浅谈加强森林病虫害防治及对策

我国自然条件复杂,林木种类丰盛,危害林木的病虫害种类也多种。虽然病虫害防治取得了一定的成绩,但是仍然存在较多的问题与不足。防止森林病虫害是指对森林、林木、林木种苗及木材、竹材的病害和虫害的预防和除治。本文主要从林业病虫害预防和除治工作的必要性,林业病虫害防治现状,森林病虫害防治方法等方面叙述了如何进行加强林业病虫害防治。     

陆地棉纤维品质基因效应研究

对不同世代的纤维品质性状进行基因效应分析,不同遗传背景下加性效应是最基本的,但显性效应和上位效应也存在。纤维长度、比强度多受加性效应控制。纤维细度主要受加显性基因效应支配。     

论森林病虫防治检疫行政处罚自由裁量权细化及程序控制

森林病虫防治检疫机构作为国家行政机关,拥有一定的行政处罚权,在检疫行政处罚中自由裁量权的存在有其必要性。文章通过阐述森林病虫防治检疫行政处罚的重要性及自由裁量权细化的意义,解释森林病虫防治检疫行政处罚自由裁量权的含义,阐明森林病虫防治检疫行政处罚自由裁量权细化的项目及其法律依据,最后提出了森林病虫防治检疫行政处罚自由裁量权的程序控制制度,为森林病虫防治检疫工作人员提供一定的理论参考。     

检疫犬行为评测背景及应用研究

随着研究检疫犬训练及使用的深入,行为评测的重要性也愈发凸显出来。行为评测定义为在设定试验环境下,由刺激引发的行为以及在相同状态下其它个体所表现的行为做比较统计,对被测试对象加以分类;其用途主要是评定幼犬和受训犬以及训成犬的行为;主要包括定性与定量两种方法;行为评测时需要注意被测犬信息以及评测可靠性等问题;文章对检疫犬行为评测的背景及应用进行了全面的研究,同时对行为评测标准化的建立进行了展望。     

做好森林病虫害防治检疫体系建设工作的几项措施

作者结合黑龙江省森林工业总局森林病虫害防治检疫工作实际,论述了新形势下继续加强做好森林病虫害防治检疫工作的重要性和具体措施。     

玉米根萤叶甲的抗逆性与防治研究进展

玉米根萤叶甲（Diabrotica virgifera virgifera Leconte）在美国是最重要的玉米害虫。它不仅对一些环戊二烯、有机磷类和氨基甲酸盐类化学杀虫剂产生了很强的抗药性,还对玉米 大豆轮作和调整播期等农业防治措施产生了适应性。此外,该虫有较广的适生性和扩展性。在过去的60年内,它从美国中西部传到了东北部沿海地区,并入侵欧洲定殖为害。新近采用的防治方法主要是种植转Bt基因抗虫玉米。表达经生物工程改良并导入的某个Bt毒素基因如Cry3Bb1、Cry34Ab1/Cry35Ab1或mCry3A的转基因抗虫玉米可毒杀取食的玉米根萤叶甲。但在转Bt基因玉米使用数年后,田间观察和温室筛选研究显示,玉米根萤叶甲具有对转基因玉米的潜在抗性。本文对该叶甲与防治有关的生物学特性、抗逆性及其机制、防治措施做了综述和讨论,旨在对该害虫的检疫防除有所帮助。     

Comparative study of genetic diversity of Clavibacter michiganensis subsp. michiganensis isolates from the Canary Islands by RAPD-PCR, BOX-PCR and AFLP

Molecular characterization of seedborne pathogens is an important issue when discerning their origin and tracking the spread of a disease. In the Canary Islands (Spain), Clavibacter michiganensis subsp. michiganensis (Cmm) was first detected in 2002, causing severe losses in many tomato-growing areas. Fifty four strains of this bacterium isolated from 2002 to 2007 and 19 strains from different countries were characterized for genetic diversity. RAPD-PCR, BOX-PCR and AFLP provided differentiation among Cmm strains whereas no differences were observed with ERIC-PCR, REP-PCR and 16S-23S ITS PCR-RFLP. RAPD-PCR and BOX-PCR revealed high homogeneity among the Canary Island strains (>80 and >75% of similarity, respectively) which could not be grouped based on tomato cultivar, location or year of isolation. By contrast, strains of Cmm from other countries displayed high diversity, providing several clusters, most of which were composed of a single strain. Similarly, AFLP analysis of 29 selected strains of Cmm gave the same profile for the Canarian ones (>90% of similarity) whereas high polymorphism was obtained with strains from different countries. Moreover, two strains, one from the USA and another from Spain, were related to the Canarian strains, according to RAPD-PCR (>60% of similarity), BOX-PCR (>75%) and AFLP analysis (>90%), suggesting a common origin. The circumstances under which the Cmm outbreaks occurred in the Canary Islands and the high homogeneity observed among the Canarian strains would suggest that the bacterium was introduced into the region from only one origin.     

Sensitive real-time PCR detection of Xanthomonas fragariae in strawberry plants

Xanthomonas fragariae , the causal agent of angular leaf spot on strawberry, is a quarantine organism in strawberry propagation material in the European Union. For the reliable screening of planting material for latent infections, a real-time PCR assay based on Taqman® chemistry for the detection of X. fragariae was developed. Primers and probe sequences were based on a DNA fragment amplified by a previously reported X. fragariae -specific technique. The sequence of this genomic fragment had no significant similarity with any published GenBank sequence. Specificity of the designed assay was tested with an extended range of X. fragariae collection strains and isolates, with other Xanthomonas spp. and with unidentified bacterial isolates from strawberry plants. A nested PCR, which until now was the reference method for sensitive detection in planta , cross-reacted with the reference strain of Xanthomonas campestris pv. campestris . In combination with an elaborated DNA extraction procedure, the Taqman® PCR enabled reliable detection down to 300 colony forming units in a 100 mg strawberry leaf sample. The assay offers a new tool for epidemiological research and for sanitary control of plant material with low level or latent infections of X. fragariae .     

种菟丝子种子数学形态特征的初步研究

本研究基于数字图像处理与分析技术,首次用FeatureExtract数学形态特征提取软件获取了3种菟丝子图像的13项数学形态特征值,并做了方差分析和聚类分析。结果表明,该技术可应用于杂草种子快速鉴定。同时提出对方法的改进建议,为最终实现杂草种子的快速鉴定奠定了基础。     

Monitoring the occurrence of tomato bacterial spot and range of the causal agent Xanthomonas perforans in Iran

A 2‐year comprehensive field survey was conducted across major tomato‐growing areas of Iran. Two hundred and thirty‐four tomato fields and six tomato‐producing greenhouses were surveyed for the potential presence of bacterial spot disease. Five hundred and ninety‐six tomato samples with and without symptoms were analysed. While Xanthomonas spp. were found in association with tomato plants both with and without symptoms from five surveyed counties, the bacterial spot disease was observed only in plants from three of them. Only strains isolated from plants with symptoms induced disease symptoms on tomato, while those isolated from symptomless plants caused symptoms only on cabbage and common bean. None of the isolates caused disease symptoms on pepper and eggplant. Phylogenetic analysis showed that X. perforans is the causal agent of tomato bacterial spot in Iran, although X. campestris and X. axonopodis were also associated with symptomless tomato plants. All X. perforans isolates in this study were sensitive to streptomycin, copper sulphate and copper oxychloride at concentrations of 50 mg L^?1, 200 mg L^?1 and 0.8 g L^?1, respectively. Unlike the type strain of X. perforans, isolates in this study did not produce bacteriocin against other Xanthomonas spp., nor were they detected using the usual species‐specific primer pair Bs‐XpF/Bs‐XpR. This suggests an atypical nature of X. perforans strains in Iran, which leads to the hypothesis that X. perforans strains in Iran may have a separate origin to those causing disease epidemics elsewhere. The aggregated dispersal pattern of the diseased tomato fields signifies the seedborne introduction of the pathogen into the country.