乳头数对母兔繁殖力的影响

按照母兔乳头数为１０和８分为试验Ａ组和试验Ｂ组，每组１６只。测定哺乳前三（组）周，每组母兔的泌乳量、仔兔每天的平均吮乳量等。试验结果表明：哺乳前三周，母兔的泌乳量、仔兔每天平均吮乳量、仔兔日增重、断奶窝重及断奶成活率，试验Ａ组分别为３１３８．６２克、２１．９８克／天、只、１４．１８克／日、５２４９．６８克和９３．９７％，分别比Ｂ组高８．３０％、１２．４３％、７．３４％、４．２７％和１０．５５％。经ｔ检验和Ｘ２检验后发现，除断奶窝重在Ａ、Ｂ两组之间差异不显著外，其它各项指标在Ａ、Ｂ两组之间均差异显著（Ｐ＜０．０５）。由此可以得出结论：有较多乳头数的母兔能哺乳更多的仔兔，其繁殖力较强     

不同熟期苦荬菜的染色体数目及核型分析

苦荬菜Lactuca indica是一种优良的牧草种质资源,熟期是苦荬菜利用的重要影响因素之一。研究对2种不同熟期的苦荬菜种子根尖细胞进行冰浴处理,染色体用醋酸洋红染色制片。染色体数目和核型分析结果表明,早熟苦荬菜和晚熟苦荬菜染色体数目均为2n=2x=18,没有差异。早熟苦荬菜核型公式为2n=2x=2m 12sm 4st;晚熟苦荬菜核型公式为2n=2x=16sm 2st,存在差异。     

无籽刺梨染色体数目观察

以无籽刺梨组培苗根尖为材料,探讨其染色体制片技术。结果表明,无籽刺梨根尖在常温下用0.003mol/L8-羟基喹啉溶液预处理6-8h或0.004mol/L8-羟基喹啉溶液预处理4-6h后,在预冷的卡诺固定液（冰醋酸：无水乙醇=3:1中）0℃下处理15min,经95%乙醇:15% Hcl=1:1的解离液处理5min或无水乙醇:36-38% Hcl=1:1处理6min,然后用卡宝品红染色15或20min,其镜检效果较佳;无籽刺梨的染色体数目为2n=2x=14。无籽刺梨染色体制片技术研究及其染色体数目的确定对其遗传改良工作有着重要的意义。     

猪孤雌激活早期胚胎线粒体分布及mtDNA拷贝数变化的研究

本研究通过线粒体分子探针标记技术检测孤雌激活早期胚胎线粒体的分布变化,运用实时荧光定量PCR技术检测mtDNA拷贝数的变化,揭示早期胚胎发育过程中线粒体分布、mtDNA拷贝数变化趋势。结果表明,成熟卵母细胞电激活后,由2-细胞胚胎开始,卵裂球内线粒体分布均匀且密集,每个细胞均有分布,卵裂球之外的空隙未见线粒体分布,直到囊胚形成,线粒体均有分布。孤雌激活4-细胞胚胎mtDNA拷贝数显著高于8-细胞胚胎mtDNA拷贝数(907210.77±145520.77,186224.33±103308.00,P<0.05),但显著低于2-细胞胚胎、桑椹胚、囊胚的mtDNA拷贝数(1563422.54±224666.51、1697626.25±176999.53和1752301.29±101146.64,P<0.05)。孤雌激活扩张囊胚mtDNA拷贝数最高,为2812545.67±156819.31,显著高于其他发育时期胚胎的mtDNA拷贝数(P<0.05)。由此可见,孤雌激活早期胚胎发育进程中线粒体分布及mtDNA拷贝数会发生变化。     

Inter‐ and intra‐individual differences in serum copper and zinc concentrations after feeding different amounts of copper and zinc over two lactations

The influence of different copper and zinc contents in rations on blood serum concentrations was tested in a feeding trial at the Institute of Animal Nutrition of the Federal Research Institute for Animal Health (FLI). A total of 60 German Holstein breed cows (38 first lactating and 22 second lactating cows) were tested. All animals received a diet based on maize‐ and grass silage ad libitum. The animals were divided into two groups with 30 cows each. Group A received concentrates supplemented with copper and zinc as recommended, whereas Group B was offered a concentrate with roughly double the amount of copper and zinc. Blood samples were taken several times during the lactation. The concentrations of copper and zinc in the serum were measured and correlations between trace element intake and their serum concentrations were calculated. The mean dry matter intake was significantly higher for cows in the second lactation (19.1 kg/day) than for cows in the first lactation (16.4 kg/day), whereas the DM‐intake was constant in the different feeding groups (17.3 and 17.4 kg/day). The correlation between feed intake in the first and the second lactation was r = 0.76. The copper concentration in the serum was not influenced by the different feedings (11.9 and 12.5 μmol/l), but high variations were found between the cows. The influence of the lactation number was not significant (12.1 and 12.4 μmol/l). In contrast to copper, the zinc concentration in the serum was significantly higher for Group B (14.0 μmol/l) than for Group A (12.2 μmol/l), respectively, for second lactating cows (13.8 μmol/l) in relation to 12.7 μmol/l for first lactating cows. The individual variation was also high as for copper. Neither the correlation between copper intake and copper serum concentration nor the correlation between zinc intake and zinc serum concentration was significant.     

微卫星标记BM3413和OB_2在5个绵羊群体中多态性的研究

选萨福克羊、德国美利奴羊、特克塞尔羊、乌珠穆沁羊以及右玉本地绵羊5个绵羊群体共250只,通过耳组织提取基因组DNA,用2对微卫星引物进行PCR扩增,通过电泳分型、凝胶成像系统分析各位点等位基因及全部个体的标记基因型,计算基因频率、多态信息含量(PIC)和杂合度等,从分子水平上分析5个绵羊品种的遗传多态性.结果表明:BM3413和OB2这2个位点的等位基因数分别为7和8,多态信息含量PIC＞0.5,杂合度为0.827 1～0.846 7,均属于高度多态性位点,用于作为与生产性能相关的遗传标记是较理想的.     

气候变化和干扰对河西走廊北部风沙源区NDVI的影响

利用1982-2005年的NASA/GIMMS半月合成植被指数(NDVI)数据,结合气候与家畜数量资料,分析河西走廊北部风沙源区东部民勤、中部酒泉和西部玉门的NDVI、气温、降水和家畜数量年变化及其关系,以探讨河西走廊北部风沙源区植被覆盖变化对气候变化和人类活动的响应.结果表明:民勤和酒泉的NDVI年变化呈增加趋势(P＜0.01和P＜0.05);民勤、酒泉和玉门的气温年变化均呈增加趋势(P＜0.01);降水与降水利用效率(RUE)年变化则相反(P＞0.05).NDVI和气温的年变异系数(CV)小,降水和家畜数量及RUE的CV大.3地的NDVI、气温、降水及家畜数量为民勤＞酒泉＞玉门,RUE为酒     

不同目数的防虫网对柑橘木虱的阻隔作用

本文研究了不同目数的防虫网对柑橘木虱的阻隔作用。结果表明：1.0*0.8mm（约45目）以下的网柑橘木虱成虫可以穿透,1.0*0.6mm（约50目）以上的网能有效的阻止柑橘木虱成虫穿透。     

我国西藏四种植物染色体数目观察

本文对西藏四种植物进行染色体观察，这四种植物的染色体数目均为国内外首次报道。     

Genome-wide Association Study of Teats Number Traits in Kele Pigs

Teats number is one of the most important reproductive traits,and closely related to the economic benefit in pig industry.In order to reveal the underlying genetics of left teats number,right teats number and total teats number traits,a genome-wide association study（GWAS）was performed.Samples of DNA were collected to genotyping for 22 Kele pigs using the Illumina Porcine SNP 60K Chip.The GWAS was performed using a mixed-effects model and linear regression approach.When a genome-wide threshold was determined using the Bonferroni method（P<2.06E-5),4 single nucleotide polymorphism（SNP）markers were potentially associated with left teats number,right teats number and total teat number.However,3 SNPs were significant associated and 18 SNPs were potentially associated in chromosomes level.304 Ensembl genes were retrieved around 1 cM of the associated SNPs.The candidate genes in Wnt and Fgf signaling pathway（BTRC,FGF5,FGF8,BMP3,RASGEF1B and HMGB3）might have effect on target traits.These results provided valuable information about the selective breeding for Kele pigs.