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261.
262.
以草本植物博落回(Macleaya cordata)为供试植物,采用沙培盆栽实验研究其对重金属铅(Pb)的耐性、富集及生理响应机制。结果表明:博落回能耐受500 mg/L的Pb胁迫而其生长发育不受影响,高于此浓度时植株生长发育受到抑制。不同组织对Pb的富集能力表现为根>茎>叶,博落回对Pb的富集与转运能力皆随Pb胁迫浓度的升高而减弱。Pb胁迫引起丙二醛(Malondialdehyde, MDA)在植物体内累积。低于500 mg/L的Pb促进叶绿素、可溶性蛋白的合成和抗氧化酶活性的提高,高于此浓度时,则表现为抑制,且导致膜脂过氧化与生物膜的损伤。Pb主要以迁移活性低的化学形态存在于细胞壁和可溶性组分中,浓度升高会导致Pb向迁移毒性强的形态转化。透射电子显微镜(TEM)观察到高浓度的Pb胁迫会损害细胞壁结构,使Pb进入细胞内部,对细胞造成毒害。傅里叶红外光谱仪(FTIR)分析表明,Pb胁迫会提高细胞内-OH、-COOH等基团和有机酸、蛋白质的含量,在低浓度时可与Pb结合,削弱其对博落回的毒性。 相似文献
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Qinghui Ai Kangsen Mai Beiping Tan Wei Xu Qingyuan Duan Hongming Ma Lu Zhang 《Aquaculture (Amsterdam, Netherlands)》2006,260(1-4):255-263
A growth experiment was conducted to investigate the effects of replacement of fish meal (FM) by meat and bone meal (MBM) in diets on the growth and body composition of large yellow croaker (Pseudosciaena crocea). Six isonitrogenous (43% crude protein) and isoenergetic (20 kJ g− 1) diets replacing 0, 15, 30, 45, 60 and 75% FM protein by MBM protein were formulated. Each diet was randomly allocated to triplicate groups of fish in sea floating cages (1.0 × 1.0 × 1.5 m), and each cage was stocked with 180 fish (initial average weight of 1.88 ± 0.02 g). Fish were fed twice daily (05:00 and 17:30) to apparent satiation for 8 weeks. The water temperature ranged from 26.5 to 32.5 °C, salinity from 32 to 36‰, and dissolved oxygen content was approximately 7 mg l− 1 during the experimental period. Survival decreased with increasing dietary MBM and the survival in the fish fed the diet with 75% protein from MBM was significantly lower than other groups (P < 0.05). There were no significant differences in specific growth rate (SGR) among the fish fed the diets with 0 (the control group), 15, 30 and 45% protein from MBM. However, SGR in the fish fed the diets with 60 and 75% protein from MBM were significantly lower than other groups (P < 0.05). No significant differences in feeding rate were observed among dietary treatments. The digestibility experiment showed that the apparent digestibility coefficients (ADC) of dry matter, protein, lipid and energy of MBM were significantly lower compared with those of FM (P < 0.05). Essential amino acid index was found to be correlated positively with SGR in the present study, suggesting that essential amino acid balance was important. Body composition analysis showed that the carcass protein and essential amino acids were not significantly affected by dietary MBM. The lipid and n-3 highly unsaturated fatty acid (n-3 HUFA) in fish muscle, however, significantly decreased with increasing dietary MBM. These results showed that 45% of FM protein could be replaced by MBM protein in diets of large yellow croaker without significantly reducing growth. It was suggested that the reduced growth with higher MBM was due to lower digestibility and imbalance of essential amino acids. 相似文献
265.
生物技术对鱼类养殖的潜在影响 总被引:1,自引:0,他引:1
随着科学技术的发展,除了传统的生物技术之外,分子技术的应用已经为提高世界水产养殖品种产量开辟了另一条途径.基因组信息库的增长,极大地提高了科技工作者对确认一些表现型基因的能力.转基因技术和目前尖端的技术:诸如DNA芯片技术、高分辨力的二维凝胶技术和高灵敏度的质谱仪等技术的发展联系起来,向水产养殖工作者展现出了一片美好的前景:包括生长率和经济效益的增加、抗病能力和抗冻能力的提高、养殖品种种质的改善以及通过改变它们的基因组成而创造出新的不同的品种.讨论了与功能基因组领域相关的技术以及它们在水产养殖领域中的应用. 相似文献
266.
The effects of salinity on hemolymph osmotic pressure, gill Na+/K+‐ATPase activity and dopamine (DA), norepinephrine (NE), serotonin (5‐HT) in the gills, and hemolymph of the adult Charybdis japonica were studied. DA levels increased significantly (P < 0.05), while the NE and 5‐HT revealed contrary change in hemolymph and gills. The iso‐osmotic point of C. japonica (911.4 mOsm/kg) was at salinity of 27.87 ppt. The Na+/K+‐ATPase activity of gill showed negative correlation with salinity in the hypotonic environment (<27.87 ppt). The results of this experiment indicated that C. japonica had great capability to acclimate to low salinity. 相似文献
267.
人工引入光合细菌于凡纳滨对虾养殖环境中,监测与养殖环境相关的水质因子(氨氮、亚硝酸氮、化学需氧量)的变化;观察不同光合细菌使用浓度下凡纳滨对虾对人工制造的胁迫环境的抗逆性;观测不同光合细菌使用浓度下凡纳滨对虾的成活率与体重增长率。研究光合细菌对水质改善和凡纳滨对虾抗逆性的影响。结果表明,光合细菌能显著(P<0.05)降低水体中的化学需氧量、氨氮含量并抑制亚硝酸盐氮的产生;当光合细菌投放浓度为3×103cfu/mL时,水体中化学需氧量、氨态氮、亚硝酸盐氮含量的均值分别比对照组降低了31.59%、43.42%、52.20%;成活率比对照组提高了18.67%,体重增长率是对照组的1.34倍;当光合细菌使用浓度为3×102cfu/mL~3×104cfu/mL时,对虾抗逆性显著(P<0.05)增强,对虾在氨氮、亚硝酸盐氮、高锰酸钾、甲醛胁迫下24 h的成活率均值分别比对照组提高了36.67%、25.00%、26.39%、10.00%。 相似文献
268.
Preliminary study to evaluate the effects of dietary bile acids on growth performance and lipid metabolism of juvenile genetically improved farmed tilapia (Oreochromis niloticus) fed plant ingredient‐based diets
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A 9‐week feeding experiment was conducted to investigate the effects of dietary bile acids (BAs) on juvenile genetically improved farmed tilapia (GIFT) (Oreochromis niloticus) based on the evaluations of growth performance and parameters relevant to lipid metabolism. Each of five vegetable protein‐based diets containing BAs at a level of 0, 0.05, 0.15, 0.45 or 1.35 g/kg diet was fed to three replicates with 40 fish (8.2 g per fish). The results showed that weight gain (WG) increased significantly with the increase in BAs from 0 to 0.15 g/kg diet and then decreased significantly at a higher BA supplementation. Dietary BAs significantly reduced the crude lipid content in the whole body, muscle and liver tissue of GIFT. Fish fed diet with 1.35 g BAs/kg diet developed serious nuclear migration and vacuolization in hepatocytes. Gall bladder appeared to contain white solid and has fragile capsules. Dietary BA supplementation had significant effects on serum biochemical indices and activities of lipid metabolism enzymes in liver and intestine. In conclusion, dietary bile acid supplementation (0.15 g/kg) can facilitate the lipid metabolism and therefore promote the growth of tilapia. However, overdosed dietary BAs induced gallstone development, disrupted lipid metabolism and depressed the growth performances of GIFT. 相似文献
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270.
长江口中华绒螯蟹(Eriocheirsinensis)蟹苗汛期预报的研究 总被引:1,自引:0,他引:1
报导了对长江口中华绒螯蟹 (河蟹 ,Eriocheirsinensis)蟹苗汛期预报的研究结果。蟹苗汛期决定于河蟹胚胎及溞状幼体发育的生物学因素、水温条件和潮汐?そ诘暮有芳性?2月底 3月初交配抱卵 ,5月初孵出溞状幼体。 1970~ 1981年的资料表明 ,从 3月 1日河蟹开始交配抱卵至大眼幼体 (蟹苗 )回归淡水 ,约需 12 77度日。按这一标准估算 ,在± 2d的变差下 ,12年中有 11年的发汛起始日在估算范围内 ,而若允许将变差时间提高到± 3d ,则 12年中的发汛起始日全部在预测范围内。长江口的大眼幼体要入江 ,必须借助潮汐的动力。而在潮汐半月周期的潮位曲线上 ,只有从起汛期至大汛期 (农历廿七到初三 ;十二到十八 ) ,潮位逐日上升 ,蟹苗才有可能从河口浅海进入江段。综合考虑度日和潮汐两个因素 ,即可预报蟹苗发汛的起始日 相似文献