不同温湿度组合对安微虫瘟霉诱发桃蚜病害的影响

用孢子浴方法,对４２批次桃蚜Ｍｙｚｕｓ ｐｅｒｓｉｃａｅ（３０－６０头／批）接种大剂量（孢子７９－９０个／ｍｍ＾２）安徽虫瘟霉Ｚｏｏｐｈｔｈｏｒａ ａｍｈｕｉｅｎｓｉｓ的分生孢子,在２０℃下保湿２４ｈ后转入不同温度（１０℃、１５℃、２０℃、２５℃、３０℃及自然变温下１．５－１６．６℃和８．５－２０．２℃）和温度（５０％、６５％、８０％、９０％９５％及１００％ＲＨ）的组合条件下观察桃蚜的反应。结果表     

安徽虫瘟霉菌株的强毒杀蚜效应与侵染速率*

报道安徽虫瘟霉（Zoophthoraanhuiensis）菌株F97028对挑蚜（Myzuspersicae）的强毒杀蚜活性。以7个孢子剂量（0．4～10．4个孢子／mm2）接种2～3龄若蚜（52～86头／剂量）,连续观察7d所获数据经时间－剂量－死亡率模型模拟分析,接种后第3～7d的LD50分别为34.8、8.7、1.5、0.7和0.4个孢子／mm2。在所用剂量范围内LT50为29～6.0d,随剂量增大而缩短。在接种后不同时段用0.1％百菌清水溶液处理被接种蚜体表面,结果显示,在15～20℃下,在0.7～1．8个孢子／mm2的剂量下接种后2h内的有效侵染率为42～58％,4h内为44％～74％,6h时达90％以上;在69～9．0个孢于／mm2的剂量下接种后1h,有效侵染率为57％～67％,2h内为77％～86％,4h内为78％～90％;高剂量（499～54．8个孢子／mm2）下接种后1h即达90％以上。与虫瘟霉属其它菌种或菌株对蚜虫的毒力比较,F97028菌株的毒力高28～117倍,为罕见的强毒杀蚜菌株。     

不同温湿度组合对安徽虫瘟霉 诱发桃蚜病害的影响

用孢子浴方法,对42批次桃蚜Myzus persicae（30～60头/批）接种大剂量（孢子79～90个/ mm²）安徽虫瘟霉Zoophthora anhuiensis的分生孢子,在20℃下保湿24 h后转入不同温度（10℃、15℃、20℃、25℃、30℃及自然变温1.5～16.6℃和8.5～20.2℃）和湿度(50%、65%、80%、90%、95%及100% RH)的组合条件下观察桃蚜的反应。结果表明,各组合条件下的桃蚜均能发病死亡,而且累计死亡率的显著差异存在于不同温度（F=7.46, P<0.01)和湿度间（F=12.54, P<0.01）。最适发病的温度为恒温20℃和变温8.5～20.2℃（日均温12.4℃）,死亡率随湿度升高而增大。在10～25℃和100% RH的组合中,温度的变化几乎不影响桃蚜的累计死亡率,但影响发病速率,在10℃、15℃、20℃和25℃下的致死时间LT₅₀值分别为8.4 天、7.1 天 、4.0 天和3.4 天。回归分析表明, 在100% RH下安徽虫瘟霉诱发桃蚜发病的起始温度为1.65℃。在10～15℃及自然变温下,病死蚜尸顺利产孢的湿度为80% RH;而在20～30℃下,蚜尸产孢的湿度为90% RH。在所有温湿组合的蚜尸中未见安徽虫瘟霉的休眠孢子发生。     

安徽虫瘟霉菌株的强毒杀蚜应与侵染速率

报道安徽虫瘟霉（Ｚｏｏｐｈｔｈｏｒａ ａｎｈｕｉｅｎｓｉｓ）菌株Ｆ９７０２８对桃蚜（Ｍｙｚｕｓ ｐｅｒｓｉｃａｅ）的强毒杀蚜活性。以７个孢子剂量（０．４￣１０．４个孢子／ｍｍ＾２）接种２￣３龄若蚜（５２￣８６头／剂量）,连续观察７ｄ,所获数据经时间－剂量－死亡率模型模拟分析,接种后第３￣７ｄ的ＬＤ５０分别为３４．８、８７、１．５、０．７和０．４个孢子／ｍｍ＾２;在所有剂量范围内ＬＴ５０为２．９￣６     

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。     

安徽虫瘟霉对桃蚜的生物测定与时间-剂量效应分析

用“孢子浴”法将人工培养的安徽虫瘟霉（Ｚｏｐｈｔｈｏｒａａｎｈｕｉｅｎｓｉｓ）对桃蚜（Ｍｙｚｕｓｐｅｒｓｉ ｃａｅ）接种而进行定量生物测定（１８℃,光周期为Ｌ∶Ｄ１２∶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 剂量 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。     

安徽虫瘟霉诱发的桃蚜流行病与流行模型

在15℃与100％RH的组合条件下以接种安徽虫瘟霉（Zoophthora anhuiensis)和未接种的桃蚜（Myzus persicae)成蚜按不同比例混合（0：6,1：5,2：4,3：3,4：2,5：1及6：0）建立蚜群,3次重复,考察流行病的发生与发展,结果表明,在带菌蚜50％以上的蚜群中,活蚜的数量增长因高强度的流行病发生而得到有效控制,活蚜数妈终未超过50头／90cm^2,第22天观察结束时与对照（0：6）jah vtk r 656udi /90cm^2相比控蚜效果高达93．24％－100％,在接菌与未接菌比例1：5和2：4的蚜群中,蚜病的发生虽未能充分控制蚜虫的数量增长,但结束时的蚜虫数量均显著低于对照,分别为356头／90cm^2和207头／90cm^2,控蚜效果亦分别达46％和68％,各处理蚜群中病害流行随时间的变化很好地拟合Gompertz模型（r^2=0.97),由此估计出虫瘟霉不同初始菌量在蚜群中的流行速度（R）及最高流行水平（K）,线性回归分析表明,初始侵染体密度确定了R（r^2=0.89)和K（r^2=0.90)估计值的90％变异,充分显示安徽虫瘟霉流行病的发生及流行强度对初始侵染体和寄主密度的依赖性。     

安徽虫瘟霉的黍米培养及其对桃蚜的侵染力

安徽虫瘟霉Zoophthora anhuiensis (Li) Humber是较难人工培养的蚜虫专化性病原真菌。将灭菌并适度熟化的黍米Panicum miliaceum L.作为固体基质与挑碎的安徽虫瘟霉平板菌落混合,在20℃和12L∶12D的温光条件下静止固体培养,获得了产孢潜能大、杀蚜活性强的米粒培养物。培养7天的黍米的产孢量达13.0×10⁴个孢子/粒,产孢持续时间长达6天。用此黍米培养物弹射的孢子对桃蚜Myzus persicae (Sulzer) 若蚜进行7.9～134.9个孢子/mm²共9个剂量的孢子浴接种,所获数据很好拟合时间 剂量 死亡率模型。接种后第5～7天各天的LC₅₀依次为59.8, 39.5和33.5个孢子/mm²,LC₉₀依次为354,234和198个孢子/mm²。在57.7～134.9个孢子/mm²的接种剂量范围内,致死中时LT₅₀从5.1天下降到4.3天。由此表明,安徽虫温霉的黍米培养不仅简单易行,而且菌种的产孢和侵染生物学特性在培养物中被充分体现,每颗米粒如同自然罹病而死的蚜尸,值得进一步研究开发和利用。     

飞虱虫疠霉继发性感染对桃蚜数量增长的控制作用

用飞虱虫疠霉（Pandora delphaics)“孢子浴”接种的桃蚜(Myzus persicae)无翅成蚜在离体甘蓝菜叶片（65cm^2)上建立蚜群,在不同温度（10－30℃）和湿度（74％－100％RH）的组合条件下任其繁衍,发病和交互感染,以评价该菌的控蚜效果。在25个温,湿度组合处理（8次重复,每重复含3头接种成蚜)中,蚜群均不同程度的发病死亡,在历时30d的观察中,以高温（20－30℃）,高湿（95％RH）组合条件下的蚜群发病快且死亡率高,蚜尸上产生的孢子有效地引起若蚜继发性感染。与相同温度下不带菌的对照蚜群相比,次于30℃下,各湿度除个别例外,第8d的控蚜率达30％以上,第20d达80％以上。在10℃和15℃下,控蚜效果一般不如上述较高温度下,且与湿度的关联程度相对较低,但最大控蚜效果均发生在100％RH处理中。结果表明,飞虱虫疠霉用于蚜虫防治的潜力很大,值得深入研究和开发利用。     

温湿度对安徽虫瘟霉在桃蚜居群中流行的影响

用安徽虫瘟霉(Zoopphthoraanhuiensis)接种桃蚜(Myzuspersicae)无翅成蚜3头和健蚜3头组成新的蚜群若干,在不同温湿组合条件下任其繁殖、发病和传染,以评价温湿度对该菌在蚜群中流行的影响.持续26d观察,在偏低温与各湿度(90～100%RH)的组合中均成功诱发了蚜病流行,其程度受湿度影响较小.在10℃与各湿度组合中,最终感病死亡率为72.9%～98.2%,15℃下为78.7%～94.4%,流行强度极大.而20℃下仅100%RH诱发了高强度流行病,其余湿度下感病死亡率仅为5.1%～12.8%.在25℃,100%RH下死亡率仅27.2%.与所有湿度组合中的对照蚜群相比,10℃下流行病控蚜效果为89.5%～96.9%,15℃下为96.1%～98.2%,20℃下为45.9%～85.7%,25℃下为56.4%～69.7%.逐步回归分析表明,安徽虫瘟霉引发的蚜病流行与温度及其相对湿度和蚜群带菌后天数的互作项密切相关(r2=0.82,a＜0.01),这些变量在很大程度上决定了安徽虫瘟霉是否在蚜群中流行.     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

The early development of the tail and the transformation of the shape of the nucleus of the spermatid of the domestic fowl,Gallus gallus

Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices     

Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L

This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10^− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418