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1.
3种农药的微核效应研究 总被引:6,自引:0,他引:6
运用蚕豆根尖微核技术研究3种农药(甲胺磷、甲基硫菌灵和盐酸吗啉胍)在不同浓度下的诱变效应。结果表明,3种农药诱发蚕豆根尖细胞微核率与对照组相比均有不同程度的上升(P<0.05或P<0.01),农药浓度与微核率呈剂量-效应关系,盐酸吗啉胍的诱变效应大于其他2种农药。 相似文献
2.
王国华 《四川畜牧兽医学院学报》2005,3(4):43-46
通过对中国加入WTO后在粮食产业发展上面临的国内外形势的比较分析,指出了我国粮食产业发展在加入WTO的新形势下如何发展的问题,同时结合重庆市粮食生产情况,为重庆市粮食产业发展提出了一系列的建设性意见和对策,以应对加入WTO对我国及重庆市粮食产业带来的冲击,对把握重庆市粮食产业的发展方向有一定的指导意义。 相似文献
3.
《红字》表达的深刻含义一直以来都是评论家们争论的焦点。文中从人性这个角度来诠释《红字》中3个主要的人物,探讨在清教的专制统治下,个人在自由与权威中的挣扎以及主人公在此压制下人性的发展,以此揭示作者霍桑本人的内心世界,即内心对爱的欲求以及呼吁人以极大的勇气抛弃虚伪、回归真实的人性。 相似文献
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试验对16种从国外引进的禾本科牧草在荒漠草原的适应性及营养价值评定进行了研究,结果表明:美国赖草、美国灰赖草、沙生冰草及西伯利亚冰草越冬率较高,均在90%以上;披碱草和赖草属牧草生长速度较快,尤其是灰赖草;美国赖草、灰赖草鲜重均达到6000kg/hm2以上,加拿大新麦草、保加利亚新麦草鲜草产量均在4000kg/hm2以上;护坡型冰草、西伯利亚冰草、沙生冰草营养价值较高、适应性强、抗逆性好,是优质牧草,可以作为荒漠草原地区推广种植的首选牧草;美国赖草、灰赖草虽然产量高,抗逆性强,能够适应荒漠草原地区低温和干旱等极端条件,但适口性较差,可作为生态用种加以利用。 相似文献
6.
Hei-Zhao Lin Yong-Jian Liu Jian-Guo He Wen-Hui Zheng & Li-Xia Tian 《Aquaculture Research》2007,38(15):1605-1611
The aim of this study was to investigate the effects of different oils on growth performance and lipid metabolism of the grouper, Epinephelus coioides. Five experimental fish meal‐based isonitrogenous and isolipidic diets were formulated containing either 5.5%‐added fish oil (FO), soybean oil (SBO), corn oil (CO), sunflower oil (SFO) or peanut oil (PO). Each diet was fed to triplicate groups of 20 fish (initial body weight 13.2±0.02 g) grown in seawater at 28.0–30.5 °C for 8 weeks. Fish were fed twice a day to visual satiety. No significant differences in the survival, weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio or hepatosomatic index were found between fish fed the FO or vegetable oils (VO) diets. Dietary lipid sources did not affect whole‐body composition among grouper fed the various diets. Muscle of fish fed the FO diet had significantly higher levels of 14:0, 16:0, 16:1n‐7, 20:5n‐3[eicosapentaenoic acid (EPA)] and docosahexaenoic acid (DHA)+EPA (except for PO fed fish) compared with those of fish fed VO diets. However, the levels of 18:1n‐9, 18:2n‐6 and DHA/EPA ratios in the muscle of fish fed FO diet were significantly lower than those of fish fed the VO diets. The liver of fish fed the FO diet had significantly higher levels of 18:0, 20:5n‐3, 22:6n‐3, n‐3 highly unsaturated fatty acids and DHA+EPA than those of fish fed the VO diets, whereas increases in 18:1n‐9, 18:2n‐6 and mono‐unsaturated fatty acid levels were observed in the liver of fish fed the VO diets. 相似文献
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Q. CHANG M.Q. LIANG J.L. WANG S.Q. CHEN X.M. ZHANG & X.D. LIU 《Aquaculture Nutrition》2006,12(2):135-139
The tongue sole Cynoglossus semilaevis, an inshore fish in China, has showed great potential in aquaculture recently. However, poor survival was recorded during the period of weaning from live Artemia to artificial diets. In this paper, the influence of co‐feeding larvae with live and inert diet on weaning performance was described. The C. semilaevis larvae were reared at 21 ± 1 °C and fed four different feeding regimes from 6 days post‐hatching (dph): A, Artemia (10 individuals mL?1); B, Artemia (5 individuals mL?1); C, mixed diet (10 Artemia individuals mL?1 and 12 mg L?1 inert diet); and D, mixed diet (5 Artemia individuals mL?1 and 12 mg L?1 inert diet). Rotifers were also supplied in all cases during the first days of feeding. Mixed diets of commercial formulated feed and live prey (rotifers and Artemia) allowed larvae to complete metamorphosis, achieving similar specific growth rate (SGR) (18.5 ± 1.4% and 18.7 ± 1.6%) and survival (40 ± 7.6% and 48.5 ± 6.8%) compared with larvae fed on live feed alone (SGR of 18.3 ± 1.2%, 19.3 ± 1.9% and survival of 41.2 ± 11.3%, 38 ± 4.9%). However, in metamorphosed fish, when live feed was withdrawn on 31 dph, there was significant difference (P < 0.05) in survival and growth among treatments. Metamorphosed fish, previously fed mixture diets during larval stages, had similar survival (62.1 ± 7.6% and 62.8 ± 3.9% for regimes C and D, respectively) but higher than that obtained for fish that previously fed on live feed (49.3 ± 2% and 42.1 ± 3.9% for regimes A and B, respectively) after weaning (day 60). The SGR of weaned fish previously fed live feed was similar (3.1 ± 0.6% and 2.92 ± 0.6% for regimes A and B, respectively) but lower than that recorded for fish that was fed from day 6 to day 30 on the mixed diet (4.5 ± 1.1% and 4.9 ± 0.3% for regimes C and D, respectively). It is suggested that weaning of C. semilaevis from early development would appear to be feasible and larval co‐feeding improves growth and survival. 相似文献
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10.
Two sesame accessions, ZZM2541 and Ezhi-2, with different tolerance to waterlogging were selected, and the seedlings at the 4-true leaf stage were treated by waterlogging for 48 h. Growth parameters were evaluated 1 d before the beginning of waterlogging and on the 3rd day after the removal of waterlogging (DARW). Morphological characteristics of root and chlorophyll fuorescence were measured on the 3rd DARW and leaf gas exchange was measured on the zero, 3rd and 15th DARW. Results showed that sesame accessions ZZM2541 and Ezhi-2 responded to waterlogging in considerably different performance.The stress induced leaf chlorosis and abscission and slowed growth of plant height in both accessions, but symptom occurred seriously in the susceptive Ezhi-2. In the more tolerant ZZM2541, plentiful of adventitious roots formed above the level.All of the average values of maximum fuorescence yield (Fm), quantum efficiency of open PSII centres (Fv/Fm), initial fluorescence (Fv/F0) and chlorophyll content (Chl) decreased at the 4-true leaf stage in both accessions after suffering to the stress.The decreases of Fm, Fv/F0 and Chl were more pronounced in Ezhi-2 than in ZZM2541. Less reductions of mean photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (gs) were observed in the leaves of waterlogged ZZM2541 than in waterlogged Ezhi-2 (compared to controls), and the leaves of Ezhi-2 showed a higher water use efficiency (WUE) after the removal of waterlogging. Based on the results, it was concluded that the tolerance to waterlogging of ZZM2541 appears to depend on a combination of photosynthetic characteristics responses and morphological adaption. 相似文献