假蜜环菌的研究II．假蜜环菌素的分离及化学结构的测定

从假蜜环菌培养物的乙醇提取物中分离得四种成分,其中之一为新的香豆素,定名为假蜜环菌甲素(Armillarisin A),为治疗胆囊炎的一种活性成分。分子式C12H10O5,熔点245—246℃,用紫外、红外光谱,质谱,核磁共振确定假蜜环菌甲素为3—乙酰基一5羟甲基一7一羟基香豆素。另一成分定名为假蜜环菌乙素,熔点162一163．5℃,分子式C9H10N2O3,用同样的方法初步测定了它的结构。     

中国东北地区三种蜜环菌的生物学特性及奥氏蜜环菌人工培养

蜜环菌属Armillaria真菌具有较高的食药用价值。由于蜜环菌的生长发育过程较复杂,还未完全实现商业化栽培,野生资源的供应受到季节性和地域性的影响。本研究以采自东北地区蜜环菌属的3个菌株为研究对象,通过培养物的形态特征及分子标记确定菌株JG19016为奥氏蜜环菌A. ostoyae,菌株JG19017为高卢蜜环菌A. gallica,菌株JG19018为中国蜜环菌生物种C。奥氏蜜环菌JG19016最适生长温度为25 ℃,高卢蜜环菌JG19017的最适生长温度为22 ℃,中国蜜环菌生物种C JG19018则在22-25 ℃时菌丝生长速度最快;3个菌株最适pH为5-6。奥氏蜜环菌JG19016对葡萄糖和蔗糖利用率较好,高卢蜜环菌JG19017对葡萄糖利用率较好,中国蜜环菌生物种C JG19018对葡萄糖和淀粉利用率较好;蛋白胨对3个菌株促进作用最强,为最适氮源。培养基中加入VB₁,对3个菌株的菌丝生长均有明显的促进作用。奥氏蜜环菌JG19016菌丝生长的最优培养基配方为：葡萄糖20 g,蛋白胨3 g,磷酸二氢钾2 g,硫酸镁1.5 g,VB₁ 10 mg,琼脂20 g,水1 L。在木屑基质中培养,其配方的最优碳氮比为38:1,最佳木屑粗细比为3:1以上。出菇条件探索结果显示,菌丝及菌索长满菌袋(17 mm×33 mm×5 mm丝聚乙烯袋)需要50-60 d,之后在18 ℃、60%湿度和12 h散射光的环境中,10 d左右可观察到原基产生。增加菇房湿度到90%-95%,2-3 d可观察到1-3 cm的幼子实体,7 d左右菌柄和菌盖完全分化,10 d左右观察到菌盖展开。     

北方蜜环菌菌索生长、发育对环境氧气及土壤湿度的响应

蜜环菌属Armillariaspp.真菌是重要的植物病原菌和兰科Orchidaceae植物天麻Gastrodia elata的专性共生菌,能以菌索形式在土壤中存活和传播,因此,土壤环境变化对蜜环菌菌索生长、发育的影响,是关系天麻栽培和森林蜜环菌病害的重要过程。为了揭示蜜环菌生长发育对土壤水分和氧气的适应特征,本研究以北方蜜环菌Armillaria borealis为研究材料,设计氧气浓度5%、15%、20%和30%的4个水平与土壤湿度20%、40%、60%和80%的双因素实验,在室内24℃及黑暗条件下培养,观察菌索发生时间(T)、测定菌索生物量(DW)、菌索长度(L)、菌索数(Nt)、菌索分枝数(Nf)和菌索直径(AD)。结果表明,土壤湿度和氧气浓度对北方蜜环菌菌索发育和生长具有显著影响,在15%的氧气浓度和60%的土壤湿度发育最快。本研究为人工模拟蜜环菌生长发育的环境提供了部分依据,对提高天麻人工栽培的产量,揭示森林蜜环菌病害发病机制具有重要价值。     

蜜环菌菌索生物学特性的研究

为提高榛蘑人工栽培中出菇的稳定性,对蜜环菌菌索的生物学特性进行了研究,通过在不同生长时间、环境温度、培养基质的条件下对蜜环菌菌索进行培养。试验发现,菌索会由具有活性的黄色菌索逐渐角质化变成黑色丝状菌索,为保持蜜环菌菌索的活性状态,最佳培养条件:培养时间应控制在15²3 d,最佳培养温度为恒温25℃,最佳培养基配方为PDA+麦麸+锯末。     

我国主要蜜环菌生物种胞外酶活性对温度的种特异性响应

蜜环菌生物种与天麻的共生关系受到温度的调节。为了揭示我国蜜环菌生物种的温度适应性,本研究以我国8个蜜环菌生物种为实验材料,采用2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐（ABTS）法和3,5-二硝基水杨酸（DNS）法研究了胞外漆酶、果胶酶和纤维素酶的活性对温度的响应特征。结果表明,各生物种的胞外酶活性存在显著性差异,各胞外酶活性具有随时间先升后降的变化趋势;各胞外酶的分泌时间和活性大小对温度的响应存在着很大的差异;且在培养过程中,首先分泌的是果胶酶和纤维素酶,然后才是漆酶。温度对蜜环菌胞外漆酶和果胶酶活性大小有影响,对产酶时间没有影响;对纤维素酶活性达到峰值的时间和活性大小都有很大影响。除此之外,蜜环菌胞外酶活性对温度的响应和我国蜜环菌的地域分布特点具有相关性,分布于秦岭-淮河线以南和以北的蜜环菌生物种胞外酶活性对温度的响应具有差异。本研究对开展蜜环菌生物学和我国天麻的野外种植区划的研究具有指导意义。     

黑龙江省蜜环菌生物种的地理分布概况

自1999年至2002年间对黑龙江省境内几个主要林区中的蜜环菌生物种进行了调查、采集和鉴定,并对其寄主种类和子实体发生规律以及地理分布特点进行了总结分析。结果表明:黑龙江省境内至少存在5个蜜环菌生物种,即芥黄蜜环菌Armillaria sinapina,高卢蜜环菌A.gallica,黄盖蜜环菌A.luteopileata,奥氏蜜环菌A.ostoyae和中国生物种F;寄主包括10个针叶和阔叶树种;与其他几种蜜环菌生物种相比较,A.gallica是黑龙江省境内出现概率最大的一个生物种;根据采集经验发现,温度和湿度是影响子实体发生的主要因子。     

蜜环菌对镁的耐性和富集特性

研究了镁对蜜环菌生长的影响, 蜜环菌对于镁的耐性和富集规律, 以及高浓度镁胁迫下蜜环菌的抗氧化酶的变化情况。3?15 g/L的Mg浓度对于蜜环菌菌体的生长有促进作用。Mg浓度19 g/L以上时, 蜜环菌菌体的生长受到抑制。蜜环菌的子实体形成和子实体生物量在Mg的浓度为11 g/L以下时不受影响, 超过11 g/L则子实体不能萌发。皮壳状菌丝和菌索中Mg的含量随培养基中Mg浓度的增大而增大, 培养基Mg浓度达到16 g/L后, 菌丝、菌索中Mg的含量都不再上升。子实体对Mg的富集量比菌丝体小的多, 在培养基Mg浓度在9、10 g/L时, 子实体中Mg的含量与对照组有显著差异。随着培养基中Mg浓度的提高, 菌丝和菌索POD、CAT、SOD活性都有增加, 而且菌丝与菌索之间抗氧化酶活力的差异随着培养基中Mg浓度的提高而增大。     

黑龙江省蜜环菌生物种的地理分布概况

自1999年至2002年间对黑龙江省境内几个主要林区中的蜜环菌生物种进行了调查、采集和鉴定,并对其寄主种类和子实体发生规律以及地理分布特点进行了总结分析。结果表明:黑龙江省境内至少存在5个蜜环菌生物种,即芥黄蜜环菌Armillaria sinapina,高卢蜜环菌A.gallica,黄盖蜜环菌A.luteopileata,奥氏蜜环菌A.ostoyae和中国生物种F;寄主包括10个针叶和阔叶树种;与其他几种蜜环菌生物种相比较,A.gallica是黑龙江省境内出现概率最大的一个生物种;根据采集经验发现,温度和湿度是影响子实体发生的主要因子。     

蜜环菌对锌的耐性和富集特性

研究了锌对蜜环菌Armillaria mellea生长的影响,蜜环菌对于锌的耐性和富集特性,以及锌胁迫下蜜环菌的抗氧化酶的变化情况。结果表明,锌浓度45mg/L下对于蜜环菌菌体的生长有显著促进作用（p＜0.05）,锌浓度90mg/L以上时,蜜环菌菌体的生长受到抑制（p＜0.05）。蜜环菌的子实体萌发和子实体生物量在锌的浓度为45mg/L以下时与对照组无显著性差异（p＞0.05）,锌的浓度超过90mg/L后子实体不能萌发。培养基锌含量在270mg/L以下时,皮壳状菌丝中锌的含量随培养基中锌浓度的增大而增大。培养基锌含量在135mg /L以下时,菌索中锌的含量随培养基中锌浓度的增大而增大。随着培养基中锌浓度的提高,菌丝和菌索POD、CAT、SOD活性都有增加,PPO的活性则是先升高后降低,而且菌丝与菌索之间抗氧化酶活力有显著差异（p＜0.05）。     

蜜环菌油超声提取工艺优化及其化学成分分析

研究了料液比、超声时间、超声温度及超声功率对蜜环菌出油率的影响,并通过正交试验确定了提取蜜环菌油最佳工艺。结果表明:最佳提取工艺是料液比(g∶m L)1∶4,时间30 min,温度40℃,功率400 W。应用气相色谱-质谱联用技术研究了野生蜜环菌子实体中油类成分及其相对含量,确认其中9个成分,分别为亚油酸、硬脂酸、软脂酸、羊脂酸、正壬酸、月桂酸、肉豆蒄酸、正十五烷酸和反式棕榈油酸。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.