海南香蕉条斑病毒的检测

香蕉条斑病毒(Banana streak virus,BSV)是香蕉上一种重要的病毒。本文运用血清学检测法和PCR检测法对海南主栽巴西蕉(Musa Cavendish,AAA)、粉蕉(Musa Pisang Awak,ABB)进行了BSV的调查检测。结果表明,参试无症状或症状各异的样品血清学检测结果均为阴性,说明这些被测品中可能不含有游离BSV粒子;上述样品中部分样品的PCR检测结果却为阳性,将PCR扩增的特异条带回收、测序和比对,显示确实扩增到BSV部分基因组序列。结合血清学检测结果,说明海南部分香蕉的基因组已经整合了BSV的基因组序列。     

香蕉线条病毒ORFⅡ基因的原核表达及抗体制备

 ORFⅡ gene of Banana streak virus GuangDong isolate (BSV-GD) was amplified from a BSV-GD recombinant plasmid by PCR, and the gene was expressed by being cloned into prokaryote expression vector pET-28b (+). The fusion protein was about 16.5 kDa in size and was soluble with SDS-PAGE analysis. The purified protein was obtained by using the histidine labeling kit of N-terminus of protein. The antiserum was obtained by immunizing healthy rabbits with the purified protein. Western blot and ELISA analysis showed that the special antiserum of BSV possessed high titer, which was tested as 1:51 200. The study was a base for further research on BSV including ORFⅡ gene function and virus detection.     

Effect of Juglone on Active Oxygen Species and Antioxidant Enzymes in Susceptible and Partially Resistant Banana Cultivars to Black Leaf Streak Disease

The black leaf streak disease (BLSD), caused by Mycosphaerella fijiensis, is the most destructive disease of bananas and plantains around the world. Breeding for resistance is the most promising strategy to fight this disease especially in small farmer plantations. Mycosphaerella fijiensis produces many phytotoxins such as juglone, which can be used, jointly with field and inoculations under controlled conditions, for screening banana cultivars for BLSD-resistance. This non-host specific phytotoxin has been shown to act on chloroplasts and disturbs the proton electrochemical gradient across the plasmalemma membrane. Moreover, an involvement of the oxidative burst during the interaction has been suggested. The present study was carried out using two cultivars that differed for either their juglone-responses or their resistance to BLSD (cv. Grande Naine susceptible to BLSD and juglone and cv. Fougamou partially resistant to BLSD and highly tolerant to juglone). The production of active oxygen species (AOS) and the enhancement of the enzymatic and/or non-enzymatic AOS-scavenging systems were investigated after treatment of the two cultivars with juglone. The time-course of AOS-production and AOS-scavenging was shown to be the key difference between these two tested cultivars after treatment with juglone. Thus, an early release of AOS (O₂⁻ radical and H₂O₂) and a quick stimulation of a preferment anti-oxidant system (superoxide dismutases, catalases, and peroxidases) was observed for cv. Fougamou as compared to cv. Grande Naine for which a late and weak generation of AOS accompanied by a late stimulation of the anti-oxidant systems were detected.     

香蕉分化芽BBTV DAS-ELISA检测方法的建立和应用

为了解海南海口香蕉分化芽携带香蕉束顶病毒(Banana bunchy top virus, BBTV)的情况, 本研究建立了双抗夹心酶联免疫反应(DAS-ELISA)检测法, 对来自海南地区组培厂的香蕉分化芽进行检测。检测结果表明, 6个品种1 852个香蕉分化芽平均带毒率为2.1%, 其中‘皇帝蕉’为1.98%, ‘粤科1号’为2.07%, ‘广粉蕉’为1.98%, ‘大蕉’为6.25%, ‘218’为1.89%, ‘巴西蕉’为2.25%。为了进一步验证ELISA结果的可靠性, 随机选取12个阳性样品提取总DNA进行PCR鉴定。鉴定结果显示, 12个样品中11个检测出有BBTV, 表明DAS-ELISA方法的准确率较高, 与分子检测结果基本一致, 可以胜任日常香蕉组培苗BBTV的检测。     

水稻细菌性条斑病和纹枯病生防细菌的复筛、室内防效及应用评价

采用活体生测法对前期工作中离体初筛出的5株水稻细菌性条斑病生防菌和5株水稻纹枯病生防菌分别进行复筛、温室防效测定和应用评价。结果表明,菌株GN233、GN222和GN223的菌悬液对水稻苗期细菌性条斑病有一定的防治效果,其中菌株GN233对细菌性条斑病的温室防效最好,达到28.90%,而药剂"稻丰TM多·福"可湿性粉剂的温室防效为34.20%;5株生防菌对水稻纹枯病均有不同防治效果,其中菌株GN222和GN211菌悬液的防治效果较好,分别达到44.4%和27.8%,而药剂"稻丰"可湿性粉剂的防效为33.3%;此外,筛选出的生防菌株GN222、GN233和GN211均对水稻生长具有促生作用。本研究结果可为水稻细菌性条斑病和水稻纹枯病的生物防治奠定基础。     

Properties of Banana Spray Oils in Relation to Sigatoka Disease Control and Phytotoxicity on Banana Leaves

Abstract

The properties of banana spray oils have been investigated by a number of researchers. The results of these investigations are reviewed in this paper, and include information on volatility (distillation range, flash point); flow characteristics (viscosity, pour point); other physical properties (specific gravity, colour, aniline point); and chemical properties (unsulphonated mineral residues, aromatics, paraffins and naphthenes).

A comparison of distillation curves is of greater significance than comparison of individual boiling points. Such a comparison will show whether any one oil product is a homogeneous oil or a mixture of heavy and light oils. Disease control is closely related to volatility of the spray oil; the lower the volatility of the oil the better the disease control. Phytotoxicity (leaf-flecking) increases as the percentage volatility of the spray oil decreases. Oil volatility governs the amount of oil remaining on the leaf after application. The initial amount of oil applied to the leaf is of less significance in the fungistatic effect than is the amount of oil remaining on or in the leaf. From a viewpoint of Sigatoka disease control, flash points are of little significance, but must be considered from the viewpoint of safety in storage, transportation and use.

As the viscosity of spray oils increases [in the range 35-100 Saybolt Universal Seconds (SUS) at 100[ddot]F] disease incidence decreases and phytotoxicity increases on sprayed banana leaves. The naphthenic oils are superior to the paraffinic oils, particularly in the viscosity range of 75-85 SUS at 100[ddot]F, for spraying bananas.

The performance of banana spray oils is related to the proportions of the major hydrocarbon groups (aromatics, naphthenes and paraffins) present in the oil. Properties such as specific gravity and aniline point are indicative of the proportions of the major hydrocarbon groups in a spray oil.

Colour of mineral oils is of no significance in the control of Sigatoka disease. Light mineral oils with unsulphonated mineral residue (U.M.R.) in the range of 70-99.9 are equally effective in Sigatoka disease control regardless of U.M.R. However, the degree of leaf damage (phytotoxicity) is directly related to U.M.R. value. The oils of high U.M.R. cause the least damage. The aromatic fraction of four spray oils tested (heavy paraffinic, light paraffinic, heavy naphthenic and light naphthenic) caused abundant phytotoxicity at a deposit level of 3 US gal/ac. There was little or no phytotoxicity and no appreciable disease control at a deposit level of 1.5 US gal/ac. Paraffinic and naphthenic oils of comparable U.M.R. value (94-95%) and viscosity (74-75 SUS at 100[ddot]F) provide good disease control within the deposit range 1.4-2.1 US gal/ac. At these deposit levels the naphthenic oil causes only 20 and 50% respectively as much phytotoxic flecking as the paraffinic oil. Photosynthesis is inhibited by the application of petroleum oil to banana leaves.

It is the opinion of the writer that a long-term trial (a minimum of two years) should be conducted to evaluate the effect of a comparable naphthenic and paraffinic oil on Sigatoka disease control and banana yield.     

多抗霉素研究现状与市场前景

本文阐述了多抗霉素产品的特点、技术研究现状以及市场前景。     

生物农药在我国小麦病虫害防治中的登记情况、研究现状及发展建议

本文对我国当前小麦病虫害防治药剂中的生物农药登记情况进行了总结,综述了未登记品种在小麦上的研究现状,并提出发展建议。     

Biology and management of the invasive weed Ageratina adenophora (Asteraceae): current state of knowledge and future research needs

Biological invasion is increasing worldwide and the management of invasive species is becoming an important priority for vegetation managers. Success of invasive species management depends on a thorough understanding of the biology of the organism in question and the effectiveness of current management efforts, in order to identify the best practices for management improvement. In this review, we synthesised current biological knowledge of a noxious invasive weed Ageratina adenophora to identify knowledge gaps and assessed management efforts to identify best practices. Finally, we proposed some priority areas for future research to fill knowledge gaps and improve management. Our analysis showed that A. adenophora has already invaded 40 countries, mainly in Asia, Oceania, Africa and Europe. Phenotypic plasticity, allelopathic interference and invasion‐mediated changes in the soil microbial community are the proposed mechanisms that facilitate rapid spread of this weed. However, allelopathy as a mechanism of invasion success of this weed has not been supported by ecologically meaningful experiments. Though mechanical, chemical and biological control measures have been used, their success remains limited and the weed continues to spread in new regions. Among seven biological control agents examined to date, gall fly (Procecidochares utilis) and leaf spot fungus (Passalora ageratinae) have been effective in limited areas to suppress growth of this weed. Some perennial native grasses (e.g. Setaria sphacellata and Lolium perenne) have shown potential to competitively suppress A. adenophora. In conclusion, understanding the invasion mechanisms, exploring further to identify effective biological control agents, combined with approaches of ecological restoration, could help in the management of this weed.     

Multiplex PCR for specific and robust detection of Xanthomonas campestris pv. musacearum in pure culture and infected plant material

The present study developed a pathovar‐specific PCR for the detection of Xanthomonas campestris pv. musacearum (Xcm), the cause of banana xanthomonas wilt, by amplification of a 265‐bp region of the gene encoding the general secretion pathway protein D (GspD). A distinct DNA fragment of the expected size was amplified from genomic DNA from all of 12 Xcm isolates tested and no amplification of DNA was observed from other xanthomonads or plant‐associated bacteria, including the two closely related species Xanthomonas vasicola pv. holcicola and Xanthomonas axonopodis pv. vasculorum. The Xcm‐specific PCR was successfully multiplexed with internal control primers targeting 16S rDNA for application on DNA from bacterial cultures and with primers targeting plant mitochondrial 26S rDNA for application on DNA extracted from plant material. Diagnostic discrimination of healthy and infected plants was subsequently demonstrated in tests on artificially inoculated screenhouse cultivars of banana and field bananas with and without symptoms sampled from different parts of Uganda. This study therefore demonstrated a robust and specific Xcm diagnostic tool with the added advantage of applying internal PCR controls for direct quality assessment of results.     

陕西省水土环境现状与问题及对策刍议

文章在分析陕西省水土环境存在的问题的基础上 ,提出了陕西省水土环境整治建设的对策与建议 ,以期能为陕西经济和社会发展有所助益。     

嘧菌酯在我国登记情况以及抗性研究现状

嘧菌酯是先正达公司于1997年上市的甲氧基丙烯酸酯类杀菌剂,它具有广谱、高效、安全的特点,自上市以来占有较大的市场份额。随着国外产品专利保护到期,我国掀起一阵注册热潮。但由于其作用为点单一,在使用过程中抗性问题日益严重。本文对嘧菌酯近年来登记情况、抗性发展研究状况、抗性产生机制以及治理措施进行了简要论述。希望为以后嘧菌酯的登记注册以及合理使用提供全面客观的依据。     

昆虫病原真菌防控草地贪夜蛾的现状、问题与展望

草地贪夜蛾是世界性重大农业害虫,危害大、防控难。昆虫病原真菌菌种资源丰富,具有易流行、害虫不易产生抗性等突出优点,在草地贪夜蛾防控中应用潜力大。本文综述了昆虫病原真菌在草地贪夜蛾防治中的现状,分析了存在的问题,重点指出了昆虫病原真菌在草地贪夜蛾防治中的发展方向,为进一步发挥昆虫病原真菌在草地贪夜蛾防控中的作用提供参考。     

中国绿洲研究发展进程的探讨与展望

以CNKI数据库作为数据源,通过检索,结合常规统计方法分析,将中国绿洲研究发展进程分为4个阶段:早期阶段,发展、建设阶段,快速发展阶段及拐点阶段。1995年在呼和浩特市召开的"绿洲建设的理论与实践"会议,总结了绿洲多年发展建设的经验与成果,丰富了绿洲研究的重要基础理论,发展、壮大了绿洲学研究,大大推进了绿洲的各项事业。目前,我国正在开展的"向西开放"及"丝绸之路经济带战略",开辟了"亚洲中部干旱区绿洲"、"绿洲现代化"等研究内容,拓展了"绿洲学科领域",从内涵与外延方面提升了绿洲研究素质,促进了研究工作再度创新、发展,更好地服务于社会、经济、文化及生态与环境建设,推进绿洲可持续发展。     

中国绿洲研究文献分析及研究进展

中国绿洲主要分布在西北和青藏高原北部的干旱区,绿洲的可持续发展关系到干旱区生态的稳定性。自2000年国家启动"中国西部干旱区生态环境演变与调控研究(973)"项目以来,绿洲研究得到了全方位、多学科的发展。通过对2000-2010年绿洲研究成果的不完全统计,近10年来,我国学术期刊发表的绿洲研究文献超过2000篇,专业著作近30部。同时,利用文献计量方法,从绿洲研究文献的数量、分布及研究主题等方面进行了深入分析,展示了近10年来我国绿洲研究的丰硕成果,并从绿洲生态系统的圈层结构特征,对绿洲研究文献进行了梳理,提出了中国绿洲研究的特点与不足,从而推动中国绿洲学的建立和发展。     

我国生态旅游研究的文献学分析及启示

在充分利用文献资源的基础上,从文献学视角透视我国生态旅游研究的进展状况。揭示了生态旅游研究的学科背景分布、空间分布特征,并且对生态旅游研究文献的核心作者群进行了分析。发现了生态旅游研究具有学科交叉相融性、空间分布不均衡性和旅游研究“趋热性”等现状,据此提出生态旅游的研究亟需转变旅游学术研究观念,加强跟进研究的观点。     

黄土高原的植被演替研究现状及发展趋势

从地质、历史时期黄土高原植被演替研究和现存植被的群落演替及群落结构特征 演化研究两方面论述了黄土高原的植被演替研究现状及发展趋势,认为黄土高原植被演替研 究对黄土高原的生态建设尤其是退耕还林还草工程建设具有重要意义,建议基于黄土高原的 植被演替规律进行仿自然植被林草建设。     

浙江、吉林两省特色作物用药登记情况进展及存在问题分析

本文概述了我国浙江和吉林两省特色作物用药登记进展情况,对存在问题进行了探讨分析,提出了解决相关问题的建议等。加强《农药管理条例》配套规章的制定,积极申请财政专项,加快解决蔬菜及特色作物用药问题,将有利于保证我国特色农产品的质量安全。