莴苣叶疫病和茎腐病的病原

2021年3–6月,从甘肃省的生菜(叶用莴苣)叶片和青海省的莴笋(茎用莴苣)茎秆罹病样本上分离得到腐霉属卵菌。通过Koch’s法则明确了分出菌株的致病性。依据形态学和分子生物学特征,将3个菌株鉴定为嗜导管腐霉Pythium tracheiphilum。在核糖体DNA内转录间隔区(rDNA-ITS)、细胞色素氧化酶亚基1(cox1)和核糖体DNA28S大亚基(rDNA-LSU)基因联合系统发育树中,甘肃菌株(LPy-B)和青海菌株(LPy-C和LPy-D)被聚在P. tracheiphilum的不同亚群里,不同菌株的适宜生长温度和产孢特性存在差异。孢子囊顶生、间生或侧生,球形,17.13–53.73μm,或近球形至葫芦状,24.58–56.72×18.62–53.73μm;休止孢球形,6.70–9.68μm;藏卵器光滑,顶生或间生,球形,15.64–23.09μm;每个藏卵器有雄器1–2个,雄器与藏卵器同丝或异丝生;卵孢子满器或近满器,球形,直径13.41–20.11μm,卵孢子壁厚0.74–2.23μm。致病性测定结果表明,除莴苣外,嗜导管腐霉还可侵染菊科的华蒲公英和刺儿菜、十字花科的...     

广东省侵染摇蚊的库蚊虫霉研究

在中国首次报道了侵染摇蚊的库蚊虫霉(Entomophtora culichs)的形态特征、侵染症状以及发生动态等。库蚊虫霉初生分生孢子,钟罩形,顶部有一明显小尖突,(14.6±1.5)μm×(10.8±1.2)μm。次生分生孢子形似初生分生孢子,但略小,(11.0±1.1)μm×(8.0±0.5)μm。休眠孢子,球形至亚球形,直径(29.3±1.9)μm。被侵染摇蚊尸体以假根附着于基物上,通体覆盖着绿色的真菌子实层。库蚊虫霉侵染率在不同植物上明显不同。库蚊虫霉侵染率随季节不同波动很大,春季最高达90.2%,其次为秋季和冬季,夏季最低为0。2006—2009年库蚊虫霉侵染率为93.5%～95.7%,年际之间变动不大。     

舍蝇的寄生真菌——堪萨虫霉

本文报道了在福建南平地区引起舍蝇(Musca domestica vicina Macquart)流行病的堪萨虫霉(Entomophthora kansana Hutchison)的鉴定工作。该菌子生孢子梨形,大小29.2—49.5×23.1—42.9/μm,平均39.6×31.4μm.次生分生孢子近球形,基部平截,平均大小23.8×21.7μm,虫菌体球形或近球形。假根,囊状体及休眼孢子缺乏。     

弯孢虫疫霉的分离和鉴定

1984—1987年,在福建的南平、福州、南安等地持续发生了由弯孢虫疫霉(Eryniacurvlspora)感染而引起库蚊(culex sp.)成虫死亡的流行病,病原菌分生孢子梗掌状分枝;分生孢子浅绿色,窄而长,略弯曲,单核,双囊壁,含有多个小脂肪粒,大小29.7—39.6×13.2—19.8(平均32.5×16.1)μm,长宽比1.5—3.0(平均2.0);次生分生孢子梨形,基部为钝的乳突,中间有一大的脂肪粒,孢子大小16.6—19.9×11.6—14.9(平均18.7×13.7)μm;休眠孢子球形,棕褐色,直径23.2—33.2(平均29.5)μm;有假根及囊状体。     

蚜虫的病原真菌新种——安徽虫疫霉

1984年初冬在安徽长江南北大面积蔬菜的桃蚜种群中发生真菌流行病。病原鉴定为虫霉目新种安徽虫疫霉(Erynia anhuiensis Li sp.nov)。分生孢子梗二歧分枝;初生分生孢子单核,双囊壁,长椭圆形、长卵形或倒拟卵形,前二者大小为17.1—33.3×5.9—12.9μm(平均24.7×8.3),长径比2.0—5.4(平均3.0),后者12.6—30.8×8.1—16.5μm(平均22.7×11.6),长径比1.4—2.5(平均2.0);有囊状体及假根,假根有固着器。外休眠孢子球形,光滑,透明,直径22.1—31.9μm(平均26.6)     

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。     

难溶性药用纳米微粒的原子力显微检测

建立用原子力显微镜(AFM)检测难溶性药用纳米微粒的方法。将纳米微粒配成一定浓度的悬浮液,以新鲜裂解的云母表面作为样品载体,在室温下用AFM的接触模式成像,用粒度分析软件进行粒度分析。以此方法对两种微粒(活性炭及氧化锌纳米微粒)进行了成像和测量,同时对两种样品进行透射电镜(TEM)观察。AFM检测结果显示,纳米活性炭微粒形态近似球形,表面较平滑,平均直径为(299±187)nm;纳米氧化锌微粒呈球形,平均直径(50±20)nm,与TEM检测结果具有较高一致性。该法简便可靠。     

白蜡虫七种寄主植物枝条树皮比较解剖研究

采用常规石蜡切片法解剖观察了白蜡虫7种寄主植物一年生枝条树皮横切面结构特征,结果表明:白蜡虫7种寄主植物一年生枝条树皮从内到外由次生韧皮部、初生韧皮部纤维束、皮层和周皮组成;次生韧皮部横向系统均由筛管、伴胞和薄壁细胞组成;轴向系统由射线组成。木栓层以美国白蜡和流苏细胞层数最多,达10～12层;华南小蜡、紫药女贞和白枪杆次之,为5～8层;女贞和白蜡树最少,分别为2～3和3～4层。初生韧皮部纤维束排列整齐连接为带状或分散,女贞属纤维连接成带状,白蜡属和流苏属纤维分散。带状纤维层厚薄不均,厚度在26.93±13～59.15±7μm之间,以白枪杆纤维层最厚,为59.15±7μm;美洲白蜡次之,为50.05±7μm;白蜡树最薄,为26.93±13μm。分散型纤维束直径在25.12±13～76.15±36μm之间,纤维束直径大小顺序为:流苏(76.15±36μm)>紫药女贞(43.44±10μm)>女贞(25.12±13μm)。女贞、紫药女贞和流苏纤维束间距分别为78.53±39μm、149.78±27μm和212.02±95μm。次生韧皮部厚度在48.52±12～377.44±24μm之间,以女贞的次生韧皮部最厚,达377.44±24μm,华南小蜡最薄,为48.52±12μm。树皮次生韧皮部厚、木栓层数少和纤维束直径小为白蜡虫优良寄主植物的显著特征。     

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—29μm,壁厚2.5—5μm。     

虫疫霉属新种和中国新记录

本文报道了虫疫霉属2个新种及1个中国新记录种。新种北虫疫霉(Eryniaborea Fan et Li sp.nov.)发生于西北及东北地区的丽蝇成虫体上,菜叶蜂虫疫霉(Eryniaathaliae Li et Fan sp.nov)发生于陕西杨陵的黄翅菜叶蜂幼虫;新记录种近藤虫疫霉(Erynia kondoiensis Milner)发生于福州的烟蚜虫体上。本文详细描述了新种的形态。     

库蚊虫霉的形态及不同因子对分生孢子萌发的影响

对1987年5月福建南平库蚊上的虫霉流行病进行观察和鉴定,结果表明库蚊虫霉(Entomophthora culicis)是流行病的主要病原菌(92.4％),其次为弯孢虫疫霉(Eryniacurvispora)(2.9％),同时在库蚊的个体上存在着这两种虫霉的复合感染(4.7％)。库蚊虫霉分生孢子钟罩形,基部平截,端部尖突。分生孢子10.3×13.3-6.6×11.6μm,平均12.1±0.15×9.0±0.15μm,长径比1.40—1.75。休眠孢子内生或外生,平均27.1±0.14μm。假根粗大,无固着器,囊状体缺乏。在蛋黄培养基上生长微弱。对不同因子影响分生孢子萌发进行了初步的研究。     

分离自西藏的两个散囊菌新种

本文报道两个新种:粪生散囊菌(Eurotium fimicola)和旱生散囊菌(Eurotium aridicola),它们不同于已报道的该属诸种。     

散囊菌属的两个新种

本文报道两个新种,肋状散囊菌(Eurotium costiforme)和少疣散囊菌(E.parviver-ruculosum)。前者的主要特征是子囊孢子的凸面有许多网结的肋状突起;在查氏琼脂上产生大量的闭囊壳,但分生孢子结构极少。后者在查氏琼脂上生长很局限;子囊孢子大,凸面近于平滑或有少量小疣等主要特点。     

Hepatic Coccidiosis in Triportheus angulatus Spix & Agassiz, 1829 (Characiformes: Triportheidae), a Tropical Fish from the Eastern Brazilian Amazon,with the Description of a New Species of Calyptospora (Apicomplexa: Calyptosporidae)

Hepatic infection involving a parasite of the family Calyptosporidae was recorded in characiform fish from the Tocantins river in the Brazilian Amazon region. In the present study, an integrated comparative analysis of morphological characteristics, histological and structural traits, and the sequence of a partial fragment of the SSUrRNA gene provides support for the identification of a new calyptosporid species, found parasitising the hepatic tissue of the fish Triportheus angulatus, collected from the Tocantins River. This new species was named Calyptospora gonzaguensis n. sp. and had ovoid oocysts with a diameter of 19.6 ± 1.4 μm and four peripheral sporocysts, 9.2 ± 0.6 μm long and 3.9 ± 0.2 μm wide, enveloped individually in fine adhesive membrane, composed of an ellipsoid body and posterior extension, with a mean length of 2.2 ± 0.4 μm.     

Description of a new species of myxobolid parasite,Henneguya pindaibensis n. sp. (Cnidaria: Myxosporea), infecting the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) from Brazil

Myxozoans are microscopic cnidarians that mainly parasitize fishes. The present study aimed to describe a new myxozoan parasite from the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) by morphological and molecular analysis. The fish was collected in 2019 at the Pindaíba River, municipality of Cocalinho, Mato Grosso State, Brazil. Whitish and circular plasmodia were found in the primary gill filaments, occupying an intralamellar position, with an average of 0.5 mm in diameter. Henneguya Thélohan, 1892 myxospores found inside the plasmodia were elongated and ellipsoidal, consisting of two long and elliptical shell valves with two long, tapering caudal appendages. Morphometric measurements revealed a total spore length of 36.1 ± 2.0 μm; spore body length of 12.8 ± 0.5 μm; spore width of 4.9 ± 0.3 μm; tail length of 23.3 ± 1.6 μm; capsule length of 7.2 ± 0.4 μm; capsule width of 1.5 ± 0.2 μm; and 10 coils in the polar filament. Phylogenetic analysis showed that the isolates from this study were grouped into the main-clade of freshwater fishes, within a group of species parasitizing fishes from Brazil. Intergenotypic difference ranged from 23%–25.9% compared with other Brazilian myxozoan isolates. Using molecular and morphological characterization, this parasite was identified as a new species of the genus Henneguya.     

Morphological and molecular analysis of Henneguya lagunensis n. sp. (Cnidaria,Myxosporea) parasitizing the gills of Eugerres brasilianus from Brazil

Plasmodia containing myxospores belonging to the genus Henneguya Thélohan, 1892 were found in the gills of Eugerres brasilianus (Cuvier, 1830). Despite the economic importance, few parasitological studies have been done with this species. We describe Henneguya lagunensis n. sp. using morphological and molecular data. The mature myxospores were rounded, measuring 29.1 ± 2.2 μm in total length, 8.2 ± 1.0 μm in body length, 7.9 ± 0.2 μm in body width, 20.7 ± 2.4 μm in tail length and 4.8 ± 1.0 μm in thickness. The polar capsules measured 3.3 ± 0.4 in length and 1.7 ± 0.3 μm in width. Polar filaments had 4–5 turns, helical. Phylogenetic analysis showed Henneguya lagunensis n. sp. as a sister species of Henneguya cynoscioni Dyková, Buron, Roumillat and Fiala, 2011, within a clade that contained mostly Henneguya species that parasitize marine fish of the order Perciformes. This is the first report of a species of Henneguya parasitizing Eugerres brasilianus.     

Developmental capacity,size and number of nuclei in pig embryos cultured in vitro

Twenty-five surgical embryo recoveries were made from 17 postpuberal gilts 3 to 6 days after mating. A total of 242 eggs was recovered. Recovery rate was 87.5%, fertilization rate was 97.5%, and 98.7% of the fertilized eggs were morphologically intact. The embryos were cultured in vitro in Krebs-Ringer-Bicarbonate (KRB) with 10% heat inactivated lamb serum for 72 or 96 h at +37°C in a humidified 5% CO₂ atmosphere. Of the cultured four-cell embryos 26.6% developed to expanded blastocysts, 16.7% to hatching blastocysts and 5.0% to hatched blastocysts. Of the eight-cell embryos 52.6% developed to hatching blastocysts, 10.5% to hatched blastocysts. When recovered as morulae, the percentage of hatching blastocysts subsequently obtained was 25.8% and 33.9% hatched. A total of 75.0% of the cultured early blastocysts were in the process of hatching (30.6%) or had hatched (44.4%). Significant differences in overall embryo diameter were determined between morulae (156.5 ± 3.94 μm) and early blastocysts (156.9 ± 3.72 μm) versus expanded (197.6 ± 12.57 μm), hatching (207.4 ± 15.86 μm) or hatched (270.0 ± 36.67 μm) blastocysts. The zona pellucida of expanded blastocysts was significantly thinner (5.5 ± 1.59 μm) than that of morulae (12.0 ± 1.01 μm). The number of nuclei was significantly higher for hatching (151 ± 49.8) and hatched (130 ± 17.9) blastocysts cultured as early blastocysts as compared to those cultured from the four-cell stage (88 ± 12.7 and 69 ± 3.6 respectively). Hatching blastocysts that had developed from early blastocysts also had significantly more nuclei than those cultured as eight-cell embryos (99 ± 32.5) or morulae (91 ± 21.2).By the culture method used in this study, a high percentage of pig embryos was capable of developing.     

Evolution of larval size in cyclostome bryozoans

Cyclostomes are the only order of stenolaemate bryozoans living today. The non-feeding larvae of modern cyclostomes metamorphose on settlement to produce a calcified dome-shaped protoecium. Protoecial diameter provides a proxy for larval size. The sparse data available on living cyclostomes suggests that protoecial diameter is about one-and-a-half times greater than larval width. Here we use protoecial diameter to estimate larval sizes in fossil and Recent cyclostome species. A total of 233 protoecia were measured, 143 from Recent cyclostomes and 90 from fossil cyclostomes, of which 84 came from the Jurassic. Protoecial diameter ranged from 82.5 to 690 μm, with 89% of protoecia having diameters between 100 and 300 μm. A comparison of 30 Jurassic with 51 Recent taxa of tubuliporine cyclostomes showed a significant difference in size frequency. Although the Recent taxa have a larger size range (83–465 μm) than the Jurassic taxa (125–249 μm), Recent species have a lower mode (125–150 μm) than the Jurassic species (175–200 μm). Most Jurassic cyclostomes may therefore have had larger larvae than their extant relatives. Reduction in larval size may be a component of the previously hypothesized reduction in overall body size resulting from competitive displacement by cheilostome bryozoans.