卵母细胞体外成熟时间对绵羊核移植效率的影响(英文)

[Objective] The study aimed to provide references for the time of oocyte maturation in vitro and enucleation in the course of sheep nuclear transfer(NT).[Method] Compared the effects of different maturation time of oocytes on enucleation efficiency and reconstructed embryo development by means of blind enucleation and fluorescence microscopy.[Result] Treatment of IVM(in vitro maturation)19-21 h was significantly higher than IVM 16-18 h treatment in oocyte maturation rate(P<0.05)and was significantly higher than IVM 22-24 h treatment in enucleation rate(P<0.05).Three treatments had no significant difference in cleavage rate and blastocyst rate(P>0.05),but IVM 19-21 h treatment was significantly higher than the other 2 treatments in average cell number of blastocysts(P<0.05).[Conclusion] The appropriate in vitro maturation time of oocytes was 19-21 h for sheep nuclear transfer,which could significantly improve the quality of blastocysts according to the cell number per blastocyst(P<0.05).     

Accumulation of Zinc and Molar Ratio of Phytic Acid and Zinc during Maize Grain Maturation

Dynamics of the accumulation of total ash and zinc, and their relationships with total dry matter, crude proteins and phytic acid during maize grain maturation were investigated. The investigation was carried out on normal maize hybrids grown under the same topographical and agrotechnical conditions over two consecutive vegetation years.
The amount of total ash, expressed on fresh and dry matter bases, changed significantly (P = 0.05 and P = 0.01) during grain maturation depending on maturity stage and variety. The dynamics of the accumulation of ash in fresh grain matter during maturation as well as the ash amount in dry matter of mature grains were significantly affected by environmental conditions.
The accumulation of zinc in fresh matter of developing grain was significantly affected (P = 0.05 and P = 0.01) by the degree of grain maturity and by variety, and correlates significantly (P = 0.001) and positively with the deposition of total dry matter, crude proteins as well as with phytic acid in both vegetation years.
The molar ratio of phytic acid and zinc increased significantly during grain maturation indicating a possible decrease of zinc availability.     

山旱区机修田当年种植玉米丰产技术研究

山旱区机修田当年种植玉米除采用人为熟化处理、早春抢墒覆膜、裁膜帘式播种外，于玉米苗期5叶和拔节期8叶每公顷喷PP2003、旱地龙及叶面肥，可以消除玉米苗期至拔节期由于气候因素和土壤因素造成的生理缺素症，具有抗旱、促长、平衡玉米植株体内营养分配的作用，促使玉米体内一系列生理功能的协调，从而达到丰产的目的。3年试验结果表明，该处理比人为熟化处理裸地播种生育期提前5个叶龄，产量提高4725kg/hm2，纯收入增加5538元／hm2。比相邻未机修田种植玉米生育期提前2个叶龄，产量提高1773kg/hm2，纯收入增加1156．5元／hm2。     

山羊卵泡卵母细胞体外成熟的研究

为了建立针对山羊卵母细胞的理想体外成熟培养体系,对山羊卵泡卵母细胞的采集方法,FSH和LH对山羊卵泡卵母细胞体外成熟的作用,及培养时间对卵母细胞体外成熟的影响进行了研究。结果表明:采用切割法平均每枚卵巢采集到的A,B级卵母细胞的数量明显多于抽吸法;采用TCM199添加体积分数为10?S,1~2 mg/L 17β_E2,10 mmol/L Hepes,0.12 mg/mL丙酮酸钠,0.1 mg/mL链霉素和0.125 mg/mL青霉素,10 mg/L FSH及20~50 mg/L LH的培养体系,有利于山羊卵母细胞的体外成熟,并放出第一极体。山羊卵母细胞体外成熟培养20,22,24 h,成熟率显著高于培养18,26,30 h(P<0.05)。     

Influence of clay content and acidity of soil on development of the earthworm <Emphasis Type="Italic">Lumbricus rubellus</Emphasis> and its population level consequences

In this paper we report on the influence of clay content and acidity of soil on growth and reproduction of the epigeic earthworm species Lumbricus rubellus (Hoffm.), which is common in most temperate soils and abundant in grasslands. Growth, cocoon production and survival of L. rubellus were tested in 12 Dutch soils which differed in soil properties. A matrix model was used to assess the population-level consequences of changes in growth and reproduction. Soil acidity had a strong negative effect on earthworm survival, and the maturation weight decreased with clay content. Individual weight gain in L. rubellus decreased with both acidity and clay content. The acidity of soils had a larger influence on population growth rate than the clay content. The acidity of the soil also changed the population composition towards younger age classes, whereas in soils rich in clay, the population composition did not change. The average individual weight of L. rubellus in clayey soils, however, was lower compared with that in soils low in clay, a result that agrees with literature data.     

日粮中维生素E、硒水平对熟化过程中牛肉氧化稳定性的影响

研究了日粮维生素E、硒水平对熟化过程中牛肉氧化稳定性的影响。选择16头体重420～560kg的健康晋南牛阉牛,按体重分为4组,每组4头,试验期为2个月。试验采用2×2因子完全随机设计:维生素E的补饲水平为每头每天0和1000IU,硒的添加水平为0 10和0 40mg/kg。结果表明:与未补饲VE组相比,补饲1000IUVE可显著提高血浆和臀中肌α 生育酚含量(P<0 004),日粮中添加0 10和0 40mg/kg硒对组织α 生育酚含量影响差异不显著(P>0 05);日粮中添加0 40mg/kg硒组全血和臀中肌硒含量显著高于0 10mg/kg组(P<0 002);补饲1000IUVE和/日粮中添加0 40mg/kg硒可显著提高全血GPx(谷胱甘肽过氧化物酶)和熟化过程中臀中肌GPx酶活力(P<0 01),但对组织SOD(超氧化物歧化酶)酶活力影响差异不显著(P>0 05);补饲1000IUVE可显著抑制熟化过程中牛肉的脂质氧化(P<0 001),对牛肉的保水性能和颜色稳定性影响差异不显著(P>0 05);虽然提高日粮硒水平可明显增强熟化过程中牛肉GPx酶活力,但GPx酶活力的提高没有降低牛肉的TBARS值、滴水损失和METMB(高铁肌红蛋白)含量,该结果提示不同日粮硒水平对牛肉氧化稳定性没有显著影响。     

ABA 和乙烯对荔枝果实成熟和着色的调控

 荔枝果实幼果期ABA 含量很高, 之后下降, 在转红前1 周急剧上升, 形成一个峰值。果皮、果肉乙烯释放量的变化与ABA 相似, 但其跃变发生在ABA 之后, 且跃变较小。伴随着乙烯的跃变, 有一个糖代谢和转化酶活性的跃变。于转熟前用STS 处理荔枝果实, 导致果实转色和成熟延迟。果实发育后期, ABA 急剧增加可能诱导了乙烯的合成, 乙烯启动果实成熟, 果皮转红着色。     

Gastrointestinal and body growth in colostrum-deprived piglets in response to whey, casein or soy protein diets

Cow's milk stimulates growth in neonates and supplementation with specific milk proteins may benefit immuno-compromized neonates exhibiting poor growth. We investigated the effects of specific milk proteins (casein and whey) and plant protein (hydrolysed soy) on body and organ growth and bone mineralization in colostrum-deprived newborn pigs. Six days after birth, both casein and whey increased body and small intestinal weight relative to soy protein. Villus morphology and epithelial permeability were similar among groups. Casein significantly increased bone mineralization, while whey stimulated soft tissue growth (internal organs, muscle and fat). The differential effects of casein and whey proteins in the early postnatal period show that specific milk proteins rapidly affect whole body and gut development, even in a state of impaired growth induced by artificial feeding of colostrum-deprived pigs.     

草莓果实成熟期花青苷、酚类物质和类黄酮含量的变化

以春星和全明星为试材,研究了不同成熟度草莓果实酚类物质、类黄酮及花青苷的动态变化。结果表明,随着果实的成熟,酚类物质和类黄酮在绿熟期有较高的含量,之后随着果实的成熟先下降,至紫红期又开始大量积累;花青苷含量随着果实的成熟逐渐增加,紫红期达最大值;低温贮藏的草莓果实酚类物质、类黄酮含量首先下降,之后随着贮藏天数的增加而不断上升;花青苷含量逐渐增加,但增加的趋势比较缓慢。