黑龙江省大兴安岭白桦天然林改培技术研究     

李华  王晓彬 《北京农业》2012,(15):167-168

在试验调查的基础上在白桦天然幼、中令林进行抚育时间、抚育方式、抚育强度的试验,提出最佳的抚育时间、抚育方式、经营密度,期望为培育速生大径级白桦材提供技术支撑。  相似文献   

Microsatellite marker isolation and cultured strain identification in <Emphasis Type="Italic">Carassius auratus gibelio</Emphasis>     

Wei Guo  Jian-Fang Gui 《Aquaculture International》2008,16(6):497-510

Microsatellites have become the preferred molecular markers for strain selection and genetic breeding in fish. In this study a total of 105 microsatellites were isolated and identified in gibel carp (Carassius auratus gibelio) by microsatellite sequence searches in GenBank and other databases and by screening and sequencing of positive clones from the genomic library enriched for AG and GATA repeats. Moreover, nineteen microsatellites were randomly selected to design locus-specific primer pairs, and these were successfully used to identify and discriminate different cultured strains of gibel carp including strains A, D, L, and F. Three different types of microsatellite pattern were distinguished by the number and length of fragments amplified from the 19 primer pairs, and some microsatellite primer pairs were found to produce different microsatellite patterns among strains and strain-specific fragments. In addition, some duplicated alleles were also detected in two microsatellite patterns. Therefore, the current study provides direct molecular markers to discriminate among different cultured strains for selective breeding and aquaculture practice of gibel carp.  相似文献   

无线传感器网络技术在养殖业污染监测上的应用   总被引：1，自引：1，他引：0  

李华  李文秀 《渔业现代化》2008,35(2):28-31

综述了国际上无线传感器网络技术发展的特点和趋势,提出无线传感器网络技术在畜禽和水产养殖业污染监测上应用需要解决的2个技术问题:一是选择合理的IP无线传输方式;二是选择合理的系统结构,达到较高的性价比。设计出适合不同地域、不同生态环境的无线传感器网络的拓扑结构,实现在户外或野外环境下对畜禽和水产养殖业污染的监测。  相似文献   

钾素对云烟202干物质积累和光合特性的影响   总被引：4，自引：0，他引：4  

李杨  于吉琳  齐华  刘明 《华北农学报》2010,25(3)

通过对云烟202旺长期干物质积累和光合生理参数的测定,研究了不同供钾水平下烟叶的干物质积累量和不同光照强度下Pn、Cond、Tr和WUE的光响应。结果显示:不同钾肥施用量对旺长期中部叶位烟叶叶绿素、Pn、Cond、Tr和WUE变化规律相似,即K2K3K1K4K0。这与干物质积累的变化规律一致。  相似文献   

凹甲陆龟人工饲养的几个关键技术     

毛杰  余建秋  左智力  杨小仪  唐华 《野生动物》2010,31(6):316-318

介绍了成都动物园凹甲陆龟的人工饲养情况,主要阐述了引种、检疫、人工填食及诱导开食、性别鉴定及编号、常见疾病防治等几个饲养关键技术,对龟类（尤其是陆龟）的人工饲养有一定的借鉴作用。  相似文献   

Effects of Salinity and Soil–Drying on Radiation Use Efficiency,Water Productivity and Yield of Quinoa (Chenopodium quinoa Willd.)     

F. Razzaghi  S. H. Ahmadi  S.‐E. Jacobsen  C. R. Jensen  M. N. Andersen 《Journal of Agronomy and Crop Science》2012,198(3):173-184

Drought and salinity reduce crop productivity especially in arid and semi‐arid regions, and finding a crop which produces yield under these adverse conditions is therefore very important. Quinoa (Chenopodium quinoa Willd.) is such a crop. Hence, a study was conducted in field lysimeters to investigate the effect of salinity and soil–drying on radiation use efficiency, yield and water productivity of quinoa. Quinoa was exposed to five salinity levels (0, 10, 20, 30 and 40 dS m^?1) of irrigation water from flower initiation onwards. During the seed‐filling phase the five salinity levels were divided between two levels of irrigation, either full irrigation (FI; 95 % of field capacity) or non‐irrigated progressive drought (PD). The intercepted photosynthetically active radiation was hardly affected by salinity (8 % decrease at 40 dS m^?1) and did not differ significantly between FI and PD. Radiation use efficiency of dry matter was similar between salinity levels and between FI and PD. In line with this, no negative effect of severe salinity and soil–drying on total dry matter could be detected. Salinity levels between 20 and 40 dS m^?1 significantly reduced the seed yield by ca. 33 % compared with 0 dS m^?1 treatment owing to a 15–30 % reduction in seed number per m², whereas the seed yield of PD was 8 % less than FI. Consequently, nitrogen harvested in seed was decreased by salinity although the total N‐uptake was increased. Both salinity and drought increased the water productivity of dry matter. Increasing salinity from 20 to 40 dS m^?1 did not further decrease the seed number per m² and seed yield, which shows that quinoa (cv. Titicaca) acclimated to saline conditions when exposed to salinity levels between 20 and 40 dS m^?1.  相似文献   

Ontogenetic Development of the Digestive System in Agastric Chinese Sucker,Myxocyprinus asiaticus,Larvae     

Cai‐Xia Liu  Xiao‐Ying Tan  Shi‐Yuan Gong 《Journal of the World Aquaculture Society》2013,44(3):350-362

This study was conducted to determine the ontogenetic development of the digestive tract and its accessory structures (liver, pancreas, and gall bladder) in agastric larval Chinese sucker Myxocyprinus asiaticus with the histological and ultrastructural approaches from hatching to 56 days after hatching (DAH). On the basis of its feeding mode, and analyzing the main histological features of the digestive system, larval development in Chinese sucker was divided into three stages from hatching: stage 1 (endotrophic period): 1–6 DAH; stage 2 (endoexotrophic period): 7–14 DAH; stage 3 (exclusively exotrophic period): from 15 DAH onward. At hatching, the digestive tract of the larvae consisted of an undifferentiated straight tube. At 4 DAH, the mouth opened, and the digestive tract was differentiated into buccopharyngeal cavity, esophagus and intestine. At 7 DAH, fish started to feed exogenously. Yolk sac was completely exhausted at 15 DAH. Until 56 DAH, the digestive tract of the larvae displayed regularly arranged microvilli, abundant vacuoles, and protein inclusion bodies. The pancreas, liver, and gall bladder were functional from 6 DAH, which enabled larvae to ingest, digest, and assimilate the first exogenous food. In comparison with teleosts that have a stomach, the development of the digestive tract of the agastric Chinese sucker seemed relatively slow .  相似文献   

盘江黄牛及其杂交牛育肥中干物质、粗蛋白、综合净能需要研究     

何光中  王华  艾方林  罗启华  艾显琼 《中国牛业科学》1999,(5)

将３６ 头盘江黄牛及其杂交牛分成１２ 组，采用不同的日粮，进行两期育肥试验，得到不同的增重水平和实际营养物质摄入量。用各组实际采食的干物质（ ＤＭ） 、粗蛋白（ＣＰ） 、综合净能（ＮＥｍｆ） 与我国试行的《肉牛饲养标准》进行比较。结果表明，除干物质与标准相差较多（ － ６ ．３ ％ ） 外，粗蛋白和综合净能与标准相当接近（ 仅相差－ １ ．５ ％ 和２ ．８ ％ ） ，说明盘江黄牛及其杂交牛在育肥中的营养需要基本与标准相符，在配制日粮时，可以参考我国的《肉牛饲养标准》。  相似文献   

甘蓝型油菜隐性核不育材料籽粒成熟特性研究     

王华  汤晓华 《贵州农业科学》2000,28(5):7-10

具有相同遗传背景的油菜黄籽与黑籽隐性核不育材料在成熟过程中单位体积干重、籽壳比、千粒重的增长呈现由慢到快再到慢的过程，符合Ｌｏｇｉｓｔｉｃ方程，各材料成熟特性无显著差异。对各成熟参数与知粒重的关系分析表明，籽粒平均增重速率、最大增重速率、Ⅱ期平均增重速率与千粒重呈极显著正相关，Ⅱ期长度与最大增重速率出现时间与千粒重呈显著相关。生产上选择增重速率及最大增重速率较快的中熟或中晚熟品种和材料是获得高产的  相似文献   

开沟覆膜滴灌条件下土壤水、温变化规律研究   总被引：1，自引：0，他引：1  

叶建威  刘洪光  何新林  龚萍  阿尔娜古丽&#;艾买提  陆华天 《节水灌溉》2017,(3)

新疆是中国葡萄重要的生产基地,但每年因盐碱与缺水导致减产现象严重。开沟覆膜滴灌技术结合膜下滴灌与开沟技术优点,理论上可有效改善作物生长的水土环境。为研究桁架葡萄下开沟覆膜滴灌技术对土壤水分与温度变化的影响,在石河子147团6连试验地用EM50仪器开展土壤水分、温度监测试验。研究结果表明:①在开沟模式为20 cm×100 cm,灌水定额为300 m3/hm~2时,无论是膜中还是膜边,灌水前后土壤含水量维持在0.22~0.38,满足作物根系吸水。加大灌水定额,在覆膜影响下,滴灌带表面积水区面积增大,使得在滴头下方形成饱和区增大;随着开沟深度的增大,覆膜中土壤含水量变化不明显,覆膜边呈下降趋势。②温度监测表明,无论是温度上升期(12时),还是夜间下降期(24时),土体温度变化幅度均在15~31℃,给葡萄生长提供良好的温度环境,利于葡萄产量与品质的提高。  相似文献