玉米大斑病菌孢子萌发和附着胞形成的影响因素研究

 Factors of influence on conidium germination and appressorium formation of Setosphaeria turcica,such as light condition,conidial concentration,nutrient resources and pH value of conidial suspension were studied.There was no significant difference among light treatments.The optimal pH for conidium germination and appressorium formation was 5.0 to 7.0.The exogenous nutrient sources were not the indispensable factors for conidium germination,but 5% sugar solution were more favorable for appressorium formation than the others.Low conidial concentration in suspension (conidia ≤ 10⁴/mL) was propitious to conidium germination and appressorium formation,which were inhibited significantly in higher concentration.It was suggested that the phenomenon was due to the self-inhibitor,a kind of lipophilic substance,existing in the site of conidium germination.     

辣椒褐斑病菌分生孢子产生条件初探

 The sporulation conditions of Cercospora capsici were tested with physical and chemical methods. Conventional and particular media, ultraviolet radiation and different treatments on mycelia suspension were applied and studied. It was found that C. capsici could produce conidia in the media of corn leaf powder agar and pepper leaf powder agar. The numbers of conidia produced in the two kinds of botanical media were 24 000 and 35 000 spores/mL, respectively. Compared with those isolated from the leaves, the conidia produced in the botanical media were more slender and pointed in morphology.     

苹果轮纹病菌诱导产孢方法

 In order to get a great quantity of spores of Botryosphaeria berengeriana f. sp. piricola, several methods to promote sporulation of the pathogen were compared. The results showed that the wounded young apple fruits within 60-day old was inoculated with mycelia of B. berengeriana f. sp. piricola and induced under the 365 nm-UV-light; when the brown lesion was shown, the young apple began to form pycnidia on the lesion around the inoculation point after 3-5 days irradiation with UV-light and extruded plenty of conidia. This method induced great more conidia than that of irradiating wounded mycelia with UV-light. However, mature apple seldom produced conidia when induced with the same method.     

2008年我国部分麦区小麦白粉病菌群体对温度的敏感性

 The sensitivity of 113 isolates of wheat powdery mildew (Blumeria graminis f. sp. tritici) sampled from 6 provinces or cities in 2008 to temperature was tested by detached leaf segment method with setting up 5 different temperatures indoor. The results showed the mean ET₅₀ (which represents the temperature that is required to obtain 50% of the maximum effect) of all isolates tested was 23.02℃. ET₅₀ values of 17.70% isolates were more than 24℃. The highest and the lowest ET₅₀ of isolates were 25.22℃ and 19.42℃, respectively. There were a certain differences for isolates sensitivity to temperature among different provinces or cites. It was also found that when temperature increased during 22-26℃, the latent period of isolates prolonged, and the latent period of different isolates was different at the same temperature, too. These results will provide a reference for the oversummering division of wheat powdery mildew, as well as the effect of climate to the disease.     

土壤中烟草根黑腐病菌的实时定量PCR检测技术研究

 Thielaviopsis basicola is a soil-borne plant pathogen which causes root rot disease in tobacco plants. Detection and monitoring of T. basicolain soil is of great significance to control this disease. Based on the differences in internal transcribed spacer (ITS) sequences of T. basicola and other fungal pathogens, a specific primer pair Tb1/Tb2 for T. basicolawas developed. The results showed that the primer pair gave a single amplicon of 330 bp from T. basicola and revealed no undesirable cross-reaction with other seven soil-borne pathogen isolates and three tobacco rhizosphere dominant fungi isolates. With a series of 10-fold genomic DNA dilutions of T. basicola, the detection limit of 1 pg/μL in conventional PCRand100 fg/μL in real-time quantitative PCR was achieved. With DNA from the soil inoculated with different numbers of T. basicola conidia, the detection limit was 10 conidia per reaction in conventional PCR and 0.4 conidia per reaction in real-time quantitative PCR.     

拮抗链霉菌B28 的分类鉴定及其生防作用研究

 An antagonistic Streptomyces strain B28, isolated from the soil collected in Tianmu mountain of Zhejiang Province, was identified as Streptomyces diastatochromogenes by morphological , physiological & biochemical characteristics and 16S rDNA sequence alignment. Antagonistic study indicated that its secondary metabolite toyocamycin had an antifungal activity on the mycelial growth of seven species of plant pathogenic fungi. The results showed that toyocamycin possessed marked inhibitory activity against Rhizoctonia solani and the EC50 value was 0. 58 μg / mL. The effective of toyocamycin against Botrytis cinerea and Fusarium oxysporum f. sp. cucumerinum was much higher than that against Colletotrichum gloeosporioides, the EC50 value of
toyocamycin in inhibiting B. cinerea, F. oxysporum and C. gloeosporioides were 13. 65 μg / mL, 12. 33 μg / mL, and 30. 15 μg / mL respectively.     

Inter-population variabilities in seed mass and germination of Panicum turgidum and Pennisetum divisum in the desert of Kuwait

Understanding variability in seed germination among populations is essential for planning an effective germplasm collection for restoration and conservation purposes.The knowledge of germination and dormancy patterns among populations of desert grasses is crucial for determining the potential of the species and populations to be used for restoration and conservation as well as forage production.Variability in seed germination of Panicum turgidum Forssk and Pennisetum divisum(Gmel.)Henr.in the desert of Kuwait was evaluated in different populations in May 2017.Experiment of seed germination(25 seeds and 4 replicates)was conducted for each population at night/day temperatures of 15℃/20℃and 20℃/30℃under the following light condition:continuous darkness or 12 h/12 h light/dark.Results showed that seed masses of both species strongly varied according to their seed provenances,and both species produced heavier seeds in population with a higher soil electrical conductivity.Seed germination percentage considerably varied between two species,and the variation in P.turgidum was greater(17%–49%)than that of P.divisum(72%–93%).Germination percentage in P.turgidum was greater at high temperature(20℃/30℃)than at low temperature(15℃/20℃).However,temperature regimes had no effect on germination percentage of P.divisum seeds.Mean germination time of both species exhibited significant inter-population variability.This result is especially relevant to assure the selection of the best population of each species and the regeneration success of the species.Besides this,inter-population variability also provides valuable information for enhancing our understanding of the mechanisms that regulate seed germination and how they might be related to seed provenance.     

陕西省小麦赤霉病菌对多菌灵敏感性研究

 The mycelium growth rate method was used to test the sensitivity to carbendazim (MBC) at distinctive concentrations in 136 isolates of Fusarium graminearum from 19 counties of 6 districts in Shaanxi Province in 2008. The distinctive MBC concentration was 4 mg / L for testing of resistance and sensitivity. The results showed that average 50% effective concentration (EC50 ) of 136 tested sensitive isolates were (0. 908 6 ± 0. 062 3) mg / L. All the isolates were sensitive to MBC. The fungicide of MBC could be continually applied wheat production in Shaanxi.     

湖南柑橘衰退病调查分析及弱毒系筛选

 The investigation showed that stem-pitting Citrus tristeza virus (CTV)occurred commonly in citrus production areas in several varieties of Hunan Province. Accurate detection of CTV strains was performed by p23/PCR method, PCR and the results indicated that the most samples were infected with several CTV isolates. Three mild strains were isolated and their pathogenicity was identified by biological identification, it indicated that p23/PCR groups had uniformity with the pathogenicity of CTV isolates. Furthermore, three mild isolates were tested in the cross protection by analysis of biological symptoms and composition of p23 gene. Different protecting effects were observed among these strains and W17 mild isolate was effective.     

青海海东地区马铃薯晚疫病菌生理小种的组成及分布

 50 isolates of Phytophthora infestans potato plants were collected and tested with 11 monogene R1-R11 of potato late blight differential host in Qinghai province from 2006 to 2007.The results showed that there were 15 races in the Haidong Region of Qinghai province and the dominant race was race 3.4.10 with frequency of 36.0%.They were distributed in all collection areas.Race 3.10 with frequency of 16.0% was distributed in Huzu,Ledu,Huangyuan,Datong and Ping'an.Race 3 with frequency of 10.0% was distributed in Huzhu,Xunhua,Huangyuan and Xining.     

黍黑孢菌生物学特性和杀菌剂筛选

黍黑孢菌在PDA培养基上生长40 h后开始产孢,但孢子萌发在产孢20 d后。1/2马铃薯葡萄糖汁(PDB)和1%酵母浸出膏显著地促进孢子萌发,萌发率分别达到99%和87.7%,而5%葡萄糖、1%胰蛋白胨和5%蔗糖对孢子萌发促进作用不显著。药剂对菌丝抑制作用的试验结果表明,多菌灵等8种药剂都对黍黑孢菌菌丝生长有着不同程度的抑制作用,其中,50%多菌灵可湿性粉剂效果最好,EC50为0.017μg/mL,EC95为0.098μg/mL。药剂对黍黑孢菌孢子萌发抑制试验结果表明,75%百菌清可湿性粉剂、30%福.腐.百可湿性粉剂、50%多菌灵可湿性粉剂、50%福.福甲胂.福锌可湿性粉剂和28%百.霉威可湿性粉剂都是有效的杀菌剂,其中,百菌清效果最好,其EC50和EC95分别为0.008μg/mL和0.107μg/mL。     

氰烯菌酯对禾谷镰孢菌分生孢子萌发及菌丝生长的影响

氰烯菌酯(2-氰基-3-氨基-3-苯基丙烯酸乙酯,JS399-19) 是一种对禾谷镰孢菌Fusarium graminearum具有专化活性的新型杀菌剂。离体条件下,采用菌丝生长速率法测定了该药剂对禾谷镰孢菌抗性菌株和敏感菌株的生长抑制活性;同时采用孢子萌发法测定了其对禾谷镰孢菌分生孢子萌发的影响。结果表明,氰烯菌酯能够强烈地抑制禾谷镰孢菌敏感菌株菌丝的生长,EC50值分布在0.092~0.141 μg/mL之间;并可降低敏感菌株分生孢子的萌发速率,以及影响其萌发的方式,使芽管从分生孢子基部和中间细胞萌发的比率增加;同时氰烯菌酯使敏感菌株分生孢子膨大、畸形,并使其芽管肿胀、扭曲,明显抑制其芽管的伸长生长;但对抗性菌株的抑制作用和致畸作用不明显。     

戊唑醇对立枯丝核菌的抑制作用及在水稻上的应用

戊唑醇是一种高效、广谱、内吸性强的三唑类杀菌剂。研究表明,在离体条件下其对立枯丝核菌Rhizoctonia solani Kuhn菌丝生长具有很强的抑制作用,EC50值为0.509 μg/mL。无论在天然培养基(LBA)还是在半组合培养基(AEA)上,戊唑醇均会抑制菌核的产生,且菌核的产量随着药剂浓度的增加而降低;虽然其对菌核的萌发无影响,但对菌核萌发后菌丝的生长有强烈的抑制作用。温室试验结果表明,立枯丝核菌菌碟经戊唑醇处理后,其对分蘖期水稻植株的致病力随着药剂浓度的提高而下降;戊唑醇可很好地被水稻叶片和根系吸收,并输送到水稻的茎部;对水稻纹枯病具有保护和治疗作用,EC50值分别为58.03和62.53 μg/mL;对立枯丝核具有较长的持效期,800 μg/mL处理水稻7 d后再接种的防效为41.46%。田间药效试验表明,43%的戊唑醇悬浮剂在有效剂量116.10 g/hm2下两次喷药后15 d的防效达71.97%。该药剂在本试验剂量范围内对水稻安全。     

白术枯斑病原鉴定、生物学特性及其对不同药剂的敏感性研究

 白术(Atractylodes macrocephala Koidz.)是浙江省传统中药材“浙八味”之一。近年来在磐安县白术主产区发生一种新的枯斑病。为明确致病菌及其生物学特性和对杀菌剂的敏感性,本研究通过病原菌分离培养、柯赫氏法则验证、形态学特征观察,及ITS、LSU、rpb2和tub2多基因序列分析,发现引起该枯斑病的病原菌为Phoma exigua。生物学特性测定表明:该菌菌丝生长的最适温度为28℃,最适pH为8,最适碳源与氮源分别为可溶性淀粉和蛋白胨;分生孢子萌发最适温度24℃、相对湿度100%;菌丝和分生孢子的致死温度分别为47℃和54℃。不同药剂敏感性测定结果表明:咯菌腈对该菌菌丝生长的抑制作用最强,EC₅₀为0.24 μg·mL^-1;吡唑醚菌酯和嘧菌酯对其分生孢子萌发具有较强的抑制作用,EC₅₀分别为0.10和0.16 μg·mL^-1。由P. exigua 引起的白术枯斑病为国内外首次报道。     

10种化学杀菌剂对苹果树腐烂病的防效评价

本试验通过采用抑制菌丝生长、促进伤口愈合以及在离体枝条上的保护和治疗试验,对市售的10种化学药剂进行了防治苹果树腐烂病效果的评价.这些药剂分别为甲硫·萘乙酸、腐植酸·铜、菌毒清、丙环唑、代森铵、丁香菌酯、噻霉酮、辛菌胺·醋酸盐、甲基硫菌灵(山西北方种业)和甲基硫菌灵(日本曹达).试验结果表明,不同的测试方法得到不同的排序.在抑菌试验中,抑菌作用最强的药剂是甲基硫菌灵(山西北方种业)和腐植酸·铜,抑菌带均为5.00 cm,其次为菌毒清、丙环唑和甲硫·萘乙酸.在伤口愈合试验中,甲基硫菌灵(日本曹达)和甲硫·萘乙酸对伤口的愈合作用最好,其愈伤组织宽度分别比对照宽2.00 mm和0.92 mm.在离体枝条保护作用试验中,甲硫·蕃乙酸、腐植酸·铜、甲基硫菌灵(日本曹达)处理均未发病.在离体枝条治疗作用试验中,甲硫·萘乙酸、菌毒清、代森铵、甲基硫菌灵(山西北方种业)、腐植酸·铜的病斑平均扩展面积均小于50 mm2,其中甲硫·萘乙酸和菌毒清的防效均为87.5％,病斑面积仅为对照的1.6％和2.2％.综合排序和分析认为,甲硫·萘乙酸是治疗腐烂病效果最好的药剂.     

水稻稻瘟病菌不同发育阶段对7种QoI类杀菌剂的敏感性

以嘧菌酯为对照药剂,研究了6种中国自主创制的QoI类杀菌剂对水稻稻瘟病菌Magnapothe grisea不同发育阶段的影响。结果表明,供试药剂对水稻稻瘟病菌菌丝扩展均表现出良好的抑制作用,EC50值为0.10 ~2.89 μg/mL;对病菌产孢量和孢子萌发的抑制作用明显,EC50值分别为0.10 ~4.92和0.75 ~7.14 μg/mL。在1.0 μg/mL的含药平板上,烯肟菌酯、嘧菌酯、丁香菌酯、SYP-2815对水稻稻瘟病菌产孢量的抑制率均大于90%;对病菌孢子芽管伸长也具有一定的抑制作用,EC50值为1.67 ~34.76 μg/mL。在1.0 μg/mL的含药平板上,7种QoI类药剂对水稻稻瘟病菌菌丝形态无明显影响,但可明显抑制其黑色素的产生。     

人参生炭疽菌(Colletotrichum panacicola)和线列炭疽菌(C. lineola)的生物学特性及其对不同杀菌剂的敏感性研究

 近年来,炭疽属真菌(Colletotrichum spp.)引起的人参炭疽病,给人参生产造成了重大经济损失。本文选取分离自我国吉林省栽培人参上的两种炭疽菌人参生炭疽菌(Colletotrichum panacicola)和线列炭疽菌(C. lineola),通过平板培养,测定了它们在不同培养基、温度、碳源、氮源、pH值和光照条件下的生物学特性;采用菌丝生长速率法测定了其对14种杀菌剂的敏感性。结果表明,两种炭疽菌的最适生长温度均为25 ℃,最适生长pH值均为7,光暗交替有利于两种菌的菌丝生长。其中,人参生炭疽菌的菌丝生长最适培养基为V8汁培养基,最适碳源和氮源分别是淀粉和硝酸钾;线列炭疽菌的菌丝生长最适培养基为PDA和PSA培养基,最适碳源和氮源分别是淀粉和硝酸铵;两种炭疽菌对13种药剂敏感,咯菌睛、戊唑醇、抑霉唑、多菌灵、氟环唑、苯醚甲环唑、己唑醇、甲基硫菌灵8种药剂对两种炭疽菌的室内抑菌活性较好,EC₅₀值均小于5.0 μg·mL^-1。咯菌睛、戊唑醇、抑霉唑、多菌灵、氟环唑、苯醚甲环唑、己唑醇、甲基硫菌灵8种药剂对两种炭疽菌的室内抑菌活性较好,EC₅₀值均小于5.0 μg·mL^-1,其中咯菌睛抑菌活性最强,EC₅₀值均小于0.1 μg·mL^-1。两种炭疽菌对同一药剂的敏感性存在差异,线列炭疽菌对吡唑醚菌酯敏感性较高,EC₅₀值小于0.1 μg·mL^-1,而人参生炭疽菌对该药剂的敏感性相对较低(EC₅₀值高于200 μg·mL^-1)。该结果为人参炭疽病发病规律的研究及其田间有效防治奠定了基础。     

黄瓜褐斑病防治药剂的离体活性筛选

离体条件下针对黄瓜褐斑病菌对19种杀菌剂进行了活性筛选。结果表明,不同杀菌剂对褐斑病菌菌丝生长和孢子萌发抑制作用不同。对褐斑病菌菌丝生长具有强烈抑制作用的杀菌剂为苯醚甲环唑、咪鲜胺、代森锰锌及嘧霉胺,其EC50分别4.21、4.67、5.59 μg/mL及4.11 μg/mL。甲氧基丙烯酸酯类杀菌剂及防治卵菌病害的药剂对褐斑病菌菌丝生长几乎没有影响。烯肟菌酯、福美双、代森锰锌、烯酰吗啉、百菌清和多菌灵对褐斑病菌孢子萌发具有强烈抑制作用,其EC50分别为3.34、6.62、0.28、3.54、0.53 μg/mL及0.26 μg/mL。50 μg/mL的嘧霉胺虽对孢子萌发抑制作用较小,但10 μg/mL时即可导致萌发的芽管出现明显卷曲、畸形。     

4种戊烷脒同系物对灰霉病的防治效果

采用载玻片萌发法、抑制菌丝生长速率法、组织测定法，结合田间小区试验，系统研究了戊烷脒及其同系物乙烷脒、丙烷脒、丁烷脒对番茄灰霉病菌的抑制活性和田间防治效果。结果表明，各化舍物对灰霉病均有一定的抑制活性，其中丙烷脒和丁烷脒对灰霉病的抑制活性较高，二者抑制菌丝生长的EC50分别为0．6821mg／L和2．1599mg／L，抑制孢子萌发的EC50分别为2．7510mg／L和5．7362mg／L；丙烷脒和丁烷脒对番茄灰霉病有较高的保护和治疗作用；在田问试验条件下，连续2次施药后，以120g ai／hm^2施用剂量防治豇豆灰霉病，丙烷脒和丁烷脒的防治效果分别为78．03％和54．52％，以100gai／hm^2施用剂量防治草莓灰霉病，防治效果分别为71．97％和68．96％，均优于对照药剂施佳乐（450gai／hm^2）和速克灵（468．8gai／hm^2）。丙烷脒和丁烷脒具有开发成为农用杀菌荆的潜力。     

7种杀菌剂对3种林木腐烂病菌的毒力测定及活性评价

林木腐烂病是苹果树、梨树和杨树等林木枝干的重要真菌性病害。为了筛选出对苹果树腐烂病菌Valsa mali var. mali、梨树腐烂病菌V. mali var. pyri和杨树腐烂病菌V. sordida等3种不同寄主腐烂病菌都能有效防控的杀菌剂,本研究开展室内毒力试验比较了7种杀菌剂对3种腐烂病病原菌菌丝生长和分生孢子萌发的抑制效果,并进一步通过田间活性测定试验比较7种杀菌剂对梨树腐烂病病斑扩展和分生孢子发生的防治效果,同时测定了增效剂8.6%聚乙二醇(PEG)对7种杀菌剂的增效作用。毒力测定结果表明,苯醚甲环唑、戊唑醇、吡唑醚菌酯和丙唑·多菌灵对3种腐烂病病原菌菌丝生长和分生孢子萌发的抑制作用较强,其中EC50平均值最低的是苯醚甲环唑,而戊唑醇的MIC平均值最低,在0.33 mg/L浓度下对3种腐烂病病原菌的菌丝生长和分生孢子萌发抑制率均达到100%。田间试验结果表明,45%苯醚甲环唑SC、43%戊唑醇SC和35%丙唑·多菌灵SE对梨树腐烂病病斑扩展和分生孢子萌发的防治效果突出,其中45%苯醚甲环唑SC 30.00 mg/L对病斑扩展防治效果达到82.23%,孢子萌发抑制效果达到85.96%,田间防治效果最好。10%丙硫唑SC+8.6% PEG处理组对病斑扩展防治效果提高了15.39百分点,达到73.46%,分生孢子萌发抑制率提高了23.75百分点,达到83.06%,增效作用显著。本研究为苹果树、梨树和杨树等3种寄主腐烂病的化学防控提供了科学依据。