seeds in storage.Bos taurus had a faster action speed than permethrin at 1.0%w/w.At 1.5%w/w of dust,all the species of mammal investigated deterred oviposition considerably in C.maculatus females,whereas only the bone charcoal dusts of O.aries and Sus scrofa were comparable with permethrin in suppressing adult emergence and seed damage;S.scrofa only was comparable with permethrin in reducing larval density.Bone charcoal dusts of O.aries and S.scrofa require chemical and olfactory analyses to know if they might have caused irritation to the insects and disrupted insect circadian rhythm,affecting behaviour and mating activities,adversely.The bone charcoal dusts of the six species of mammal at a highest test dose of 1.5%w/w allowed high seed viability in both laboratory and field.Conclusion:The study recommends the use of bone charcoal dusts of O.aries and S.scrofa at economical-and quality-favourable dose 1.5%w/w for managers seeking to control C.maculatus insect attacking cowpea seeds in storage.The transitive components of the bones,abrasion of the insect epicuticle lipid layer by the charcoal dust,and combustion-related toxic factors were responsible for the insecticidal activities of the bone charcoal dusts of the mammals.
文摘Toxicity of bruchid-resistant cultivars MIT04K-399-1 and MIT07K-299-92 powders as cowpea protectants against Callosobruchus maculatus(Fab.)was investigated at an ambient temperature of 28±2°C and a relative humidity of 75±5%.Their efficacy was tested at dosage,0.5,1.0,1.5,2.0,2.5,and 3.0 g/20 g of cowpea seeds on adult mortality,oviposition,adult emergence,progeny development,seed damage,weight loss,and Beetle Perforation Index(BPI)by cowpea bruchid.The result showed that toxicity of the bruchid-resistant cowpea cultivar powders on adult bruchid is dosage-and time-dependent.At a dosage of 3.0 g/20 g,cultivars MIT04K-399-1 and MIT07K-299-92 powders achieved 70%and 72.5%lethal effect on adult C.maculatus after 4 days of treatment,respectively.Oviposition and percentage adult emergence of C.maculatus decrease with an increase in powder dosage.Conversely,reduction in progeny development of C.maculatus increases with an increase in powder dosage.The mean number of adult emergence decreased at 2 g/20 g,2.5 g/20 g and 3 g/20 g.The MIT04K-399-1 and MIT07K-299-92 powders significantly affected egg development.The MIT07K-299-92 powder was more effective against oviposition and adult emergence at higher concentrations than MIT04K-399-1 powder,an effect that was not significantly different(P>0.05)from each other.The BPI of 9.1 and 6.2 was recorded on cowpea seeds treated with MIT04K-399-1 and MIT07K-299-92 powders at a dosage of 3 g/20 g,respectively.The fear of residual toxicity on nontargeted organisms is not associated with the use of resistant cowpea cultivars as seed protectant.Subsistence farmers are familiar with the technology involved in the preparation and application of powders as protectants.Integration of bruchid-resistant cowpea cultivars MIT04K-399-1 and MIT07K-299-92 powders into the management of coleopteran pests will ensure availability of viable seeds for future farming in developing nations such as Nigeria.
