RAPD技术和聚类分析在小麦条锈病菌生理小种研究中的应用   总被引：12，自引：0，他引：12  

朴春根  唐文华 《植物病理学报》1996,26(3):205-210

 试用45个随机引物对我国小麦条锈病菌的6个生理小种(CYR17,SU11,CYR23,CYR28,CYR29和CYR30)进行了RAPD分析,其中10个适宜引物具有鉴别作用,共扩增出89条RAPD图带,多态性为73%。自CYR23、CYR28和CYR29三个生理小种中扩增出了特征性RAPD图带。根据RAPD分析结果,将这一结果与6个小种对不同小麦品种苗期和成株期致病性的聚类分析作了比较。可将供试小种分为两组,第一组包括CYR17、SU11和CYR23,其中前两者的相似性最大;CYR28和CYR29也较相近,属于第二组;新小种CYR30与其它小种的相关性尚待进一步研究。  相似文献   

Effects of chito-oligosaccharide supplementation on the growth performance, nutrient digestibility, intestinal morphology, and fecal shedding of Escherichia coli and Lactobacillus in weaning pigs   总被引：1，自引：0，他引：1  

Liu P  Piao XS  Kim SW  Wang L  Shen YB  Lee HS  Li SY 《Journal of animal science》2008,86(10):2609-2618

A total of 50 weaning pigs (16 d of age; 4.72 +/- 0.23 kg of BW) were selected to investigate the effect of dietary chito-oligosaccharide (COS) supplementation on growth performance, fecal shedding of Escherichia coli and Lactobacillus, apparent digestibility, and small intestinal morphology. Pigs housed in individual metabolic cages were assigned randomly to 5 treatments (n = 10), including 1 basal diet (control), 3 diets with COS supplementation (100, 200, and 400 mg/kg), and 1 diet with chlortetracycline (CTC) supplementation (80 mg/kg). Fresh fecal samples were collected to evaluate shedding of E. coli and Lactobacillus on d 0, 7, 14, and 21 postweaning. Fresh fecal samples collected from each cage from d 19 to 21 were stored frozen for determination of apparent total tract digestibility. On d 21, all pigs were killed to collect the middle sections of the duodenum, jejunum, and ileum for determination of mucosa morphology. Supplementation of COS at 100 and 200 mg/kg and supplementation of CTC improved (P < 0.05) overall ADG, ADFI, and G:F in comparison with the control. Supplementation of COS at 200 mg/kg as well as supplementation of CTC increased (P < 0.05) apparent total tract digestibility of DM, GE, CP, crude fat, Ca, and P, whereas COS at 100 mg/kg increased (P < 0.05) the digestibility of DM, Ca, and P in comparison with the control diet. Pigs receiving diets supplemented with COS or CTC had a decreased (P < 0.05) incidence of diarrhea and decreased diarrhea scores compared with control pigs. Fecal samples from pigs receiving diets supplemented with COS had greater (P < 0.05) Lactobacillus counts than those from control pigs and pigs receiving diets supplemented with CTC on d 14 and 21. However, supplementation of COS at 200 mg/kg and supplementation of CTC decreased (P < 0.05) E. coli counts in the feces on d 21 compared with the control diet. Dietary supplementation of COS at 200 mg/kg and of CTC increased (P < 0.05) the villus height and villus:crypt ratio at the ileum and jejunum, and COS at 100 mg/kg also increased (P < 0.05) the villus height in the ileum compared with the control diet. The current results indicated that dietary supplementation of COS at 100 and 200 mg/kg enhanced growth performance by increasing apparent digestibility, decreasing the incidence of diarrhea, and improving small intestinal morphology.  相似文献   

平阳霉素诱变研究的进展   总被引：3，自引：0，他引：3  

朴铁夫  孙云农  齐晶  杨忠群  许耀奎 《核农学报》1999,13(5):316-320

本文报道了平阳霉素对植物、动物、微生物的诱变研究的综述。研究资料表明平阳霉素是一种对动物及微生物有较强的诱变作用的新诱变剂。  相似文献   

饲粮精氨酸添加物影响断奶初期仔猪小肠微脉管发育     

Zhan Z F Ou D Y Piao X S Kim S W Liu Y H Wang J J 《饲料博览》2008,(9):39-39

试验旨在评价饲粮精氨酸水平时断奶初期仔猪小肠微脉管发育的影响。选择24头初始体重为（5．0±0．3）kg的杂交仔猪,单独饲养,并随机分配到3个饲粮组中,每个饲粮组8头。试验饲粮L-精氨酸含量分别为0、0．7％和1．2％。仔猪自由采食,试验期10d。在试验第3、6和10d采集血样。在第10d,每组随机选择6头并屠宰采集组织样。与对照猪相比,饲粮添加L-精氨酸O．7％显著增加试验第6、10d亚硝酸盐和硝酸盐（一氧化氮的稳定氧化产物）的空肠浓度,肠绒毛高度,血浆脯氨酸和精氨酸浓度（P〈0．05）。与对照组和添加L-精氨酸1．2％组相比,饲粮添加L-精氨酸0．7％显著增加十二指肠黏膜下层、回肠黏膜及黏膜下层中CD34免疫活性表达,十二指肠黏膜下层、空肠黏膜及黏膜下层和回肠黏膜中脉管内皮生长因子（VEGF）表达（P〈0．05）。与对照组相比．饲粮添加L-精氨酸1．2％显著增加空肠内皮素-1浓度（P〈0．05）。在试验第6、10d,与对照组相比,添加L-精氨酸1．2％使十二指肠黏膜中VEGF免疫表达和血浆赖氨酸浓度显著降低（P〈0．05）。总之,结果显示L-精氨酸在更低水平时对微脉管发育有有益作用,但是在更多摄入时有不利作用。饲粮添加L-精氨酸0．7％是改善断奶初期仔猪小肠微脉管发育的一个有效方法。  相似文献   

薇甘菊与三裂叶蟛蜞菊粗提液对莴苣指管蚜的影响     

许华  杨飘  余松夏  程碧军 《湖北农业科学》2015,(10)

以薇甘菊(Mikania micrantha)与三裂叶蟛蜞菊(Wedelia trilobata)粗提液为试验材料,通过培养皿培养法,研究了薇甘菊粗提液对莴苣指管蚜成虫、幼虫死亡率和成虫繁殖率的影响,以及三裂叶蟛蜞菊粗提液对莴苣指管蚜幼虫死亡率与蜕皮率的影响。结果表明,薇甘菊粗提液对莴苣指管蚜成虫和幼虫具有毒杀作用,对成虫的繁殖有抑制作用,当薇甘菊粗提液浓度为5%时效果最好,成虫和幼虫的死亡率最高,成虫的繁殖率最低;三裂叶蟛蜞菊粗提液对莴苣指管蚜幼虫同样具有明显的毒杀作用,浓度为7.5%时毒杀效果最明显,并能提高莴苣指管蚜的蜕皮率,但不显著。  相似文献   

三裂叶蟛蜞菊对土壤养分及微生物的影响     

许华  黄嘉仪  朱敏杰  杨飘  余松夏  李志鹏  陈超 《湖北农业科学》2015,54(6)

比较三裂叶蟛蜞菊(Wedelia trilobata)群落内土壤与群落外土壤的全氮、全磷、p H及自生固氮菌、硝化细菌和反硝化细菌情况。结果表明,相对于群落外土壤,群落内土壤全氮、全磷、自生固氮菌和硝化细菌数量显著降低,但土壤p H和反硝化细菌数量显著升高;土壤全氮、全磷均与土壤自生固氮菌、硝化细菌数量呈显著正相关,与土壤反硝化细菌数量和p H呈显著负相关;土壤p H与土壤自生固氮菌、硝化细菌数量呈显著负相关,与土壤反硝化细菌数量呈显著正相关。三裂叶蟛蜞菊入侵引起土壤功能微生物群落和土壤p H发生变化,直接或间接地降低了土壤全氮和全磷,使土壤质量下降。  相似文献   

养鱼池底泥耗氧速率的研究     

雷衍之  朴文豪  白禄君  张丽霞 《大连水产学院学报》1991,(Z1)

本文用新的底泥耗氧速率的测定方法,探讨了此方法的精密度和水温及底泥中有机质对鱼池底泥耗氧速率的影响。用此方法研究鱼池底泥耗氧速率.发现在培育期内北力养鱼池底泥耗氧速率一般为0.4～1.6gO_2·m~(-2)·d~(-1),鱼池底泥耗氧速率占鱼池总耗氧的比率在5％～20％之间,还对新老池底泥耗氧速率进行了比较。  相似文献   

《神农本草经》一词多义浅析 ——胡随瑜教授《神农本草经》讲记（三）     

邱新建  罗杰坤  唐涛  王哲  张春虎  崔曼  江菊  赵琳琳  郑飘 《勤云标准版测试》2015,35(10):13-14

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ESTIMATION OF ABUNDANCE AND DISTRIBUTION OF MOOSE POPULATION IN CHINA     

Piao Renzhu Cai Dongxui Jin Shibao Wildlife Institute of Heilongiiang Province 《林业研究》1993,4(1):82-90

The geographical distribution and the abundance of Moose(Alces alces)popula-tion were studied in Northeastern China between 1985 and 1987,309 trails on the snow crossingthe 2,446km sampling lines were counted.The Moose range had been shrunked to northwest for100-200 km since 1976,and at present they covered an area about 190,000 km~2.The densitiesvaried from 0.0187 Mooses/km~2 to 0.1226 Mooses/km~2 and the average was 0.0519Mooses/km~2.The Moose population size was 9,955±397 Mooses(α=0.2,P=84.5%),about7000 of them was distributed in Daxinganling Mountains and the others were in XiaoxinganlingMountains.The present population had decreased to 53.4%in 1976,and the annual decreaserate was 6.27%.At present,Moose population is likely rare in China and should be strictly pro-tected.  相似文献   

Soil-released carbon dioxide from microbial biomass carbon in the cultivated soils of karst areas of southwest China   总被引：1，自引：0，他引：1  

H. C. Piao  Y. Y. Wu  Y. T. Hong  Z. Y. Yuan 《Biology and Fertility of Soils》2000,31(5):422-426

 Soil microbial biomass and the emission of CO₂ from the soil surface were measured in yellow soils (Ultisols) of the karst areas of southwest China. The soils are relatively weathered, leached and impoverished, and have a low input of plant residues. The measurements were made for a 1-year period and show a reciprocal relationship between microbial biomass and surface CO₂ efflux. The highest (42.6±2.8 mg CO₂-C m^–2 h^–1) and lowest (15.6±0.6 mg CO₂-C m^–2 h^–1) CO₂ effluxes are found in the summer and winter, respectively. The cumulative CO₂ efflux is 0.24 kg CO₂-C m^–2 year^–1. There is also a marked seasonal variation in the amount of soil microbial biomass carbon, but with the highest (644±71 μg C g^–1 soil) and lowest (270±24 μg C g^–1 soil) values occurring in the winter and summer, respectively. The cumulative loss of soil microbial biomass carbon in the top 10 cm of the soil was 608 μg C g^–1 year^–1 soil over 17 sampling times. The mean residence time of microbial biomass is estimated at 105 days, suggesting that the carbon in soil microbial biomass may act as a source of the CO₂ released from soils. Received: 13 July 1999  相似文献