蛹虫草(Cordycepsmilitaris)无性型的多型现象

在萨氏琼脂和PDA上,蛹虫草Cordycepsmilitaris（Vuill）Fr.无性型,蛹草拟青霉Paecilomycesmilitaris(Kob）Br.＆Sm．的一些单孢子株可自发产生突变,基于多型现象及其它形态特征可分三种类型：（1）具野生型菌株特征;产孢结构拟青霉型（Paecilomyces－type）,稳定,菌落通常不自发产生角变,大多数单孢子株属此类群。（2）属此类群的单孢子株,在PDA上可形成亮褐色至橙黄色的角变,它们典型的产孢结构为瓶梗轮生,分生孢子常聚集成头状的轮枝孢型（Verticillium－type）。在查氏培养基上则相反,拟青霉型的产孢结构占优势。单孢子株Cm-71是这一类群的代表。（3）单孢子株Cm－42是在所观察单孢子株中形态特征独特的菌株。在PDA上菌丝生长纤细,蛛网状,产孢结构轮枝孢型。蛹草拟青霉对氯酸钾（KClO3）不敏感,在浓度为6％（W／V）的KMM培养基上,23～24℃14天菌落的直径仅1～2cm,无气生菌丝生长。各单孢子株形成的不利用硝酸盐突变株（nit突变株）的途径和形态特征,也可分成类似于粉被虫草CordycepspruinosaPeteh不利用硝酸盐突变株（nit突变株）的三种类型。     

蛹虫草（Cordceps militaris）无性型的多型现象

在萨氏琼脂和ＰＤＡ上,蛹虫草Ｃｏｒｄｙｃｅｐｓ ｍｉｌｉｔｅｒｉｓ（Ｖｕｉｌｌ）．Ｆｒ无性型,蛹草拟青霉Ｐａｅｃｉｌｏｍｙｃｅｓ ｍｉｌｉｔａｒｉｓ（Ｋｏｂ）．Ｂｒ＆Ｓｍ．的一些单孢子株可自发产生突变,基于多型现象及其它形态特征可分为三种类型：（１）具野生型菌株特征,产孢结构拟青霉型（Ｐａｅｃｉｌｏｍｙｃｅｓ－ｔｙｐｅ）,稳定,菌落通常不自发产生角变,大多数单孢了株属此类群。（２）属此类群的单孢子     

粉被虫草无性型单孢子株间和单孢子株内的营养亲和性

在含5％氨酸钾的KMM和KPS培养基上,粉被虫草无性型以3种途径产生不利用硝酸盐的突变株（nit突变株）。（1）由菌落基质菌丝形成的快速生长气生菌丝角变;（2）菌落表面快速生长的气生菌丝;（3）菌落基质菌丝缓慢生长形成的基质菌丝角变。来自18个单孢子株的94个nit突变株中,64.8％的突变株是稳定的。配对试验结果表明:在全部19个配对中,单孢子株内配对率为57.9％,单孢子株间配对率为42.1％。在全部nit突变株中,Cp-14c3突变株与其它突变株间的配对率最高（18.2％）。单孢子株间配对率高的孢子株是Cp-14Cp-7,Cp-5和Cp-6,将来自Cp-14同一单孢子株的Cpe-14C3分别与Cp-14cl和Cp-14c4nit突变株配对后发现,它们形成的浓密生长配接线的颜色是不相同的,前者橙色,后者白色。统计结果发现,所试全部的单泡子株可分成11个营养亲和群（VCGs）,那些含有易与其它菌株配对的nit突变株的单孢子株,如Cp-1,Cg-4,Cp-5,Cp-6,Cp-7,Cp-13,和Cp-14等皆在同一营养亲和群内。用Hochest33258荧光染色观察发现,野生型菌株的菌丝和分生孢子单核,nit突变株的少量分生孢子中可见双核,互补配对形成的浓密菌丝丛中的分生孢子则常见双核。     

粉被虫草无性型单孢子株间和单孢子株内的营养亲和性

在含５％氯酸钾的ＫＭＭ和ＫＰＳ培养基上,粉被虫草无性型以３种途径产生不利用硝酸盐的突变株（ｎｉｔ突变株）。（１）由菌落基质菌丝形成的快速生长气生菌丝角变;（２）菌落表面快速生长的气生菌丝;（３）菌落基质菌丝缓慢生长形成的基质菌丝角变。来自１８个单孢子株的９４个ｎｉｔ突变株中,６４．８％的突变株是稳定的。配对试验结果表明：在全部１９个配对中,单孢子株内配对率为５７．９％,单孢子株间配对率为４２．１％     

虫草多型现象的5.8S rDNA 和ITS2 序列测定研究

新定名的甘肃虫草Cordycepsgansuensi与冬虫夏草Cordycepssinensi形态相似。蛹虫草Cordycepsmilitaris具有拟青霉型（Paecilomyces-type）和轮枝孢型（Verticillium-type）两类无性型。此研究对5.8SrRNA基因及ITS2间区DNA序列的分析结果表明,甘肃虫草和冬虫夏草的DNA序列相同,属于同一种;蛹虫草的两类无性型具有分子水平上的遗传趋异性。     

虫草多型现象的5.8SrDNA和ITS2序列测定研究

新定名的甘肃虫草Cordyceps gansuensi与冬虫夏草Cordyceps sinensi形态相似。 蛹虫草Cordyceps militaris具有拟青霉型（Paecilomyces-type）和轮枝孢型（Verticillium-type）两类无性型。此研究对5.8S rRNA基因 及ITS2间区DNA序列的分析结果表明,甘肃虫草和冬虫夏草的DNA序列相同,属于同一种;蛹虫草的两类无性型具有分子水平上的遗传趋异性。     

虫草多型现象的5.8S rDNA和ITS2序列测定研究

新定名的甘肃虫草Ｃｏｒｄｙｃｅｐｓ ｇａｎｓｕｅｎｓｉ与冬虫草Ｃｏｒｄｙｃｅｐｓ ｓｉｎｅｎｓｉ形态相似。蛹虫草Ｃｏｒｄｙｃｅｐｓ ｍｉｌｉｔａｒｉｓ具有拟青霉型（Ｐａｅｃｉｌｏｍｙｃｅｓ－ｔｙｐｅ）和轮枝孢型（Ｖｅｒｔｉｃｉｌｌｉｕｍ－ｔｙｐｅ）两类无性型。此研究对５．８Ｓ ｒＲＮＡ基因及ＩＴＳ２间区ＤＮＡ序列的分析结果表明,甘肃虫草和冬虫夏草的ＤＮＡ序列相同,属于同一种;蛹虫草的两类无性型具有     

蛹虫草单孢菌株的生物学特性及稳定性

蛹虫草菌株在继代培养过程中极易退化。本研究选取5株蛹虫草菌株作为出发菌株,基于单孢分离和显微技术从每株出发菌株中获得50株单孢菌株。通过PCR方法对单孢菌株进行交配型类型鉴定,全部为单一交配型单孢菌株,且不同出发菌株分离得到的MAT1-1和MAT1-2交配型单孢菌株比例差异较大,分别为27:23、34:16、42:8、28:22和7:43。从不同出发菌株获得的单孢菌株中随机选择MAT1-1和MAT1-2交配型单孢菌株各5株(共计50株),进行菌落直径、产孢量和虫草素含量测定。与出发菌株相比较,14株单孢菌株菌落直径具有显著差异(其中10株显著减小),24株产孢量具有显著差异且全部下降,29株单孢菌株虫草素含量具有显著差异(其中21株显著下降)。进一步,将50株单孢菌株连续继代培养,测定菌株菌落直径、产孢量和虫草素含量,计算第七代与第一代比值评估菌株性状稳定性。结果表明,与出发菌株相比较,14株单孢菌株菌落直径比值具有显著差异且全部增加,41株单孢菌株产孢量比值具有显著差异(其中40株显著下降),44株虫草素含量比值具有显著差异且全部下降。本研究表明同一菌株中的不同单孢菌株个体之间,在生...     

尖孢镰孢一新硝酸盐营养突变类型与营养体亲和性

从73个尖孢镰孢(Fusarium oxysporum)不同专化型菌株上获得684个硝酸盐营养突变株(nit mutant)。作相关氮源利用试验及亚硝酸反应后,鉴定出一新硝酸盐营养突变类型:亚硝酸盐还原酶结构基因类型,命名为nit8,占总突变株的6.7%。同时被鉴别的还有nit1、nit3和Nit M三种突变类型,它们分别占突变株总数的81.0%,3.8%和8.5%。此外,首次引入一种亚硝酸反应在这类研究中的应用,还提出了互补指数概念与公式来表示nit突变株营养体之间亲和的能力。     

大丽轮枝菌异核体及其后代的形态与致病力变异*

以硝酸盐利用缺陷型突变（nit突变）和抗杀菌剂突变两种遗传标记,对大丽轮枝菌（Verticilliumdahliae）异核体后代的形态和致病力进行研究,结果表明,菌核型菌株与菌丝型菌株经菌丝融合形成异核体后,菌丝型菌株能恢复形成微菌核,其后代单孢菌落形成微菌核的数量明显低于菌核型亲本,且遗传性状不稳定;随着转代次数的增多,微菌核形成能力的丧失较菌核型亲本菌株快。异核体后代对棉苗的致病力变化较大,一般均低于致病力强的亲本菌株,或介于两个亲本致病力之间,或与亲本致病力相近。     

蜻蜒拟青霉多型性的扫描电镜观察及RAPD分析

通过电镜扫描观察,清楚地显示了靖蜒拟青霉（Ｐａｅｃｉｌｏｍｙｃｅｓ　ｏｄｏｎａｔａｅ　Ｌｉｕ,Ｌｉａｎｇ＆Ｌｉｕ）的两种类型产孢结构,即拟青霉型椭圆形分生抱子的链状排列和校顶孢霉型柱状分生抱子头状排列。同时将椭圆形分生孢子和柱状分生孢子进行单孢分离,对各单孢株作了培养特征观察,形态学观察和ＤＮＡ随机片段扩增分析。结果表明,在形态学上两种孢子单孢子株之间的培养特征和显微特征均无明显差异,同时具有相同的ＤＮＡ随机扩增片段电泳谱。     

芹菜斑枯病菌生物学特性研究

以沈阳地区芹菜斑枯病菌的纯培养菌株为试材,通过对菌丝生长、孢子萌发的营养及环境条件的多因子试验,明确了芹菜斑枯病菌菌丝生长以在CDAMS—VI培养基上最好,其次是CSA、CCSA和PDA,菌丝生长及产孢对碳源、氮源种类有明显的选择性。菌丝生长的最适pH值为4～5,最适温度为21℃,致死温度为39℃（处理40min）,光照明显抑制菌丝生长。病菌分生孢子在水和芹菜汁中不能萌发,在水琼脂上萌发最好;孢子萌发的适宜pH值为4．6～6．6,适温为17—25℃,致死温度为42℃（处理20min）,RH100％最适宜孢子萌发。光照和变温处理可促进分生孢子器的形成,病菌在PDA上从孢子萌发到分生孢子器形成并释放出分生孢子需要16～18d。     

虫草及其无性型中的抗肿瘤细胞活性成分

较系统地总结了目前在虫草及其无性型中发现的抗肿瘤细胞活性成分.其中冬虫夏草、蛹虫草、大团囊虫草、单侧虫草、戴氏虫草和拟蛹虫草等虫草以及它们的无性型蛹拟青霉、细脚拟青霉、金龟子绿僵菌和球孢白僵菌等虫生真菌代谢物中抗肿瘤细胞活性成分,其结构包括多糖类、甾醇类、含氮化合物和杂环化合物等多个类型.     

蛹虫草菌丝生长研究

通过对 4种不同来源的蛹虫草菌种 ,在 5种不同配方培养基上菌丝生长情况进行了比较研究。结果表明 ,不同培养基配方对不同来源的蛹虫草菌种培养菌丝的长速和长势存在较大的差异。     

The causal agents of damping-off disease of buglosse from Iran

Iran is considered a major genetic for medicinal plant in the world. Because of this significant diversity and historical background in identification and utilization to remedy human and animal diseases, export of medicinal plant can help to strengthen local as well as natural economy. Buglosse (Fig. 1) is one of the most important and common medicinal plants in Iran and exist as Echium amoneum and Borago officinalis. This work was conducted in order to identify the causal agent(s) of damping off disease in buglosse. Plant disease samples were taken from Esfahan and Tehran provinces. Symptoms on original plant including root, crown rot, dark tissue, pith and hallow root were collected in order to isolate disease agent(s). Symptomatic root and crown tissues after surface sterilization with 96% ethanol were transferred on to PDA and WA media and also on moist filter paper in petri dishes. Two fungal colonies grew from tissue segments and spore culture was subsequently purified. The fungal isolate identified as Rhizoctonia solani based on the following test. Hyphal tip was removed from colony margin placed on PDA and PSA media and incubated in dark. Colony diameter of one hundred hyphae measured and nucleus was stained according to Bandoni (1979), Kronland and Stanghellini (1988). It was observed that in each cell of hyphae there are more than two nuclei. Single spore culture were obtained from macroconidia of Fusarium isolate. After 24 hr of incubation, growing single spore were transferred to KCL medium to detect spore chains. Fungal isolates transferred to PSA and PDA media for sporulation. After 7 days colonies appeared as white cream to pinkish on top and cream to dark pink at the bottom of petri dish with abundant micro and macro conidia. Colonies were snow white, felting shape, with ample causal hyphae on PSA medium. On KCL medium, fungal growth was superficial and colonies were colorless with long macroconidia and individual sausage-shape macroconidia being thinner one side and having maximum four septa. Microconidia were long double compartment round on both side, straight to slightly curved. Base on morphology and dimension of conidia and production of chlamidospore the funguses identify as Fusarium solani.     

Characteristics of the saprophytic reference strain FA ofClaviceps paspali

Growth properties and morphological features of the saprophytic collection cultureClaviceps paspali strain FA were investigated. The strain was characterized by a range of utilization of 13 carbon sources in a basic synthetic and a peptone medium. A temperature of 23 °C was more favourable for growth than 28 °C. Stages of changes of the culture cultivated for a long time on Sabouraud’s medium were detected by electron microscopy. The white culture was characterized by true septated mycelium with different types of terminal parts of hyphae. Arthrospores occurred after a 14-d cultivation, small spherical conidia released individually from hyphae were quite rare. As compared with other strains of the same species, strain FA did not form spherical clusters of conidia. On the other hand, a spontaneous rupture of the surface cell wall in different parts of hyphae and release of the cytoplasm were observed. In corn-steep containing media the formation of individual, pair and chain-like forms of arthritic conidia was stimulated. Destructive autolytic changes of hyphae were detected in the medium with potato extract.     

Phylogeny and morphology of Hirsutella tunicata sp. nov. (Ophiocordycipitaceae), a novel mite parasite from Peru

A new species of Hirsutella was isolated from unidentified mites on Petri plates inoculated with soil and root fragments collected from asparagus rhizosphere at Virú, Northern Peru. The fungus differs from other Hirsutella species by an envelope surrounding the conidium, conidia dimension and DNA sequences. In PDA cultures, the mycelium produced aerial hyphae with conidiogenous cells mainly at right angles, occasionally showing a secondary conidiophore. The solitary conidia are cymbiform, slightly apiculate, 5.0–6.0 × 3.0–4.0 μm. Phylogenetic analyses with partial rRNA and β-tubulin gene sequences confirmed the fungus as an Hirsutella (Ophiocordycipitaceae). Closest species shown by maximum likelihood and neighbor-joining trees were H. nodulosa and H. aphidis, from which the new species differs for conidium or conidiogenous cells dimensions, lack of synnemata and host type. A recombination event was also detected in the rRNA of the holotype strain, involving Ophiocordyceps sinensis as major parent and O. cochlidiicola as minor parent. A complement, inverted insertion was also found in its rRNA, involving part of the ITS2 and 5.8S regions, flanked by two short nucleotide arrays. Due to conidia dimension and phylogenetic position, the fungus is described as Hirsutella tunicata sp. nov. A review of mononematous Hirsutella species is provided.     

蛹虫草几个问题的最新研究进展

蛹虫草由于具有多种生理活性功能, 在医疗保健及食品开发中具有很好的经济价值。本文重点评述了蛹虫草研发中的(1)无性型菌种的分类地位, (2)有意义的培养研究方法, (3)菌种 “退化” 与遗传变异, 和(4)生物活性物质及生理功能的新研究进展等问题。