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1.
磁珠富集法与小片段克隆法筛选鲤微卫星的比较研究   总被引:44,自引:10,他引:34       下载免费PDF全文
用2种方法克隆黑龙江鲤(Cyprinus(Cyprinus)carpio haonatopterus)的微卫星序列。这2种方法分别是:①经典的小片段DNA克隆库,用末端标记的[γ^-32]ATP的CA重复序列为探针筛选;②将酶切获得的小片段DNA用结合有磁珠的并连接有15个CA重复序列的生物素进行富集,获得的含有CA重复的DNA片段并经过两次PCR扩增再克隆的方法获得富集微卫星片段的克隆库。从前一个方法的克隆库中筛选2000个菌落,获得阳性克隆45个,有22个含有微卫星,完美型的占63.6%,非完美型的占22.7%,混合型的占13.7%,重复次数超过10的有9个,占40.9%;从方法②的克隆库中筛选2600个菌落,获得阳性克隆1300个,测序其中的390个克隆,微卫星314个,完美型的占79.0%;非完美型的占14.3%;混合型的占6.7%,重复次数超过10的有293个,占93.3%。结果表明,用生物素结合磁珠富集法克隆微卫星效率高,成本低,所获微卫星质量高,是一种值得推荐的微卫星制备方法。  相似文献
2.
高州水库浮游植物群落结构及其与环境因子的关系   总被引:4,自引:0,他引:4       下载免费PDF全文
摘要:为掌握高州水库浮游植物群落结构变化规律及其与环境因子的关系,2011年4月至2012年3月对高州水库浮游植物群落周年动态进行调查和分析。结果表明:高州水库共鉴定浮游植物7门97种,库区浮游植物细胞密度年变化范围为7.8×105-9.72×106 cells/L;全年主要优势种为铜绿微囊藻(Microcystis aeruginosa)与梅尼小环藻(Cyclotella meneghiniana)。Shannon-Wiener多样性指数和均匀度指数分析结果显示,高州水库各区域属于中污染状态;CCA分析结果表明,氮磷营养盐是影响高州水库浮游植物群落分布的重要因子,温度、pH与CODMn对浮游植物群落分布也有一定程度的影响。  相似文献
3.
亚硝酸盐对长尾墨金丝神仙幼鱼的急性毒性试验   总被引:2,自引:0,他引:2  
采用静水生物试验测定了NO2^- -N对长尾墨金丝神仙幼鱼(2.541±0.349em)的急性毒性,并探讨了CaCl2和NaCl的解毒效果。结果表明,24h、48h、72h、96h半致死浓度(LC50)分别为164.25mg/L、98.41mg/L、76.73mg/L、48.90mg/L;安全浓度为4.89mtg/L;50mg/L的CaCl2具有较好地减小NO2^- -N毒性的效果。  相似文献
4.
底栖硅藻中诱导鲍鱼幼体附着和变态的物质研究进展   总被引:2,自引:0,他引:2  
胡金梅  魏东 《水利渔业》2005,25(6):15-17
底栖硅藻不但能提供促进鲍鱼幼体附着和变态的物质,还能作为鲍鱼幼体的饵料生物为其发育提供营养.底栖硅藻诱导鲍鱼幼体附着和变态的主要物质有胞外多糖、氨基酸、多不饱和脂肪酸等,对其营养功能和诱导附着变态作用等方面进行了综述,以期为鲍鱼育苗以及优质配合饲料的开发提供指导.  相似文献
5.
宝石鲈摄食节律和日摄食率的初步研究   总被引:1,自引:0,他引:1  
为了解宝石鲈昼夜摄食规律和日摄食量,采用饱满度指数法在7-9月对124尾宝石鲈在不同昼夜节律下的摄食节律和日摄食率进行了研究。试验结果表明,9:00-17:00为摄食高峰期,凌晨1:00摄食活动最弱,翌日5:00摄食强度明显升高。7-9月,该鱼的日摄食率(用占体质量的百分比表示)分别为6.07%、3.34%、2.37%。宝石鲈有明显的摄食节律,属于白天摄食类型。  相似文献
6.
双抗对紫彩血蛤幼虫发育的影响   总被引:1,自引:0,他引:1  
孙虎山  王宜艳 《海洋渔业》1997,19(4):160-163
本文研究了青霉素钾盐和硫酸链霉素(双抗)混合使用对紫彩血蛤(Nutallia olivacea)幼虫发育的影响。结果表明:1~80ppm的双抗均有很好的抑菌效果,均可显著地提高幼虫的存活率,最高可提高52%,最低也可提高38%,同时对幼虫生长和变态均有明显的促进作用。其中以2~4ppm效果最好,幼虫生长最快,变态率最高;高浓度组对幼虫也无明显的副作用,幼虫生长速度、变态率和存活率也都高于对照组。  相似文献
7.
The combined effects of acute temperature and salinity on osmolality, expressions of heat shock proteins mRNA (hsp70, hsp90a and hsp90b) and superoxide dismutase mRNA (sod) were investigated in the sea cucumber Apostichopus japonicus Selenka. There were 12 treatments (combinations of temperature at 16, 20, 24 and 28 °C and salinity at 22, 27 and 32 ppt). In low salinity environments, the osmolality of the sea cucumber’s coelomic fluid decreased immediately and reached osmotic balance within 6 h. The decline of osmolality after 2 h of hypo-osmotic stress was faster at high temperatures (28 °C) than that at low temperatures (16 and 20 °C). Cellular level stress was indicated by up-regulation of hsp70, hsp90s and sod mRNA, and the maximal expression of all genes occurred at 6 h after stresses. The up-regulation of hsps and sod mRNA indicated the emergence of protein denaturation and oxidative damage and also suggested an increase in energy consumption at high temperature and low salinity. These results indicated that high temperature and low salinity could change biochemical pathways and energy budgets and then potentially impair the osmoregulation of the sea cucumber. Therefore, effective ways should be taken (e.g., draining off the upper freshwater, exchanging water and adding man-made sea water) to prevent the damage to sea cucumber culture caused by low salinity induced by rainstorms, especially at high temperature.  相似文献
8.
Rainbow trout were fed a diet containing phytase-sprayed and phytase-pretreated soybean meal with different phytase levels. The single factor random block design was used to analyze the effects on rainbow trout of dietary phytase supplementation on growth performance, nutritional ingredient digestibility and nutrient excretion. After 90 days, the results showed that feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly improved and specific growth rate (SGR) was not affected by spraying phytase, but SGR, FCR and PER were not significantly improved by phytase pretreatment. A digestibility trial conducted after the feeding trial showed that apparent digestibility coefficient (ADC) of diet protein and minerals was increased with phytase supplementation. However, there was a negative effect of phytase on the ADC of lipid. The excretion experiment showed that the supplementation of phytase resulted in decreased nutrient excretion in feces, but lipid excretion was slightly increased with phytase supplementation. In addition, the results of P excretion and ADC of P analyzed by t-test showed that phytase pre-treatment method should be a more rational method than the spraying method. The results of SGR, ADC of P and P excretion analyzed by quadratic regression indicated that 2,000–3,000 U/kg levels by the spraying method could be a rational range of phytase supplementation, and about 1,000 U/kg should be an optimal level by the pretreatment method. Thus, use of phytase in rainbow trout feeds can have economic and environmental benefits.  相似文献
9.
The effects of four modes of diel temperature-fluctuation with two designated fluctuating temperatures (15 ± 3°C and 18 ± 3°C) on the growth and energy budget of young sea cucumber, Apostichopus japonicus Selenka, were studied to develop a highly efficient temperature-control scheme for aquaculture of the species. Sea cucumbers with a mean wet body weight of 8.0 ± 1.2 g (mean ± SD) were allocated to each treatment randomly with five replicates. After a 38-day trial, specific growth rate (SGR) and food conversion efficiency (FCE) decreased with increasing temperature in constant-temperature treatments. Among the four modes of temperature fluctuation, SGR of sea cucumbers reared under a mode which simulated the natural fluctuation of the temperature (mode C) of seawater was significantly higher than that of sea cucumbers reared at the corresponding constant temperatures. This enhancement of growth rate by use of mode C was attributed to higher FCE and lower energy allocated to respiration and feces. In large-scale culture, a temperature-control mode designed based on mode C could enhance not only growth but also efficiency of food utilization by the young sea cucumber.  相似文献
10.
采用溶剂浸泡法从红白锦鲤皮肤、尾鳍、鳞片红色部分提取红色素,并研究不同有机物对红色素稳定性的影响。结果表明:淀粉、乳糖、柠檬酸、蔗糖、草酸、苯甲酸对红白锦鲤红色素具有保护作用,且作用依次增强;苦味酸、肌醇、水杨酸、纤维素粉、葡萄糖、反丁烯二酸对红色素具有破坏作用,且作用依次减弱。  相似文献
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