Aplanes braunii (Phylum Oomycota) causes mortality in Anabas cobojius

The fresh water fish Anabas cobojius (Hamilton-Buchanan 1822), was found to be parasitised by Aplanes braunii de Bary 1888. It is the first report of Aplanes braunii to cause disease on any fish. A. braunii is a virulent parasite that caused cotton-wool disease involving the skin, fins and muscles of A. cobojius. The hyphae also penetrated deep into the tissues of the infected fish and all of them ultimately died.This revised version was published online in October 2005 with corrections to the Cover Date.     

Record of a fatal oomycotic disease of the fresh water fish Anabas cobojius in India caused by Aplanes braunii

The fresh water fish Anabas cobojius (Hamilton-Buchanan 1822), was found to be parasitised by Aplanes braunii de Bary 1888. It is the first and only report of any Aplanes de Bary to cause disease on any fish. A. braunii was found to be a virulent parasite ofA. cobojius causing cotton-wool disease involving the skin and fins. The hyphae also penetrated into the tissues of the infected fish and all of them ultimately died.This revised version was published online in October 2005 with corrections to the Cover Date.     

A fatal oomycotic disease of the fresh water fish Aplocheilus panchax in India caused by Aphanomyces laevis

The fish, Aplocheilus panchax (Hamilton-Buchanan, 1839), is recorded as a new host of Aphanomyces laevis de Bary, 1860. It is the first and only report of any oomycete causing disease on A. panchax. Aphanomyces laevis was found to be a virulent parasite of A. panchax that caused cotton-wool disease involving the skin and fins. The hyphae also penetrated deep into the tissues of the infected fish and all of them ultimately died. This revised version was published online in June 2006 with corrections to the Cover Date.     

Spontaneous Generation and Disease Causation: Anton de Bary’s Experiments with Phytophthora infestans and Late Blight of Potato

Anton de Bary is best known for his elucidation of the life cycle of Phytopthora infestans, the causal organism of late blight of potato and the crop losses that caused famine in nineteenth-century Europe. But while practitioner histories often claim this accomplishment as a founding moment of modern plant pathology, closer examination of de Bary’s experiments and his published work suggest that his primary motiviation for pursing this research was based in developmental biology, not agriculture. De Bary shied away from making any recommendations for agricultural practice, and instead focused nearly exclusively on spontaneous generation and fungal development – both concepts promoted through prize questions posted by the Académie des Sciences in the 1850s and 1860s. De Bary’s submission to the Académie’s 1859 Alhumbert prize question illustrates his own contributions to debates about spontaneous generation and demonstrates the practical applications of seemingly philosophical questions – such as the origin of life.     

Effect of Bacillus Bacteria on Hydrogen Peroxide Content and Gene Expression of Hydrolase Inhibitors in Potato Plants Infected with Phytophthora infestans (Mont.) de Bary

Russian Journal of Plant Physiology - Late blight of potato (Solanum tuberosum L.) caused by the oomycete Phytophthora infestans (Mont.) de Bary was studied in respect to the disease resistance...     

Book Reviews

Book reviewed in this article:
Kröber, H ., Erfahrungen mit Phytophthora de Bary und Pythium Pringsheim. [Experiences with Phytophthora de Bary and Pythium Pringsheim].
J. A. Roberts and G. A. Tucker (Eds.) , Ethylene and Plant development.     

Food habits, feeding behaviour and impact of triploid bighead carp, Hypophthalmichthys nobilis, in experimental ponds

Food of sterile triploid bighead carp, Hypophthalmichthys nobilis , was examined in ponds receiving water from a hypereutrophic take in Florida. No distinctive seasonal changes in food composition were found. The fish fed selectively on Botryococcus braunii Kuetzing, a large nuisance algal species, which constituted 61% of the volume and 50% of the dry weight of the food. Zooplankton was highly selected, but constituted only 3% of the food volume because of the low zooplankton density in the ponds. The remaining proportion of food consisted mainly of blue-green algae. Final fish biomass was low, ranging from 60 to 97 kg ha⁻¹ in individual ponds. Low biomass was due to slow fish growth and high fish mortality. Despite low biomass, the fish lowered the ratio of blue-green/green algae in the ponds and tended to lower phyto- and zooplankton abundance.     

N、P营养盐胁迫对两株布朗葡萄藻生长的影响

采用批次培养方法,在光照强度60、110mol/m2s下分别设置了7个不同的氮、磷浓度(N:0-3500g/L,P:15-775g/L),研究两株布朗葡萄藻(Botryococcus braunii)对氮、磷胁迫的敏感性差异,筛选高营养利用效率的优良藻株。结果表明:两株藻对氮磷营养胁迫的耐受性存在差异,B.braunii764株对氮胁迫具有较高耐受性,而B.braunii765株对磷胁迫具有较高耐受性。光照强度110mol/m2s,不同氮浓度下B.braunii764株其平均生长速率均显著高于其他各处理组;不同磷浓度下B.braunii765株其平均生长速率显著高于B.braunii764株。在试验设定的光照强度条件下,适当增加光照强度能够显著降低氮胁迫对布朗葡萄藻生长的抑制效应。在光照强度110mol/m2s下,氮浓度3500g/L时两株布朗葡萄藻平均生长速率与在正常Chu-10培养基条件下无显著差异。磷浓度775g/L时两株布朗葡萄藻的平均生长速率均显著低于正常Chu-10培养基条件,增加光照强度对磷胁迫下藻细胞的生长无显著作用。两株布朗葡萄藻在第2天时磷吸收与初始磷浓度呈正相关关系,氮吸收在3500g/L时出现饱和现象。布朗葡萄藻的生长更容易受到培养基中磷营养胁迫的影响。       

Regulation of the O-acetyl-L-serine(thiol)lyase activity in Monoraphidium braunii

Total level of O-acetyl-L-serine(thiol)lyase (OASTL) activity observed in Monoraphidium braunii fed-repleted cells decreases up to 40% after 24 h the carbon source was removed from the culture; however, no significant change in the activity is observed in N-starved cells. On the other hand, sulfur starvation induces OASTL activity in M. braunii, which may increase 2.5-fold after 36 h. Normal intracellular level of the activity is restored when a sulfur source, such as sulfate, sulfite, L-cysteine, L-methionine or glutathione is added to the culture. The induction of the OASTL activity requires de novo synthesis of protein, and thus the presence in the culture of adequate carbon and nitrogen sources. The OASTL isoenzymes from M. braunii cells are differently affected by S-starvation.     

PHYLOGENETIC POSITION OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE) BASED ON SMALL SUBUNIT RIBOSOMAL RNA SEQUENCE DATA1

A small subunit ribosomal RNA (16S-like rRNA) in the hydrocarbon-rich microalga Botryococcus braunii Kützing (Chlorophyceae) was amplified using RNA polymerase chain reaction, and its sequence was determined. The sequence data of B. braunii were analyzed with those of several other algae in order to determine phylogenetic relationships among these algae. Phylogenetic analysis indicated B. braunii to be a member of the Chlorophyta and possibly related to Characium vacuolatum and Dunaliella parva.     

Influence of CO2 on growth and hydrocarbon production in Botryococcus braunii

Botryococcus braunii is a green colonial fresh water microalga and it is recognized as one of the renewable resources for production of liquid hydrocarbons. CFTRI-Bb-1 and CFTRI-Bb-2 have been reported for the first time and their performance with regard to growth and biochemical profile is presented here. The present study focused on effect of carbon dioxide (CO2) on biomass, hydrocarbon, carbohydrate production, fatty acid profile, and carotenoid content in various species of B. braunii (LB-572, SAG 30.81, MCRC-Bb, N-836, CFTRI-Bb-1, and CFTRI-Bb-2) at 0.5, 1.0, and 2.0% (v/v) levels using a two-tier flask. CO2 at 2.0% (v/v) level enhanced growth of the organism, and a two-fold increase in biomass and carotenoid contents was observed in all the B. braunii strains studied compared with control culture (without CO2 supplementation). At 1% and 2% (v/v) CO2 concentrations, palmitic acid and oleic acid levels increased by 2.5 to 3 folds in one of the strains of B. braunii (LB-572). Hydrocarbon content was found to be above 20% at 2% CO2 level in the B. braunii LB-572, CFTRI-Bb-2, CFTRI-Bb-1, and N-836 strains, whereas it was less than 20% in the SAG 30.81 and MCRC-Bb strains compared with control culture. This culture methodology will provide information on CO2 requirement for growth of algae and metabolite production. B. braunii spp. can be grown at the tested levels of CO2 concentration without much influence on culture pH.     

Morphological changes during the life cycle ofAureobasidium pullulans (de Bary) Arnaud

Aureobasidium pullulans (de Bary) Arnaud was isolated from different natural materials plant blossoms in particular. Elements of vegetative multiplication, structure of colonies and cultures in liquid media were analyzed in detail, leading to construction of the life cycle of this organism. Morphological polymorphism was found to be combined with the production of melanin and the polysaccharide pullulan. Morphological analysis served for a directed selection for studies of physiological properties of this organism and its practical application.     

马铃薯非共生血红蛋白基因StHb1的克隆及表达

采用RT-PCR技术成功分离了马铃薯StHb1基因序列.经半定量RT-PCR分析表明,StHb1基因的表达在抗性品种(陇薯三号)和感性品种(荷兰十五)块茎中均受致病疫霉的侵染所抑制;StHb1基因在正常生长的马铃薯块茎组织中表达量最高;外源NO和H2O2的作用可明显地抑制StHb1基因的表达,但在抗性品种中该基因受抑制的程度低于感性品种.上述试验结果暗示了StHb1基因与马铃薯对致病疫霉侵染的抗性应答具有一定的相关性.     

6 种无机絮凝剂对布朗葡萄藻的絮凝效应

探讨了6种无机絮凝剂对布朗葡萄藻的絮凝效应。采用光密度法测定布朗葡萄藻的生物量,分别研究了硫酸铝、硫酸铝铵、硫酸铝钾、硫酸镁、硫酸铁、氯化铁对布朗葡萄藻的絮凝效应。结果表明,光密度法可应用于布朗葡萄藻生物量的测定,可间接测定絮凝效应,且最佳测定波长为680nm;6种无机絮凝刺的絮凝时间为60min,同时6种无机试剂对布朗葡萄藻均有明显的絮凝效应,硫酸铝、硫酸铝钾、氯化铁对布朗葡萄藻的絮凝效应较硫酸铝铵、硫酸镁、硫酸铁明显（P〈0．05）。硫酸铝浓度控制在1．1g／L,硫酸铝钾浓度控制在0．45g／L以内,氯化铁浓度控制在0．9g／L。     

Effect of Date of Sowing on the Incidence of Sclerotinia Stem Rot and Wilt of Gram (Cicer arietinum L.)

Gram (Cicer arietinum L.) was sown at different dates, viz., 15, 22, 29 Oct., 5, 12, 19 and 26 Nov., and 3 and 10 Dec. in 1978–1979 and 1979–1980 in four replications to enable observations to be made on the occurrence and severity of stem rot and wilt infection caused by Sclerotinia sclerotiorum (Lib.) de Bary. The plant height and canopy width were also measured and correlated with the disease intensity. Yield of each plot was taken as the criterion for suggesting to farmers the best period of sowing the gram crop. November was the most suitable period for this purpose.     

Glutamate dehydrogenases of unicellular green algae: effects of nitrate and ammonium in vivo]

The constitution and control by the inorganic nitrogen source of glutamate dehydrogenases of some unicellular green algae have been studied. The Ankistrodesmus braunii and Scenedesmus obliquus cells contain two different glutamate dehydrogenases, one of which is NADP-specific, the other is active with both NAD and NADP. Their synthesis does not depend on the nitrogen source. The activity of NADP-specific glutamate dehydrogenase increases sharply during nitrogen starvation. In Chlorella pyrenoidosa 82 and Ch. ellipsoidea only one constitutive double specific glutamate dehydrogenase is observed. Its activity does not change depending on the nitrogen nutrition conditions. In the cells of the thermophylic Chlorella strain Chlorella sp. K. ammomium induces a de novo synthesis of NADP-specific glutamate dehydrogenase in addition to the constitutive double specific glutamate dehydrogenase. Thus, the algae tested contain constitutive double specific glutamate dehydrogenase. The NADP-specific enzyme is absent in two Chlorella strains, is constitutive in A. braunii and S. obliquus, and is ammonium-inducible in three thermophylic Chlorella strains.     

植病生防菌盾壳霉的研究进展

盾壳霉是世界性病原真菌核盘菌的主要拮抗真菌之一。许多研究表明盾壳霉具有控制温室和田间多种作物菌核病的潜力。目前欧洲一些国家已有盾壳霉商品制剂销售。为了加速盾壳霉产业化进程和更好地发挥其控制菌核病的作用 ,以及为了使人们对盾壳霉的研究不断深入 ,综述了盾壳霉生态学特性、遗传改良、对核盘菌的生防机制、在菌核病防治上的应用及基因工程研究等方面的研究进展。     

菌核病防治研究进展

菌核病是一种寄主种类广泛的重大植物病害,可侵染450多种重要作物和草类,在我国每年给油菜、大豆以及多种蔬菜带来10～30亿元的损失.介绍了菌核病的症状、危害以及致病机理等,概述了主要的防治措施,并报道了国内外在关于菌核病生物防治、转基因育种、分子机理等方面的研究进展.     

Late blight on potato is suppressed by the biosurfactant-producing strain Pseudomonas koreensis 2.74 and its biosurfactant

Potato late blight disease caused by the zoospore-producing pathogen Phytophthora infestans (Mont.) de Bary is one of the most destructive plant diseases world-wide and currently its management mainly relies on the frequent use of fungicides. This study investigated the possibility of reducing potato late blight by biocontrol with the biosurfactant-producing strain Pseudomonas koreensis 2.74. Significant disease reduction with the biosurfactant-producing strain and its biosurfactant was observed in greenhouse trials using a detached-leaf assay. A direct effect of the biosurfactant on zoospores of P. infestans was also observed, whereas the biosurfactant only caused a minor reduction in mycelial growth rate and had no effect on the rate of sporangia production in pure culture.