甘薯茎线虫病病原线虫的订正

甘薯茎线虫病的病原线虫,以往一直错误地沿用Ditylenchus dipsaci(Kühn) Filipjev,1936,国外称它为起绒草茎线虫,国内称为甘薯茎线虫。近几年来,我们对其病原线虫的形态作了较详细的观察和研究,按照de Man和Cobb公式对虫体进行了测量和计算,进行了一系列接种试验。结果认为导致甘薯茎线虫病的病原线虫不是D.dipsaci而是D.destructor Thorne,1945。在我国D.destructor首先在甘薯上找到,它不仅侵染茎部而且侵染根部和块根,造成腐烂。因此建议其中文名称为甘薯腐烂线虫或马铃薯腐烂线虫;由该虫种在甘薯上引起的病害称为甘薯腐烂线虫病。     

榉树枯萎病的发生为害调查及病原鉴定

榉树枯萎病(blight disease ofZelkova schneideriana)是在榉树上发现的一种新的病害,为了解该病害的发生发展,确定该病害的病原,笔者对病害的发生和为害情况进行了实地调查,用柯赫氏法则确定了病原,并对病原进行了形态与分子鉴定。研究结果表明,病害在林地和苗圃均有分布,导致榉树大树和幼苗死亡,榉树地上部分逐渐失绿枯萎,根部变色腐烂。对枯萎病病原进行了分离、接种和再分离,确定该病病原,并通过形态学特性和rDNA-ITS序列分析,鉴定该病害病原为尖孢镰刀菌(Fusarium oxysporum)。对该病的传染性进行分析确定了该病害为土传病害,病害的发生与地形地势有关,低洼地段病害往往发生较重,有随地表水流到处传播特点。病原物尖孢镰刀菌产生大量厚垣孢子,孢子从植物根部入侵,造成根部皮层腐烂,地上部分枯萎。     

加工番茄田间果实发病与腐烂的研究与分析

在夏季果实成熟期，加工番茄果实发病和腐烂造成大幅度减产减收以及加工制品的品质下降的问题尤为突出。本研究根据2003—2004年新疆北部加工番茄病害的情况，2005年有针对性地选点、抽样和跟踪调查，重点研究了加工番茄田间果实发病和腐烂的主要类型、特点及病因、病原菌；调查研究了田间发病情况及其与果实发病与腐烂的关系；研究了人工接种条件下主要病原菌对果实的侵染情况。通过研究与分析，对加工番茄田间果实发病与腐烂问题有了进一步的认识，为生产上解决该问题提供了依据。     

江苏南京郊区和山东部分地区大白菜软腐病田间发生和潜伏侵染调查研究

1983—1992年在南京郊区4个蔬菜生产基地、2个试验点和山东4市一县5个地点作了调查,表明软腐病在大田主要发生在大白菜生长后期,发病率和发病程度因品种和地点不同而异。经对成株进行厌气检测发现,多数品种都有潜伏侵染,潜伏侵染率为33％—100％不等。贮藏期间可继续发生腐烂,并造成产量损失,因品种的不同,产量损失率约为15％至60％。对潜伏侵染的两种细菌共54上菌株作了鉴定,表明病原细菌是软腐欧文氏菌(Erwinia carotovora susp. carotovora     

菊欧氏杆菌和水稻细菌性基腐病

福建省东北部的福鼎县早在20世纪的60年代初期就发现了一种水稻茎节部腐烂并伴有恶臭的新病害,就其症状判断．其病原极可能是一种细菌。沿海平原稻区、低洼田、受淹田发病尤重，晚稻发病重于早稻。若在苗期发病，有可能萌发再生分蘖．拔节期发病则形成枯穗,一般产量损失为10％-20％。限于当时的技术水平，笼统地称该病为“水稻基腐病”，并常将其与水稻小球菌核病、恶苗病甚至纹枯病相混淆。     

一株拮抗魔芋软腐病的苏云金芽胞杆菌研究

魔芋软腐病严重影响着魔芋的生长,本实验室从魔芋软腐病出发,分离筛选出一株对其具有强拮抗作用的菌株16-4,并测定了其抑菌活性.经过形态观察、显微鉴定和分子鉴定确定该菌株是一株苏云金芽孢杆菌.拮抗实验结果表明16-4对魔芋软腐病具有很强的拮抗能力,平板对峙法显示该菌株对魔芋软腐病的抑菌圈达到75.4mm,魔芋块的实验说明16-4菌悬液与病原液3∶1的比例加入能很好地控制魔芋软腐病的发作,模拟田间管理的植株实验,当16-4菌悬液是病原液的3倍时就可达到较理想的防治效果.所有实验结果为魔芋软腐病的生物防治奠定了良好的基础.     

小麦茎基褐腐病的发生特点及其对产量的影响

对小麦茎基褐腐病在江苏省48个县（市）的发生情况进行了调查研究,结果显示：沿江、沿海及苏商丘陵地区（镇江）病害一般发生较重,病株率48%～90%;里下河和沿洪泽湖地区病害发生多属轻到中等,病株率10%～39%;苏北的徐州、连云港、宿迁等地病害发生很轻微,病株率在1%以下,调查发现：小麦茎基褐腐病发病程度与小麦纹枯病发病程度呈负相关,产量损失测定表明：小麦茎基褐腐病对不同小麦品种影响不一,扬麦158产量损失率较高,达8.5%,豫麦18产量损失率最低,仅0.19%。     

浅谈花生根结线虫病的发生与防治

花生根结线虫病是种植花生的一种主要的病虫害,由于该病害的隐蔽性较强,所以对于该病虫害的防治往往不及时,导致病害扩大化,给防治工作带来较大的影响,在生产上也带来较大的经济损失.本文阐述了花生根结线虫的表现症状、病原形态已经相应的发病规律,并提出了有关防治方法.     

楸树根结线虫病及其病原线虫的初步研究

作者自1986年5月至1987年11月对山东蒙阴县境内天麻林场等地的楸树根结线虫病的感染率、危害、症状及其病原线虫种类进行了调查,并通过对病原的雌虫、雄虫和二龄侵袭期幼虫的形态观察、测量、寄主反应及北卡罗来纳鉴别寄主试验,确认中山寺林场楸树根结线虫病病原为爪哇根结线虫(Meloido-gyne javanica(Treub,1885),Chitwood,1949),杨庄苗圃病原为北方根结线虫(M.hapla Chitwood,1949),而天麻林场与蒙阴县苗圃病原主要为以上二种根结线虫,其中以爪哇根结线虫为优势种,偶见极少量南方根结线虫(M.incognita Chitwood,1949)。本文还对二种主要病原线虫的重要鉴别特征作了较详细的描述,为楸根结线虫病的防治提供了必要的基础资料。     

临沧马铃薯晚疫病综合防治

晚疫病是马铃薯的主要病害，发病范围广。一般发病田块，病株率可达40—80％，流行年份全田毁灭。被晚疫病侵染的块茎，除在田间腐烂外，贮藏过程中病情还会进一步发展，严重的造成毁窖。用病薯作种薯，幼芽、幼苗腐烂致死，造成缺苗断垄，为害极大。2006年，临沧市马铃薯种植面积19．6万亩，晚疫病发病面积12．4万亩，占61．7％，呈现出发病范围广、发病率高、病害程度日趋严重的特点，严重制约着我市马铃薯产业的发展。     

轿子山自然保护区急尖长苞冷杉林群落特征研究

轿子山的急尖长苞冷杉(Abies georgeivar.smithii)林是西南地区同类森林中分布纬度和海拔最低的类型,具有重要的地理学意义和保护价值.急尖长苞冷杉林目前残存于昆明北部禄劝县和东川区,主要分布于轿子山保护区内,分布海拔为2700~4000m.基于10个20m×25m的样地资料的研究,结果表明其生物多样性特征是:群落样地由252种维管植物组成.种子植物属的分布区类型以北温带成分为主,占40.77%.种以中国特有成分为主,占30.74%.②生活型谱以地面芽植物为主,占38.53%.其次是高位芽植物,占32.90%.③该群落叶型以单叶(81.82%)、纸质叶(50.65%)、非全缘叶(54.11%)、中型(51.95%)和小型叶(40.69%)、非渐尖(77.49%)占优势.④群落中草本层的物种丰富度最大,Simpson指数和Shannon-Wiener指数均是草本层灌木层乔木层,Pielou均匀度指数是草本层乔木层灌木层.     

马占相思苗木茎腐病的调查和病原鉴定

于2001年4～7月，对广西高峰林场总场中心苗圃和银岭分场新造林地的马占相思（Acacia mangium Willd）苗木茎腐病进行调查和病原鉴定。结果发现，茎腐病对1年生以内的马占相思扦插苗危害严重，3月份开始发病，4～6月份为盛发期，新造林地，炼苗苗床，扦插苗床的平均发病率分别为12.1%、18.3%、72.6%，平均病死率分别为10.5%、16.2%、53.5%，苗木幼嫩、有伤口、培养基质带菌，温暖潮湿等条件有利于该病的发生与曼延，病原菌为立枯丝核菌（Rhizoctonia solani Kuhn）和尖镰孢霉菌（Fusarium oxysporum Schiecht），2种菌的致病力均很强。     

WIND observations of plasma waves inside the magnetic cloud boundary layers

Based on the WIND observational data for the plasma waves from thermal noise receptor （TNR） working on the frequency 4-256 kHz and the solar wind and the magnetic fields, we analyze the plasma wave activities in the 60 magnetic cloud＇s boundary layers （BLs） and find that there are often various plasma wave activities in the BLs, which are different from those in the adjacent solar wind （SW） and the magnetic clouds （MC）. The basic characteristics are that： （1） the enhancement of the Langmuir wave near the electronic plasma frequency （fpe） is a dominant wave activity, which occupies 75% investigated samples; （2） the events enhanced both in the langmuir and ion acustic （f〈fpe） waves are about 60% of investigated samples; （3） broadband, continuous enhancement events in the plasma wave activities were observed in the whole frequency band of TNR, and about 30% of the 60 samples, however, were not observed in the SW and the MC investigated events; （4） although the ratio of the temperatures between the electon and proton, Te/Tp ≤1, the ion caustic wave enhancement activities are still often observed in the BLs, which makes it difficult to explain them by the traditional plasma theory. New results reported in this paper further show that the magnetic cloud＇s BL is an important dynamic structure, which could provide useful diagnosis for understanding the cloud＇s BL physics and could expand a space developing space plasma wave theory.     

A new mechanism of invader success： Exotic plant inhibits natural vegetation restoration by changing soil microbe community

Since the 1950s of the last century, the exotic plant, Eupatorium adenophorum, has spread rapidly across southwest China, damaging native ecosystems and causing great economic losses. We examined the pH, N, P, K, and organic matter concentrations, and the bacterial community character (by Biolog EcoPlateTM) in soils from sites heavily and lightly invaded by this exotic species. Also, soil from the lightly invaded site was treated with a water extract of E.adenophorum roots to examine the effect of the plant on soil properties. We grew three plant species, one native and two exotic, in pot experiment using soil from heavily invaded site to examine the effects of the soil on these plants growth. The soil analysis demonstrated that the pH, organic matter, total N, total P and total K in soils from the heavily invaded site were only slightly different from those of the lightly invaded site, but concentrations of NH4^ , NO3^- and available P and K in the heavily invaded site were greater than those in the lightly invaded site. The catabolic activity of soil bacterial community in the heavily invaded site was different from that in the lightly invaded site. The catabolic activity of bacterial community in soils treated by the water extract of E.adenophorum roots changed and became similar to that in soils from the heavily invaded site. The pot experiment showed that the exotic plants growth in heavily invaded soil were not different from in lightly invaded soil; however, the native plant biomass decreased dramatically when grown in soil from the heavily invaded site as compared to soil from the lightly invaded site; and the same phenomenon was found when any potential allelopathic effects by E. adenophorum were eliminated by added activated carbon to those soils. Difference in soil nutrient availability and allelopathy could not explain this phenomenon of the native plant in the soils from the heavily and lightly invaded sites. Changes observed in the soil bacterial community were obviously related to native plant growth in those tow soils. Those results suggest that changing soil microbial community may be an important part of E. adenophorum invasion process. Since the soil microbial community serves as bridge in connection of exotic and natural plants, the exotic plant could inhibit the natural plant growth and reproduction by changing the soil microbial community in invaded site.     

Isolation and identification of Sclerotinia stem rot causal pathogen in Arabidopsis thaliana

A new stem rot disease is found to occur naturally on Arabidopsis plants in greenhouses of Fuzhou, China. In order to identify its pathogen, we conducted a series of fungal isolation and purification, plant reinoculation, and ascus and ascospore induction from the sclerotia. The isolate caused typical water-soaked lesions after reinoculation and produced sclerotia both on Arabidopsis plants and culture medium plates, and the sclerotia could be induced to produce discal apothecia and 8 binucleate ascospores per ascus. These disease symptom and fungal morphology data revealed that the fungus Sclerotinia sclerotiorum （Lib.） de Bary was the pathogen for Arabidopsis stem rot. To confirm this, we further amplified its large subunit ribosomal DNA （LSU rDNA） by polymerase chain reaction （PCR）, and compared the sequence with the known LSU rDNA sequences in GenBank. The results show that the sequence shares the highest identities with the LSU rDNAs of different S. sclerotiorum strains. Taking all these data together, we concluded that the fungus that caused the Arabidopsis stem rot is S. sclerotiorum （Lib.） de Bary. This is the first report that Arabidopsis is naturally infected by S. sclerotiorum.     

Fluorescence study on the interaction between apoCopC and cupric

The interaction between apoCopC and cupric was investigated by fluorescence spectra, in phosphate （20 mmol/L） buffer at pH 6.0. Results suggest that the environment is measured to be hydrophobic completely around tryptophan （83）. At the same time, apoCopC fluorescence at 320 nm was significantly quenched with the addition of cupric and the 1：1 stoichiometric ratio of apoCopC to cupric was confirmed by fluorescence. In addition, the conditional binding constants were calculated to be Kcu-copc=（1.8±0.58）×10^13 mol^-1 L on the basis of the results of fluorescence titration curves. The apoCopC has the ability to bind specifically cupric ion.     

含籼率对连晚直播稻产量的影响

连作晚稻田中的秋籼,对连晚直播粳稻的产量影响很大。含籼1％减产2．5％,但未选显著标点;含籼5%减产17．0％;含籼10％减产22．1％;含籼超过15％减产32．6％以上,均达到极显著标点。所以,连晚直播稻的含籼率临界值为1％。减产的主要原因是有效穗和每穗实粒锐减。     

中国横断山的地衣(2)——雪花衣属(蜈蚣衣科)

毛边雪花衣(Anaptychia ciliaris)、裂芽雪花衣(A.isidiza)、掌状雪花衣(A.palmulata)和污白雪花衣(A.ulotrichoides)在横断山地区被报道,其中毛边雪花衣和裂芽雪花衣在中国西南地区是首次记录.给出了这4种雪花衣的检索表、形态图以及在横断山的地理分布图,并详述了它们的形态特征、地衣化学及生境.     

入侵植物紫茎泽兰叶斑真菌多样性及其致病性研究

 从云南、广西等12个地区的紫茎泽兰和其他8种植物叶片上共分离得到47个真菌菌株.根据菌落、菌丝以及孢子形态,结合18SrRNA基因限制性酶切片段长度多态性(RFLP)分型和序列测定分析,47个菌株共分为了19个类群,系统发育关系与Aspergillusniger,Cladosporiumcladosporioides,Sporisoriumreilianum,Colleto-trichumlupini,Alternaria sp.,Sporobolomycesroseus,Dothideomycetesp.,Phoma sp.,Filobasidiumelegans,Aureobasid-iumpullulans,Rhodotorulaslooffiae,R.glutinis,Penicilliumdecumbens,Pestalotiopsismaculans,Cryptococcusaureus,Bimurianovae-zelandiae,Xylariaceae sp.类似.这些菌株中仅有5个对紫茎泽兰离体叶片表现致病性,在系统发育树上分别和Myrothecium sp.,C.lupini,Alternaria sp.,C.cladosporioides,Dothideomycete sp.聚类.有2个R.gluti-nis菌株对马铃薯和白菜有致病作用,但对紫茎泽兰没有致病力.     

Effect of total aluminum concentration on the formation and transformation of nanosized Al13 and Al30 in hydrolytic polymeric aluminum aqueous solutions

Influence of total aluminum concentration （CAIT） on the generation and transformation of nanosized AI13 and AI30 in hydrolytic polyaluminum aqueous solutions was investigated using high field 27AI NMR and time-developed AI-Ferron complex colorimetry. When prepared at the optimal basicity （B） of Al13 generation and 80℃, the All3 species in polyaluminum solution tends to further polymerize and convert to AI30 and higher polymers when CAI; 〉0.2 mol· L^-1, but Al13 does not convert to AI30 quantificationally, as the formation of Alu from Al13 and AI30 is accelerated in the same way. The conversion rate of All3 is accelerated by the increase in CAIT. When CAlT 〉0.75 mol·.L^-1, Al13 content decreases rapidly, and AI30 content increases continuously and becomes the dominant nanometer polynuclear aluminum species. AIm is one of prerequisites of Al13 conversion to AI30. When CAI; increases and B reduces, the polymerization rate between Al13 and Aim increases, and at the same time, the dissociation reaction rate of All3 and AI30 by H^＋ also increases. The latter becomes the dominant reaction in polyaluminum solution with low B value, so AI30 decreases with the increasing CAlT. The hydrolytic polyaluminum solution with Al13 content beyond 80% can only be prepared under the condition of CAlT〈0.5 mol· L^-1 and optimal B value.