Comparison of birth weight and umbilical and placental characteristics of cloned and artificial insemination-derived piglets

Somatic cell nuclear transfer (SCNT)-derived piglets have significantly higher stillbirth rate and postnatal mortality rate than artificial insemination (AI)-generated piglets. The question whether the low survival rate of SCNT piglets was related to birth weight, umbilical cord or placenta development was investigated. In this study, stillbirth rate, neonatal death rate, birth weight, umbilical cord status, placental parameters and placental gene expression patterns were compared between SCNT and AI piglets. Results showed that mortality rates at birth and during the neonatal stage of SCNT piglets were significantly higher than those of AI piglets. The incidence of abnormal umbilical cord in SCNT and SCNT-liveborn (SCNT-LB) piglets was significantly higher than in AI and AI-liveborn (AI-LB) piglets. Birth weight, placental weight, placental surface area and placental efficiency in SCNT and SCNT-LB piglets were significantly lower than those of AI and AI-LB piglets. Placental expression profiles of imprinting, angiopoiesis and nutrient transport-related genes were defective in SCNT-LB piglets compared with those in AI-LB piglets. Thus, the low survival rate of SCNT piglets may be associated with abnormal umbilical cord and placenta development. These characteristics may have resulted from aberrant expression of angiogenesis, nutrient transport, and imprinting-related genes in the placentas.     

不同种源文冠果1年生苗生长节律及性状相关性研究

为揭示文冠果苗期生长规律,以内蒙古赤峰市乌丹镇、坤都镇和天山镇及河南三门峡市陕县、河北张家口市蔚县的1年生实生苗为材料,观测分析不同种群苗木生长节律及变异。结果表明,种源间及种源内苗高、地径、主根长、根、茎生物量、根茎比均差异极显著,各性状都是陕县最高;苗高及地径生长均呈“慢-快-慢”的“S”型曲线,Logistic方程均达极显著拟合水平。苗高、地径速生期分别是31~47d和24~44d,速生期内日均生长量分别为0.42cm和0.06cm。陕县和蔚县种源速生期持续时间较长,各生长阶段净生长量也是陕县和蔚县较高。在北京开展文冠果造林可以重点考虑陕县和蔚县种源。     

外部条件对水稻镉吸收的影响研究进展

综述了土壤环境、土壤酸碱度和氧化还原电位、水稻根系分泌物、水分管理模式、温度对水稻镉吸收积累的影响,提出可以从农田镉生物修复技术的系统研究、降镉综合栽培技术研究、Cd胁迫对水稻生长发育、生理生化及品质的影响机理等方面开展进一步研究.     

水分管理对水稻镉吸收的影响

以晚稻品种玉针香和湘晚籼12号为供试材料,研究了3种水分灌溉方式(W1,长期淹水灌溉;W2,湿润灌溉;W3,阶段性湿润灌溉)对水稻糙米镉含量的影响。结果表明,在水稻生长的3个关键时期(分蘖期、灌浆期、成熟期),各部位镉含量、富集系数均以W3处理最高,W1处理最低;玉针香糙米镉含量W1处理分别比W2、W3处理低56.52%和66.67%,且W1处理与W3处理间存在显著差异;湘晚籼12号糙米镉含量W1处理分别比W2、W3处理低65.22%和52.94%,但各处理间差异不显著。可见,长期淹水灌溉是一项能够有效降低糙米镉含量的农艺措施。     

~(60)Coγ射线辐照扶芳藤枝条的表型变异研究

用60Coγ射线辐照扶芳藤枝条,扦插苗平均分枝数与辐照剂量呈极显著负相关。随着辐照剂量的增大,倾斜和匍匐生长的植株比例呈增加趋势。80 Gy处理有利于使植株的叶色在冬季仍保持绿色。V1代筛选出株高、平均节长、粗/长、叶形指数、叶面积以及枝条枯梢、分叉、叶序变化等性状的变异体。     

pH和曝气对水生植物去除富营养化水体中氮磷等物质的影响

利用植物浮床系统,通过室内静态模拟试验,研究了pH和曝气对水生植物净化富营养化水体影响。试验结果表明,不同pH处理6 d后,植物系统在pH8.9下对TN,CODMn,BOD5的去除效果最好,TP的去除效果在pH6.7下最好,Chla的去除效果在pH5.0下最好。然而,无植物系统中,TN,TP的去除效果在pH8.9下最好,BOD5的去除效果在pH6.7下最好,CODMn,Chla的去除效果在pH5.0下最好。有无植物系统中,曝气处理6 d后对TN影响很大,但去除率明显小于不曝气处理(P<0.001),除在豆瓣菜系统中,曝气还对CODMn去除产生一定的影响,但对TP和Chla的去除无影响。本试验结果还表明,植物修复系统和无植物系统中,不同pH处理下,水体中NH4-N,NO3-N,NO2-N的去除效果均在pH8.9处理下最好,且在pH8.9 曝气联合作用下水体中NH4-N,NO3-N,NO2-N的去除率也最高。     

Dietary copper supplementation modulates performance and lipid metabolism in meat goat kids

Forty-eight male Lezhi black goat kids with similar body weight ((12.09±1.70) kg) and age ((60±5) d) were used to determine the effect of dietary copper (Cu), in the form of reagent grade Cu sulfate (CuSO₄∙5H₂O), on performance, serum lipid profile, and the relative mRNA abundance of genes involved in lipid metabolism.  Goat kids were stratified by body weight and randomly assigned to one of 4 treatment groups.  Each treatment consisted of 12 replicate pens with each pen containing one goat kid.  Treatment groups received the basal diet with no supplemental Cu (control), basal diet plus 10 mg of Cu kg^–1 of dry matter (DM), basal diet plus 20 mg of Cu kg^–1 of DM, or basal diet plus 30 mg of Cu kg^–1 of DM.  Goats were housed individually in pens and fed a high-concentrate pelleted diet for 60 d.  Average daily gain, average daily feed intake and feed:gain of goats were not affected by dietary Cu supplementation (P>0.10).  No differences were detected in serum total cholesterol, triglyceride, and high density lipoprotein cholesterol concentrations of goat kids fed with different Cu concentrations (P>0.05).  However, serum low density lipoprotein cholesterol concentrations decreased linearly (P=0.01) as the concentration of dietary Cu increased.  Intramuscular fat content of longissimus muscle increased (P=0.002) quadratically and liver Cu concentrations increased (P<0.001) linearly as dietary Cu concentration increased.  Compared with the control, dietary supplementation of 20 mg Cu kg^–1 DM decreased the relative mRNA abundance of fatty acid-binding protein 4 (P=0.01) and lipoprotein lipase (P=0.05), and tended to decrease the relative mRNA abundance of carnitine palmitoyltransferase I (P=0.06) in longissimus muscle of goats.  The relative mRNA abundance of peroxisome proliferator-activated receptor alpha (P<0.001), carnitine acetyltransferase (P=0.001), and carnitine palmitoyltransferase I (P=0.001) were also decreased in liver by Cu supplementation.  These results indicate that dietary supplementation of Cu modified lipid metabolism by increasing muscular fat and decreasing serum low density lipoprotein cholesterol, and the modification might be associated with the reduction of relative mRNA abundance of genes for oxidation of long-chain fatty acid in muscle and liver of Lezhi black goat kids.     

多功能根际生防促生放线菌的分离鉴定及其对辣椒的益生效果

从健康辣椒根际土壤筛选具防病促生功能的菌种并应用于生物障碍土壤,可为辣椒提质增产和根腐病的防治提供优质的菌剂资源。本研究以辣椒根腐病的病原菌——腐皮镰孢菌（Fusarium solani）为靶标菌,采用平板对峙法筛选优良生防菌株,对其固氮、溶磷、解钾、分泌3-吲哚乙酸（3-indole acetic acid,IAA）、产铁载体、产纤维素酶和蛋白酶、利用酚酸类连作障碍物质等能力进行定性和定量测定。采用形态学、生理生化及16S rRNA基因序列对分离菌株进行鉴定,并采用田间原位栽培试验检测其生防和促生效果。结果表明,从设施连作抗病辣椒根际土中获得6株具有抑菌作用的放线菌,通过定性、定量测试发现菌株G-1拮抗效果最强,其对设施蔬菜5种常见病原菌均具有较好的抑制效果,抗菌谱广,且具有分泌IAA、产铁载体、产纤维素酶和蛋白酶、溶解有机磷、利用酚酸类化感物质等特性。结合形态学、生理生化及16S rRNA进化树分析结果,将其鉴定为弗氏链霉菌（Streptomyces fradiae）。田间原位栽培试验显示,G-1菌剂对辣椒根腐病具有较好的防病作用,可显著降低根腐病的病情指数,促进辣椒根系生长,且可使辣椒增产31.04%。研究表明,弗氏链霉菌G-1具有优良的防病促生功能,其固体菌剂的田间应用对辣椒根腐病具有较好的防治效果,且对辣椒具有明显的促生增产作用,可作为辣椒益生菌剂的候选菌株资源。     

大兴安岭南段东南麓低山丘陵牧草种质资源初探

为了充分了解及有效保存内蒙古地区的牧草种质遗传资源,对大兴安岭南段东南麓低山丘陵各类天然草场资源的分布及组成进行了调查研究,根据采集植物标本的鉴定结果统计,该地区共有野生种子植物和蕨类植物774种,属88科329属,饲用植物占植物总数的82.17%.同时调查还发现,该区草地资源存在过度放牧、良种未得到充分保护等问题,并提出了一些针对性的建议,为进一步完善该地区牧草育种和良种繁殖体系及有效地保护和利用牧草种质资源提供参考.