几种杀菌剂对草霉灰霉病菌的室内毒力测定

在实验室条件下,采用室内菌丝生长速率法测定了6种杀菌剂对草莓灰霉病菌( Botrytis cinerea)的毒力。测定结果表明,咪鲜胺、多菌灵、速克灵、扑海因、烯唑醇和三唑酮对草莓灰霉病菌的EC50值分别为0.0233 mg/L、0.0421 mg/L、0.1724 mg/L、0.2837 mg/L 、0.3021 mg/L和0.3263 mg/L。其中,草莓灰霉病菌对咪鲜胺最敏感（EC50值为0.0233 mg/L）。     

7种杀菌剂对玉米大斑病病原菌的毒力测定试验

研究旨在鉴定出玉米大斑病病原菌,筛选出防治玉米大斑病的最佳药剂。试验采用组织分离法对玉米大斑病病原菌进行分离鉴定,用含毒培养基生长速率法测定7 种杀菌剂对玉米大斑病病原菌的抑制效果。经分离鉴定,该病原菌为链格孢Alternaria alternate。毒力测定试验结果表明：药后48 h,异菌脲EC50值为0.27 mg/L,毒力指数最大,对链格孢菌抑制效果非常显著;丙环唑和苯醚甲环唑EC50值为0.51、0.53 mg/L,抑制效果较显著;氟硅唑和嘧霉胺的EC50值为1.66、1.91 mg/L,效果显著;代森锰锌和醚菌酯的EC50值分别为25.82、929.78 mg/L,毒力指数较低,抑制效果差;药后72 h 各药剂对链格孢的抑制效果与药后48 h 抑制效果相似。在7 种杀菌剂中异菌脲对链格孢菌抑制效果最好,当试验浓度为50 mg/L 时,抑制率可达95%。     

4种杀菌剂对葡萄灰霉病菌的毒力测定及复配试验

为了筛选出能有效防治葡萄灰霉病的药剂,为葡萄灰霉病的防治和复配制剂的研究奠定理论基础。采用菌丝生长速率法,测定了吡唑醚菌酯、咯菌腈、嘧菌环胺和啶酰菌胺4种杀菌剂对葡萄灰霉病菌的毒力,并研究吡唑醚菌酯和咯菌腈的复配效果。毒力测定结果表明：4种杀菌剂对葡萄灰霉病菌都有较强的抑制作用,咯菌腈的毒力最强,EC₅₀值为0.0845 mg/L;吡唑醚菌酯和嘧菌环胺的抑制作用次之,EC₅₀值分别为3.6023、5.6300 mg/L;啶酰菌胺的抑制作用最低,EC₅₀值为68.2860 mg/L。联合毒力测定和评价结果表明：吡唑醚菌酯和咯菌腈5种混配组合对葡萄灰霉病菌的EC₅₀分别为0.3483、0.5291、0.5741、1.8751、3.9185 mg/L,共毒系数(CTC)分别是397.50、166.64、28.75、4.85、2.24。配比为1:25时增效作用最明显,共毒系数(CTC)为397.50。     

丙烷脒防治番茄灰霉病效果初报

采用室内毒力测定和田间药效试验方法,对丙烷脒防治番茄灰霉病（Botrytis cirerea）进行了研究。丙烷脒对灰霉病菌菌丝生长和孢子萌发的EC50分别为2.1599 mg/L和2.7510 mg/L;在组织法测定中,丙烷脒对灰霉病表现出较高的保护和治疗作用;田间药效试验表明,丙烷脒在施用剂量为(a.i.) 90~180g/hm2、施药4次、间隔7d的条件下对番茄、黄瓜、草莓等作物的灰霉病有良好的防治效果,防效优于对照药剂嘧霉胺和腐霉利,与菌核净的防效相当。     

7种杀菌剂对茼蒿霜霉病的防效试验

为筛选出防治茼蒿霜霉病的最佳药剂,采用组织分离纯化的方法,鉴定出病原菌为莴苣盘梗菌(Bremia lactucae)。采用含毒培养基生长速率的方法进行防效试验,测定7种杀菌剂对莴苣盘梗菌的防治效果,结果表明,药后72 h,克菌灵EC50值为1.46 mg/L,毒力指数最大,对莴苣盘梗菌防治效果最显著;安克和大生EC50值分别为4.31、5.63 mg/L,防治效果较显著;甲霜灵的EC50值为9.19 mg/L,防治效果较好;普力克和杀毒矾的EC50值分别为26.31、101.32 mg/L,防治效果一般;优氯特EC50值最大,防治效果最差。药后96 h各药剂对莴苣盘梗菌的防治效果与药后72 h防治效果相似。在7种杀菌剂中克菌灵对莴苣盘梗菌防效最高,防治效果最好。     

丁子香酚对人参灰霉病防效较好

<正>沈阳农业大学植物保护学院科研人员近期采用菌丝生长速率法测定了14种生物杀菌剂对人参灰霉病菌的室内毒力,并进行了7种生物杀菌剂对人参灰霉病的田间药效试验。室内毒力测定结果表明:0.3%丁子香酚可溶液剂和2%蛇床子素乳油对人参灰霉病菌毒力最强,其EC50分别为0.129、0.623mg/L,2%春雷霉素水剂、10%多抗霉素可湿性粉剂、3%中生菌素     

湖南新田县茄果腐烂病的诊断及药剂筛选

2012年8月湖南新田县蔬菜基地发生茄子果实腐烂病,损失严重。从感病茄果上分离到一种真菌,镜检表明为茄褐纹拟茎点霉,此菌rDNA-ITS序列亦与茄褐纹拟茎点霉高度同源。因当地反映百菌清、多菌灵、代森锰锌等药剂均无明显效果,故尝试了室内试验以筛选出有效防治该病的药剂。采用菌丝生长速率法,用11种杀菌剂做了室内毒力测定。咪鲜胺对茄褐纹病菌的抑制效果最好,EC50值分别为0.021 mg/L;其次是甲基硫菌灵和苯醚甲环唑,EC50值是0.252 mg/L 和0.434 mg/L;百菌清与醚菌酯的抑制效果最差,EC50值分别为44.400 mg/L和54.470 mg/L。建议在病区选用咪鲜胺防治茄褐纹病。     

7种杀菌剂对寄生疫霉菌的毒力测定试验

旨在鉴定出潺菜病叶病原菌和筛选出防治寄生疫霉(Phytophthora parasitica Dastur)的最佳药剂。本试验对潺菜病叶进行了组织分离,经过纯化鉴定病原菌为寄生疫霉。试验使用7种杀菌剂并采用了含毒培养基生长速率法来测定对寄生疫霉的抑制效果。试验结果表明:药后48 h,百菌清的EC50值为13.60 mg/L,毒力指数较大,对寄生疫霉菌抑制效果非常显著;恶霜锰锌和代森锰锌的EC50值为16.99、28.62 mg/L,抑制效果较显著;甲霜锰锌、霜霉威和烯酰吗啉的EC50值分别为为56.23、57.16、60.71 mg/L,效果一般;二氯异氰的EC50值为319.21 mg/L,毒力效果较差;药后24 h各药剂对寄生疫霉的抑制效果与药后48 h抑制效果相似。在7种杀菌剂中百菌清对寄生疫霉抑制率最高,抑制效果最好。     

几种杀菌剂对草莓灰霉病菌的室内毒力测定

在实验室条件下,采用菌丝生长速率法测定了6种杀菌剂对草莓灰霉病菌(Botrytiscinerea)的毒力。结果表明,咪鲜胺、多菌灵、速克灵、扑海因、烯唑醇和三唑酮对草莓灰霉病菌的质量浓度EC50值分别为0.0233、0.0421、0.1724、0.2837、0.3021和0.3263mg/L。草莓灰霉病菌对上述6种杀菌剂均表现敏感,其中,供试草莓灰霉病菌对咪鲜胺最敏感。     

7种杀菌剂对番茄早疫病的防效试验

旨在通过测定7种杀菌剂对番茄早疫病的防效筛选对番茄早疫病的最优菌剂。对番茄早疫病叶上的病原菌进行分离和提纯,鉴定出病叶上的病原菌为茄链格孢Alternaria solani;采用含毒培养基菌丝生长速率法,测定7种杀菌剂对番茄茄链格孢菌的防效。结果表明:药后48 h,世高和施加乐的EC50值分别为0.27、0.81 mg/L,毒力指数最大,对茄链格孢菌有良好的防治作用效果;唑菌胺酯和克菌星的防效良好,EC50值为1.29、1.54 mg/L;扑海因和敌力脱也有较高的防效,EC50值为2.07、2.79 mg/L;大生防效较低,EC50值为5.17 mg/L。药后72 h,各药剂对番茄茄链格孢菌的防效与48 h相似。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...