长寿花叶片再生体系的研究

以长寿花红色品种“Rako”为试材，研究建立叶片的离体再生体系。结果表明：激素配比影响叶片的再生能力；叶片背面接触培养基比正面接触培养基更有利于分化再生；用新生幼叶作外植体，再生频率为70％以上，瓶苗生根率为95％，移栽成活率为98％。     

白玉兰离体培养和快速繁殖

试验建立了白玉兰离体繁殖体系。种子为外植体 ,初代培养基为 :B5 +BA0 .5mg/L +NAA0 .0 5mg/L + 30g/L糖 +琼脂 6g/L ,萌发率 85 %。继代培养基为 :B5 +BA1.5mg/L +NAA0 .15mg/L + 30g/glucose/sucrose + 6g/Lagar+Vco0 .5g/L ,月增殖率可达 5 .0± 0 .1。生根培养为 :1/2B5+NAA0 .5mg/L +AC1.0mg/L +VB2 0mg/L。以试管苗茎段、根段做外植体 ,培养基B5 +BA2mg/L+ 2 .4 -D0 .5mg/L +VC0 .5g/L ,可获得少量愈伤组织 ,继代存活率仅为 30 %。没有再分化成苗     

核桃试管苗生根培养的研究

以新疆绵核桃为试材,对继代培养无根试管苗的生根进行了研究.结果表明：生根诱导方法、外源IBA水平及IBA处理时间、光周期以及试管苗发育状态等均对不定根发生具有明显影响.选取生长旺盛、节间较长,叶片嫩绿的幼态苗,采用间接诱导生根法,即用50～80 mg/L IBA浸渍处理试管苗基部60～90 min,然后转至不含生长调节物质的1/2 DKW培养基,先黑暗诱导14 d,再在16 h/d光照下培养,可诱导试管苗生根率达60%以上.     

香椿组织培养与快速繁殖的研究

香椿试管苗在不同培养条件下增殖速度明显不同.太行山香椿试管苗的最佳增殖条件为改良MS十SBA1.0十GA_32.0+IAA0.0;燕山香椿试管苗则为WPM+6BA1.0+GA_32.0+IAA0.0。试管苗的生根能力在IBA0.2～1.0的范围内逐渐提高.增殖倍数不同试管苗其K的摄入量、碳水化合物含量以及POD和EST同工酶图谱亦有明显差别。     

Predation by invasive signal crayfish on early life stages of European barbel may be limited

1. To determine whether or not signal crayfish Pacifastacus leniusculus and native white‐clawed crayfish Austropotamobius pallipes prey on European barbel Barbus barbus eggs, interstitial free‐embryos and emergent larvae, experiments were undertaken in salmonid (substratum) incubators (six treatments, four controls) fitted with video recorders.
2. No corpses or remains of emergent barbel larvae or eggs, or parts thereof, were observed in any of the incubators containing buried eggs, and no emergent larvae showed any sign of attack. However, video evidence of a signal crayfish catching and consuming a barbel larva was obtained.
3. There were no statistically significant differences between white‐clawed and signal crayfish either in carapace length or weight at the beginning and end of the experiments. The conservation implications of these results are discussed.

     

Effects of Adding Mannan Oligosaccharides to Diets with Different Concentrate to Forage Ratios on Ruminal Fermentation of Sheep in vitro

The test was aimed at determining the effects of adding MOS to diets with different concentrate to forage ratios on ruminal fermentation of sheep in vitro.The 4×6 two-factor experimental design was chosen.There were 4 diets with different concentrate to forage ratios(20:80, 30:70, 40:60 and 50:50) and added to 6 dosages MOS(0, 0.4%, 0.8%, 1.2%, 1.6% and 2.0%), respectively.The method of gas production in vitro was used to measure the total gas and CH₄ production, IVDMD, IVCPD and IVOMD after cultured for 3, 6, 9, 12 and 24 h.The results showed that the gas(except 12 and 24 h) and CH₄ production(except 9 h) were not impacted by the two factors(P>0.05).The IVDMD, IVCPD and IVOMD were significantly affected by concentrate to forage ratios(P<0.05), while the IVCPD at 24 h was significantly affected by MOS(P<0.05).Meanwhile, all the indexes were not influenced by the interaction of two factors(P>0.05).The IVDMD and IVOMD increased with the rising of concentrate approximately, while the IVCPD decreased with the rising of MOS roughly.The biggest associative effect was gained in 30:70 concentrate to forage diet when adding 1.2% MOS.     

Effect of Human Menopausal Gonadotropin,17β-estradiol and Epidermal Growth Factor on the Quality of in vitro Maturation Bovine Oocytes

For optimizing in vitro maturation system of bovine oocytes,we firstly examined the influence of four different hormonal regimes(FSH+LH,HMG,FSH+LH+E₂ and HMG+E₂) on oocyte maturation rates.Then we studied the effects of epidermal growth factor (EGF) in the above defined medium on bovine oocyte maturation,in vitro development and quality of parthenogenetic embryos.The cell apoptotic index of parthenogenetic blastocysts was detected by TUNEL.No significant difference was observed in maturation rates in four groups supplemented with different hormones.However,human menopausal gonadotropin (HMG) provided steady maturation results in replicates.Maturation of oocytes was promoted by supplementation with 17β-estradiol (E₂).Combination of HMG and E₂ gave rise to steady and efficient mature results.The presence of EGF at 30 ng/mL concentration significantly increased maturation rate and blastocyst rate and reduced apoptotic cells in parthenogenetic blastocysts.Therefore,the optimal oocyte maturation solution could be supplemented with 0.075 IU/mL HMG,1 μg/mL E₂ and 30 ng/mL EGF.     

Insights from in vitro exploration of factors influencing iron,zinc and provitamin A carotenoid bioaccessibility and intestinal absorption from cereals

Developments in genetics, agronomics and processing has positioned staple cereals as important sources of iron, zinc and provitamin A (pVA) carotenoids for nutritionally vulnerable populations. Significant effort has been placed on understanding the bioavailability of these micronutrients from cereal foods, including the exploration of underlying mechanisms by which their bioavailability can be modified. While micronutrient bioavailability is preferably assessed in clinical trials, relevant in vitro digestion and intestinal cell culture models have been applied to study effects of genetic, agronomic, post-harvest and food processing on micronutrient bioavailability. This review (1) critically assesses the application of in vitro models in the exploration of mechanisms associated with iron, zinc and provitamin A carotenoid bioaccessibility and intestinal absorption from cereal foods, and (2) identifies remaining gaps in order to frame future strategies to improve the nutritional impact of cereal foods.     

Potential bioavailability of protein and lipids in feed ingredients for the three‐spot cichlid Amphilophus trimaculatus: An in vitro assessment

For the commercial culture of the three‐spot cichlid (Amphilophus trimaculatus), it is important to have available a set of protein and lipid ingredients suitable for feed manufacturing, which allow to optimize the culture at affordable costs. The in vitro digestibility was evaluated with pH‐stat technique, using stomach and intestine multi‐enzymatic extracts from A. trimaculatus juveniles. The digestion of protein ingredients was taken place both in acid and in alkaline conditions, quantifying the total of free amino acids at the end of the hydrolysis, whereas the digestion of lipid ingredients was taken place only in alkaline conditions. The digestive enzymes of this species showed a better affinity to raw materials of animal origin such as beef meal, fish meal and premium chicken meal, which presented better digestibility. The best lipid ingredient that could be used is the fish oil. However, it is possible to use ingredients from the plant sources, such as soy or cereals, and vegetable oils such as olive, corn or soy oil. It is necessary to complement this study in vitro with the digestibility analysis in vivo, in order to determine the inclusion percentages in feeds and costs and therefore to develop an efficient feed formulation for the aquaculture of A. trimaculatus.     

马氏珠母贝肉酶解产物的抗酒精性肝损伤作用

为探究马氏珠母贝肉酶解产物(Enzymatic hydrolysate from Pinctada martensii,EP)对酒精性肝损伤(Alcoholic liver damage,ALD)的保护作用,该研究将EP超滤分级为截留分子量>10 kD(EP-Ⅰ)、3~10 kD(EP-Ⅱ)和<3 kD(EP-Ⅲ)3个组分,检测其体外抗肝损伤活性及对ALD小鼠肝保护作用的影响。体外试验结果显示,EP-Ⅲ可显著激活体外乙醇脱氢酶(ADH)活性(P<0.01),3个超滤组分均具有一定的体外抗氧化能力且EP-Ⅲ>EP-Ⅱ>EP-Ⅰ;动物试验结果显示,与模型对照组相比,各超滤组分均能够显著降低小鼠血清中谷丙转氨酶(ALT)和谷草转氨酶(AST)活力、小鼠肝脏指数及肝脏中丙二醛(MDA)和甘油三酯(TG)含量,同时显著增强小鼠肝脏中超氧化物歧化酶(SOD)、乙醇脱氢酶(ADH)和乙醛脱氢酶(ALDH)活力,提高肝脏中的谷胱甘肽(GSH)含量。综上,马氏珠母贝肉酶解超滤组分对急性ALD具有一定的辅助保护作用,其中EP-Ⅲ的保护作用效果最佳,其机制可能与加快机体乙醇代谢和减缓乙醇对机体造成的氧化损伤相关。