芹菜斑枯病菌生物学特性研究

以沈阳地区芹菜斑枯病菌的纯培养菌株为试材,通过对菌丝生长、孢子萌发的营养及环境条件的多因子试验,明确了芹菜斑枯病菌菌丝生长以在CDAMS—VI培养基上最好,其次是CSA、CCSA和PDA,菌丝生长及产孢对碳源、氮源种类有明显的选择性。菌丝生长的最适pH值为4～5,最适温度为21℃,致死温度为39℃（处理40min）,光照明显抑制菌丝生长。病菌分生孢子在水和芹菜汁中不能萌发,在水琼脂上萌发最好;孢子萌发的适宜pH值为4．6～6．6,适温为17—25℃,致死温度为42℃（处理20min）,RH100％最适宜孢子萌发。光照和变温处理可促进分生孢子器的形成,病菌在PDA上从孢子萌发到分生孢子器形成并释放出分生孢子需要16～18d。     

草坪草离体再生培养的研究现状及发展前景

草坪业是近年来我国兴起的一个新产业.草坪草的品质直接关系到草坪的质量和寿命.为了适应当前草坪业的需要,科学工作者不断寻求各种途径选育新品种.离体再生培养无疑是其中十分有效的手段之一.主要阐述了草坪草离体再生培养的研究意义和现状,并展望了离体再生培养应用于草坪草新品种选育的美好前景.     

河北省玉米小斑病菌玉米离蠕孢dsRNA病毒的检测及带毒菌株的生物学特征

玉米小斑病是我国玉米生产上的重要病害之一,每年造成玉米大幅减产.真菌病毒能够在真菌体内进行复制和繁殖,可以作为生物防治的潜在资源.为了明确河北省玉米小斑病菌玉米离蠕孢dsRNA病毒的多样性及生物学特性,为玉米小斑病的防控提供潜在生防资源,本研究采用单孢分离的方法分离纯化玉米小斑病菌150株,通过dsRNA提取及凝胶检测...     

长蠕孢菌产孢条件的研究

对番茄褐斑病原菌—长蠕孢菌产孢条件进行了研究,结果表明燕麦片琼胶培养基、Czapek培养基和PDA＋番茄叶片能促进产孢子,V8汁、PSA和番茄汁培养基抑制产孢;碳源果糖明显促进产孢,甘露醇抑制产孢子;氮源氯化铵促进产孢,蛋白胨和硫酸铵抑制产孢;光照和紫外线照射对长蠕孢菌产孢有明显促进作用,特别是紫外线照射60～80min时产孢量达到最大;偏低温或偏高温以及微碱性环境能促进长蠕孢菌产孢,温度为15℃或30℃,pH8～9时最有利于产孢。     

麦根腐平脐蠕孢有性生殖生物学研究

本文报道麦根腐平脐蠕孢Bipolaris sorokiniana(有性型为Cochliobolus sativus)人工诱导形成子囊座,并获得该菌A和a两种不同交配型。子囊座形成的最佳条件是:以麦秆浸汁琼脂为培养基(pH6—6.5)。以透析袋为培养基物,24℃培养1周,移至20℃培养2周。培养中光照不是重要因素。在无培养基物的培养基上不形成子囊座。对不同地区、不同寄主植物上麦根腐平脐蠕孢72个菌株交配型测定结果,两个不同交配型在自然界分配比例为1:1,交配型菌株的分布与地理、寄主植物的差异无相关性。     

华蟹甲草对几种植物病原真菌的离体抗菌活性研究

从华蟹甲草共获得46个提取、分离样品,首先测定这些样品在100 mg/L浓度下对5种植物病原真菌菌丝生长的抑制活性,然后测定活性较高的Y-S16/23～90/96号样品对9种真菌菌丝生长的有效抑制中浓度(EC50)以及对辣椒炭疽病菌孢子萌发的抑制作用.结果表明:对于华蟹甲草的不同组织器官,花提取物的活性相对最高,对供试的5种植物病原菌均有不同程度的抑制活性,其次是叶片提取物,但均是对辣椒炭疽病菌的活性最高;而在所有样品中,Y-S16/23～90/96号样品的活性最高,在100 mg/L浓度下对辣椒炭疽病菌和番茄灰霉病菌的菌丝生长抑制率均超过50%,其作用谱较广,对供试的9种植物病原真菌均有抑制活性,其中对番茄灰霉病菌和辣椒炭疽病菌的活性最高,EC50分别为68.96和99.17 mg/L,对黄瓜疫霉病菌、苹果腐烂病菌、玉米小斑病菌等3个病菌的活性次之,EC50介于137.37～161.68 mg/L之间,对水稻稻瘟病菌、辣椒疫霉病菌、苹果斑点落叶病菌、小麦赤霉病菌等4个病菌的活性相对较差,EC50介于303.05～362.54 mg/L之间;Y-S16/23～90/96号样品对辣椒炭疽病菌分生孢子萌发的抑制活性较低.     

被内生真菌侵染的禾草提取液对真菌的抑制作用

以带有与不带有Neotyphodium属内生真菌的醉马草Achnatherum inebrians、披碱草Elymus dahuricus和野大麦Hordeum brevisubulatum的草粉浸提液对细交链孢Alternaria alternata、根腐离蠕孢Bipolaris sorokiniana、燕麦镰孢Fusarium avenaceum和绿色木霉Trichoderma viride进行了抑菌活性研究。结果表明:披碱草、醉马草和野大麦草粉浸提液对细交链孢、根腐离蠕孢、燕麦镰孢和绿色木霉的菌落生长、孢子萌发率和芽管长度均有一定的抑制作用。而披碱草中的Neotyphodium可显著增强披碱草草粉浸提液对细交链孢、燕麦镰孢、绿色木霉菌落生长及对细交链孢和根腐离蠕孢孢子萌发及燕麦镰孢芽管长度的抑制作用;醉马草中的Neotyphodium显著增强了醉马草草粉浸提液对燕麦镰孢、绿色木霉菌落生长和芽管长度,以及细交链孢、根腐离蠕孢和燕麦镰孢孢子萌发的抑制作用;野大麦中的Neotyphodium显著增强了野大麦草粉浸提液对绿色木霉菌落生长、孢子萌发和芽管长度的抑制作用。     

中国平脐蠕孢属的分类研究I

来自山东泰安和安徽合肥匍柄霉属的两个新种分别命名为棉匍柄霉Stemphylium gossypii和莴苣匍柄霉Stemphylium lactucae。模式标本保存于山东农业大学植物病理系标本室（HSAUP）。本文报道了平脐蠕孢属的一个新种,早熟禾平脐蠕孢Bipolaris poae-pratensis,2个中国新记录种,即野牛草平脐蠕孢Bipolaris buchloes和弯曲平脐蠕孢Bipolaris papendorfii,对其他4个平脐蠕孢属的种的有关分类问题进行了讨论,澄清了一些种名的混乱。标本保存在山东农业大学植物病理学系标本室（HSAUP）和中国科学院真菌标本室（HMAS）。     

中国平脐蠕孢属的分类研究Ⅰ

本文报道了平脐蠕孢属的一个新种,早熟禾平脐蠕孢Bipolaris poae-pratensis,2个中国新记录种,即野牛草平脐蠕孢Bipolaris buchloes和弯曲平脐蠕孢Bipolaris papendorfii,对其他4个平脐蠕孢属的种的有关分类问题进行了讨论,澄清了一些种名的混乱.标本保存在山东农业大学植物病理学系标本室(HSAUP)和中国科学院真菌标本室(HMAS).     

4株海生毛壳菌生物学特性的研究

研究了营养、温度、光照和pH值对4株海生毛壳菌(Chaetomium spp.)的生长及孢子形成和萌发的影响,为进一步利用海洋真菌提供理论依据。结果表明:4株毛壳菌在10～35℃均能生长,WHM12、WHM33和WHM34的生长适温为20～30℃,WHM41的生长适温为15～25℃;4株菌在燕麦片琼脂(OA)培养基和YGA培养基上生长最好;在pH值5～10均能生长,但喜中性及偏碱性的环境;全黑暗处理有利于4株菌的生长;除光照外,营养、温度和pH值对其产孢均有影响。     

URP‐based DNA Fingerprinting of Bipolaris sorokiniana Isolates Causing Spot Blotch of Wheat

Spot blotch, caused by the pathogen Bipolaris sorokiniana is an important disease of wheat and is responsible for large economic losses world wide. In this study, molecular variability in B. sorokiniana isolates collected from different regions of India was investigated using URP‐PCR technique. All the 40 isolates used in the study were pathogenic when tested on susceptible host, Agra local, although they varied in pathogenicity. Isolate BS‐49 was least virulent showing 4.5 infection index while BS‐75 was the most virulent with 63.4 infection index. The universal rice primers (URPs’) are primers which have been derived from DNA repeat sequences in the rice genome. Out of the 12 URP markers used in the study, 10 markers were effective in producing polymorphic fingerprint patterns from DNA of B. sorokiniana isolates. The analysis of entire fingerprint profile using unweighted pair group method with arithmetic averages (UPGMA) differentiated B. sorokiniana isolates obtained from different geographic regions. One isolate BS‐53 from northern hill zone was different from rest of the isolates showing less than 50% similarity. Broadly, three major clusters were obtained using UPGMA method. One cluster consisted of isolates from North western plain zone; second cluster having isolates from North eastern plain zone and third cluster consisted of isolates from Peninsular zone showing more than 75% genetic similarity among them. One of the markers, URP‐2F (5′GTGTGCGATCAGTTGCTGGG3′) amplified three monomorphic bands of 0.60, 0.80 and 0.90 kb size which could be used as specific markers for identification of B. sorokiniana. Further, based on URP‐PCR analysis, the grouping of the isolates according to the geographic origin was possible. This analysis also provided important information on the degree of genetic variability and relationship between the isolates of B. sorokiniana.     

小麦根腐病菌索氏平脐蠕孢SYBR Green I实时荧光定量PCR检测技术研究

由索氏平脐蠕孢Bipolaris sorokiniana引起的小麦根腐病,常和其他土传真菌病害混合发生,传统的症状鉴别方法很难区分,导致病害防控难度增加。为建立病菌实时荧光定量检测体系,根据ITS序列设计引物,筛选出1对特异性引物BS‐F/R,扩增片段大小为280bp。以菌丝DNA为标准品构建实时荧光定量标准曲线,并对其灵敏度、特异性、可重复性进行评价。结果表明,建立的实时荧光定量PCR检测方法速度快,灵敏度高,特异性强,重复性好。构建的荧光定量PCR标准曲线循环阈值与模板浓度呈良好的线性关系,溶解曲线的吸收峰单一,扩增效率良好。利用该定量检测体系,可以检测出田间小麦样品中52.8fg/μL的病菌DNA。     

Identification of resistance source in wheat germplasm against spot blotch disease caused by Bipolaris sorokiniana

Four hundred and twenty-two spring wheat germplasm (Triticum aestivum L.) lines belonging to Indian, CIMMYT and Chinese wheat programme were evaluated for their tolerance against natural epiphytotic conditions of spot blotch caused by Bipolaris sorokiniana at the hot spot location, Pusa, Bihar, India. Of the 422 entries screened, none of the genotype showed immunity to the disease, whereas 52 were resistant, 180 moderately susceptible, 171 susceptible and 19 highly susceptible. Indian germplasm lines tended to be more susceptible than lines originated from CIMMYT and China. Chirya 3, Chirya 7 and Mayoor from CIMMYT showed high degree of resistance to the disease both under field and polyhouse conditions. On the basis of the disease severity under field conditions, 20 promising resistant genotypes and 10 highly susceptible lines were isolated for further testing under artificial epiphytotic conditions in polyhouse for genetic analysis and their potential for spot blotch resistance breeding.     

Potentiality of organotin(IV) compounds in the control of foliar blight disease of wheat (Triticum aestivum) caused by Bipolaris sorokiniana

Three different types of eight organotin(IV) compounds (of which four were newly synthesised) were screened against Bipolaris sorokiniana. The new compounds were characterised by elemental, IR, ¹H and ¹³C NMR spectral analyses. The experiments were carried out in the field and laboratory between the months of November 2006 to March 2007 and November 2007 to March 2008 at Uttar Banga Krishi Viswavidyalaya, Cooch Bihar, W.B., India. All of the organotin(IV) compounds were tested for the toxicity assay against Indian wheat (Triticum aestivum L.), cv. Sonalika. The spore germination and growth of B. sorokiniana and the biochemical changes associated with the induction of resistance by these chemicals were also tested. The influence of the organic groups (attached to tin atom) of the three different types of compounds studied on the fungicidal activity is remarkably distinct. Some of the compounds tested are more active in controlling the fungus than a commonly used commercial product.     

Sources and donors of resistance to wheat spot blotch caused by Bipolaris sorokiniana Shoem. (Cochliobolus sativus Drechs. ex Dastur)

The resistance of wheat lines and cultivars from the Institute of Crop Breeding (Harbin, China) and synthetic, hexaploid wheat lines derived from T. durum and T. tauschii (CIMMYT) were screened for resistance to spot blotch Bipolaris sorokiniana Shoem. using field and laboratory tests. The highly and moderately resistant wheat samples were determined. The satisfactory coincidence of data obtained from evaluation of type reaction of seedlings and disease severity in adult plant stage was demonstrated. The genetics of resistance in Chinese lines Long 98-4554, Long 98-4546, Long mai 24, Long mai 23 and Canadian line 181-5 was studied using hybridological analysis. The resistance in these lines was inherited as quantitative traits and was conditioned by a few (one or two) genes. The absence of susceptible plants in F₂ in crosses of resistant lines Long 98-4554, Long 98-4546, Long mai 24 and 181-5 can testify to the presence of a common gene of resistance. Our data reveals the poor genetic diversity for spot blotch resistance in studying wheat genotypes.     

牛筋草离孺孢生物学特性及代谢产物活性测定

对牛筋草离孺孢属(Bipolaris sorokiniana)NJ-08菌株的生物学特性及代谢产物除草活性测定结果表明：此菌株的菌丝体生长速度慢, 但产孢量大, 致病性强。菌丝体生长最适温度25°C, 致死温度是55°C/10 min, 最适pH值为8, 碳源以葡萄糖最佳, 供试氮源则不利于菌丝体生长。产生分生孢子最适温度25°C, 最适pH值为8, 碳源以葡萄糖最好, 氮源以硝酸钠产孢量最高。分生孢子萌发温度在20°C~35°C之间没有差异, 适宜pH值为5~7, 碳源以D-木糖的孢子萌发率最高, 氮源以蛋白胨的孢子萌发率最高, 不同处理间存在明显差异。NJ-08菌株产生的代谢产物作用于牛筋草, 可使叶片黄化或枯死, 代谢产物对指示植物及杂草如柱花草、地桃花、猪屎豆和辣椒的胚根胚芽生长都有明显的抑制作用, 抑制率均超过了90%, 显示出很好的除草活性。     

Induced accumulation of tyramine,serotonin, and related amines in response to Bipolaris sorokiniana infection in barley

The inducible metabolites were analyzed in barley leaves inoculated with Bipolaris sorokiniana, the causal agent of spot blotch of barley. HPLC analysis revealed that B. sorokiniana-infected leaves accumulated 4 hydrophilic compounds. They were purified by ODS column chromatography and preparative HPLC. Spectroscopic analyses revealed that they were tyramine (1), 3-(2-aminoethyl)-3-hydroxyindolin-2-one (2), serotonin (3), and 5,5′-dihydroxy-2,4′-bitryptamine (4). Among these, 2 and 4 have not been reported as natural products. They showed antifungal activity in an assay of inhibition of B. sorokiniana conidia germination, suggesting that they play a role in the chemical defense of barley as phytoalexins. The accumulation of 1–4 was examined also in the leaves of rice and foxtail millet. Rice leaves accumulated 2, 3, and 4, whereas foxtail millet leaves accumulated 3 and 4 in response to pathogen attack, suggesting the generality of accumulation of 3 and 4 in the Poaceae species.     

Genetic Improvement and Crop Management Strategies to Minimize Yield Losses in Warm Non-traditional Wheat Growing Areas due to Spot Blotch Pathogen Cochliobolus sativus

Spot blotch caused by Cochliobolus sativus emerged as a major threat to wheat production in the warmer non-traditional wheat growing areas in the late 1980s. This foliar disease causes significant yield losses annually (15–20% on average in South Asia) endangering the livelihoods of millions of small farmers. Effective measures in the field are needed to mitigate the impact of spot blotch on food security in affected areas. This review summarizes the global knowledge on genetic improvement and crop management strategies to minimize yield losses based on latest field research. Recent studies have shown that spot blotch severity is highly influenced by stress factors affecting crop physiology which in turn affects host tolerance and resistance to the pathogen. Soil nutrient and water stress aggravate spot blotch-induced grain yield losses. Heat stress which is gradually increasing in Asia causes higher levels of disease damage. Genetic improvement is the cornerstone of a sustainable control of spot blotch in all affected regions. Resistance is essentially based on Chinese and South American sources and inter-specific crosses with broadly adapted semi-dwarf germplasm. A list of genotypes consistently reported in the last 10 years to harbor at least partial resistance to spot blotch, along with their inheritance of resistance, has been compiled to help breeding programmes. As the fungus is aggressive under conditions of high relative humidity and heat which in turn influences plant susceptibility, a synthesis of the different tools for scoring disease severity is given. Because resistance is incomplete, the ultimate goal is the accumulation of minor genes of resistance in adapted high yielding genotypes. This paper shows how the use of resistant varieties, timely seeding, adequate fertilization, crop rotation, and the judicious use of fungicides can be part of an integrated management strategy for controlling yield losses due to spot blotch.