A chorismate mutase from Radopholus similis plays an essential role in pathogenicity

In the process of infecting plants, plant parasitic nematodes release a series of proteins that play an essential role in the successful infection and pathogenesis of plant cells and tissues through stylets or body walls. In this study,based on transcriptome data, a chorismate mutase gene of Radopholus similis(RsCM) was identified and cloned,which is a single copy gene specifically expressed in the oesophageal gland and highly expressed in juveniles and females. Transient expression of RsCM in tobacco leaves showed that it was localised in the cytoplasm and nucleus of tobacco leaf cells, which inhibited the pattern-triggered immunity(PTI) induced by flg22, including callose deposition and defence gene expression, and cell death induced by immune elicitors BAX, but could not inhibit cell death induced by immune elicitors Gpa2/RBP-1. The RNA interference(RNAi) transgenic tomato of RsCM obviously inhibited the infection, pathogenicity, and reproduction of R. similis. However, the resistance of the overexpression transgenic tomato of RsCM to R. similis infection was significantly reduced, and the expression levels of two salicylic acid(SA) pathway genes(PR1 and PR5) in roots infected by the nematode were significantly down-regulated,which indicated that RsCM might be involved in the inhibition of SA pathway. The results of this study demonstrate that RsCM suppresses the host immune system and might be a new target for the control of R. similis, which also provides new data for the function and mechanism of CM genes of migratory parasitic plant nematodes.

Community Diversity of Associated Bacteria of Radopholus similis

[ Objective ] The paper was to reveal the species abundance of associated bacterial community of Radopholus similis, and the diversity of its bacteria. [Methods] Through the construction of 16S rDNA cloning library of bacteria, the positive clone was carried out ARDRA analysis, and the phylogenetic tree was constructed. [ Results] OUT （ Operational Taxonomic Units） was classified according to sequences similarity of 97%, and the constructed 16S rDNA library of bacteria contained 13 OTUs, belonging to Alphaproteobacteria, Betaproteobacteria and Gammaproteobacterla, respectively. The dominant species was Betaproteobacte- ria, especially Burkholderia was the dominant bacterium. [Condusions] The diversity of associated bacteria of R. similis was high, and these bacteria may have certain ecological significance to R. similis.

Biological Aspects of Orius similis Zheng Reared on Two Preys at Three Constant Temperatures

Mass-rearing of Orius similis Zheng on two preys,Aphis craccivora Koch and eggs of Corcyra cephalonica Stainton at three constant temperatures(22,26 and 30°C)and 60%±10%RH and 16:8 L/D photoperiod under laboratory conditions was investigated to study the effect of different temperatures and different preys on the biology of O.similis.The highest survival rate(%)of nymphal stages was 81.14%and the longest oviposition period for females(20.6 d)was recorded at 26°C.Also,the highest fecundity of female also recorded at 26°C.The highest rate of nymphal feeding consumption was(122.5 individuals of A.cracivora)also,recorded at 26°C.As well as,the two preys had significant effects on the biological characteristics of O.similis.The highest survival rate for nymphal stage was recorded when O.similis nymphs fed on A.cracivora.Therefore,the longest survival rate was founded in the nymphs which fed on the individuals of A.cracivora.During the nymphal period of O.similis which consumed more individuals of A.cracivora than the eggs of C.cephalonica.These results on the effect of three constant temperatures and two preys on the biology of O.similis will share to improve the rearing of O.similis in biological control agents in China and share to suppress the population of pests in field and greenhouse.

Study on burrowing nematode, Radopholus similis, pathogenicity test system in tobacco as host

Radopholus similis(Cobb 1893) Thorne(1949) is a destructive migratory endoparasitic plant nematode. In this study,the pathogenic process of R. similis infection in Nicotiana benthamiana(tobacco) was studied using quartz sand culture in laboratory. The results showed that R. similis mainly parasitised the root cortex, leading to cortical cell decomposition and tissue decay. We optimised the inoculation conditions to establish a method for determining the pathogenicity of R. similis as follows:(1) a glass culture tube was filled with quartz sand(about 1/3 of the height) and sterilised twice;(2) 20-day-old N. benthamiana seedlings were transplanted into test tubes and cultivated for 10 days at(25±1)°C;(3) R. similis female nematodes were inoculated in the root rhizosphere at a rate of 150 nematodes per plant;(4) the number of nematodes, disease severity, and growth of the plant at 30 days post-inoculation(dpi) were determined. The pathogenicity of eight R. similis populations from different hosts was determined, which proved the feasibility of this method.

Two new aristolane sesquiterpenes from Laurencia similis

Two new aristolane sesquiterpenes, namely, aristolan-10-ol-9-one and aristolan-8-en-1-one, were isolated from the red alga Laurencia similis. Their structures were established on the basis of various NMR spectroscopic analyses, including 2D NMR techniques ((1)H–(1)H COSY, HMQC, HMBC, and NOESY) and HR-FAB-MS.

Two new bromoindoles from red alga Laurencia similis

Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods （including 1D and 2D NMR technique）, their structures have been elucidated as 2,2＇,5,5＇,6,6＇- sixibromo-3, 3＇-bi-lH-indole and 3, 5-dibromo-1-methylindole, respectively.

Evaluation of Acute Chromium (III) Toxicity in Relation to Daphnia Similis

Acute chromium (III) toxicity in relation to Daphnia similis, most appropriate for Brazilian environment has been evaluated. The preliminary toxicity test showed that the median effective concentration was 10 mg/l. After having performed the final test, the immobility percentage was calculated for each concentration in relation to the total number of the used organisms within the chosen pH range. It was shown that the proposed methodology rendered realistic results and the 48-h CE50 value under the test conditions is 3.24 mg/l. The minimum concentration that did not show any toxicity to Daphnia similis was 2.5 mg of chromium (III) per liter. The obtained level is superior to the maximum limit recommended by the Brazilian norms, 0.5 mg/l.

一株特殊生境荒漠药用植物沙蓬内生真菌Rhinocladiella similis中苯甲酸大环内酯化合物

从一株特殊生境荒漠药用植物沙蓬的内生真菌Rhinocladiella similis中分离得到4个苯甲酸大环内酯化合物,包括2个新化合物rhinoclactones E(2)和F(1)、2个已知化合物8,9-dihyrogreensporone D(3)和8,9-dihydrogreensporone A(4)。基于高分辨质谱与核磁共振谱数据以及相关文献比对,确定了新化合物与已知化合物的结构。化合物1和2是一对立体异构体,在大环内酯环中并有一个呋喃环,这种环系统在自然界比较稀少。化合物1-4对3株肿瘤细胞株和植物病原真菌没有抑制活性。本结果进一步丰富了该真菌的化学成分研究,暗示特殊生境荒漠植物内生真菌具有产生结构新颖的次级代谢产物的潜力,是发现新活性天然产物的一个新的重要宝库;此外,根据化合物的结构特征与生物活性结果,本文还探讨了这些化合物潜在的生态学功能。

Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective inte-grated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in bait which is lower than currently used in commercial baits for commensal rodent con-trol. We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed [Current Zoology 57 （5）： 625~529, 2011].

CLADIELLISIN——A NEW DITERPENE FROM THE SOFT CORAL Cladiella similis

Extraction of the soft coral Cladiella similis with 95% ethanol followed by partition between petroleum ether and water, and extensive chromatography on silica gel column eluting with petroleum ether-acetone (9.5:0.5, 9:1 and 8:2) afforded fractions in the part of 8:2 petroleum ether-acetone from which white crystals of a new compound, dadiellisin(1), were

Invasive black spiny-tailed iguanas(Ctenosaura similis)on Gasparilla Island,Florida,USA

The native range of Ctenosaura similis extends from southern Mexico through Panama. From an initial intro­duction of 3 animals in 1979, the species now numbers in the thousands on Gasparilla Island in southwest Flor­ida. In response to complaints of property damage from residents and threats to native species, local officials and the US Department of Agriculture Wildlife Services began a removal program in 2008. Through 2011, trap­pers removed 9467 ctenosaurs. The number removed declined from 32 iguanas/day in 2008 to 1.9 iguanas/day in 2011 despite no easing of the control effort. We necropsied 2757 ctenosaurs to document aspects of their nat­ural history. Females outnumbered males overall, although the largest size class (>300 mm snout-vent length) included 32 males and just 2 females. Reproduction was seasonal. We found oviducal eggs in females from ear­ly Apr to early Jun, approximately 2 months later than C. similis in its native range. We trapped hatchlings from late Jul to early Oct coincident with the summer rainy season. Clutch size increased with female body size, with 62 being the largest clutch size recorded. In general, the biology of the invasive population on Gasparilla Island resembles native C. similis populations in Central America, except for the lack of large individuals. We suggest that shorter day length and colder temperatures create environmental conditions that are suboptimal for individ­ual growth compared to those in the native range.

ROC曲线分析在评价入侵物种分布模型中的应用

生态位模型(ecological niche models,ENMs)已广泛应用于物种潜在分布区预测,ENMs的应用也为外来入侵物种的风险分析提供了重要的定量化分析工具,但如何评价不同模型之间的预测效果成了当今研究的热点问题。本文介绍了受试者工作特征(ROC)曲线分析在评价不同生态位模型预测效果中的应用原理和分析方法,并以一种植物病原线虫-相似穿孔线虫(Radopholus similis)为例,应用ROC曲线分析法对其5种模型(BIOCLIM,CLIMEX,DOMAIN,GARP,MAXENT)的预测结果进行了比较分析。5种模型的ROC曲线下面积AUC(Area Under Curve)值分别为0.810,0.758,0.921,0.903和0.950,以MAXENT模型的AUC值最大,表明其预测效果最好;方差分析结果表明,除GARP与DOMAIN模型之间AUC值差异不显著外,其余各模型之间差异显著。

基于CLIMEX的相似穿孔线虫在中国可能适生区域的初步预测

相似穿孔线虫(Radopholussimilis)为热带地区果树上最重要的寄生线虫之一。温度和湿度是影响相似穿孔线虫分布的重要气候因子。根据相似穿孔线虫对温湿度等气候因子的反应,采用CLIMEX软件对相似穿孔线虫在中国的适生区进行了预测。利用CLIMEX中的18个参数,以已知的澳大利亚适生分布区,反复调试修正上述这些参数值,使之与已知广泛分布的地区达到最大程度的吻合。预测表明除我国的新疆、青海、内蒙、黑龙江、吉林省(区)及甘肃(安西、玉门)以外,相似穿孔线虫在我国许多地区均能够适生(E>0)。辽宁及华北地区为相似穿孔线虫在我国可能分布区的边缘,我国的华东(江苏徐州除外)、华南、华中、西南及香港、台湾地区十分适合相似穿孔线虫的生存(EI≥20)。

南方小花蝽控制害虫的研究现状

南方小花蝽(Orius similis Zheng)是农田生态系统中一类重要的捕食性天敌昆虫,利用其对害虫进行有效控制是当前生物防治的研究热点。本文综述了南方小花蝽控制能力及影响其控制能力的因素,并提出了提高南方小花蝽控制效果的方法,以期为小型害虫的生物防治提供参考。

Chemical constituents of marine algal-derived endophytic fungus Exophiala oligosperma EN-21

Seven compounds (1–7) were identified from the cultivation of the endophytic fungus Exophiala oligosperma (EN-21) that was isolated from the inner tissue of the marine red alga Laurencia similis. Their structures were identified with spectroscopic and chemical methods as 2-phenoxynaphthalene (1), (2S, 3R, 4E, 8E)-1-O-β-D-glucopyranosyl-3-hydroxy-2-[(R)-2′-hydroxyoctadecanoyl] amino-9-methyl-4, 8-octadeca-diene (2), (22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol (3), (22E, 24R)-3β, 5α, 9α-trihydroxy- ergosta-7, 22-dien-6-one (4), (22E, 24R)-5α, 6α-epoxy-ergosta-8, 22-dien-3β, 7α-diol (5), (22E, 24R)- ergosta-4, 6, 8(14), 22-tetraen-3-one (6), and euphorbol (7). This paper reports for the first time the chemical constituents of fungus Exophiala oligosperma and the discovery of compound 1 as a natural product from the fungus.

Assessment of Non-chemical Alternatives for Controlling the Burrowing Nematode on Banana in Costa Rica

The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.