番茄资源对叶霉病的抗性鉴定和SSR标记遗传变异分析

 对62份番茄种质资源进行了抗番茄叶霉病鉴定, 共筛选出抗病材料17份, 其中对全部生理小种(1.2.3、1.2、2.3、1.2.3.4、1.2.4)均表现抗病或免疫的材料9份;抗3个生理小种的材料4份;抗2个生理小种的材料2份;抗4个生理小种的材料2份。并应用SSR标记技术对62份种质资源进行了遗传多样性分析, 50对SSR引物中筛选出11对多态性明显、条带清晰、反应稳定的引物, 共扩增出94条谱带, 平均每个引物扩增出8.55条带, 多态性条带比例达63.94%, 遗传相似系数在0~1之间, 表现出丰富的遗传多态性, 可将番茄野生种和栽培种分开, 反映了种间的遗传差异。     

玉米大斑菌Ht-毒素组分分析

 对分别属于玉米大斑病菌(Helminthosporium turcicum)1号和2号生理小种的致病毒素进行硅胶TL层析、薄层扫描和生物监测的结果发现,两个小种的毒性组分不同。2号小种可分离到I(Rf0.50)、Ⅱ(Rf0.36)、Ⅲ(Rf0.67)、Ⅳ(Rf0.80)、Ⅴ(Rf0.13)、Ⅵ(Rf0.25)6种组分,而1号小种最多可分离到除Ⅳ以外的其它5种组分,这些组分均有不同程度的紫外吸收。对在200~360nm有明显紫外吸收的4种组分(Ⅰ、Ⅱ、Ⅲ、Ⅳ)的生物监测结果表明,只有组分Ⅲ对带Ht₁基因和不带Ht₁基因的Oh43和B372对玉米自交系不具任何致病活性,组分Ⅰ、Ⅱ对不带Ht₁基因的玉米自交系具有致病活性,而对带Ht₁基因的玉米自交系却无毒性。值得重视的是组分Ⅳ的致病特性与组分Ⅰ、Ⅱ正好相反,即对带Ht₁基因的玉米自交系具有致病活性,却对不带Ht₁基因的玉米自交系没有致病作用。结论指出,Ht-毒素的TLC组分Ⅰ、Ⅱ、Ⅳ玉米斑菌诱致玉米发病的主要活性成份,其中组分Ⅳ是2号小种与Ht₁基因玉米互作的特异性因子。     

河北省棉花枯萎菌遗传多样性及致病力分化

为明确河北省棉花枯萎菌（Fusarium oxysporum f.sp.vasinfectum, FOV）变异及致病力分化情况,利用AFLP技术对采自河北省的75株FOV和3号、7号、8号生理小种的标准菌株进行遗传多样性分析,并比较了不同AFLP类群菌株对棉花品种冀棉11号的致病力差异。结果表明,78株FOV可划分为4个AFLP类群（AFLP groups, AGs）,AGsⅠ为3号生理小种,AGsⅡ为8号生理小种,AGsⅢ包括7号生理小种和67株田间采集菌株,AGsⅣ包括8个田间采集菌株,该类群菌株与3号、7号、8号生理小种遗传差异较大。致病力初步测定表明,3号、7号、8号生理小种的标准菌株属中等致病力水平,而田间采集的75株枯萎菌菌株致病力存在明显差异,其中强致病力菌株占66.67%,中等致病力菌株占21.33%,弱致病力菌株占12%。表明河北省FOV群体遗传结构复杂,有遗传差异较大的新菌株出现,而且同一生理小种菌株之间存在显著的致病力分化。     

高梁丝黑穗病菌生理分化研究

 在辽宁省最先推广种植以ATx622为母本的杂交高粱产区营口,发现了高粱丝黑穗病菌(Sporisorium reilianum(Kuhn) Langdon & Full.)新的生理小种,定名为3号小种。此小种的致病力与1、2号小种显著不同。3号小种能侵染1、2号小种不能侵染的ATx622和BTx622,并具有较强的致病力,其鉴别寄主为ATx622,BTx622,ATx623和BTx623。     

不同寄主植物青枯菌菌株的比较研究

 根据番茄、茄、马铃薯、花生、甘薯、姜、桑、油橄榄、木麻黄九种植物上22个青枯菌的菌株,进行形态、染色、生理生化反应、致病性等方面的比较研究的结果,证明它们都是属于青枯假单胞菌(Pseudomonas solanacearum Smith)。因此,以前报道的甘薯瘟的病原细菌Pseudomonas batatas Tseng and Fan,应改为Pseudomonas solanacearum Sncith,不同寄主青枯菌菌株,它们的有些生理生化反应有明显的差异,但更为明显的是它们的致病性不同。测定的7种寄主上的青枯菌菌株,根据它们对茄的致病力很强,番茄、茄、姜、花生、甘薯、油橄榄和木麻黄菌株可归入小种1;马铃薯菌株对马铃薯的致病力很强,而对茄、番茄和辣椒的致病力中等,归入小种3。属于小种1的7种植物的菌株,致病性也有所不同,它们可作为不同的菌系。桑菌株的致病性较为特殊,很难归入已报道的小种。根据对6种糖和醇的利用以及脱氮作用的能力,番茄、茄、花生、油橄榄菌株属生物型Ⅱ;姜、木麻黄、甘薯菌株属生物型Ⅳ;马铃薯菌株属生物型Ⅱ,桑菌株属生物型Ⅰ。但桑菌株人工接种不侵染茄和马铃薯。烟叶过敏反应的测定表现黄斑而从未表现过敏反应,它的归属尚待进一步研究。青枯假单胞菌划分为小种和生物型,目前意见还不一致,加上我们测定的菌株有限,有关这方面的工作,也待进一步研究。     

香蕉枯萎病菌致病力分化与ISSR遗传多样性分析

香蕉枯萎病是一种破坏香蕉维管束的全株性土传病害。本研究旨在探讨香蕉枯萎病菌致病力分化和遗传多样性。以30株采自我国广西的香蕉枯萎病菌,16株分别来自澳大利亚和我国广东、海南、福建、云南等地的香蕉枯萎病菌为对象,采用伤根灌淋法测定香蕉枯萎病菌的致病力,然后用筛选到的ISSR引物对46个香蕉枯萎病菌菌株和4个对照菌株(3个非致病性尖孢镰刀菌和1个茄腐镰刀菌)进行ISSR遗传多样性分析。结果显示,分离到广西香蕉枯萎病菌1号生理小种(FOC1)8株,致病力强、中、弱类型比例分别为62.5%、12.5%和25%;广西香蕉枯萎病菌4号生理小种(FOC4)22株,致病力强、中、弱类型比例分别为18.18%、63.64%和18.18%。14条ISSR引物扩增出237个条带,多态性条带161个,多态性比例为67.93%,遗传相似系数0.76～0.96。聚类分析显示,以遗传距离0.80为阈值时菌株被分为8个类群,所占比例分别为4%、10%、60%、16%、4%、2%、2%、2%。第三类群全部为香蕉枯萎病菌4号生理小种。第一、二、四和五类群总量的70.59%为香蕉枯萎病菌1号生理小种。第八类群为香蕉枯萎病菌3号生理小种。结果表明,在香蕉枯萎病菌与寄主协同进化中,广西的FOC1和FOC4出现明显致病力分化。1号生理小种的遗传多样性比4号生理小种丰富。广西香蕉枯萎病菌4号生理小种与海南、广东的FOC4遗传相似性较高。香蕉枯萎病菌生理小种类型与遗传多样性相关。致病力变异与遗传多样性无相关性。研究结果对香蕉枯萎病菌种群扩张机制探讨、遗传动态分析以及有效防控措施的制定具有一定的指导意义。     

稻瘟病菌生理小种变化与水稻品种抗瘟性丧失之间的关系

本文根据近年稻瘟病菌生理小种鉴定研究结果,对生理小种变化与水稻品种抗瘟性丧失之间的关系进行了初步分析。(1)我省稻瘟病菌生理小种组成发生了变化。优势小种由1979—1982年的G群变为1983年后的B群小种;(1)品种的抗性随潜在致病力强的生理小种出现频率上升而降低;(3)伴随抗病品种种植面积比率的扩大,潜在致病小种迅速增殖,丧失抗性的危险性加大;(4)品种抗性随抗优势种群频率下降而降低。     

我国水稻当家品种对稻瘟病、白叶枯病的兼抗反应初探

用多个致病力不同的白叶枯病菌株,和全国10省12个研究单位提供的稻瘟病混合菌以及10个生产上常见的生理小种,于1987、1988年对全国种植面积达10万亩以上的145个水稻品种进行了抗白叶枯病谱、抗稻瘟病混合菌和生理小种测定。结果表明国际稻26、金早6号、金早7号、扬稻1号(BG910)、青华矮6号等21个品种能抗多个白叶枯病菌株和抗多个稻瘟病小种混合菌。对10个生理小种的抗谱率相差较大。     

青枯雷尔氏菌无致病力hrpB突变菌株的纯化分离及其异质性研究

获得纯度高的青枯雷尔氏菌无致病力菌株,是研发青枯病植物疫苗和防治青枯病害的一种新途径。作者以青枯雷尔氏菌强致病力菌株FJAT-91为出发菌株,通过对hrpB基因敲除,获得无致病力突变菌株FJAT-91ΔhrpB。高效离子交换色谱分离结果表明:FJAT-91和FJAT-91ΔhrpB色谱峰型不同,主要表现在峰的保留时间上,FJAT-91只有单一色谱峰,保留时间为6 min;FJAT-91ΔhrpB有P_1和P_2 2个色谱峰,保留时间分别为0.6 min和4.5 min。利用高效离子交换色谱对FJAT-91ΔhrpB进行纯化,获得只有P_1峰的高纯度菌株FJAT-91ΔhrpB-P。FJAT-91ΔhrpB和FJAT-91ΔhrpB-P与其出发菌株FJAT-91的菌落和菌体形态差异明显。致病力测定结果表明:FJAT-91接种4 d番茄植株开始发病,10 d发病率达100%;FJAT-91ΔhrpB和FJAT-91ΔhrpB-P接种20 d均未发病。防效试验结果表明:纯化后的菌株FJAT-91ΔhrpB-P对番茄青枯病的防效(81.64%)比未纯化FJAT-91ΔhrpB防效(61.04%)提高了33.75%。本研究获得一株高纯度的青枯雷尔氏菌无致病力突变菌株FJAT-91ΔhrpB-P具有良好的生防潜力。     

枯草芽孢杆菌G3菌剂防治番茄叶霉病田间试验

番茄叶霉病由黄枝孢菌 (Cladosporiumfulvum)引起 ,严重为害番茄叶片和果实。随着温室大棚大面积推广 ,上海郊区番茄叶霉病越发严重 ,成了番茄栽培的重要问题。该病在上海通常于 3月份发病 ,5月达到高峰[1] 。但随着近年来的暖冬效应 ,少数大棚 1月份便开始发病 ,3月份达发病高峰。常规化学杀菌剂 ,如百菌清、多菌灵防效甚微且污染环境 ,急需高效低毒的药剂取而代之。作者曾报道产几丁质酶枯草芽孢杆菌 (Bacillussubtilis)G3菌剂在盆栽试验中对番茄叶霉病有较好的防治效果[2 ] 。本文报道G3菌剂田间防治该病的效果1　材料与方法1 .1　供试…     

Insecticidal activity of N,N-diethyl-, N,N-dipropyl-, N,n-di-isopropyl-, and n,n-di-isobutylalkanamides against mosquito larvae

N,N-Diethyl-, N,N-dipropyl-, N,N-di-isopropyl, and N,N-di-isobutylalkanamides in which the acyl moiety ranged from C₈ to C₂₁ were synthesised, and their larvicidal activity was determined against the first-instar larvae of the southern house mosquito Culex quinquefasciatus Say. The four homologous series of amides generally showed an increase in their larvicidal activity as the carbon number in the acyl moiety of the amides increased, until the activity reached a maximum. Subsequently, an increment of carbon number resulted in declining activity in the higher homologues, until the activity disappeared. N,N-Diethyltetradecanamide, N,N-dipropylundecanamide, N,N-di-isopropylundecanamide, and N,N-di-isobutlynonanamide or -dodecanamide were the most active compounds in their respective homologous series of amides; however, they were less active than their analogous N,N-dimethylalkanamides previously studied.     

长武旱塬不同麦玉轮作系统产量效应模拟研究

利用EPIC模型对不同麦玉轮作系统进行模拟,通过对其输出结果的分析,综合考虑产量、经济效益、干旱胁迫和氮肥生产率等因素,对不同麦玉轮作系统进行综合评价,从而比较不同麦玉轮作系统的优劣。结果表明:(1)在模拟研究期间,8种麦玉轮作系统的产量均呈波动性下降趋势,其平均值分别为4.61、4.40、4.16、4.48、4.28、4.29、4.714、.55 t/hm2。所有的麦玉轮作系统中,麦玉轮作系统"春玉米→冬小麦"的经济效益最好。(2)在模拟研究期间,麦玉轮作系统"春玉米→冬小麦→冬小麦"的冬小麦和春玉米所遭受的年均干旱胁迫日数最少(29.51d)。在干旱年份麦玉轮作系统中的冬小麦较春玉米更容易遭受干旱威胁。综合产量、经济效益、作物所遭受的干旱胁迫天数和麦玉轮作系统的氮肥生产率等因素,在长武地区适宜采用的麦玉轮作系统为春玉米→冬小麦。     

东北日光温室葡萄园水热通量特征及其对气象因子的响应

运用温室葡萄水热平衡观测资料,分析了东北日光温室葡萄的能量平衡和能量分量日变化、生育期变化以及分配规律,同时也分析了潜热通量（λET）对环境因子的响应。结果表明：水热通量各分量在整个生育期日变化总体上呈现为单峰趋势,净辐射（R_n）的峰值最大为618.75 W·m^-2,λET峰值最大为242.73 W·m^-2,感热通量（H）峰值最大为327.93 W·m^-2;在新梢生长期,白天λET较小,为34.55 W·m^-2,随着生育期推进,λET逐渐增大,在果实着色成熟期达到最大值（78.49 W·m^-2）之后减小;H在各生育期能量中均占了绝大部分;白天潜热通量占净辐射的比例（λET/R_n）在新梢生长期最小,为25.28%,在果实着色成熟期最大,为44.17%;感热通量占净辐射比例（H/R_n）整个生育期几乎都达50%以上,土壤热通量占净辐射比例（G/R_n）相对较小,变化范围为4.46~12.32 W·m^-2;在整个生育期能量比率大小依次为H/R_n>λET/R_n>G/R_n。在不同生育阶段瞬时尺度上,R_n是影响潜热变化最主要的气象因子,R²高达0.88。在日尺度上,各气象因子对潜热通量的影响在逐渐变弱,相对湿度（RH）与λET相关系数仅为0.28。但无论从瞬时尺度还是日尺度,R_n都是影响潜热通量最主要的气象因子。各气象因子对潜热通量的影响大小依次为：R_n>VPD>T_a>RH。     

施肥对小麦、玉米和大豆连作土壤微生物群落功能多样性的影响

为了明确长期施肥和不施肥条件下作物连作对土壤微生物群落功能多样性的影响,以典型黑土为研究对象,选取长期定位实验站长期施肥和不施肥条件下的小麦、玉米和大豆连作处理,通过稀释平板法和Biolog Eco微平板法,测定土壤细菌、真菌、放线菌数量、碳源代谢活性等指标,为建立合理的农田管理措施提供数据支撑和理论依据。结果表明:长期施肥条件下大豆、小麦和玉米连作土壤细菌、真菌和放线菌数量均高于不施肥处理,且均以大豆连作处理细菌和真菌数量最高。不施肥条件下小麦和玉米连作土壤细菌总数较大豆连作处理分别下降了24.8%和31.0%,真菌总数分别下降了64.0%和51.2%;施肥条件下小麦和玉米连作土壤细菌总数则较大豆连作处理分别下降了29.0%和45.5%,真菌总数分别下降了26.7%和31.5%。Biolog结果表明,不施肥条件下小麦连作处理的平均颜色变化率(AWCD)高于玉米和大豆连作处理,施肥条件下则是大豆连作处理的AWCD值高于小麦和玉米连作处理。不施肥条件下大豆、玉米和小麦连作处理利用最多的碳源是碳水化合物类,施肥后不同连作处理利用最多的是碳水化合物类和多聚物类。大豆和小麦连作不施肥条件下土壤微生物利用率最高的碳源均是α-D-乳糖,施肥条件下利用率最高的碳源均是D,L-α-甘油,而不论施肥与否,玉米连作条件下土壤微生物利用率最高的碳源均是D-半乳糖醛酸;葡萄糖-1-磷酸盐和γ-羟基丁酸是农田黑土微生物群落特异利用的关键碳源。主成分分析得出,施肥对土壤微生物碳源代谢能力的影响大于作物的影响。     

Establishment of, and preliminary impact studies on, the rust, Maravalia cryptostegiae, of the invasive alien weed, Cryptostegia grandiflora in Queensland, Australia

The rust fungus Maravalia cryptostegiae , from south-west Madagascar, was introduced into Australia in 1995 as a classical biological control agent against the highly invasive rubber-vine weed Cryptostegia grandiflora , a woody climber endemic to Madagascar. The rust was released at 69 sites between 1995 and 1997 and is now established throughout the plant's exotic range in Queensland, estimated at over 40 000 km². Dispersal was low in the first 3–4 months but was virtually linear thereafter, and the rust spread over 100 km within the first year; after 3 years it was recorded 550 km away from the nearest release site. Spraying both dry and aqueous inoculum of uredinioid teliospores from the ground using mist-blowers, as well as from the air by atomizing spore suspensions, resulted in rust-induced defoliation, producing an overall reduction in fecundity and biomass of the weed. In sites with low water tables, weed growth decreased markedly, with a reduction in plant volume from 9 m⁻³ to 1 m⁻³ over a 4-year period. Both rust- and drought-induced stress combined to cause up to 75% plant mortality at some sites, and at all monitored sites, seedling recruitment was virtually nil. Improved growth of indigenous grasses amongst rubber-vine thickets has increased fuel loads and created opportunities to use fire as a component of an integrated approach to the management of this economically and ecologically damaging weed.     

Mercury, arsenic, and cadmium in fish, water, and sediment of American Falls Reservoir, Idaho, 1974.

Mercury and cadmium were found in fish, water, and sediment of American Falls Reservoir (AFR), Idaho. Mercury and cadmium levels in some fish exceeded human health standards set by the Food and Drug Administration, U.S. Department of Health, Education and Welfare, and the World Health Organization. Analyses performed on the flesh of rainbow trout showed mercury residues of up to 1.20 mg/kg, which were higher than residues previously reported in trout collected in 1970 and 1971 from AFR. Cadmium residue levels were as high as 0.80 mg/kg. Although arsenic was found in reservoir sediment at levels of 1.36-2.40 mg/kg, it was not detected in fish.     

Comparison of trifluralin,oryzalin, pronamide,propham, and colchicine treatments on microtubules

The mode of action of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), oryzalin (3,5-dinitro-N⁴,N⁴-dipropylsulfanilamide), pronamide(N-(1,1-dimethylpropynyl) 3,5-dichlorobenzamide), and propham (isopropyl carbanilate) on purified microtubules from pig brains and on the ultrastructure of wheat (Triticum aestivum L. “Mediterranean,” C. I. 5303) and corn (Zea mays L. “yellow dent, U. S. 13”) roots was compared with that known for colchicine. Colchicine disrupts the in vivo cortical and spindle microtubules of root cells. Like colchicine, the herbicides trifluralin, oryzalin, and pronamide caused the loss of both cortical and spindle microtubules of root cells. The rate of microtubule disappearance depended on the type of herbicide and length of exposure of roots to the herbicide. Unlike colchicine, cortical microtubules were present in propham-treated roots but they were disoriented within the cell.In vitro polymerization studies with pig brain microtubules (Sus scrofa) showed that the herbicides failed to inhibit the assembly of purified microtubular protein into microtubules and that radioactively labeled herbicides did not bind to the microtubular protein. Colchicine inhibited the polymerization of microtubular protein and readily bound to the microtubular subunits. These results indicate that the mode of action of the herbicides is not similar to that of colchicine and that the loss of microtubules from root tip cells treated with trifluralin, oryzalin, and pronamide may be caused by these herbicides interfering with synthesis of microtubular protein or metabolism of endoplasmic reticulum membranes involved in microtubule assembly. The mode of action of propham appears to be on the microtubular organizing centers rather than on microtubules per se.     

Action of some herbicides on growth,respiration, plasmalemma integrity,and proton extrusion of Acer pseudoplatanus cells: II. Amides,diphenyl ethers,nitriles, phenols,triazines, and uracils

The activity of 15 herbicides from different families was assayed on nonphotosynthetic Acer pseudoplatanus cells, in batch suspension culture. They inhibited growth, stimulated the oxygen consumption by cells, and changed the pH evolution of the culture medium. Amides did not seem to disturb the membrane properties. Some diphenyl ethers and phenols directly modified the proton compartmentation of cells whereas some other diphenyl ethers, nitriles, triazines, and uracils altered permeabilities to potassium and leucine. Changes in membrane permeabilities to protons and medium constituents were discussed.     

Modeling the Risk of Entry, Establishment, Spread, Containment, and Economic Impact of Tilletia indica, the Cause of Karnal Bunt of Wheat, Using an Australian Context

ABSTRACT Modeling techniques were developed to quantify the probability of Tilletia indica entering and establishing in Western Australia (WA), and to simulate spread, containment, and the economic impact of the pathogen. Entry of T. indica is most likely to occur through imports of bulk grain or fertilizer (0.023 +/- 0.017 entries per year and approximately 0.009 +/- 0.009 establishments per year). Entry may also occur through straw goods, new or second-hand agricultural machinery, and on personal effects of travelers who have visited regions with infected plants. The combined probability of entry and establishment of T. indica, for all pathways of entry, is about one entry every 25 years and one establishment every 67 years. Alternatively, sensitivity analysis does show that increases in quarantine funding can reduce the probability of entry to about one entry every 50 years and less than one establishment every 100 years. T. indica is spread efficiently through contaminated farm machinery, seed and soil, rain, air currents, and animals. Depending on the rate of spread of the pathogen and the amount of resources allocated for detection, the time until first detection could range from 4 to 11 years and the economic impact could range from 8 to 24% of the total value of wheat production in WA.     

Pb、Cd胁迫对紫茎泽兰N、P、K吸收的影响

采用模拟Pb、Cd污染土壤培养法研究了紫茎泽兰在重金属Pb、Cd胁迫下植株不同部位对3种营养元素(N、P、K)吸收的影响。结果表明,紫茎泽兰各组织在Pb胁迫下对N、P的吸收总体上均保持一定的促进作用,对K则表现出一定的抑制效应;Cd胁迫下对N、P有良好的吸收,低浓度Cd促进K的吸收,高浓度则表现出抑制作用。Pb-Cd复合污染胁迫下根茎叶均对N的吸收有一定的促进作用,而对K的吸收有较强的抑制效应。这表明,紫茎泽兰在重金属Pb、Cd胁迫下可通过大量吸收N、P等元素来有效缓解重金属的毒害作用,这可能也是紫茎泽兰能适应高Pb、Cd胁迫的一种耐性机制。