干旱地区提高刺槐造林质量的技术方法

中阳县地处干旱的黄土丘陵沟壑区，造林成活率低，成林难。该文在总结多年造林实践的基础上，从旱地育苗，提前整地，截干栽植，造林密度等方面，提出了提高刺槐造林质量的技术方法。     

Detection of genomic DNA of the crayfish plague fungus Aphanomyces astaci (Oomycete) in clinical samples by PCR

A diagnostic procedure, based on a polymerase chain reaction method (PCR) was developed to detect infection of crayfish with the Oomycete Aphanomyces astaci. A set of oligonucleotide primers was designed to specifically amplify A. astaci DNA in the ITS region surrounding the 5.8S rDNA gene. The PCR amplifies a 115 bp amplicon. The specificity of the primers was demonstrated by testing on 27 A. astaci strains and against 20 non-A. astaci Oomycetes and 5 fungal species. Most of the non-A. astaci Oomycete or fungal species included in the study are either known parasites of freshwater crayfish cuticle or can be found in their natural environment. Specificity was also tested against crayfish tissue and some known parasites and bacteria infecting crayfish.

A protocol for the extraction of A. astaci DNA from infected crayfish tissue was developed. The optimised method allows the detection of two genome equivalents of purified A. astaci genomic DNA.

The method was tested on noble crayfish (Astacus astacus), artificially infected with A. astaci. Detection of A. astaci was possible at the very first time of sampling, which was 2 days after the beginning of spore exposure.     

我国饲料型四倍体刺槐研究进展

四倍体刺槐Robinia pseudoacacia自1997年引入我国以来,国内学者对其主要进行了如下几个方面的研究:1)不同地域不同立地条件下的适应性、生物量及叶片营养含量,肯定了饲料型四倍体刺槐的引种价值。2)常规和微繁育苗技术:常规育苗技术中的插根和嫁接繁殖技术已经成熟,达到了规模化生产的要求;微繁技术已找到了愈伤组织诱导及其分化为苗的培养基组合和培养条件以及组培苗的适宜移栽方式。3)抗盐基因遗传转化:已成功地将甜菜碱醛脱氢酶基因(BADH)转入四倍体刺槐,得到了15个抗盐植株,抗盐植株对NaCl的相对抗性提高了2‰~3‰。从引种、造林、微体快繁技术和遗传转化4个方面综述了这些研究成果,并探讨了存在的问题及可能的解决方法。     

鸡新城疫的诊断与防治措施

鸡新城疫(newcastle disease,ND)是由新城疫病毒(newcastle disease virus,NDV)引起的一种急性、热性、败血性和高度接触性传染病,具有很高的发病率和病死率,是危害养禽业的一种主要传染病。本文将就ND的诊断和防治措施做一详细的综述。     

Two-compartment models for describing temporal variation in the effective leaf area index of Robinia pseudoacacia stands on the Loess Plateau

Leaf area index (LAI) is a key parameter in many ecological models and its phenology significantly affects on net ecosystem production in deciduous forests. We examined trends in LAIe (effective leaf area index) using two-compartment models to test effects of stand age and slope aspect on seasonal rates of LAIe increase (k₁) and decrease (k₂). LAIe measurements were acquired from 24 sample plots over five months and used to develop robust predictive models for modeling LAIe dynamics. Generally, the stands’ k₁ values were substantially greater than their k₂ values. The LAIe increased rapidly between leaf emergence and saturation, and then lower slowly from leaf saturation to senescence. The strongest increase in LAIe was observed in 11- to 15-year-old stands on shady slopes (k₁ = 4.76) and in young stands (<10 years) on sunny slopes (k₁ = 3.94), but k₂ values were largest in mature stands. The trees on shady slopes generally had higher k₁ and lower k₂ values than those on sunny slopes, except in the youngest stand. The results showed that two-compartment models can robustly describe leaf growth and loss rates in black locust stands, and that both stand age and aspect both strongly affect the rate and magnitude of changes in LAIe during the growing season. Hence, the two-compartment model is recommended as an effective method when monitoring the LAIe quantitative dynamics of broad-leaved forest.     

鸭瘟活疫苗外源病毒检验方法（鸡检查法）的修订

对二〇〇五年版《中华人民共和国兽药典》中鸭瘟活疫苗外源病毒检验的鸡检查法进行了修订,确定选用9-12周龄SPF鸡,在原药典规定方法的基础上增加低剂量基础免疫程序,并用该外源病毒检验方法对5批鸭瘟活疫苗进行了验证,结果表明修订后的鸭瘟活疫苗外源病毒检验方法可靠,可操作性强。     

Effects of afforestation on microbial biomass C and respiration in eroded soils of Turkey

ABSTRACT

Soil erosion is a major socioeconomic and environmental problem in Turkey. Almost 86% of the land in Turkey has suffered various degrees of soil erosion. The objective of this study was to determine whether differences in tree species affect soil characteristics and microbial activity in degraded soils. Results from this study showed that organic C (C_org) was highest in the black locust soil at 0–20 cm depth and lowest in the bare land. Microbial biomass C (C_mic) increased in the order black locust > Scotch pine > bare land at two soil depths. One-way ANOVA demonstrated that afforested soils contain significantly higher microbial biomass C than those in the bare land soils. Microbial quotient (C_mic/C_org) of soils are positively influenced by afforestation as the bare land soils exhibited lower microbial quotient than the associated Scotch pine and black locust soils. Microbial communities in black locust soils were energetically more efficient—had a lower metabolic quotient (qCO₂)—with a higher C_mic/C_org compared to those in Scotch pine soils. However, the microbial quotient in our study was still below range and cannot reach equilibrium again 15 yr after afforestation. Restoration of degraded lands could be a long-term process from microbial activity in the observed regions.     

采用Real-time PCR技术评价三种药物体外抗鸭瘟病毒效果

本研究采用real-time PCR技术,对阿昔洛韦、利巴韦林及禽重组干扰素等三种药物体外抗鸭瘟病毒的作用进行了评价。结果显示,该方法具有客观、快速、敏感、高通量等特点;阿昔洛韦能有效抑制鸭瘟病毒在鸭胚成纤维细胞中的增殖。研究结果为抗鸭瘟病毒药物筛选提供了一种有效的技术平台,同时说明阿昔洛韦制剂有可能作为一种有效的抗鸭瘟病毒药物用于其感染的防治。     

匈牙利刺槐改良与经营(英文)

刺槐是 17世纪初由北美引入欧洲的第一批林木树种 .刺槐之所以在世界快速传播 ,归功于其对环境条件的广泛适应能力 ,易于培育的特性 ,结实频繁、结种量大 ,萌蘖力强 ,种苗保存率高而且速生高产 ,同时又是优良的蜜源植物 .事实上 ,很少有什么病虫对其造成伤害 .刺槐是匈牙利现有林分中最重要的成林树种之一 ,它覆盖 2 0 %的林地 .匈牙利的刺槐的木材产量占全国产量的 18% .鉴于许多国家对培育刺槐的兴趣越来越浓 ,在此将匈牙利的经验和研究结果整理成文 ,期望在刺槐课题方面有所裨益     

纸坊沟流域人工刺槐林生长状况与土壤水分条件研究

本文对安塞纸坊沟小流域不同土地类型刺槐林生长状况进行了分析、并且分析了林地水分生态环境对刺槐生长的影响。分析结果认为,该流域水土流失严重,刺槐应营造水土保持林为主,但在水分条件较好的沟谷地和沟坡地可营造部分用材林,以解决当地木林短缺的矛盾;同时,应加强林地的管理,提高土壤水分的利用率。