线虫分子生物学分类研究进展

线虫是多样性仅次于昆虫的一个动物类群,在动物发育的研究和生物防治中起着巨大的作用。本文综述了20世纪80年代以来国内外有关限制性长度多态性(RFLP)、扩增片段长度多态性(AFLP)、随机扩增多态性DNA(RAPD)和核酸序列分析等分子标记在线虫遗传结构分析、亲缘关系鉴定和遗传图谱的构建等方面的应用。     

外来入侵生物相似穿孔线虫的风险分析

相似穿孔线虫(Radopholus similis)是一种危险性外来入侵生物,使发生的国家造成极大的损失。相似穿孔线虫具有很强的适应性,地理分布达到59个国家和地区,寄主达到360多种,且具有一定的检验难度,其入侵会造成农业生产上巨大的经济损失;结合国内寄主植物分布和种植情况,确定了其在中国具有传入、定殖和扩散的可能性。依据国际植物检疫措施标准(ISPM)规定的有害生物风险分析程序(PRAS),采用多指标综合评估方法,对各指标进行赋值运算,获得总指标值R为2.6,符合高风险的检疫性有害生物标准。因此将相似穿孔线虫列入香蕉、花卉等经济植物的一类检疫性有害生物名单,实施外来入侵物种的风险管理。     

斯氏线虫属一新种(小杆目:斯氏线虫科)

本文描述了斯氏线虫属一新种:尖尾斯氏线虫,并根据形态特征与属内的已知种进行了比较。     

斯氏线虫属-新种(小杆目:斯氏线虫科)

本文描述了斯氏线虫属一新种：尖尾斯氏线虫,并根据形态特征与属内的已知种进行了比较。     

松材线虫的天然毒素研究进展

概述了松材线虫病的现行防治措施及存在问题,介绍了植物源和真菌源天然毒素毒杀松材线虫的研究现状及研究中遇到的问题,指出天然毒素在未来松材线虫病生物防治中的研究方向。     

线虫蛔甙(Ascarosides)信息素研究进展

大多数生物通过信息素系统来对环境进行感应和个体间交流,并指导其行为、发育和生理代谢。线虫是在地球上生存策略最多样的动物之一,但其信息素系统却鲜为人知。近年来发现一组称为蛔甙(ascarosides)的线虫种内化学信号物质,在秀丽隐杆线虫(Caenorhabditis elegans)的交配、聚集和滞育等行为及发育调控方面起着至关重要的作用。随后发现蛔甙在线虫界广泛存在。对蛔甙进行深入全面的了解有利于促进线虫化学生态学学科发展,并填补传统化学生态学中关于化学信息对生物发育调控的知识。因此,对近年来蛔甙的最新研究进展进行了系统总结,包括蛔甙结构与鉴定、组成和功能、生物合成与代谢调控、化学感受信号途径及信息调节模式,从而更好地理解化感信号对线虫乃至高等生物的行为、发育、新陈代谢及衰老的调控机制,为研究生命科学中信息素调控理论提供新的参考。     

相似穿孔线虫拮抗细菌的筛选及分子鉴定

【背景】相似穿孔线虫是一种重要的检疫性有害生物,其寄主范围广,危害具有毁灭性,已给我国农业生产造成潜在威胁。由于目前大多化学杀线剂毒性较高,筛选获得对相似穿孔线虫具有拮抗活性的微生物菌株对线虫防控具有重要意义。【方法】广泛从染病香蕉植株根际采集土壤样本,运用等比稀释涂布平板法分离菌株;采用摇瓶发酵法制备拮抗菌株上清液和发酵液。通过室内生物测定和盆栽试验,筛选出对相似穿孔线虫具有拮抗作用的细菌菌株,并通过16S rDNA的PCR扩增和序列分析,对拮抗菌株进行种类鉴定。【结果】获得5株对相似穿孔线虫具有较理想拮抗活性的细菌菌株。其中,菌株HD-86的作用效果最好,其发酵上清液处理24 h后的相似穿孔线虫死亡率达100%。盆栽试验表明,菌株HD-86发酵液处理42和70 d后对相似穿孔线虫的相对防效分别为77.34%和90.51%,均优于对照药剂阿维菌素。【结论与意义】菌株HD-86对相似穿孔线虫具有很强的拮抗作用,将其鉴定为洋葱伯克氏菌Burkholderia cepacia。本研究可为相似穿孔线虫生防制剂的研发和病害的防控提供依据。     

寄生于粘虫的卵索线虫属一新种——中华卵索线虫(线虫纲:索科)

本文报道从河南省驻马店地区和山东省临沂地区麦田内采集的粘虫幼虫的寄生线虫优势种卵索线虫属一新种,命名为中华卵索线虫,新种Ovomermis sinensis sp.nov.     

麂属(Muntiacus)的分类及其系统发育研究

麂属(Muntiacus)是一群中小型草食有蹄类,为东洋界的特有属,是典型的热带、亚热带类群。在我国,麂属的分布仅限于长江流域及其以南各地,为我国南方的重要毛皮兽。 以往对麂属的研究多限于一般的形态分类,对其系统发育尚未深入研究。在种级分类上至今还存在一些混乱现象。本文试图用分支系统学(Cladistics)的方法,对麂属的种级分化进行系统整理,并对其系统发育作一初步探讨。     

Occurrence of Biotypes in Radopholus citrophilus

Two morphologically and karyotypically identical populations of the citrus burrowing nematode, Radopholus citrophilus, differed in their ability to damage and reproduce in roots of citrus rootstocks previously identified as either resistant or tolerant. These populations are considered to be biotypes, and their occurrence may explain the appearance of spreading decline symptoms in plantings of rootstocks previously considered resistant.     

丛枝菌根真菌分类最新进展

近10a来,随着分子生物学技术在丛枝菌根(arbuscularmycorrhiza,AM)研究中的应用,AM真菌分类学得到迅速发展。重点介绍AM真菌的最新分类系统,并对其发展简史作一简单回顾。     

Parthenogenesis in the Two Races of Radopholus similis from Florida

Single larval inoculations of both the citrus and banana races of Radopholus similis from Florida indicate parthenogenetic reproduction is possible. These races normally reproduce amphimictieally. Both races produced all-female populations from single larva inoculations after 80 d and male-female populations after 180 d. The all-female populations produced female progeny with viable eggs, but no spermatozoa were present in the spermatheca, indicating tychoparthenogenesis occurred. Uninseminated females in the latter study produced both male and female progeny. Approximately 95% of the female progeny of the male-female populations were inseminated, indicating that cross-fertilization had occurred. The proportion of males to females was as expected in a normal bisexual population. No intersex males were observed. The mechanism of sex determination is not fully understood but assumed to be enviromnentally induced.     

新疆小孢发属地衣的分类

根据多年的野外调查和相关的研究资料,对小孢发属(BryoriaB rodo & Hawksw.)地衣进行了分类学研究,报道新疆小孢发属地衣10种。其中Bryoria chalybeiformis,Bryoria fuscescens,Bryoria nadvornikiana和Bryo-riasimplicior为中国新记录种,Bryoria lanestris,Bryoria nitidula,Bryoria trichodes ssp.trichodes,Bryoria pseudo-fuscescens为新疆新记录种。     

Karyology and Oogenesis of Radopholus similis (Cobb) Thorne

Two morphologically indistinguishable races of Radopholus similis from Florida are presently identifiable only by host preference tests. One race attacks banana and other hosts, but not citrus. The other race attacks both citrus and banana, as well as other hosts. The two races normally reproduce by amphimixis. The morphology of the female reproductive systems of both races were examined and appeared to be identical. However, slight differences were observed in developmental stages of oogenesis between the two races. The two races were distinct with respect to karyotype. There were four chromosomes in the banana race and five chromosomes i n the citrus race. Karyotypic uniformity was found i n the two Florida populations of the citrus race.     

中国小鲵科属、种分类变更的回顾

小鲵科为亚洲特有的有尾两栖动物,是现生有尾目10科中第三大科.中国是小鲵科动物属、种分布的主要区域,且研究其分类历史较久,学者较多,故导致学术观点差异较大.本文对中国小鲵科分类地位发生变更的部分属(巴鲵属Liua、拟小鲵属Pseudohynobius、肥鲵属Pachyhynobius)、种(秦巴巴鲵L. tsinpaensis、满洲小鲵Hynobius mantchuricus、豫南小鲵H. yunanicus、弱唇褶山溪鲵Batrachuperus cochranae和太白山溪鲵B. taibaiensis)的变更历史进行回顾,旨在为小鲵科动物的分类提供一个清晰的背景知识.     

Variation in Radopholus citrophilus Population Densities in the Citrus Rootstock Carrizo Citrange

Seedlings of the hybrid citrus rootstock, Carrizo citrange (Citrus sinensis × Poncirus trifoliata) do not uniformly limit development of the citrus burrowing nematode, Radopholus citrophilus. Variation in nematode population densities in roots of seedlings germinating from the same seed suggests that factors responsible for nematode incompatibility are not functional or are not inherited uniformly among progeny. Seeds which produced a single seedling were more likely to produce plants which suppressed citrus burrowing nematode population increase than were seeds which produced two or three seedlings.     

Biochemical Identification of the Two Races of Radopholus similis by Polyacrylamide Gel Electrophoresis

Analysis of proteins of the banana and citrus race of Radopholus similis was carried out by several different types of polyacrylamide gel electrophoresis. These included standard slab gel, SDS slab gel, gradient slab gel, and two-ditnensional slab gel electrophoresis. A major band difference was detected between the two races by slab gel electrophoresis. However, several other poorly resolved but consistent hands of high molecular weight proteins near the gel origin also were considered as diagnostic. Resolution of protein bands was greatly improved by SDS and gradient slab gel electrophoresis, but no differences could be detected among the proteins resolved between the two rares with these techniques. Two-dimensional gels revealed a large number of proteins, but background staining obscured them hindering interpretation. When nematode races were reared on three different host plants, no differences in protein patterns were detected between them, indicating host preferences does not play a role in determining the types proteins occurring in these nematodes.     

Morphological Differences Between Radopholus citrophilus and R. similis

SEM observations of the external morphology of populations of Radopholus citrophilus and R. similis revealed several diagnostic differences. The cloaco-spicular orifice on males of R. citrophilus had three to seven genital papillae (anterior hypoptygmata), whereas males of R. similis were either smooth or had one or two shorter genital papillae (anterior hypoptygmata). Females of R. citrophilus had four annules in the region of the vulval opening, but R. similis had five annules in the same region. The labial disc and lateral lips appeared to be of diagnostic significance, but these areas were more susceptible to artifacts due to fixation. An unknown population of Radopholus from Puerto Rico with a chromosome number of n = 4 was morphologically similar to R. similis. These morphological differences provide additional support that R. citrophilus and R. similis are distinct species.     

Biochemical Identification of the Two Races of Radopholus similis by Starch Gel Electrophoresis

Analysis of genetic variation between the banana and the citrus races of Radopholus similis by starch gel eleclrophoresis demonstrated that 7 of 16 enzyme-encoding loci could be used for their diagnostic separation. The two races are closely related arid share approximately 75% of the enzymes evaluated. The level of dissimilarities o1 inherited bands indicates that no gene flow occurs between the races. Aldolase, α + β esterase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, lactate dehydrogenase, malate dehydrogenase, and phosphoglucose isomerase are diagnostic markers of the races.