VA菌根对茄子、黄瓜、籽瓜促生防病效应的研究

在盆栽条件下研究了ＶＡ菌根茵对茄子、黄瓜、籽瓜的侵染、促生和防病作用。结果供试菌均可侵染供试作物，但促生和防病效应具特异性．Ｇｌｏｍｕｓ．Ｖｅｒｓｉｆｏｒｍｅ和Ｇ．ｍｏｓｓｅａｅ均促进茄子的生长，但只前者减轻了茄子黄萎病。Ｇ，ｓｐ３促进黄瓜提早开花，但不防病；Ｇ．ｍａｃｒｏｃａｒｐｕｍ减轻了黄瓜细菌性角斑病的发生，却并无促生作用。Ｇ．ｓｐ４不但促进籽瓜的生长，而且是短期内减轻籽瓜炭疽病的有效组合。     

Fusarium oxysporum对苗期大豆根部的致病性和侵染规律

Fusarium oxysporum对苗期大豆具有较强的致病作用。病原菌自伤口或直接侵入大豆幼苗根部的皮层组织,随着病原菌的侵入和扩展,细胞出现坏死,组织发生崩解,根部组织表现红褐色病斑。环境因素对病原菌的侵染时期和在大豆体内潜育时间的长短有着明显的影响。侵染时期主要受病原菌侵入前自身所处状态和寄主的影响,侵入后潜育时间的长短则受植株状态的影响。土壤环境条件直接影响着病原菌的侵入和寄主的抗病性,间接影响着病原菌在大豆植株体内的扩展和病症的表现。     

松材线虫病入侵陕西的风险分析

松材线虫病自1982年在我国发现后，扩散和危害呈逐年扩大和加重趋势，严重影响了我国生态安全和经济发展。本文通过对松材线虫病定量的风险分析，得出风险值R=2．775，表明松材线虫病对陕西省而言属于特别危险的林业有害生物，应加强监测、检疫和除治管理，防止传入陕西省并造成扩散危害。     

叶面喷施丰产素在黄瓜上的应用效果

本试验在黄瓜上叶面喷施丰州牌丰产素，其浓度分别为２０００倍、４０００倍和６０００倍。试验结果表明，３种浓度对黄瓜的生长势都有增强的作用，并对早期产量有较大的提高。其中２０００倍液对早期产量的增产幅度最大，比对照提高４２．８１％。并且对黄瓜的营养成份有不同程度的影响，其中６０００倍液对维生素ｃ和含糖量都有较大的提高，因此，对黄瓜品质的改进有较好的效果。     

棉花枯、黄萎病菌营养亲和性研究进展

介绍了棉花枯、黄萎病菌营养亲和性研究方法和营养体亲和群研究,并着重总结了利用营养亲和群结合DNA多态性技术,研究尖孢镰刀菌(FusariumoxysporumSchlechtend:Fr)专化型、生理小种、亲和群之间的关系,以及棉花黄萎病菌(VerticilliumdahliaeKleb.)亲和群与致病型关系的研究进展。     

Pelargonium flower-break and pelargonium line pattern viruses in the Netherlands; purification,antiserum preparation,serological identification,and detection in pelargonium by ELISA

Two viruses, detected frequently in the Netherlands in pelargonium, were identified by serology and test plant reactions. Antisera were prepared and an ELISA procedure was developed to detect the viruses in pelargonium.One of the viruses, PFBV-N, proved to be pelargonium flower-break virus. With the antiserum to PFBV-N, it could be detected reliably throughout the year inPelargonium zonale Springtime Irene.The other virus, PLPV-N, was serologically closely related to pelargonium line pattern virus (PLPV) and to pelargonium ring pattern virus (PRPV), as were an old virus isolate from Saturnus, collected in the Netherlands in 1971 (L128), and PLPV isolates from Yugoslavia (PLPV-Y) and Denmark (PLPV-D). There were only minor differences in host-plant reactions between the virus isolates. Based on these tests, PLPV and PRPV are considered as isolates of the same virus, for which, for practical reasons, the name pelargonium line pattern virus is proposed.PLPV could be reliably detected by ELISA inP. zonale Springtime Irene and Amanda throughout the year with only a few exceptions. InPelargonium peltatum Tavira, however, reslts were erratic due to uneven distribution of virus in the plant. Best results were obtained when petioles of fully expanded leaves were tested.     

Fusarium head blight and mycotoxin contamination of wheat,a review

Summary An infection of bread wheat by fusarium head blight contaminates the crop with mycotoxins, particularly deoxynivalenol (DON) and nivalenol (NIV). The toxicity and natural occurrence of these mycotoxins in wheat are reviewed. Based on 8 years data of fusarium head blight epidemics of wheat in the Netherlands, DON contamination of the grain was estimated. Fusarium head blight ratings averaged an infection of 1.7% of all spikelets; estimates for DON contamination averaged 0.9 mg kg^–1. Taking a guideline level for DON in uncleaned bread wheat of 2 mg kg^–1, in 1979 and 1982 a wheat crop was produced with estimated DON concentrations above the limit of tolerance. Human and animal exposure to mycotoxins in the Netherlands appears to be small but chronic. The information presented in this paper illustrates the need for an annual evaluation of the crop for fusarium head blight incidence and mycotoxin content, and the necessity of fusarium head blight resistant wheat cultivars.Samenvatting Aaraantasting van tarwe doorFusarium culmorum enFusarium graminearum leidt tot vorming van mycotoxinen in het graan, waarvan deoxynivalenol (DON) en nivalenol (NIV) de belangrijkste toxinen zijn. In dit artikel wordt een overzicht gegeven van de toxicologische aspecten, en het voorkomen van deze toxinen in tarwe. Informatie over DON en NIV in tarwe in West-Europa is schaars. Gebaseerd op gegevens vanFusarium epidemieën in de jaren 1979–1986 wordt een schatting gegeven van de concentratie DON in Nederlandse tarwe. Rekening houdend met de herkomst en verwerking van tarwe, blijken zowel in dierlijk als menselijk voedsel lage concentraties DON chronisch voor te komen. Op basis van een maximaal toelaatbare dagelijkse dosis DON van 3 g kg^–1 lichaamsgewicht is de schatting van de dagelijkse opname van DON in het jaar volgend op de oogst van 1982 net op de grens. Zowel een jaarlijkse inventarisatie vanFusarium aantasting en DON besmetting van het graan, als de ontwikkeling vanFusarium-resistente rassen zijn noodzakelijk.     

不同砧木嫁接网纹甜瓜试验

为预防网纹甜瓜枯萎病等土传病害,以新土佐、灰甘瓜、全能铁甲南瓜,甬砧3号甜瓜为砧木,以当地主栽的拿玻里网纹甜瓜为接穗,进行嫁接试验。结果表明:拿玻里网纹甜瓜嫁接后,植株的抗病性有了显著提高,对枯萎病的防效高达100%,对白粉病的防效也有所提高,综合抗性增强。其中甬砧3号在4个参试砧木品种中,与接穗拿玻里网纹甜瓜的亲和性最好,抗病性提高明显,品质也较自根苗好。     

Effects of Latent Infection of Stock Plants and Abundance of Thrips on the Occurrence of <Emphasis Type="Italic">Tomato spotted wilt virus </Emphasis>in Chrysanthemum Fields

DAS-ELISA proved to be reliable enough to detect a latent infection by Tomato spotted wilt virus (TSWV) in asymptomatic stock plants of chrysanthemum. A high density of Frankliniella occidentalis, the predominant vector, in the presence of latently infected stock plants resulted in a high incidence of disease in the chrysanthemum production field. The incidence of disease was low when the vector thrips were not abundant in spite of the presence of latently infected stock plants. These results suggest that an infestation of the vector thrips causes severe secondary spread of TSWV originating from latently infected stock plants in chrysanthemum production fields. Received 27 July 2001/ Accepted in revised form 27 November 2001     

Physiological Races and Vegetative Compatibility Groups of Fusarium oxysporum f. sp. lactucae Isolated from Crisphead Lettuce in Japan

One hundred and sixteen isolates of Fusarium oxysporum f. sp. lactucae obtained from 85 fields in three crisphead lettuce-producing areas in Nagano Prefecture, Japan were typed for races using differential cultivars Patriot, Banchu Red Fire and Costa Rica No. 4. They were also grouped into vegetative compatibility groups (VCGs) using complementation tests with nitrate non-utilizing (nit) mutants. Two California strains reported as F. oxysporum f. sp. lactucum, a type culture of F. oxysporum f. sp. lactucae, and 28 avirulent isolates of F. oxysporum obtained from crisphead lettuce were included for comparison. Among Nagano isolates, 66 isolates were identified as race 1, and 50 as race 2. Race 1 strains derived from Shiojiri and Komoro cities and race 2 from Kawakami village and Komoro city. All isolates of race 2 were biotin auxotrophs, and the race could be distinguished based on its requirement for biotin on minimal nitrate agar medium (MM). Pathogenic isolates were classified into two VCGs and three heterokaryon self-incompatible isolates. Strong correlations were found between race and VCG. All the race 1 strains were assigned to VCG 1 except self-incompatible isolates, and all the race 2 strains to VCG 2. The 28 avirulent isolates of F. oxysporum were incompatible with VCG 1 and VCG 2. California strains was vegetatively compatible with VCG 1, and they were assigned to race 1. Based on vegetative compatibility, these two races of F. oxysporum f. sp. lactucae may be genetically distinct, and F. oxysporum f. sp. lactucae race 1 is identical to F. oxysporum f. sp. lactucum. Received 7 May 2002/ Accepted in revised form 6 September 2002