五营林业局杨树河林场林种结构调整     

孙惠杰  宋国华  贾树庭  郭修生  董艳君 《林业勘查设计》2006,(2):53-55

在建立ArcViewGIS平台的杨树河林场地理信息系统的基础上,通过建立杨树河林场二维坡向图和坡度图、三维地面模型、二维河流、公路、城镇和林型分布专题图,用缓冲分析方法进行护岸林,护路林,环境保护林,水源涵养林等公益林的规划;商品林和一般用材林用蓄积等值图规划,在空间尺度上进行合理的划分林种,对杨树河林杨植物群落生长的立地条件进行研究。最后经过调整林种结构和林龄结构,以达到提高森林可持续经营能力的目的。  相似文献   

吉林市城市林业发展及水资源保护     

王选丽  初艳 《吉林林业科技》2004,33(5):36-39

根据吉林市自然、社会和经济条件，结合城市景观布局，对吉林市的城市林业生态网络体系建设和水资源保护提出了建设性的建议。  相似文献   

巴山松优良单株选择和等级划分     

张晓明  李军  胡盛华  楚金强  袁强 《陕西林业科技》2007,(1):11-13

采用3株大树法,在优良林分中选择优良单株67株,以材积为主,附加形率、树冠因素,分级评分,按总分值将优树划分为五个等级。  相似文献   

轴流式风力灭火机的研究初探     

褚双磊  俞国胜 《林业机械与木工设备》2007,35(4):24-26

阐述了国内外便携式风力灭火机的发展现状,同时从灭火性能方面对轴流风机与离心风机的优缺点进行了比较,探讨了研制轴流式风力灭火机存在的问题.  相似文献   

Phylogenetic analysis of Newcastle disease viruses isolated from wild birds in the Poyang Lake region of China     

Shengtao FAN  Tiecheng WANG  Xiaolong GAO  Ying YING  Xue LI  Yongcheng LI  Yuanguo LI  Jinzhu MA  Heting SUN  Dong CHU  Yu XU  Songtao YANG  Qihan LI  Yuwei GAO  Xianzhu XIA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1143-1149

Newcastle disease virus (NDV) causes a highly contagious viral disease in poultry and wild birds, and it can cause significant economic loss worldwide. Eight viral strains were isolated by inoculating embryonated chicken eggs from the Poyang Lake region of China with swab samples. All eight of the NDV isolates were identified as class I genotype 3 strains, but they diverged notablely from class II viruses. Further analysis revealed that all eight NDV isolates were lentogenic strains containing the ¹¹²ERQER↓L¹¹⁷ motif at the F protein cleavage site. The strains were highly identical and were more species specific (chicken and waterfowl) than site specific (Nanchang and Duchang regions). The close phylogenetic proximity of these isolates indicates that viral transmission may happen between poultry and wild birds. Our study demonstrates that lentogenic class I NDVs exist in clinically healthy wild waterfowl and poultry within the Poyang Lake region. Active surveillance of these viruses to determine their evolution and origin is one of the most realistic strategies for preventing and controlling NDV outbreaks.  相似文献   

绵羊多羔主效基因BMPR1B的研究进展   总被引：1，自引：0，他引：1  

潘章源  狄冉  刘秋月  储明星 《家畜生态学报》2015,36(5):1-6

骨形态发生蛋白受体1B(Bone morphogenetic protein receptor 1B,BMPR1B)是一种重要的跨膜受体蛋白,主要参与转化生长因子β(TGF-β)通路,其在调控成骨分化、细胞扩散以及卵巢卵泡发育等过程中起重要作用,并直接影响如绵羊等动物的繁殖性状。绵羊BMPR1B基因发生A746G突变(命名为FecB突变),导致第249位氨基酸由谷氨酰胺(Q)转变为精氨酸(R),进而使得绵羊排卵数和产羔数显著增加,因此BMPR1B成为目前最受关注的绵羊多羔主效基因。论文就绵羊BMPR1B基因定位、功能机制研究进展及其对高繁殖力绵羊的影响进行了综述,同时也对BMPR1B功能研究中一些亟待解决的问题展开了讨论。  相似文献   

加工番茄系统抗性诱导促生菌的筛选鉴定及其促生防病效果     

林青  史应武  王娜  华兰兰  杨红梅  楚敏  曾军  高雁  霍向东 《新疆农业科学》2022,59(6):1466-1474

【目的】 筛选具有诱导番茄系统抗性的促生菌并验证其对加工番茄早疫病、灰霉病的防效,为新疆加工番茄病害的生物防治提供理论依据和菌种资源。【方法】 采用稀释涂布法,分离番茄等作物的根部土壤细菌,以无菌生理盐水和稀释至10⁴倍数未接菌的NB培养基为空白对照,利用发芽实验初筛加工番茄促生菌;用菌株发酵液灌根处理加工番茄幼苗,以清水处理为空白对照,测量叶片中茉莉酸含量,复筛系统抗性诱导菌株,分别挑战接种番茄早疫病、灰霉病病原菌,统计疫情指数和诱抗效果。测定菌株16S rDNA序列,初步进行菌种鉴定。【结果】 共分离到147株细菌,筛选得到19株显著(P<0.05)促进加工番茄种子萌发、增加根长的促生菌,有4株促生菌显著(P<0.05)提高加工番茄叶片中茉莉酸含量,防病验证最终得到3株能同时有效防治加工番茄早疫病、灰霉病的菌株,诱抗防效在27.59%~39.44%。菌株FY10、FY12、FY93鉴定为Bacillus atrophaeus,Pseudomonas wadenswilerensis和Bacillus pumilus。【结论】 获得3株具有系统抗性诱导功能且有效防治加工番茄早疫病、灰霉病的促生菌。  相似文献   

ZTC1+1澄清剂在清咽复方水提液澄清工艺中的应用     

楚婷花  田密  麻开香  李英 《安徽农业科学》2021,49(18):172-176

[目的]研究清咽复方水提液的澄清工艺.[方法]先通过单因素试验研究澄清剂用量、药液浓度(生药量:药液量)、絮凝温度分别对出膏率、绿原酸和总皂苷含量的影响,再通过正交试验优化最佳工艺条件.[结果]澄清剂用量对综合指标的影响最大,药液浓度次之.最佳澄清工艺:在药液浓度(生药量:药液量)为1:6(g:mL)时,加入8％B组分和4％A组分,水浴温度80℃.在此工艺条件下,出膏率为19.13％,绿原酸含量为592.81 mg/g,总皂苷含量为473.15 mg/g.[结论]ZTC1+1天然澄清剂对清咽复方水提液的澄清效果良好,且工艺稳定可行.  相似文献   

Dynamics of maize grain drying in the high latitude region of Northeast China          下载免费PDF全文

CHU Zhen-dong  MING Bo LI Lu-lu  XUE Jun  ZHANG Wan-xu  HOU Liang-yu  XIE Rui-zhi  HOU Peng  WANG Ke-ru  LI Shao-kun 《农业科学学报》2022,21(2):365-374

A high grain moisture content at harvest has been an important problem in the high latitude region of Northeast China, and it is closely related to the genotypes of varieties, local meteorological factors and planting management. However, delayed harvest at a low temperature could not effectively reduce the grain moisture content. In this study, we continuously observed the grain drying during the late stage of different maturing types of maize varieties in Daqing, Heilongjiang Province, China in 2016 and 2017. A two-segment linear model was used to analyze the different stages of the drying processes: 1) Two-segment linear model fitting can divide the grain drying process of all varieties into two separate linear drying processes with different slopes. 2) During the rapid drying stage, the drying was faster at a higher temperature. The rate of slow drying was influenced by air vapor pressure. 3) The moisture content and meteorological factors when the drying rate turns from one stage into the other were not consistent between varieties and years. After entering the frost period, temperatures below 0°C will significantly reduce the rate of grain drying. 4) Due to the short growth period of early-maturing varieties, the drying time was prolonged, and the grain moisture content was lower than that of the mid-late maturing varieties. Local meteorological conditions do not allow the drying of mid-late maturing varieties to achieve a lower moisture content. When the temperature falls below 0°C, the drying rate of grain decreases markedly. Therefore, one feasible way to solve the problem of high moisture content is to replace the early-maturing varieties and implement the corresponding cultivation techniques.  相似文献   

八仙花萼片有色原生质体游离及应用     

张盖天  祁惠  杨锁宁  褚志云  袁素霞  刘春 《中国农业科技导报》2022,24(9):50-57

为建立八仙花（Hydrangea macrophylla）有色原生质体游离体系,以八仙花萼片为试验材料,分别对材料的预处理方式、酶液组分、酶解时间、纯化离心力等影响酶解的关键因素进行研究。结果表明, 预处理方式选择分离花萼片上下表皮法,纤维素酶和离析酶水平分别为4%和0.4%（质量体积分数）,甘露醇0.6 mol·L^-1,酶解液加热冷却后加入 0.1%（质量体积分数）BSA和10 mmol·L^-1 CaCl₂,酶解2 h,低温离心机4 ℃、1 426 r·min^-1离心5 min,为最优的八仙花萼片原生质体游离条件。利用所建的原生质体游离体系对4个不同品种的八仙花萼片进行有色原生质体游离,200× 镜下单视野内可获得13~35个有色的原生质体;对有色原生质体进行液泡的H⁺流测定,发现蓝色液泡较粉色液泡H⁺流的外排趋势明显,说明同一八仙花品种蓝色液泡的pH高于粉色液泡。  相似文献