侵染双翅目昆虫的新种、新记录、新组合及新修订

记录了最近在中国记载的侵染双翅目昆虫的虫霉目两个新种,毛蚊虫疠霉(Pandora bibionis)发现于浙江庆元的毛蚊(Bibio sp),其初生分生孢子拟卵形,多对称144～20.5×7.2～11.5μm(平均16．5～174×8.4～10.4μm), L／D 1.4～2.3(平均1.7～2.0);假根2倍粗于分生孢子梗,末端膨大为吸盘状固着器;休眠孢子外壁刺毛状,19．1～23.4μm。食蚜蝇干尸霉(Tarichium syrphis)发现于陕西镇坪县的斑翅狭口食蚜蝇上,其休眠孢子外被圆锥形长刺,长2.2～5.0μm,直径21.2～28.1μm。在毛蠓上发现中国新记录胶孢虫疠霉,并根据本文所采用的Humber(1989)系统,将其组合为胶孢虫瘴霉(Furia gloeosora comb. Nov.);此外,还将北虫疫霉(Erynia borea)组合为北虫疠霉(Pandoraborea comb. Nov.),并同时给予修订。     

中国单轴霉分类的研究*II.寄生在伞形科上的新种和已知种

本文报道在我国伞形科植物上寄生的4种单轴霉(Plasmopara)。其中寄生于鸭儿芹(Cryptotaenia japonica Hassk)上的鸭儿芹单轴霉(Plasmopara cyptotaeniae sp nov．)和寄生于水芹[Oenanthe iavanica(BI．)DC．]及卵叶水芹(O．Rosthornii Diels)上的水芹单轴霉(Pl-asmopara oenanlheae sp．nov．)是2个新种。寄生于变豆菜(Sanicttla chinensis Bunge)上的变豆菜单轴霉(Plasmopara saniculae Traian et O．Savulescu)是亚洲的新记录种。     

甘蓝与菜心中间杂种F1代花药培养初报

花药培养和小孢子培养是大量获得单倍体和纯合二倍体的主要方法之一。在芸苔属中,花药培养和小孢子培养已在白菜(　B．Pekinensis)、甘蓝(B．Oleracea)、油菜(B．Napus)、芥菜(B．Juncea)和阿比西尼亚芥(B．Carinata)等蔬菜中有许多成功的报道,并在培养条件、基因型作用、培养基选择和供体植株选择等方面有较深入的研究^{[2,3,5,7－11]},但种间杂种F1代的花药培养尚未见报道。为了探讨芸苔属种间杂种花药培养的可能性,获得有价值的异源染色体杂种,我们开展了本研究工作。     

沙棘和胡颓子属根瘤放线菌的分离和回接

从胡颓子属(Elaaenus)黄果沙枣(Elaeagnus oxycarpa Schlecht．)根瘤上分离得到放线菌Frankia sp．Eoc 85、Frankla sp．Foe 811。从沙棘(Hippophae rhamnoidcs)根瘤中分离得到放线菌Frankia sp．Hrc 97、Frankia sp·}hc 922。又从多花胡颓子(Blaeagnus multiJlora．Ovata)及角花胡颓子(Elaeagnus gonyanthcs)’的根瘤中分离得到Frankia s p．F~noc 1211和Fran&ia sp．Egc 107,均获得纯培养。用光学显微镜和扫描电镜观察其形态特征,确认是属具有孢囊的放线菌。该菌慢生长型,无气生菌丝体,基内茵丝体发育好。液体培养,在底部生长,属于微好气性。孢囊形状不规则,囊内包着大量的不游动的孢囊孢子。菌丝分枝有隔,粗细不匀,革兰氏阳性。将分离菌Eoc 85、E0c 811、Hrc 97、Emoe 1211、Egc 107回接其宿 主,均感染结瘤。根癌的乙炔还原活力分别为：6．05、2．68、0 63、7．15、3 53μmol C2H4／g·鲜重。     

冠耳霉的分离和鉴定

本文报道了在福建南平发现的感染毛蠓(PsycAoda sp.)成虫的冠耳霉(Conidiobolutcoronatus)有关分离、培养和鉴定等工作。在虫尸上,分生孢子卵圆形至梨形,大小13.6—30.6×13.6—20.4μm,平均23.6×16.8μm。未见囊状体、假根及休眠孢子。易于人工培养。在培养基上初生分生孢子球形,直径26.4—49.6μm,平均37.8μm。初生分生孢子容易萌发,形成次生分生孢子、以及三生分生孢子、四生分生孢子。许多小型分生孢子外生于初生分生孢子上,卵形,平均大小16.5×13.2μm。分生孢子还可以转化成长柔毛分生孢子。     

异孢耳霉的分离和鉴定*

本文报道了1987年冬季在南平地区分离的一个腐生耳霉新纪录——异孢耳霉(Conidiobolus incongruus),分生孢子梗无色,不分叉,6—10×50—130μm,分生孢子无色,多数球形,少数亚球形至椭圆形,13—33×16—35μm,易萌发,多数形成菌丝体,少数可形成次生分生孢子或三生分生孢子,弹射在水琼脂上的分生孢子常能迅速产生小分生孢子。接合孢子球形,淡黄色,光滑,直径18—29μm,壁厚2.5—5μm。     

异孢耳霉的分离和鉴定*

本文报道了1987年冬季在南平地区分离的一个腐生耳霉新纪录——异孢耳霉(Conidiobolus incongruus),分生孢子梗无色,不分叉,6—10×50—130μm,分生孢子无色,多数球形,少数亚球形至椭圆形,13—33×16—35μm,易萌发,多数形成菌丝体,少数可形成次生分生孢子或三生分生孢子,弹射在水琼脂上的分生孢子常能迅速产生小分生孢子。接合孢子球形,淡黄色,光滑,直径18—29/μm,壁厚2.5—5μm。     

黄色直丝链霉菌新种

34-773链霉菌对产朊圆酵母(Torulopsis utilis)细胞及稻瘟菌(Piricularia oryzae)菌丝有溶菌作用,对形态、培养特征、生理生化特性等方面的研究指出,34—773链霉菌的孢子丝直形,孢子长杆状,表面光滑;气生菌丝体先蚌肉白,后豆汁黄;基内菌丝体淡鹅掌黄、淡雅梨黄;无可溶性色素。经鉴定和国内、外文献中报道的近似种比较定为新种——黄色直丝链霉菌(Streptomyces flavorectus n. sp．)。     

盘梗霉属一新种——甜菜盘梗霉

本文报道了寄生于藜科(Chenopodiaccae)甜菜(Beta. Vulgaris L．)上的盘梗霉属一新种——甜菜盘梗霉(Bremia betae sp. Nov.)。对此新种作了汉文和拉丁文描述．     

安徽虫瘟霉对桃蚜的生物测定与时间一剂量效应分析*

用“孢子浴”法将人工培养的安徽虫瘟霉(Zoophthora anhuiensis)对桃蚜(Myzuspersicae)接种而进行定量生物测定(18℃,光周期为L：D 12：12),包括10个剂量(1．5～197．7个分生孢子／mm²),每剂量处理蚜虫64～120头,逐日观察记载死亡数至第7d。接种后第3d在高剂量处理中始见少量死蚜,第4～6d为死蚜盛期。所获数据很好地拟合时间一剂量一死亡率模型,由模型参数估计出该菌作用于桃蚜的时间效应随剂量增大而减小,在37.1～197.7个分生孢子／mm² 的剂量范围内LT₅₀值为4.5～6.7d．剂量效应在接种后随时间递减,第5～7d的LD₅₀分别为86.8、43.7和34.1个分生孢子／mm²。结果表明,安徽虫瘟霉是一种较为理想的杀蚜微生物,在寄主体内的潜伏期为4～5d。     

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.