霜霉属二新种

本文报道霜霉属（Ｐｅｒｏｎｏｓｐｏｒａ）新种二个：即寄生在石竹科植物异叶假繁缕（Ｐｓｅｕｄｏ ｓｔｅｌｌａｒｉａ ｈｅｔｅｒｏｐｈｙｌｌａ（Ｍｉｑ．）Ｐａｘ．）上的假繁缕霜霉（Ｐ．ｐｓｅｕｄｏｓｔｅｌｌａｒｉａｅ Ｇ．Ｙ．Ｙｉｎ ｅｔ Ｚ．Ｓ．Ｙａｎｇ）和寄生在荨麻科植物薮Ｎｉｎｇ麻（Ｂｏｅｈｍｅｒｉａ ｊａｐｏｎｉｃａ Ｍｉｑ．）上的Ｎｉｎｇ麻霜霉（Ｐ．ｂｏｅｈｍｅｒｉａｅ Ｇ．Ｙ．Ｙｉｎ ｅｔ     

霜霉属二新种

本文报道霜霉属(Peronospora)新种二个:即寄生在石竹科植物异叶假繁缕(Pseudo stellaria heterophylla(Miq.)Pax.)上的假繁缕霜霉(P.pseudostellariae G. Y. Yin et Z.S.Yang)和寄生在荨麻科植物藪苧麻(Boehmeria japonica Miq.)上的苧麻霜霉(P.boehmeriae G.Y.Yin et Z.S.Yang)。文中有拉丁文及中文描述。标本保存于南京农业大学真菌标本室和中国科学院微生物所真菌标本室。     

繁缕和无瓣繁缕六个居群的数值分析

对繁缕（Stellaria media）和无瓣繁缕（S.apetala）的6个居群的57个性状进行Q－聚类和R－聚类的研究。结果表明：（1）Q－聚类中,用一条结合线,可以把繁缕的4个居群聚为一类,无瓣繁缕的2个居群聚为一类。这一结果支持肥繁缕和无瓣繁缕划分为两个物种;（2）R－聚类中,发现了呈现完全正相关、极大正相关和极大负相关的性状,并根据R－聚类的结果,运用一条适当的结合线,把繁缕和无瓣繁缕的57个性状划为5个类群,并分析了各性状的分类学意义。     

中国石竹科一新属

本文发表了石竹科一新属,假卷耳属ＰｓｅｕｄｏｃｅｒａｓｔｉｕｍＣ．Ｙ．Ｗｕ,Ｘ．Ｈ．ＧｕｏｅｔＸ．Ｐ．Ｚｈａｎｇ。该属模式种为假卷耳ＰｓｅｕｄｏｃｅｒａｓｔｉｕｍｓｔｅｌｌａｒｉｏｉｄｅｓＸ．Ｈ．ＧｕｏｅｔＸ．Ｐ．Ｚｈａｎｇ,近于卷耳属,繁缕属和鹅肠菜属。另报道一个中国地理分新分布种,异型花缕ＳｔｅｌｌａｒｉａｄｉｖｅｒｉｓｆｌｏｒａＭａｘｉｍ．。     

黑斑对象生物学特性及对繁缕的控制作用

<正> 黑斑叶象Hypera basalis(Voss),属鞘翅目象虫科叶象亚科叶象属。是麦田杂草天敌,专食繁缕Stellaria media(L.)Cyr.繁缕是我地区麦田中主要杂草之一。近几年来,由于叶象取食繁缕,麦子受繁缕的为害明显减轻。有关这方面资料,国内未见报道,为了丰富综合防治内容更好地保护利用天敌,保持生态平衡。1984～1986年,我们对叶象生物学特性和对繁缕的控制作用,进行了初步调查观察,现将结果报告如下。     

石竹科繁缕属与孩儿参属的数量分类

石竹科繁缕属(Stellaria L.)和孩儿参属(Pseudostellaria Pax)的关系一直备受关注。为了弄清它们之间的关系及属下分类等问题,选择繁缕属22种和孩儿参属8种,共30种植物51个形态特征,利用NTSYS-pc 2.10e软件中的UPGMA聚类分析方法和主坐标分析方法,对这2个属进行数值分类学研究。结果表明,繁缕属与孩儿参属是2个自然类群,除繁缕属的繁缕(S.media(L.)Cyr.)和鸡肠繁缕(S.neglecta Weihe ex Bluff et Fingerh)在聚类中不能分开外,其它物种都能很好地分开。两属有较近的关系,其中巫山繁缕(S.wushanensis Williams)是过渡种。此外,数量分类结果建议将细叶孩儿参(P.sylvatica(Maxim.)Pax)作为一个独立组处理。对性状的主坐标排序分析显示,根的形状、叶缘质地、花的形态(是否具花瓣、花瓣长度、花瓣裂数、深裂还是浅裂)和种子表面纹饰(是否具齿轮状、疣状突起)等在繁缕属与孩儿参属的分类中具有重要作用。     

中国繁缕(Stellaria chinensis Regel)一新变种

发表了中国繁缕一新变种,即缘毛中国繁缕Stellaria chinensis Regel var. ciliata C. S. Zhu et H. M. Li.     

石竹科繁缕属与鹅肠菜属的数量分类

石竹科繁缕属(Stellaria L.)和鹅肠菜属(Myosoton Moench.)的系统关系一直存在争议.为了弄清它们之间的关系及属下分类等问题,选取55个形态特征对繁缕属和鹅肠菜属进行数量分类学研究.聚类分析和主坐标分析结果显示,鹅肠菜(M.aquaticum (L.) Moench.)与繁缕组繁缕亚组的关系较近,故支持将鹅肠菜属并入繁缕属.此外,研究结果还支持将繸瓣组作为独立的组.对性状的主坐标排序分析显示,茎的形状及是否被毛、叶长、叶宽、是否具叶柄、叶形及毛被、上下表皮气孔指数与密度、是否具花瓣及花瓣裂片数、雄蕊数目、蒴果长度、花柱与种子的数目、种子表面纹饰等性状特征是繁缕属与鹅肠菜属分类的重要依据.     

中国繁缕属植物研究资料

一、简介 繁缕属Stellaria L.隸于石竹科Caryophyllaceae繁缕亚科Alsinoideae Vierhapper由瑞典植物学家林奈建立于1753年,其命名模式为硬骨草繁缕S.holostea L.根据文献记载这一属在全世界约有120种,产于南北两半球温寒两带,在编写中国植物志繁缕属的过程中,对全国各主要标本室及有关高等院校的该属标本,进行了系统的整理鉴定工作,根据初步研究表明中国产44种10变种及1变型,这些种类分别隸于5个组及11个系中,其中的新分类群在此一并报导。     

基于ITS和trnL-F序列碱基差异的繁缕及其近缘种的亲缘关系分析

应用PCR产物直接测序法分析了繁缕[Stellaria media(L.)Villars]及其近缘种和鹅肠菜[Myosoton aquaticum (L.)Moench]的ITS和trnL-F序列的碱基差异,并以孩儿参[Pseudostellaria heterophylla(Miq.)Pax]为外类群构建N-J系统树,分析了这些种类的种间亲缘关系.结果表明,供试的繁缕属(Stellaria L.)种类及鹅肠菜的ITS和trnL-F序列长度分别为521～784和788～951 bp,各有变异位点77和59个,其中信息位点分别为18和11个,种间碱基差异百分率分别为6.5%和3.1%.ITS的碱基组成为A 22.1%、T20.9%、G 28.5%和C 28.5%,G+C含量57.0%;trnL-F的碱基组成为A 35.9%、T 33.7%、G 15.7%和C 14.8%,G+C含量30.5%.繁缕、雀舌草(S.alsine Grimm)和箐姑草(S.vestita Kurz)的ITS和trnL-F序列一致;鹅肠菜的ITS序列中有4个位点与前述种类不同,但trnL-F序列则相同;中国繁缕(S.chinensis Regel)的ITS和trnL-F序列与孩儿参较相似.在N-J系统树中,鹅肠菜与繁缕、雀舌草和箐姑草聚为一支,表明它们的亲缘关系相对较近,支持将鹅肠菜重新归入繁缕属的分类处理.研究结果显示,ITS和trnL-F序列分析均可用于繁缕及其近缘种的鉴别,且ITS是更为适宜的分子标记.     

Molecular confirmation of a Trichophyton violaceum isolate from human black-dot ringworm

A clinical isolate from a black-dot ringworm lesion of a 28-year-old female Japanese was investigated by morphological and biochemical analyses as well as molecular analyses. The isolate grew well onthiamine enriched agar and did not produce violetpigment, macroconidia or microconidia on Sabouraud's dextrose agar. Approximately 620-bp genomic DNA fragments of the CHS1 gene were amplified from Trichophyton mentagrophytes, T. rubrum, T. tonsurans and T. violaceum by polymerase chain reaction (PCR) and sequenced. The chitin synthase 1 (CHS1) nucleotide sequences of the clinical isolate showed more than 97% similarity to that of T. violaceum and less than 96% similarity to that of T. mentagrophytes, T. rubrum and T. tonsurans. The phylogenetic analysis of their sequences revealed that the clinical isolate was genetically close to T. violaceum and distinct from T. mentagrophytes, T. rubrum and T. tonsurans. Therefore, the isolate was confirmed as T. violaceum by mycological examination and molecular analyses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Intraguild Predation and Feeding Preferences in Three Species of Phytoseiid Mite Used for Biological Control

The ecological impact of introduced biological control agents on native species of arthropods is a matter of considerable debate. This study investigated the ability of the non-native predatory mite Neoseiulus californicus to feed on the native Typhlodromus pyri and vice versa, as both species now co-occur in UK orchards. Typhlodromips montdorensis is a candidate for introduction into the UK as a glasshouse biological control agent. The ability of T. montdorensis to feed on the widely used N. californicus was investigated to identify possible intraguild predation, which might influence the effectiveness of either or both species as predators of Tetranychus urticae. Both N. californicus and T. pyri consumed larval stages of each other, but in choice experiments both showed a preference for T. urticae. Both N. californicus and T. montdorensis also fed on each other, but whereas N. californicus again showed a preference for T. urticae, T. montdorensis fed equally on T. urticae and N. californicus. Interactions between N. californicus and T. pyri and N. californicus and T. montdorensis are discussed in relation to their effectiveness as biological control agents in the glasshouse and the natural control of spider mite in the field.     

Pre-adult development of Phytoseiulus persimilis on diets of Tetranychus urticae and Tetranychus lintearius: implications for the biological control of Ulex europaeus

Predation by the phytoseiid mite, Phytoseiulus persimilis, is considered a major threat to the effectiveness of biological control of gorse, Ulex europaeus, using Tetranychus lintearius. To assess this threat and to determine if the impact of P. persimilis on T. lintearius populations is comparable to its impact on T. urticae populations, its development and predator : prey generation time ratios were assessed. The pre-adult mortality and development time of two populations of P. persimilis fed on two diets, T. urticae and T. lintearius, were determined at two temperatures, 14 and 24°C. There were no significant differences in either mortality or development time between the two populations of P. persimilis at these temperatures. There is therefore no evidence that the two tested populations of P. persimilis are behaving as different strains. Similarly, diet had no significant effect on either mortality or development time at these temperatures. At 14°C the mortality of P. persimilis was significantly higher and development was significantly longer than at 24°C. Using pre-adult development as a surrogate for generation times, predator : prey generation time ratios were calculated between P. persimilis and both T. urticae and T. lintearius using data from this and other studies. The predator : prey generation time ratios between P. persimilis and T. lintearius were lower than those between P. persimilis and T. urticae. These results indicate that the impact of P. persimilis on T. lintearius populations is likely to be comparable to its impact on T. urticae populations. This provides further evidence that predation by P. persimilis is having a deleterious effect on T. lintearius populations and therefore reducing its effectiveness as a biological control agent for gorse.     

Life history of the predatory mite <Emphasis Type="Italic">Phytoseiulus fragariae</Emphasis> on <Emphasis Type="Italic">Tetranychus evansi</Emphasis> and <Emphasis Type="Italic">Tetranychus urticae</Emphasis> (Acari: Phytoseiidae,Tetranychidae) at five temperatures

Tetranychus evansi Baker and Pritchard and Tetranychus urticae Koch (Acari: Tetranychidae) are important pests of Solanaceae in many countries. Several studies have demonstrated that T. urticae is an acceptable prey to many predatory mites, although the suitability of this prey depends on the host plant. T. evansi, has been shown to be an unfavorable prey to most predatory mites that have been tested against it. The predator Phytoseiulus fragariae Denmark and Schicha (Acari: Phytoseiidae) has been found in association with the two species in Brazil. The objective of this work was to compare biological parameters of P. fragariae on T. evansi and on T. urticae as prey. The study was conducted under laboratory conditions at 10, 15, 20, 25 and 30°C. At all temperatures, survivorship was lower on T. evansi than on T. urticae. No predator reached adulthood at 10°C on the former species; even on the latter species, only about 36% of the predators reached adulthood at 10°C. For both prey, in general, duration of each life stage was shorter, total fecundity was lower and intrinsic rate of population increase (r _m ) was higher with increasing temperatures. The slower rate of development of P. fragariae on T. evansi resulted in a slightly higher thermal requirement (103.9 degree-days) on that prey than on T. urticae (97.1 degree-days). The values of net reproduction rate (R ₀), intrinsic rate of increase (r _m ) and finite rate of increase (λ) were significantly higher on T. urticae, indicating faster population increase of the predator on this prey species. The highest value of r _m of the predator was 0.154 and 0.337 female per female per day on T. evansi and on T. urticae, respectively. The results suggested that P. fragariae cannot be considered a good predator of T. evansi.     

梅毒螺旋体外膜蛋白研究进展

梅毒是由梅毒螺旋体(Treponema pallidum)亚种苍白螺旋菌引起的性传播感染性疾病,主要通过母婴感染或性接触的方式传播.梅毒螺旋体的外膜蛋白在梅毒螺旋体的传播和宿主的黏附等方面起重要作用,因此,鉴定可以作为抗生素作用靶点的梅毒螺旋体外膜蛋白一直是梅毒疫苗开发的研究重点.本文重点阐述了梅毒螺旋体外膜蛋白的结构...     

沙门菌致病岛2 Ⅲ型分泌系统研究进展

沙门菌(Salmonella)是革兰氏阴性的兼性胞内菌,可引起其广泛宿主的一系列疾病,严重时可导致全身性感染,威胁生命安全。沙门菌致病岛2(SPI2)是与沙门菌全身性感染密切相关的重要毒力基因簇,其编码的Ⅲ型分泌系统2(T3SS2)在沙门菌侵入宿主细胞后开始组装合成,经该装置分泌的多种效应蛋白对沙门菌在宿主细胞内的生存和增殖起着重要作用。近些年来,与沙门菌T3SS2相关的研究一直都是病原微生物领域关注的焦点之一。本文简要综述了SPI2的基因特征、SPI2基因表达的调控、T3SS2的结构和组成、T3SS2的效应蛋白及与T3SS2相关的疫苗研究等方面的主要研究进展。     

Phylogenetic and populational study of the Tuber indicum complex

When examined using SEM, Chinese samples of Tuber indicum and T. sinense displayed the same ascospore ornamentation as that of T. pseudohimalayense, T. indicum, collected in India by Duthie in 1899, and samples renamed T. himalayense in 1988. The different authors who named the four taxa (T. indicum, T. himalayense, T. sinense, T. pseudohimalyense) described differences in the surface of the peridium which could be considered as usual variations within a single species. We consider T. indicum, T. himalayense, T. sinense and T. pseudohimalayense as one species, T. indicum. Within this T. indicum complex, according to ITS and β-tubulin sequences, there are two groups in China, which could be considered as geographical ecotypes. This study is the first to identify a genetic and phylogeographical structure within the Chinese Tuber species.     

Comparative bioactivity of selected extracts from Meliaceae and some commercial botanical insecticides against two noctuid caterpillars, <Emphasis Type="Italic">Trichoplusia ni</Emphasis> and <Emphasis Type="Italic">Pseudaletia unipuncta</Emphasis>

Plant-derived extracts and phytochemicals have long been a subject of research in an effort to develop alternatives to conventional insecticides but with reduced health and environmental impacts. In this review we compare the bioactivities of some plant extracts with those of commercially available botanical insecticides against two important agricultural pests, the cabbage looper, Trichoplusia ni and the armyworm, Pseudaletia unipuncta. Test materials included extracts of Azadirachta indica (neem), A. excelsa (sentang), Melia volkensii, M. azedarach (Chinaberry) and Trichilia americana, (all belonging to the family Meliaceae) along with commercial botanical insecticides ryania, pyrethrum, rotenone and essential oils of rosemary and clove leaf. Most of the extracts and botanicals tested proved to be strong growth inhibitors, contact toxins and significant feeding deterrents to both lepidopteran species. However, there were interspecific differences with T. ni generally more susceptible to the botanicals than the armyworm, P. unipuncta. All botanicals were more inhibitory to growth and toxic (through feeding) to T. ni than to P. unipuncta, except for M. azedarach which was more toxic to P. unipuncta than to T. ni. Athough, pyrethrum was the most toxic botanical to both noctuids, A. indica, A. excelsa, and M. volkensii were more toxic than ryania, rotenone, clove oil and rosemary oil for T. ni. As feeding deterrents, pyrethrum was the most potent against T. ni, whereas A. indica was the most potent against the armyworm. Based upon growth inhibition, chronic toxicity, and antifeedant activity, some of these plant extracts have levels of activity that compare favorably to botanical products currently in commercial use and have potential for development as commercial insecticides.     

Physiology of Organotrophic and Lithotrophic Growth of the Thermophilic Iron-Reducing Bacteria Thermoterrabacterium ferrireducens and Thermoanaerobacter siderophilus

Growth physiology of the iron-reducing bacteria Thermoterrabacterium ferrireducens and Thermoanaerobacter siderophilus was investigated. The stimulation of the organotrophic growth of T. ferrireducens and T. siderophilusin the presence of Fe(III) was shown to be due to the utilization of ferric iron as an electron acceptor in catabolic processes and not to the effect exerted on the metabolism by Fe(II) or by changes in the redox potential. It was established that Fe(III) reduction in T. ferrireducens is not a detoxication strategy. In T. siderophilus, this process is carried out to alleviate the inhibitory effect of hydrogen. T. ferrireducens was shown to be capable of lithoautotrophic growth with molecular hydrogen as an electron donor and amorphous ferric oxide as an electron acceptor, in the absence of any organic substances. The minimum threshold of H₂ consumption was 3 × 10^–5 vol % of H₂. The presence of CO dehydrogenase activity in T. ferrireducens suggests that CO₂ fixation in this organism involves the anaerobic acetyl-CoA pathway. T. siderophilus failed to grow under lithoautotrophic conditions. The fact that T. ferrireducens contains c-type cytochromes and T. siderophilus lacks them confirms the operation of different mechanisms of ferric iron reduction in these species.