雪腐捷氏霉中国菌系对小麦的致病性研究

系统研究了采自中国的新疆、陕西、青海、宁夏、四川、贵州、湖北等7个省 (区)和捷克的12个雪腐捷氏霉菌系对小麦的致病性和症状特点。各菌系对小麦的各部位均有很强的致病性,但对穗部的致病性较弱。原采自红色雪腐病病株和成株雪霉叶枯病的两类菌系引起相同的症状。参试菌系间致病性强弱有明显差异,但同一菌系在小麦不同生育期对不同器官致病性的强或弱相一致。

β-1，3-葡聚糖酶基因克隆、表达及抗菌活性的研究

通过RT-PCR的方法分别从小麦和水稻的cDNA中克隆获得β-1,3-葡聚糖酶基因(Glu基因),分别命名为TaGlu9507和OsGlu30。它们的序列分析表明这两个克隆均含一个1002bp的开放阅读框(ORF),编码334个氨基酸,各自的N-端含有一个长20和29个氨基酸残基的信号肽序列。将不含信号肽序列的TaGlu9507和OsGlu30编码区DNA片段分别克隆进pET28-a(+)表达载体,并转入大肠杆菌BL21(DE3),经0.5mmol/L IPTG诱导3h后获得了高量表达,表达量分别占大肠杆菌可溶性蛋白的49.7%和26.7%,表达产物对黑曲霉、酵母等真菌生长均有较为明显的抑制作用。本结果更进一步表明β-1,3-葡聚糖酶基因是植物真菌病防治的潜在目的基因群之一。

玉米核糖体失活蛋白基因的克隆及序列分析

将提取的玉米RNA反转录成cDNA ,以此为模板 ,合成特异性引物 ,应用多聚酶链式反应 (PCR)技术扩增出目的片段。对PCR片段直接进行序列分析 ,测定并克隆玉米的核糖体失活蛋白 (RIP)基因。序列分析表明 ,已测定的玉米RIP基因序列长为 983bp ,其中编码区长 82 8bp ,共编码有 2 75个氨基酸和一个终止密码子 ,GC含量为5 8 3%。与已发表的序列相比较其核苷酸序列及推导的氨基酸序列的同源性分别为 98 4%和 97 4%。

水稻品种抗瘟性诱导机制研究

前胡、白芷的有效诱导成分主要是水溶性物质，加入粘布剂的水提物比未加粘布剂的抗性诱导效果好，所用诱导剂对稻瘟菌菌丝生长和孢子萌发均无明显的抑制作用，对水稻种子萌发及根、芽生长均无影响．前胡、白芷对水稻生长有一定的促进作用．朝六早（Ｓ）和特特勃（Ｒ）稻苗经诱导处理后，稻叶内过氧化物酶活性和多酚氧化酶活性明显增强，抗性诱导效果与两种酶活性的增加有明显的相关性．感病和抗病品种经诱导和接种后过氧化物酶同工酶活性均有所加强．诱导后稻株内脯氨酸含量无明显变化，但接种４８ｈ大量积累，９６ｈ后降至比接种前更低水平．感病品种朝六早在接种前经Ｎａ２ＳｅＯ４和前胡处理后稻叶中有抑菌物质积累，接种后诱导和未诱导的稻叶中均大量积累抑菌物质，但诱导并接种的稻叶比未诱导只接种的稻叶抑菌物质积累更多；在抗病品种上，未接种和接种的稻叶中均有抑菌物质积累。

稗叶枯菌及其毒素的研究——Ⅱ.病菌寄主范围和对稗的致病性

病原菌孢子悬浮液经人工接种可侵染稗、高梁、玉米和大麦,但不侵染水稻、小麦和小米.病菌的培养滤液稀释液对稗、高粱、小米表现毒性,对水稻、小麦、玉米、大麦不表现毒性.用培养滤液配成的孢子悬浮液接种2叶期稗苗.10d 后最高死苗率为60.5%,病情指数为86.63.

湖南省辣椒疫病的流行规律

报道了辣椒疫病（ＰｈｙｔｏｐｈｔｈｏｒａｃａｐｓｉｃｉＬｅｏｎ）在湖南的发生概况，品种抗性和发生流行规律．６～７月份温度在２５～３０℃，雨水多，该病即可大发生，连作地较轮作地发病重，高畦栽培可减轻病害的发生．本地品种河西牛角辣椒抗病，而湘研１号、湘研５号易感病．还对该病的综合防治提出了建议．

稗叶枯菌及其毒素的研究——Ⅰ. 病原鉴定及产孢产毒条件

从稗叶枯病株分离病原菌(Helminthosporium monoceras D rechsler)11个菌株,其培养滤液均可抑制稗的胚根生长,与对照比胚根平均相对生长率为28.47%～53.60%,适于菌株的生长和毒素产生的培养液为10%稗汁葡萄糖和改良Fires培养液,适于菌株生长和产毒的温度为25～30℃,pH 6～7.通气有利于菌株的生长,但对产毒无显著影响,连续光照或连续黑暗有利于菌株产毒,菌株在pH 6～7的PDA培养基上,于30℃连续黑暗的培养产孢量最多。

水稻品种抗瘟性诱导效果研究

研究了Ｎａ２ＳｅＯ４，ＭｎＳＯ４，ＦｅＣｌ３和前胡和白芷诱导水稻对稻瘟病的抗性．在苗期，几种诱导剂处理丽江新团黑谷、朝六早品种，相对抗性诱导的效果分别为１３．１７％～６４．３０％和１２．０２％～６８．６２％，其中以白芷的诱导效果最好，浸种＋喷雾处理比单独浸种或喷雾处理的抗性诱导效果好．几种诱导剂使用的最佳浓度分别为：ＭｎＳＯ４２００ｍｇ／ｋｇ，Ｎａ２ＳｅＯ４１０－４“ｍｏｌ／Ｌ，前胡１００倍水，白芷１００倍水．在穗期，用前胡、白芷和ＭｎＳＯ４，Ｎａ２ＳｅＯ４，ＦｅＣｌ３，处理８７－１５６品种，其中Ｎａ２ＳｅＯ４和白芷对穗颈瘟获得了较好的抗性诱导效果，分别为３３．１４％～５４．６４％和３９．８６％～５５．７７％。圆秆后３０ｄ喷雾处理效果最佳，抗性诱导效果随喷雾次数的增加而增加．

Recent Achievements in the Bio-control of Orobanche Infesting Important Crops in the Mediterranean Basin

Orobanche spp. （broomrapes） are holoparasitic plants distributed predominantly in the Northern Hemisphere parasitizing the roots of a range of plant species mainly in wild ecosystems. Orobanche species cause severe yield reduction of many important crops. There are only very few herbicides which are able to selectively control broomrapes and different approaches have been put forward to develop natural product based pesticides to control Orobanche. Several phytopathogenic fungi were evaluated for their use as potential mycoherbicide and for ability to produce toxic metabolites which could be applied as herbicides. Using the alternative approach ＂suicidal germination＂, interesting results were obtained by testing two microbial metabolites （fusicoccins and ophiobolin A） especially with Orobanche species whose germination is not induced by the synthetic strigolactone GR24. From pea root exudates, peagol and peagoldione, close related to strigolactones, and three polyphenols, named peapolyphenols A-C, together with already well known polyphenol and a chalcone, were isolated. They showed a selective stimulation of Orobanche seed germination with the last two and peapolyphenol A showing a specific stimulatory activity on O. foetida. This review describes the most recent results achieved on Orobanche bio-control, mainly focusing on those regarding O. ramosa, O. crenata and O. foetida.

Effect of Some Biopreparations on Health Status of Strawberry （Fragaria ananassa Duch.）

The study aimed at comparing the effect of selected biopreparations （Boni protect forte, beta-chikol, Trianum P） and fungicide treatment Switch 62.5 WG （cyprodinil ＋ fludioxonil） on the health status of strawberry grown in the fruiting field at the strawberry farm in Jasionka, Lublin region. The experiment was conducted for three years （2012-2014）. Results showed that the application of all biopreparations and fungicide significantly reduced the number of diseased plants and the disease index. The effect of three biological products was similar. The mycological analysis of plants showed that among the fungi potentially pathogenic to strawberry, Fusarium spp., Cylindrocarpon spp., Botrytis cinerea and Alternaria were predominated. The fewest colonies of pathogenic fungi were isolated from plants treated with Trianum P.

Proteomic study of three component interactions: plant, pathogens and antagonistic fungi

The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean, tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi (Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The proteome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens, the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots. In silico analysis of some of those spots revealed homology with intracellular enzymes (GTPases, hydrolases) and with stress-related proteins (heat shock proteins HSP70, bacteriocin cloacin). Specific proteins in the plant proteome, i.e. pathogenesis-related proteins, have been identified during the in vivo interaction of bean with R. solani and T. atroviride strain P1. This is in agreement with the demonstrated ability of these beneficial fungi to induce plant systemic disease resistance by activating expression of defence-related genes. Proteins extracted from T. atrovride strain P1 which were analysed by mass spectrometry, revealed some interesting homologies with a fungal hydrophobin of Pleurotus ostreatus and an ABC transporter of Ralstonia metallidurans. These could represent molecular factors involved in the antagonistic mechanisms of Trichoderma and play a role in the three-way interaction with the plant and other microbes.

Effect of rare earth application on the growth of Trichoderma spp. and several plant pathogenic fungi

Rare earth elements (REEs) enriched fertilisers are currently used in China for soil and foliar applications to crops, but little is known about the effect of REEs applications on the growth of beneficial and detrimental soilborne microorganisms. The growth of biological control agents Trichoderma atroviride strain P1, Trichoderma harzianum strain A6 and strain T22, plant pathogens Botrytis cinerea, Alternaria alternata, Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum was investigated in the presence of REEs. An in vitro assays was used to monitor the effect of different concentration levels of either a mix of REEs (La, Ce, Pr, Nd) nitrates or lanthanum alone in comparison to treatments conducted with potassium nitrate and water. Although all fungi were affected when the REEs mix or lanthanum were present at concentrations higher than 100 mM, the growth inhibition depended mainly upon the combination of compounds, the dose and the fungal species or strains tested. Trichoderma strains and B. cinerea were more sensitive than A. alternata, F. solani, R. solani or at higher concentrations. Differing growth responses of some fungi to treatments with REEs mix vs. lanthanum alone indicated that in given situations the effect of the REEs compounds may be caused by elements other than lanthanum or by element mixtures. Further investigations are in progress to determine the effect of REEs on important interactions in the soil community between beneficial fungi, pathogenic fungi and/or the plant. REEs are naturally present in the environment and in biological systems but accumulation in soil can take place following successive applications. Therefore, it would be useful to achieve a better understanding of the effect of REEs accumulation on the activity of rhizosphere microorganisms given the widespread use in some regions of rare earths as fertilizers and their presence as fertilizer contaminants.

Alteration in Biochemical Response in Sesamum indicum upon Different Plant-Pathogen Interactions

Sesamum, an important oil yielding crop suffers a huge loss in its yield due to attack of large number of fungal pathogens. In semi-arid regions Sesamum is mainly affected by two major plant-pathogenic fungus viz. Macrophomina phaseolina and Fusarium oxysporum. The aim of the study was to analyze the metabolic alterations in Sesamum after infection with both pathogens. This accomplished by individually by （the word estimating is not quantitative） the levels of total phenolic compounds and the activities of phenylalanine ammonia lyase （PAL） of one week old plants. The PAL showed high activity in infected plants, revealing the active phase in the synthesis of secondary metabolites in the Sesamum plant after infection. As a consequence, in infected plants the contents of polyphenols along with salicylic acid （SA） considerably exceeded when compared to control plants. This in vivo study of M. phaseolina and F. oxysporum infection reveals the differences of resistance levels in sesame against these two pathogens. These results provide important information regarding the plant-pathogen interactions and also forfor Sesamum improvement programs seeking the adaptation to diverse range of fungal attack along with adverse environmental factors.

Airborne Fungal Spores of Subalpine Zone of the Karkonosze and Izerskie Mountains(Poland)

The incidence of the airborne fungal spores was determined in the air of subalpine zone of the Karkonosze Mountains and of the Izerskie Mountains in the borderland between Poland and the Czech Republic. The experiment was conducted in2011 and 2012 at three to four week intervals from May to October. Air samples were taken from three locations in the Karkonosze Mts. and one from the Izerskie Mts. To examine the air, the Air Ideal 3P sampler and acidified PDA medium were used. The results show that Cladosporium cladosporioides was the most abundant spore type in all the sampling locations(up to 30%), followed by Alternaria alternata(16%–20%), Fusarium(up to 10%) and Sclerotinia sclerotiorium(up to 6%). The lower spore counts were recorded in May samples, compared to the other months. In this case the snow cover, that was still present in the area at the beginning of May,may be the reason for the lower, compared to June,July and August samplings, CFU(Colony Forming Unit) counts in that month.. The influx of air masses from SE, S and SW sectors in the area under study may affect dissemination of the plant-pathogenic fungi from the Czech Republic and from the South of Europe in general.

In Vitro Hyphal Growth Inhibition of Plant Pathogenic Fungi by Corrigiola Telephiifolia Extracts

The sugar beet root rot and Bayoud disease, respectively caused by Sclerotium rolfsii and Fusarium oxysporum albedinis, are major agricultural problems in Morocco, affecting its economical and social conditions. As of now, no effective control method of these phytopathogens is available. Therefore the search for new efficient and ecologically undamaging fungicides was essential. The present study reports the antifungal activity of five organic extracts of Corrigiola telephiifolia Pourr., a Moroccan medicinal plant, against these fungi using mycelial growth inhibition assays （in vitro）. The extracts concentration varied from 0.01 to 1 mg.mlt. Also, preliminary information on the chemical composition of the extracts is included. The results showed a difference in sensitivity of both fungi toward the plant extracts. The mycelia growth of Sclerotium rolfsii was concentration and time-dependant. It was markedly inhibited by the polar extracts especially at high dose （p〈 0.001）. While Fusarium oxysporum f. sp. albedinis was much less sensitive.

Polymorphism of microsatellite sequence within signal transduction coding genes in phytopathogenic fungus, Magnaporthe grisea

Sixteen polymorphic microsatellite markers suitable for population genetic structure analysis and signal transduction coding genes variation measurement were developed for rice blast fungus, Magnaporthe grisea. Polymorphism was evaluated by using forty-six isolates collected from diverse geographical locations （including japonica grown zone, indica grown zone） and rice varieties. Preliminary results indicated that each locus resolved multiple alleles ranging from three to fourteen. The results showed that these SSR-containing genes are also polymorphic in the nature population.

Overexpression of GhPFN2 enhances protection against Verticillium dahliae invasion in cotton

Growing evidence indicates that actin cytoskeleton is involved in plant innate immune responses, but the functional mechanism remains largely unknown. Here, we investigated the behavior of a cotton profilin gene （GhPFN2） in response to Verticillium dahliae invasion, and evaluated its contribution to plant defense against this soil-borne fungal pathogen. GhPFN2 expression was up-regulated when cotton root was inoculated with V. dahliae, and the actin architecture was reorganized in the infected root cells, with a clear increase in the density of filamentous actin and the extent of actin btmdling. Compared to the wild type, GhPFN2-overexpressing cotton plants showed enhanced protection against V. dahliae infection and the actin cytoskeleton organization in root epidermal cells was clearly altered, which phenocopied that of the wild-type （WT） root cells challenged with V. dahliae. These results provide a solid line of evidence important for defense against V. dahliae infection. showing that actin cytoskeleton reorganization involving GhPFN2 is

The role of soil-borne fungi in driving the coexistence of Pinus massoniana and Lithocarpus glaber in a subtropical forest via plant-soil feedback

Aims Plant–soil feedback(PSF)is a key mechanism that can facilitate tree species coexistence and diversity.Substantial evidence suggests that species-specific soil-borne pathogens around adult trees limit the performance of home(conspecific)seedlings relative to foreign(heterospecific)seedlings.However,the underlying mechanism remains largely elusive.Methods Here,we conducted a reciprocal transplant pot experiment using seedlings and from two tree species,Pinus massoniana and Lithocarpus glaber that are dominant and coexist in a subtropical,evergreen,broad-leaf forest in Gutianshan,Zhejiang Province of eastern China.We examined how seedlings from the two tree species responded to soils originating from underneath their own versus the other tree species,using a full-factorial design.Additionally,we added a fungicide(benomyl)to half of the pots to evaluate the role of soil-borne fungi on seedling growth.Important Findings We found that the seedlings from L.glaber grew better in soils that were collected from beneath the canopy of P.massoniana,while seedling growth of P.massioniana was not affected by soil origin.The addition of fungicide benomyl resulted in a shift towards more positive PSF effects for L.glaber,indicating that L.glaber seedlings performed better in their own soils than in soils from P.massoniana in the absence of fungi.Our findings highlight the importance of soil-borne pathogenic and ectomycorrhizal fungi in driving PSF,and indicate that PSF may promote the coexistence of two subtropical tree species by reducing the performance of L.glaber in own soils.

Correlation between Chemical Structure and Biological Activity of Host-Selective Plant Pathogen Mycotoxins

Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.