大豆灰斑病菌生理小种同功酶分析

 本文首次利用聚丙烯酰胺凝胶电泳技术对黑龙江省大豆灰斑病菌10个生理小种进行了酯酶等5种同功酶及可溶性蛋白的分析。分析结果表明各供试小种间存在着同功酶表型异质性。小种间相似系数在0.22~0.96之间,且分析出4号小种与其它小种亲缘关系最远,具有特殊的遗传背景。进一步从生化角度证明灰斑病菌致病力有一定的差异。同时建议制定一套同功酶标准图谱作为生产上监测生理小种毒力变异工作的辅助性手段。     

运用随机扩增多态性DNA标记检测中国东北大豆灰斑病菌株遗传变异

 运用致病力和DNA多态性检测中国东北地区的35个大豆灰斑病菌分离物的遗传变异、根据菌株在9个品种(系)上的致病力反应可将其分为7个组。利用13个随机引物扩增供试菌株共计产生105个RAPD标记,其中78.1%具有多态性。通过聚类分析计算了各菌株间的遗传距离,并产生树状图,发现同一地区内及不同地区间的病菌表现遗传变异、致病性和DNA多态性间具有一定相关性。     

通径分析在大豆灰斑病流行研究中的应用

本文应用通径分析的原理，对１９８０～１９９２年大豆灰斑病的试验资料进行分析，力图剖析大豆灰斑病发生发展中各气象因子的相对重要性和相互关系，在所选定的七个气象因子中，确定了大豆开花后２０～３５ｄ之间降雨量、ＴＲＨ日、降雨日数和相对湿度等为主导因子，并在此基础上建立了流行预测模型。     

运用随机扩增多态性DNA标记检测中国东北大豆灰斑病菌遗传变异(英文)

运用致病力和ＤＮＡ多态性检测中国东北地区的３５个大豆灰斑病菌分离物的遗传变异,根据菌株在９个品种（系）上的致病力反应可将其分为７个组,利用１３个随机引物扩增供试菌株共计产生１０５个ＲＡＰＤ标记,其中７８．１％具有多态性．通过聚类分析计算了各菌株间的遗传距离并产生树状图,发现同一地区内及不同地区间的病菌表现遗传变异,致病性和ＤＮＡ多态性间具有一定相关性．     

Impact of intercropping on epidemics of groundnut leaf spots: defining constraints and opportunities through a 7‐year field study

Plant diversity can have a profound impact on disease dynamics, with important applications for enhancing sustainability. Disease is often reduced by intercropping, but variability can be high. This study investigated integration of several management approaches to stabilize this variability for early leaf spot (ELS) and late leaf spot (LLS) of groundnut, over seven seasons in three phases. In phase 1, monocrops and alternating row and strip intercrops with maize were artificially inoculated with ELS in an area with little groundnut production. Reductions in AUDPC of 37–73% in strip treatments compared to monocrops prompted testing of the efficacy of intercropping in intensive production areas for phases 2 and 3. Additional treatments included cotton strip intercrops, and integration of intercropping with reduced fungicide treatments and partial resistance to leaf spots. In phase 2, the use of cotton strip intercrops lowered natural ELS epidemics by 25–41% (AUDPC) through delayed disease onset, but maize had inconsistent effects. Intercropping was not effective against LLS, which dominated in phase 3. Reduced fungicide regimes and partial resistance lowered disease, and in one case interacted with intercropping to enhance disease suppression. Groundnut yields generally were inversely proportional to disease levels and not significantly reduced by intercropping. Separate studies to determine maize impacts on ELS infection implicated disruption of dispersal as the mechanism of disease reduction. This work demonstrates that intercropping may be most effective where low levels of ELS are present, using strip patterns with cotton, and combined with other tools such as resistance and reduced fungicide application.     

Effect of the new pyrazole carboxamide fungicide penthiopyrad on late leaf spot and stem rot of peanut

BACKGROUND: Management of early leaf spot (Cercospora arachidicola Hori.), late leaf spot [Cercosporidium personatum (Berk. & MA Curtis) Deighton] and stem rot (Sclerotium rolfsii Sacc.) of peanut (Arachis hypogaea L.) in the southeastern USA is heavily dependent upon sterol biosynthesis inhibitor (SBI) and quinone outside inhibitor (QoI) fungicides. Effective new fungicides with different modes of action could improve overall disease control and extend the utility of the current fungicides. Penthiopryad is a pyrazole carboxamide fungicide being evaluated for use on peanut. Field experiments were conducted from 2004 to 2007 to determine the effect of a range of rates (0–0.36 kg AI ha^?1) of penthiopyrad on leaf spot and stem rot and the relative efficacy of penthiopyrad and current fungicide standards chlorothalonil, tebuconazole and azoxystrobin. RESULTS: Leaf spot control in plots treated with penthiopyrad at 0.20 kg AI ha^?1 or higher was similar to or better than that for the chlorothalonil standard. The incidence of stem rot for all penthiopyrad treatments was usually less than that for the tebuconazole or azoxystrobin standard treatments. Pod yields for all penthiopyrad treatments were similar to or higher than those for the respective standards. CONCLUSION: Penthiopyrad has excellent potential for management of late leaf spot and stem rot of peanut, and may complement current SBI and QoI fungicides. Copyright © 2008 Society of Chemical Industry     

大豆灰斑病发生发展规律的研究

１９８０～１９８９年利用室内和室外试验相结合的方法研究了黑龙江省密山虎林地区大豆灰斑病的再侵染条件，初步结果表明大豆叶片病斑在温度２４℃左右，日保湿润１６ｈ以上最利于病菌产孢。病菌孢子在温度２２℃条件下生命力６～１１ｄ，高温环境不利于病菌孢子存活。大豆成林期叶部发病程度取决于日平均气温高于１８℃、日最低温度高于１２℃及日平均相对湿度大于８０％或有降雨量多于０．１ｍｍ的气象条件出现的日数。大豆籽粒发病率与大豆开花后２０～３５ｄ之间的降雨量、雨日、平均相对温度、日平均湿度≥２０℃且日平均相对湿度≥８５％的天数呈显著正相关。     

Potential for Incorporation of Early and Late Leafspot Resistance in Peanut*

A detached leaf technique was used to evaluate components of resistance to both early and late leafspot caused by Cercospora arachidicola Hori and Cercosporidium personatum (Berk, and Curt.) Deighton, respectively, for F₂ plants of two peanut (Arachis hypogaea L.) crosses (FESR 5-P2-B1 /PI 269685 and PI 35068Q/GP-NC 343), No negative correlations were obtained when comparing components of resistance to early leafspot with components of resistance to late leafspot, indicating that the resistances are inherited independently. A small number of F₂ plants had greater partial resistance to both leafspots than their parents when evaluated by an index including percent necrotic area, latent period and sporulation. Broad sense heritabilities of resistance components were moderate to high (0.4 to 0.8) for the F₂ populations. A visual sporulation rating scale was significantly correlated (0.8 to 0.9) with conidia per lesion and conidia per necrotic area. The data suggest that peanut cultivars resistant to both leafspots can be developed.     

Enquête sur les maladies fongiques de l'arachide (Arachis hypogaea) en Côte-d'Ivoire. II. Epidémiologie de la rouille de l'arachide (Puccinia arachidis)

Résumé Des données ont été rassemblées sur les maladies foliaires de l'arachide, et notamment, sur la rouille, au cours d'une enquête dans les cultures traditionnelles de Côte d'Ivoire. Des interprétations sont proposées à partir d'analyses factorielles des correspondances, et d'analyses en composantes principales. Les caractéristiques épidémiologiques de la rouille qui se dégagent de cette étude sont: des exigences assez strictes vis-à-vis du régime des pluies et de la température, an développement qui est lié au bon état physiologique de l'hôte, et une forte propension de la maladie à se propager à moyenne et grande échelles. Ces caractéristiques s'opposent à celles des cercosporioses, et en particulier, à la cercosporiose due àCercospora arachidicola. Cette maladie ne présente pas, en effet, d'exigences climatiques très marquées, se développe dans des stations d'aspect médiocre et ne possède pas les mêmes capacités de dispersion. Les résultats concernant la rouille sont en bon accord général avec les données obtenues précédemment au cours d'études monocycliques. Ils mettent, enfin, en évidence les risque problables qui accompagneraient un processus d'intensification de la culture.

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A survey of fungal diseases of groundnut (Arachis hypogaea L.) in Ivory Coast. II. Epidemiology of the groundnut rust (Puccinia arachidis)

A survey was conducted in small farmers' fields in Ivory Coast to study the foliar diseases of groundnut caused by fungi. The results were interpreted by use of correspondence and principal component analyses. Some epidemiological features distinguish groundnut rust fromCercospora leaf-spots: marked weather requirements for its optimal development, a preference for vigorous plants of well-tended crops, and strong dispersal abilities at mesoscale and macroscale. These characteristics contrast with those ofC. arachidicola, which has a wider range of suitable weather conditions, and causes severe attacks in poor stands. Results are in good agreement with previous monocyclic studies. This study points at the probable risks which would accompany an intensification process in groundnut cultivation.Samenvatting Bij een enquête naar de teelt van aardnoot door kleine boeren in Ivoorkust werden gegevens verzameld over de bladziekten, vooral over de aardnootroest. De gegevens werden statistisch bewerkt met behulp van factoriële correspondentie-analyse en principale componenten-analyse. Deze analyses leidden tot een aantal epidemiologische kenmerken van de roest: tamelijk strikte eisen aan regenval en temperatuur, een ont-wikkeling gekoppeld aan een goede fysiologische toestand van de waard, en een sterke neiging van de schimmel tot verspreiding over midden-lange en lange afstanden.Voor de cercosporiosen, in het bijzonder die veroorzaakt doorCercospora arachidicola, gold het tegendeel. Deze ziekte had geen uitgesproken milieu-eisen, ontwikkelde zich op middelmatige standplaatsen, en had veel minder mogelijkheden tot verspreiding. De resultaten verkregen voor de roest waren in goede overeenstemming met de gegevens eerder verkregen uit monocyclische studies. Zij tonen de risico's die waarschijnlijk gepaard zullen gaan aan een proces van intensivering van de aardnootteelt.