乌梅提取物对溶藻弧菌的抑制效应与机理

[背景] 溶藻弧菌（Vibrio alginolyticus）能够感染鱼、虾、贝等海洋经济动物,给海水养殖业带来了严重的经济损失,对公众健康及食品安全也构成较大威胁。[目的] 通过研究乌梅（Fructus mume）对溶藻弧菌的抑菌效应及其机理,为乌梅在水产养殖中的进一步开发利用提供理论依据。[方法] 采用试管二倍稀释法测定乌梅提取物（Fructus mume Extract,FME）对溶藻弧菌的最小抑菌浓度（Minimal Inhibitory Concentration,MIC）和最小杀菌浓度（Minimum Bactericidal Concentration,MBC）,电导率仪检测溶藻弧菌的相对电导率,分光光度法分析溶藻弧菌的核酸泄露和呼吸链脱氢酶活性及生物膜抑制率,蛋白质电泳检测溶藻弧菌的蛋白质合成情况,扫描电子显微镜观察溶藻弧菌的亚显微结构。[结果] 乌梅提取物对溶藻弧菌的MIC和MBC分别为1.953 mg/mL和3.906 mg/mL;乌梅提取物显著增加了溶藻弧菌的相对电导率和核酸泄露,明显降低了溶藻弧菌蛋白质的合成能力,对于弧菌的亚显微形态产生了较大影响。同时乌梅提取物显著抑制了溶藻弧菌生物膜的形成和呼吸链脱氢酶的活性。[结论] 乌梅提取物通过增加溶藻弧菌细胞膜通透性及显著抑制生物膜的生成、呼吸链脱氢酶活性及蛋白质的合成,实现抑制及杀灭溶藻弧菌的目的。     

Genetic relatedness and genetic diversity of ornamental mei (Prunus mume Sieb. et Zucc.) as analysed by AFLP markers

The genetic diversity and genetic relatedness of mei (Prunus mume; 2n = 16) were studied using amplified fragment length polymorphism (AFLP) markers. Eight EcoRI–PstI AFLP primer combinations were applied to 121 distinct genotypes of mei cultivars and related species. A total of 508 AFLP product bands were produced, of which 382 were polymorphic. The unweighted pair group method with arithmetic averages analysis was carried out based on these AFLP markers. From this analysis, “Qugeng Mei,” “Yan Mei,” “Chaodou Mei,” and mei cultivars were seen to share the same P. mume genetic stem. The AFLP data were able to clearly discriminate P. mume from other species in the genus Prunus, with P. armeniaca aligning as its closest related species. Two major groups and nine subgroups of mei flower were identified, and there was a strong coincidence of these AFLP-based groupings with the respective morphological characters of the accessions. The genetic diversity of mei accessions was greatest in the Yunnan Province and decreased toward Eastern China and Japan, so supporting the hypothesis that the southwest of China represents the genetic diversity center of the species.     

Establishment of AFLP technique and assessment of primer combinations for mei flower

Mei flower is one of the most famous ornamental flowers in eastern Asia for its blossoming in early spring. Amplified fragment length polymorphism (AFLP) is one of the most frequently used techniques for analysis of genetic variation and is used herein for the first time inPrunus mume. This research provides a detailed and modified AFLP protocol for Mei genomic DNA digested withEcoRI/PstI restriction endonuclease combinations. The 10 best primer pairs of high polymorphism were screened from 256 primer combinations that could reliably and repetitively distinguish 14 Mei samples and would be suitable for genetic analysis of more cultivars. Ten primer pairs produced up to a total of 524 AFLP bands and up to 233 polymorphic bands. The ratio of polymorphic bands scoped from 35.71% to 59.67%, and the average ratio was 44.46% in the 10 primers. AFLP is an effective, inexpensive, and timesaving technique for the genetic differentiation of the Mei cultivars, as evidenced in this study.     

New record of the fungus <Emphasis Type="Italic">Coniochaeta prunicola</Emphasis> on peaches from Slovakia

The first record of Coniochaeta prunicola Damm & Crous (Coniochaetales, Sordariomycetes, Ascomycota) as a pathogen of Persica vulgaris Mill. described and illustrated from Nitra district, Slovakia. C. prunicola was isolated from symptomatic leaves of host tree and based on morphological attributes identified for the first time as a causative agent of peach tree damage. C. prunicola is characterized by dark brown ascomata clothed with setae, the fasciculate, unitunicate, cylindrical asci and broadly almond-shaped, ellipsoidal ascospores with a longitudinal germ slit.     

梅花垂枝性状次生木质部解离研究

为探究梅花纤维发育对枝条形态的影响,采用光学显微镜和过氧化氢—醋酸解离法,选取直枝形与垂枝形梅花4个品种一年生枝条,分基部、中部、梢部对枝条重力方向上下侧次生木质部进行解离观察。结果表明:直枝形梅花枝条基部下侧纤维显著长于上侧,垂枝形枝条基部上侧纤维显著长于下侧,中部、梢部无显著差异;4个品种枝条基部中部梢部纤维直径均无显著差异。说明枝条纤维不均匀发育影响梅花枝条形态。     

Negative effects of hydroxyl radical-generating mists (simulated dew water) on the photosynthesis and growth of Japanese apricot seedlings (Prunus mume)

The hydroxyl (OH) radical, which is generated in polluted dew water on leaf surfaces of the Japanese apricot (Prunus mume), is known to be a potent oxidant. In order to investigate the effects of the OH radical formed in polluted dew water on the photosynthesis and growth of 3-year-old seedlings of P. mume, OH radical-generating solutions simulating polluted dew water were sprayed in the early morning as a mist throughout a growing season onto the leaf surfaces of seedlings growing in experimental greenhouses. Four OH radical-generating solutions (0, 6, 18 and 54 M H₂O₂ with Fe(III) and an oxalate ion) were used in the mist treatment. Five months after the beginning of treatment, the leaves exposed to the mist containing 54 M H₂O₂ showed a significantly smaller maximum CO₂ assimilation rate (A_max) and stomatal conductance (g_s) as compared to the leaves exposed to the mist containing 0 M H₂O₂. Exposure of P. mume seedlings to the OH radical-generating mist had caused a reduction in the dry weight and relative growth rate (RGR) of the above-ground parts (stem + branch) at the end of the growing season. A significant positive correlation was shown between RGR and A_max. Thus, the effects of oxidants generated in polluted dew water on leaf surfaces can be considered to be a cause of the decrease in leaf photosynthesis and growth of P. mume.     

Micropropagation ofPrunus mume

Shoot proliferation from axillary buds ofPrunus mume Sieb. et Zucc. was obtained on Woody Plant Medium (WPM) supplemented with 1 to 5 M benzyladenine, 3% sorbitol and solidified with 0.5 to 0.7% agar. Effects of different carbon sources on shoot proliferation were examined. Glucose provided better shoot proliferation than sucrose, sorbitol and fructose. In the presence of sucrose, leaf chlorosis occurred and shoots gradually declined. Best rooting percentage was obtained on WPM supplemented with 1 M naphthaleneacetic acid. Rooted plantlets were acclimatized under intermittent mist. However, survival rate was relatively low (20 to 30%).     

Association between blooming time and climatic adaptation in Prunus mume

Prunus mume Sieb. et Zucc. is an important fruit crop of the subtropical region, originating in China. It blooms earlier than other deciduous fruit trees, but different regions have different blooming periods. The time of anthesis is related to the dormancy period, and a certain amount of chilling promotes bud break and blooming. To identify the relationship between blooming time and the climatic adaptation of P. mume cultivars in China, the nuclear and chloroplast genomes of 19 cultivars from the main cultivation areas of P. mume in China were resequenced. The average depth of coverage was 34X–76X, and a total of 388,134 single nucleotide polymorphisms were located within the coding regions of the gene (CDs). Additionally, the 19 cultivar accessions were divided into three groups based on their blooming time: early, mid, and late. Associated with the blooming time groups, 21 selective sweep regions were identified, which could provide evidence supporting the possible model of P. mume domestication originating due to natural selection. Furthermore, we identified a flowering gene, FRIGIDA‐LIKE 3 (FRL3), seems to affect the blooming time and the climatic adaptation of P. mume cultivars. This study is a major step toward understanding the climatic adaptation of P. mume cultivars in China.     

Miricatena prunicola (Hyphomycetes), a new genus and species causing leaf spots of Prunus serotina in the UK

A fungus causing conspicuous leaf spots of Prunus serotina was recently collected in Surrey, UK. It proved to represent an undescribed species which also cannot be referred to any known genus. The species is described as Miricatena prunicola gen. et sp. nov.     

Pollen-ovule patterns in tribeTrifolieae (Leguminosae)

Relative pollen and ovule production in the genera of the legume tribeTrifolieae is explored particularly as to howMedicago with its explosive pollination mechanism compares with its allies.Medicago produces much larger, although much fewer pollen per ovule than the other five genera in the tribe; this is interpreted as a consequence of its highly specialized, irreversible pollination mechanism, which allows only one effective exchange of pollen with pollinators.Melilotus andTrifolium produce a comparatively large quantity of pollen; this can be related to their floral characteristics requiring abundant pollen to achieve fertilization. InMedicago andTrigonella, annuals convert a higher proportion of pollen grains and ovules into seeds than perennials.     

毛茛科六新种

该文描述了毛茛科六新种：(1)托里乌头,与阿尔泰乌头近缘,区别为其茎和叶无毛,总状花序极密集,雄蕊花丝多有1或2小齿。(2)门源翠雀花,与大通翠雀花近缘,区别为其茎极短,花序总状,退化雄蕊瓣片不分裂。(3)云台山铁线莲,与裂叶铁线莲近缘,区别为其叶为二回羽状复叶,花较小,雄蕊花丝呈黑色,无脉。(4)黑丝铁线莲,与前种云台山铁线莲在亲缘关系上极为相近,区别为其小叶较小,多呈狭卵形或披针形,聚伞花序也较小,通常只具3花。(5)五台山毛茛,与砾地毛茛相似,区别为其基生叶被柔毛,花瓣蜜槽具鳞片,心皮具短而粗的花柱和小柱头。(6)靖西铁线莲,与宝岛铁线莲在亲缘关系上接近,区别为其茎疏被短柔毛,小叶卵形或狭卵形,不分裂,聚伞花序有1~3花,萼片较大(长1.7~2 cm,宽0.5~0.7 cm)。     

Progress on the genetics of the N2-fixing actinorhizal symbiont Frankia

The actinomycete Frankia is of fundamental and ecological interests for several reasons including its wide distribution, its ability to fix nitrogen, differentiate into sporangium and vesicle (specialized cell for nitrogen-fixation), and to nodulate plants from about 24 genera. Here, we present a review on the genetics performed so far on Frankia. At the end of July 2001, 293 kbp of Frankia DNA sequences were found in the databases. Thirty five percent of these sequences corresponded to full gene or gene cluster sequences. These genes could be divided according to their role into 6 key activities: gene translation (rrnA and tRNA ^pro gene), proteolysis (pcr genes), assimilation of ammonium (glnA and glnII), protection against superoxide ions (sodF), nitrogen fixation (nif cluster), and plasmid replication. We present a review of these genetic islands; their function, expression, localization and particular properties are discussed. A comparative analysis of Frankia nif genes from various strains and species is presented. An improved nomenclature for some of these genes is suggested to avoid conflicts. Frankia plasmids DNA sequences are also presented. The novel trends in Frankia genetics are described.     

Physiological effect of the host plant on the suitability ofTetranychus urticae as prey forPhytoseiulus persimilis [Acari: Tetranychidae,Phytoseiidae]

Weight gain of adult femalesPhytoseiulus persimilis Athias-Henriot was determined after they were fed eggs or adult females ofTetranychus urticae Koch reared on either Lima bean (Phaseolus vulgaris L.) or nightshade (Solanum douglasii Dunal). No significant difference was found when the predator was fed eggs ofT. urticae reared on either host. Predators were heavier when fed adult femaleT. urticae reared on bean. Apparently, a factor determining the prey's suitability is incorporated into its hemolymph or tissues and is not restricted to its gut content.      

Efficacy of the Ventral Abdominal Secretion of the Cockroach Eurycotis floridana (Blattaria: Blattidae) as a Defense Allomone

In assays investigating the abdominal sternal secretion of the cockroach Eurycotis floridana, it was determined that the secretion provides an effective deterrent against potential predators. Analysis of grooming patterns of Peromyscus leucopus mice revealed significant increases in mouth grooming and loss of coordination following exposure to E. floridana secretion. Mouse–cockroach interactions also changed following exposure of the mouse to the spray, as the mouse incited fewer interactions and more frequently struck with its forepaws than with its mouth. Monomorium sp. and Camponotus sp. ants also were repelled by the secretion, and Periplaneta americana were significantly irritated by the application of E. floridana secretion. The secretion is able to deter without physical contact, presumably via noxious volatiles. Eurycotis floridana is capable of accurately aiming the discharge as well as ejecting it several times the length of its body. It also was found that E. floridana exhibits autotoxic responses following contact with the secretion of conspecifics.     

Antibiotic N", N""-Dibenzyleremomycin with a Reduced 1,2-Peptide Bond

Eremomycin derivatives with benzylated amino groups of both residues of eremosamine and with (R) or (S)-2-amino-4-methylpentyl substituted for N-methyl-D-Leu, the first amino acid residue of its heptapeptide, were synthesized in order to study the role of the peptide bond between the first and second amino acid residues of the heptapeptide moiety of the antibiotic in its interaction with the precursors of the bacterial cell wall peptidoglycan and the exhibition of its antibacterial activity. Comparison of the antibacterial activities of N",N"-dibenzyleremomycin, de-(N-methyl-D-Leu)-N",N"-dibenzyleremomycin, and its N-(2-amino-4-methylpentyl)-derivative (1,2-deoxo-N",N"-dibenzyleremomycin) demonstrated that cleavage or replacement of the first amino acid residue by the corresponding aminoalkyl residue results in a decrease in its antibacterial activity towards both vancomycin-sensitive and vancomycin-resistant strains of microorganisms.     

A new fungal genus, Teracosphaeria, with a phialophora-like anamorph (Sordariomycetes, Ascomycota)

The new genus and species Teracosphaeria petroica is described for a perithecial ascomycete and its anamorph occurring on decayed wood collected in New Zealand. The fungus produces immersed, non-stromatic ceratosphaeria-like perithecia in nature, with hyaline, septate ascospores produced in unitunicate, non-amyloid asci. The anamorph produced in vitro is phialophora-like with lightly pigmented phialides terminating in flaring, deep collarettes that are often noticeably brown with conspicuous periclinal thickening. Phylogenetic analysis of LSU rDNA sequence data indicates that this fungus is distinct from morphologically similar fungi classified in the Chaetosphaeriales, the Trichosphaeriales or the Magnaporthaceae. It forms a monophyletic group with recently described, chaetosphaeria-like ascomycetes, such as the pyrenomycete genus Mirannulata, and shows affinity with the anamorphic species Dictyochaeta cylindrospora. The usefulness of describing anamorph genera for morphologically reduced anamorphs, when anamorph characteristics are actually part of the holomorph diagnosis, is discussed. An apparently contradictory example of the so-called Cordana and Pseudobotrytis anamorphs of Porosphaerella spp. is also discussed.     

Comparison of carbonic anhydrase activity among various species of plantlets

During plant tissue culture, the culture container is small and sealed; the concentration of CO₂ in the microenvironment is relatively low. The plantlet growth is restrained for the shortage of CO₂ in the culture container. Carbonic anhydrase is a zinc-containing metalloenzyme that catalyzes the reversible conversion of bicarbonate to CO₂. The determination of carbonic anhydrase of leaves from Atractylodes lancea (thunb.) DC, Orychophragmus violaceus (L.) O.E. Schulz, Brassica juncea (L.) Czern.et Coss. cv. Luzhousileng, Brassica campestris L. cv. Chuanyou No.8, Brassica napus L cv. Oro, Brassica carinata Braun, Raphanus sativa L. var. raphanistroides Makino and their plantlets indicates that the carbonic anhydrase activity of leaves from both plantlets and fields varies from plant species to plant species, the carbonic anhydrase activity of leaves of Atractylodes lancea (thunb.) DC is the lowest among those plants, and the leaves of all plantlets are lower in carbonic anhydrase activity than the same species of plants from fields. The comparison of the growth rates of those plantlets shows that their relative growth rates are significantly different, plantlets of Atractylodes lancea have the slowest relative growth rate among those plants, and plantlets of Brassica juncea have the greatest relative growth rate. The relationship between RGR of plantlets and their CA activities is a significant linear function. It seems that there was certain correlation between carbonic anhydrase activities of plants and their growth rates. It suggests that in vitro, the greater the carbonic anhydrase activity of plantlet is, the higher its net photosynthetic rate, and the faster its growth rate. Those results offer a foundation to a rational medium choice in plant tissue culture.     

Interactions between an eucoilid [Hymenoptera] and a staphylinid [Coleoptera] parasitoid of the cabbage root fly

The interaction betweenTrybliographa rapae andAleochara bilineata, 2 parasitoids of the cabbage root fly, is discussed. Larvae ofA. bilineata could not differentiate between cabbage root fly pupae containingT. rapae in its endoparasitic state and unparasitized pupae but could recognize pupae containingT. rapae once the latter had reached its ectoparasitic state. Attack byA. bilineata whileT. rapae was still in its endoparasitic state usually resulted in the staphylinid killing the eucoilid. IfT. rapae had reached the ectoparasitic state before the host pupa was attacked byA. bilineata larvae the eucoilid survived attack by the beetle larva. Multiparasitism, however, resulted in increased levels of mortality of both parasitoid populations.      

应用matK基因鉴别青天葵及其常见混伪品

分析了青天葵及其混伪品matK序列,以期在分子水平建立青天葵及其常见混伪品的鉴别方法。采用一对通用引物对matK基因进行PCR扩增并测序,所得序列用DNAMAN、MEGA等软件进行分析。获得青天葵及其混伪品的matK基因序列长度为587 bp,平均GC含量为32.8%。青天葵的种内遗传距离为0,与混伪品种间遗传距离范围为0.016～0.375。基于matK基因序列构建的NJ聚类树能明显地区别青天葵及其混伪品。因此,应用matK基因序列可以有效鉴别青天葵及其混伪品。