高寒干旱地区新引桃树良种抗寒耐旱性研究

通过抗寒耐旱生理指标测试分析、露地越冬表现调查、不同栽培措施分析,选择出抗寒耐旱性强、特别是抗寒性强,适宜于张掖川灌区气候条件的桃树品种与品种群,以及抗寒栽培模式与措施,为张掖川灌区及同类地区桃树良种推广栽培提供科学依据。     

赤霉素和温度对贵州特有观赏植物习水报春种子萌发的影响

以习水报春种子为试验材料,采用不同温度梯度和20℃恒温下不同浓度赤霉素处理,研究了各种处理对习水报春种子的发芽率、发芽势和发芽指数的影响,以期找到最适萌发条件。结果表明:15℃处理发芽率(44.45%)最高;20℃处理发芽势(32.22%)最高和发芽指数(4.64)最高;25℃处理各项指标最低,发芽率1.11%,与10、15、20℃处理差异显著(P0.05),发芽势1.11%,与20℃处理差异显著(P0.05),发芽指数0.27,与20℃处理差异显著(P0.05)。最适萌发温度范围为15~20℃。在20℃恒温条件下,200mg·L~(-1) GA3溶液处理发芽率(41.11%)最高;100、200mg·L~(-1) GA3溶液处理发芽势(34.44%)最高,100mg·L~(-1) GA3溶液处理发芽指数最高(5.53)。400、500mg·L~(-1) GA3溶液处理与CK相比发芽率、发芽势差异均显著(P0.05),200、300、400、500mg·L~(-1) GA3溶液处理与CK相比发芽指数差异显著(P0.05),GA3溶液的最适萌发浓度范围为100~200mg·L~(-1)。     

Effects of Dietary Ginger Root,Star Anise and Dan-shen Root on Antioxidant Status and Reproductive Performance of Sows during Late Gestation and Lactation

The experiment was conducted to study the effects of diatary ginger root, star anise and dan-shen root on antioxidant status and reproductive performance of sows during late gestation and lactation.A total of 36 Laiwu Black pregnant sows with average weight of 164.28 kg±1.30 kg and similar parity were randomly divided into 4 treatments with 9 replicates per treatment.The control group was fed a basal diet, and the experimental groups were fed the basal diet supplemented with 10 g/kg ginger root, 5 g/kg star anise and 10 g/kg dan-shen root, respectively(ie Cont., GIN, SA, DS groups).The results showed that the concentrations of glutathione in serum and milk protein in colostrum, activity of total antioxidant capacity in colostrum of GIN, SA and DS groups were significantly higher than that of Cont.group(P<0.05).The concentration of milk fat in colostrum of GIN and DS groups were higher than that of Cont.group(P<0.05).Comparing to Cont.group, the concentration of lactose in colostrum was significantly higher(P<0.05) of SA and DS groups.All groups had similar number of born live, 21 d survival rate, birth weight of born and 21 d weight of born(P>0.05).In conclusion, dietary supplementation of 10 g/kg ginger root, 5 g/kg star anise and 10 g/kg dan-shen root could increase antioxidant status of serum and colostrum of sows, improve the nutritional value of colostrum, but had no effect on reproductive performance.     

Analysis of Ribosome Genotyping and Antimicrobial Resistance in Enterococcus faecalis Isolated from Pigs and Chickens

This study was to investigate the ribosome genotyping and antimicrobial resistance in Enterococcus faecalis strains isolated from 2 large-scale farms in Shanghai.40 isolates were evaluated for their sensitivity to 12 antimicrobial agents by broth microdilution,and the ribosome genotyping (ribotype) was characterized by the Riboprinter^® Microbial Characterization System.The resistance rates of most antimicrobial drug were relatively high and multidrug resistant strains were detected with more than 80%.4 strains of Enterococcus faecalis isolated from pigs were resistant to vancomycin,including 2 strains of vancomycin highly resistant (MIC>64 mg/L) with the same time highly resistant to gentamicin and streptomycin (MIC>2 048 mg/L).The results showed that multidrug resistance of Enterococcus faecalis was a serious issue,and the resistant phenotypes of the same type of ribotype was not entirely consistent.     

Substitution between Virulent and Avirulent PPRSV Vaccine Strains with Reverse Genetics System

The Nsp9 gene of porcine reproductive and respiratory syndrome virus（PRRSV）coded the RNA polymerase,which played an important role in the virus replication.In order to determine the interaction between the Nsp9 gene and virulence,replication capacity and cell tropism,the Nsp9 gene sequence of PPRSV vaccine strain CH-1R was cloned,and ligated to a virulent strain XH-GD infectious clone after restriction enzyme digestion,and transformed the virus under the basis of the reverse genetics.The results showed that the virus was successfully saved.And the results of biological characteristics test showed that titers and growth rate of saved virus were obviously higher than that of parental strain rXH-GD,but were lower than vaccine strain CH-1R.While plaques of two strains were similar in size.The polymerase of vaccine strain CH-1R could help to improve the drop degree of the virus,and this test could lay the foundation for further study of the effect of Nsp9 gene on virus virulence.     

小鼠胚胎胃肠道细菌的分离与初步鉴定

对常规饲养、正常妊娠的小白鼠胚胎后期胃肠道细菌进行分离鉴定,通过细菌培养特性、形态特征和生化试验鉴定,初步确定小鼠胚胎后期胃肠道中存在的微生物菌群有微球菌属（Micrococcus）、葡萄球菌属（Staphylococcus）、变形杆菌属（Proteus）和双岐杆菌属（Bifidobacterium）等细菌,其中G^＋细菌占据了绝对优势,小鼠胚胎胃肠道中细菌的平均数量达到1．2&#215;10^2CFU／g-3．2&#215;10^2CFU／g。本研究为哺乳动物胚胎时期存在于胃肠道中细菌的深入研究奠定了基础。     

乙肝疫苗研究进展

乙肝病毒(HBV)可通过多种途径感染人体,引起肝病的传播,对乙型肝炎预防和治疗的研究具有重大的经济效益和社会效益。目前使用的乙肝疫苗存在诸多问题,作者就乙肝疫苗存在的问题及解决方法进行综述。     

大果杨梅新品种-慈荠.

 -慈荠. 杨梅是从-荸荠. 杨梅中选育出的大果优质新品种。果实风味浓郁。单果质量 14125 g, 果径31 00 cm, 均显著大于-荸荠. 。树势中庸, 以春梢结果为主, 丰产稳产, 适宜中性至微酸性 砂砾土壤种植。