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991.
厚朴林下轮作玄参、大黄种植技术研究 总被引:1,自引:1,他引:0
为更好地指导厚朴规范化种植,充分利用土地资源,大力发展林下经济,增加农民收入。2002年,在龙坪乡开展了厚朴林下轮作玄参、大黄种植模式和厚朴单作种植模式对比试验研究。试验结果表明:在厚朴林下轮作玄参、大黄种植模式下,厚朴各测树因子及皮产量较对照具有明显地增长和增产作用,同时每个轮作期内比对照增产大黄药材520 kg/666.7 m2、玄参药材320 kg/666.7 m2。 相似文献
992.
利用Arcgis地理信息系统平台,运用空间分析技术手段,以湖北襄阳鹿门寺景区地形图和卫星影像等数据为基础,选择不同观测点进行视域分析,设定了景区林火视频监控摄像头的位置,为森林防火管理辅助决策提供了依据。 相似文献
993.
A total 61 clone parents and 320 open-pollination progenies from 8 clone individuals were identified by 12 polymorphic SSR loci.The result showed that the level of genetic diversity in progeny population was the same as in maternal population, progeny population had all alleles detected in maternal population,and there were not obvious surplus phenomenon of homozygotes in progeny population (F= 0.046).The south crown had more strobili than the north crown,however the genetic diversity of the north crown strobili was not substantially reduced.The progeny of neutral trees had the same level of genetic diversity as in the progeny of partial female trees,with the fixation index tended to be zero,which was accorded with Hardy-Weinberg equilibrium.The multilocus outcrossing rate in the seed orchard was 1.097,and there was no significant inbreeding between parents(t_m-t_s= - 0.031).The multilocus outcrossing rate and singlelocus outcrossing rate in the south crown were higher than that in the north crown.The multilocus outcrossing rate of partial female trees was the same as in neutral trees,and the neutral tree had no obvious declining outcrossing rate with reduced proportion of female and male strobilus compared with partial female tree, with the fixation index tended to be zero.The progeny of the second generation clonal seed orchard still had rich genetic diversity,gene exchange among clones was relatively sufficient,and biparental inbreeding was not significant. 相似文献
994.
995.
996.
Molecular characterization of low pathogenic avian influenza viruses, isolated from food products imported into Singapore 总被引:1,自引:0,他引:1
Dawn Su-Yin Yeo Sock-Hoon Ng Chin-Wen Liaw Ley-Moy Ng Eugene Jing-Hui Wee Elizabeth Ai-Sim Lim Shirely Lay-Kheng Seah Wai-Kwan Wong Chee-Wee Lim Richard J. Sugrue Boon-Huan Tan 《Veterinary microbiology》2009,138(3-4):304-317
We have completed the genetic characterization of all eight gene segments for four low pathogenic avian influenza (LPAI) viruses. The objective of this study was to detect the presence of novel signatures that may serve as early warning indicators of the conversion of LPAI viruses to high pathogenic avian influenza (HPAI) viruses. This study included three H5N2 and one H5N3 viruses that were isolated from live poultry imported into Singapore as part of the national avian influenza virus (AIV) surveillance program. Based on the molecular criterion of the World Organisation for Animal Health (OIE), sequence analysis with the translated amino acid (aa) sequence of the hemagglutinin (HA) gene revealed the absence of multibasic aa at the HA cleavage site, identifying all four virus isolates as LPAI. Detailed phylogenetic tree analyses using the HA and neuraminidase (NA) genes clustered these isolates in the Eurasian H5 lineage, but away from the HPAI H5 subtypes. This analysis further revealed that the internal genes clustered to different avian and swine subtypes, suggesting that the four isolates may possibly share their ancestry with these different influenza subtypes. Our results suggest that the four LPAI isolates in this study contained mainly avian signatures, and the phylogenetic tree for the internal genes further suggests the potential for reassortment with other different circulating avian subtypes. This is the first comprehensive report on the genetic characterization of LPAI H5N2/3 viruses isolated in South-East Asia. 相似文献
997.
C-L Xu J-B Zhou B-T Zhao G-C Lan M-J Luo Z-L Chang H-S Sui J-H Tan 《Reproduction in domestic animals》2009,44(5):771-778
The suitability of certain commercial and self‐made chemically defined extenders for liquid storage of goat semen was tested and the effects of storage temperatures, dilution rates and sperm washing and pH of extenders on the goat sperm during liquid storage were observed. Semen was collected from nine goat bucks of the Lubei White and Boer breeds using an artificial vagina. Each ejaculate after initial evaluation was diluted with a specific extender, cooled and stored at a desired temperature. Stored semen was evaluated for sperm motility and other parameters every 24 or 48 h of storage. The ranking order of the existing milk‐ and yolk‐free extenders in sustaining goat sperm motility was Androhep > Zorlesco > Beltsville thawing solution > the Tris–glucose medium. The new extender (mZA) which was formulated based on Zorlesco and Androhep was more suitable for goat sperm than Androhep. The mZAP extender with Bovine Serum Albumin (BSA) replaced with polyvinyl alcohol (PVA) worked as efficiently as the mZA in maintaining sperm motility, membrane integrity, acrosome intactness and capacitation status. Goat sperm motility was best maintained at 5°C during liquid preservation, but decreased significantly as the temperature increased. When semen was sixfold diluted, sperm motility was maintained longer (p < 0.05) after centrifugation, but sperm motility did not differ between the centrifuged and non‐centrifuged groups when semen was 11‐fold diluted. When the extender pH was adjusted from 6.6 to 6.04, the efficiency increased significantly in both Androhep and mZAP. A forward sperm motility of 34% was maintained for 9 days when buck semen was 11‐fold diluted and stored at 5°C in mZAP, with pH adjusted to 6.04. It is concluded that for liquid storage of buck semen, the mZA extender was more suitable than other extenders; BSA can be replaced with PVA in mZA; centrifugation to remove seminal plasma can be omitted by adequate dilution; and the storage temperature and pH of extenders affected sperm motility significantly. 相似文献
998.
999.
大蒜素对断奶仔猪血清生化指标及生长相关激素的影响 总被引:2,自引:0,他引:2
为了研究大蒜素(allicin)对断奶仔猪血清生化指标和生长相关激素的影响,试验选择21日龄体重5.6kg左右的断奶仔猪(杜×长×大)24头,随机分为3个处理,每个处理4个重复,每个重复2头,处理1饲喂基础日粮(对照组),处理2饲喂基础日粮+0.01%大蒜素(试验组),处理3饲喂基础日粮+0.07%抗生素(抗生素组),试验期21d,测定了仔猪血清生化指标、生长相关激素的变化。结果表明:大蒜素能改善断奶仔猪血清生化指标和生长相关激素水平。大蒜素组血清LDL(低密度脂蛋白)、CHO(总胆固醇)和GLU(葡萄糖)含量在断奶后第7d比对照组高23.9%、38.1%(P<0.05)、11.4%;第14d高14.7%(P<0.05)、15.6%、12.0%。断奶后SUN(血清尿素氮)含量升高,大蒜素组和抗生素组低于对照组;各处理血清ALP(碱性磷酸酶)活性有升高的趋势。大蒜素组FT3、IGF-1含量及FT3/FT4显著高于对照组(P<0.05)。整个试验期大蒜素组与抗生素组各项指标差异不显著。 相似文献
1000.
Haojie Cui Fan Liu Xionghan Feng Wenfeng Tan Ming Kuang Wang 《Journal of Soils and Sediments》2010,10(8):1540-1547