牛冷冻精液解冻后在不同温度下的存活时间

牛冷冻精液解冻后在3～8℃、室温及37℃条件下保存,分别于2、4、8、12及24小时,观察其活力变化。结果表明:环境温度对精子的存活时间影响很大,活力的下降速度有明显差异。     

暗纹东方鲀在不同冻藏温度下品质变化的动力学研究

为研究河豚鱼在冻藏过程中的品质变化,通过不同温度下的冻藏试验对河豚鱼品质变化的动力学模型进行探讨。将河豚鱼冻藏在263、255、248和243K条件下,测定河豚鱼的挥发性盐基氮、盐溶性蛋白及巯基等品质指标随贮藏时间的变化。在Arrhenius动力学方程基础之上,建立了挥发性盐基氮、盐溶性蛋白及巯基的质量分数与冻藏时间及冻藏温度之间的动力学模型。结果表明：一级化学反应动力学模型和Arrhenius方程对挥发性盐基氮和盐溶性蛋白的质量分数及巯基的质量摩尔浓度的变化具有较高的拟合精度。挥发性盐基氮质量分数变化预测模型中的活化能EA及速率常数k0分别为10.72kJ/mol和0.556 0,盐溶性蛋白质量分数变化的EA及k0分别为：26.79kJ/mol和2 668.20,巯基质量摩尔浓度变化的EA及k0分别为：20.68kJ/mol和186.52。挥发性盐基氮随着贮藏时间的延长而增加,且随着贮藏温度的升高而增加迅速,其盐溶性蛋白及巯基含量指标随着贮藏时间的延长而下降,且随着贮藏温度的升高而下降迅速。     

烫漂时间对速冻马铃薯的影响研究

对烫漂时间对马铃薯片的品质影响进行了研究。结果表明:(1)随着烫漂时间的增加,马铃薯片的硬度逐渐减小;(2)烫漂后马铃薯片中Vc含量大量减少,但与漂烫时间无明显关系;(3)随着烫漂时间的增加,马铃薯片中的酶失活程度增加;(4)随着烫漂时间的增加,马铃薯片的褐变度值逐渐减小,并在60s后逐渐趋于平稳。结合烫漂时间对马铃薯片的硬度、Vc含量、酶失活程度、褐变度的影响以及燃料等消耗成本的考虑,确定用100℃沸水烫漂厚度为0.5cm的马铃薯片时的最佳烫漂时间为60s。     

滇重楼内生真菌的分离及其对滇重楼种子胚发育的效应(英文)

[目的]本研究旨在分离滇重楼的内生真菌并探究其对内生真菌胚发育的效应。[方法]分离滇重楼的内生真菌并进行形态学鉴定,并用石蜡切片和显微照相术研究内生真菌并探究其对滇重楼种子胚发育的效应。[结果]从滇重楼根状茎中分离到9种属于3目、5科、7属的内生真菌,即PPYEF-1,PPYEF-2,PPYEF-3,PPYEF-4,PPYEF-5,PPYEF-6,PPYEF-7,PPYEF-8和PPYEF-9。除了PPYEF-4(枝孢霉属)外,其他真菌都能促进滇重楼种子的胚发育,大多数达到极显著或显著水平;PPYEF-9(木霉属)能导致滇重楼种子发育的最长胚长和最高胚率。[结论]本文可为滇重楼内生真菌在打破滇重楼种子休眠中的应用提供参考。     

萝卜与苤蓝属间杂种胚离体培养…

以萝卜雄性不育系DH303A为母本,以苤蓝为父本进行属间远缘杂交,萝卜与苤蓝杂交的不亲和性发生在胚珠发育过程中,杂交荚荚长快速生长期在授粉后的第2~5天,而横径快速生长期在授粉后第2~4天。在杂种胚发育后第6天和第7天进行胚抢救,用诱导培养基:MS+2,4-D 2.0 mg/L+KT 0.5 mg/L+蔗糖3%+琼脂0.6%;继代培养基:MS+2,4-D 2.0 mg/L+KT 0.5 mg/L+蔗糖3%+琼脂0.6%;分化培养基:MS+IAA 0.5 mg/L+KT 1.5 mg/L+蔗糖3%+琼脂0.6%;生根培养基:MS+NAA 0.2 mg/L+IAA 0.5 mg/L+蔗糖3%+琼脂0.6%,能成功获得幼苗。     

Effect of lead exposure on mRNA expression of NMDA receptors in zebrafish embryos and larvae

AIM:To investigate the effect of lead exposure on mRNA expression of N-methyl-D-aspartate(NMDA) receptors in zebrafish embryos and larvae. METHODS:Zebrafish embryos(wild type; AB line) were exposed to lead acetate(PbAc) at concentrations of 0, 0.1, 0.5, 2.5 and 12.5 μmol/L, respectively. Total RNA was extracted from zebrafish embryos or larvae at the time points of 24, 48, 72, 96 and 120 hours post fertilization(hpf). The mRNA levels of NR1.1, NR1.2 and NR2B were determined by real-time quantitative PCR. RESULTS:The mRNA expression of NR1.1, NR1.2 and NR2B gradually increased during embryonic development, raised rapidly at 72 hpf, peaked at 96 hpf(vs that at 24 hpf, P<0.01), and still kept in high level at 120 hpf in control group. The impact of lead exposure on the mRNA expression of NR1.1, NR1.2 and NR2B varied with lead concentrations. With the increasing concentrations of PbAc, the mRNA expression of NR1.1 generally increased and reached the highest level ahead of 96 hpf. The peak mRNA level of NR1.1 was observed at 72 hpf under the condition of PbAc exposure at the concentrations of 2.5 and 12.5 μmol/L, and were higher than that in control group(P<0.05). Similarly, the mRNA levels of NR1.2 and NR2B showed an increasing trend with PbAc exposure. However, the peaking time of NR1.2 and NR2B in mRNA expression spanned from 72 to 120 hpf. The significant correlations between the expression levels of NR1.1, NR1.2 and NR2B were observed(P<0.01) and the Pearson’s correlation coefficient values of r_NR1.1-1.2, r_NR1.1-2B and r_NR1.2-2B were 0.681, 0.637 and 0.514, respectively. CONCLUSION:The mRNA expression of NR1.1, NR1.2 and NR2B gradually increases throughout the embryonic development of zebrafish and reaches the highest levels at early stage of larva. Close correlations between the mRNA expression of NR1.1, NR1.2 and NR2B are present during the period of embryo and larva. Lead exposure induces up-regulation and forward shift of NR1.1, NR1.2 and NR2B at mRNA level, indicating that lead induces abnormal expression of NMDA receptors.     

TCM199对陇东绒山羊细管精液的冷冻效果

目的研究陇东绒山羊细管精液冷冻时,通过在葡萄糖一柠檬酸盐稀释液中添加TCM199,观察其对陇东绒山羊细管冷冻精冷冻效果的影响。方法选用4个试验组和对照组进行对比试验,试验组是在稀释液基础上分别添加TCM199标准液,含量为0．5％、1％、3％、5％（V／V）。结果表明：添加19／6的TCM199标准液的试验组（B）效果较好,其冷冻解冻后精子活力高于对照组和其它试验组,但差异不显著（P〉0．05）,质膜完整率试验组和对照组相比差异不显著（P〉0．05）,在精子穿卵活力试验中（SPA）,试验组和对照组相比差异不显著（P〉0．05）。但在细管解冻后不同时间段活力测定试验中,解冻后5h、8h、12h,试验组（B）和对照组活力差异显著（P〈0．05）,且随着时间延长呈下降趋势。因此制作陇东绒山羊精液细管冷冻时,添加1％TCM199标准液具有比较好的效果。     

奶牛性控冻精和常规冻精活力对比试验分析

试验观测对比奶牛性控冻精和常规冻精解冻后精子存活时间,为进一步把握输精时间,提高受胎率提供依据。试验结果表明:性控冻精刚解冻时活力较高,为0.5级以上,但活力下降快、存活时间较短,解冻后6h活力降低为零;常规冻精刚解冻时活力在0.4～0.5级之间,但存活时间较长,活力下降速度慢,解冻后8h活力降低为零。所以性控冻精解冻后,要求输精技术员尽快输精。     

The Relationship Between the Positive Identification of the Embryo Proper in Equine Pregnancies Aged 18-28 Days and its Future Viability: A Field Study

Early embryonic loss (EEL) negatively affects the reproductive efficiency of equine reproduction. A sign of future EEL is when the embryo proper (EP) fails to develop within the embryonic vesicle after 30 days of gestation. The earlier the identification of impending EEL, the earlier the mare can be rebred to allow a second chance of pregnancy. The objectives of this study were to determine the percentage of embryonic vesicles with a visible EP at 18-28 days of gestation and to study the association between the presence/absence of the EP at different days of gestation and the future viability of the pregnancy. A total of 1,256 pregnancies were identified and followed by transrectal B-mode ultrasonography 12-45 days post ovulation in mares of the same Thoroughbred farm. The identification of the EP was attempted once during days 18-28. Pregnancy reconfirmation was performed on days 35-45. The percentage of vesicles with an EP increased gradually from days 18 (2.8%) to 21 (86.9%) (P < .05). From day 20 onward, the EEL rate of mares with vesicles without an EP was significantly higher (P < .05) than that of vesicles with a positive identification of an EP. In conclusion, the EP of the equine vesicle can be identified reliably with B-mode ultrasonography in the majority of mares (>71%) on day 20 of gestation. The lack of a positive identification of an EP from day 20 onward is associated with a higher EEL rate.     

绵羊胚胎移植技术在柴达木地区的应用

2006年在青海省海西州德令哈市洋嘉生态农业开发有限公司进行了绵羊胚胎移植试验,试验中同期发情和超数排卵处理青海高原毛肉兼用半细毛羊共86只,同期发情率达88.37%,其中将超排效果好的11只羊做为胚胎移植受体羊,同时处理供体羊特克赛尔羊7只。试验结果:11只受体羊平均超数排卵点2.8个/只,7只供体羊平均超数排卵11.9枚,取卵9.7枚,卵子受精率17.65%,移植12枚胚胎,其中1只受体羊移植双胚,最后观察到移植的11只受体羊中妊娠5只,产羔5只(移双胚的羊产1只羊羔),移植受胎率达45.45%,羔羊成活率达100%。