Untersuchungen über den Einfluß von Cuticularwachsen auf die Infektionsfähigkeit pathogener Pilze

The effect of cuticular waxes on the infection rate of pathogenic fungi. 2. Rhytisma acerinum, Microsphaera alphitoides and Fusarium oxysporum . Cuticular waxes of Acer and Quercus species stimulate germination rate and germ-tube development of certain foliar pathogens. The stimulation increases with host susceptibility. In the case of Rhytisma acerinum, the chemical composition of the leaf wax may be responsible for the host specificity of physiological races. Cuticular waxes showed a marked effect on Fusarium oxysporum also. In some cases, individual chemical components of different fractions seem to play a role in the mechanism of resistance.     

Physiologie in vitro des basidiospores de Melampsora pinitorqua Conséquences pour la compréhension des infections

Physiology of in vitro germination of Melampsora pinitorqua Rostr. basidiospores; consequences for the understanding of the infection process. The in vitro germination of Melampsora pinitorqua Rostr. basidiospores is affected by several environmental factors: temperature, moisture, and by host substances: shoot diffusates, epicuticular waxes, terpenes. The failure of basidiospore spraying inoculations and the possible resistance factors of pines are discussed in view of the results obtained.     

Veranderung der Krankheitsdisposition von Forstpflanzen durch Herbizide

Modification in disease-sensibility of forest plants by herbicide treatment. II. Laboratory studies on Lophodermium pinastri. The effect of TOP-KH (2, 4, 5-T) and Dichlobenil on the growth of Lophodermium pinastri in culture was studied in the laboratory. The effect of aqueous solutions of TOP-KH on germination of Lophodermium spores was also tested. Assessments were also made of the number of apothecia produced on herbicide-treated plants, their size and the number of spores emitted. A final discussion of results is given.     

Untersuchungen zur Variabilität von Lophodermium pinastri

Studies of the variability of Lophodermium pinastri. I. Cultural Variants. Lophodermium pinastri is a variable fungus species. From its behaviour in artificial culture 3 constant, morphological main types are observed. These are described in detail. Observations on sectoring found and on reaction types between various fungus isolates are given.     

Veränderung der Krankheitsdisposition von Forstpflanzen durch Herbizide1

Modification in discase-sensibility of forest plants by herbicide treatment. I. Field trials with Lophodermium pinastri. The effect of two herbicides TOP-KH (salt of 2,4,5-T) and Casoron G (Dichlobenil) on incidence of Lophodermium pinastri on Scots pine (Pinus sylvestrií L.) was investigated in field trials with potted plants. Treatment with TOP-KH led to increase in infection with higher herbicide concentrations and to higher numbers of severely infected plants in comparison with controls. Differences were greatest in spring. With Casoron G, however, smaller numbers of sevcrely infected plants were seen in spring and at the end of the growing season the damage was not much greater than in the controls. Possible reasons for changes in degree of infection are discussed as well as effects that could be expected on the epidemiology of pine needle cast.     

Fractal dimension ofPopulus davidiana leaf surface rough extent

The rough extent of leaf surface may be described by protruding of waxes which like as wart and of stomatal aperture and of width of the cuticular ledge around guard cells. Because the morphology of the leaf surface has obviously similar itself, so one can use the theory of the fractal dimension to deal with the problems of leaf surface rough. The paper studied the rough extent and the result showed: with the leaf growing up, the waxes accumulate more and more, the leaf surface is more rough and the dimension is larger. The dimension D _w ^p which indicates the rough extent of warts protruding is about 2.10–2.20 on the above epidermis; On the beneath epidermis the dimension D _s ^p of stomatal opening protruding is about 2.00–2.24; Maximum widthL of cuticular ledge is about 1.0–7.4μm. The project supported by Natural Science Foundation of China     

Untersuchungen zur Variabilität von Lophodermium pinastri

Studies of the variability of Lophodermium pinastri. II. Differences in physiological behaviour . In culture trials with numerous strains of Lophodermium pinastri of different provenances the influence of temperature, pH and vitamins on growth was studied as well as ability to produce starch hydrolyzing enzymes. On the basis of these tests, the strains investigated could be divided into five groups.     

Züchtung von Reinkulturen des Pilzes Lophodermium pinastri (Schrad.) Chev. zur Entstehung von sexuellen Fruchtkörpern (Hysterothecien)

Production of hysterothecia from pure cultures of Lophodermium pinastri (Schrad.) Chev. A method is described for the production of hysterothecia from pure cultures of L. pinastri. Previously sterilized needles of Finns sylvestris, after being overgrown on the culture dish are removed and put on living moss under natural conditions. In 2–2,5 months hysterothecia appear.     

松落针病药剂防治试验

通过测试多菌灵、百菌清、炭疽福美、福美双、代森锌、代森锰锌、甲基托布津、代森铵、苯菌灵、退菌灵、炭特灵、克菌丹等12种不同杀菌剂对松针散斑壳菌(Lophodermiumpinastri(Schrad )Cher )孢子萌发的抑制作用,认为不同杀菌剂对松针散斑壳菌作用效果不同,药剂筛选结果表明代森铵、多菌灵、百菌清和退菌特等杀菌剂对松针散斑壳菌有较好的抑制作用。对马尾松幼林的松落针病作小区和林间防治试验,结果表明,林间应用45%代森铵水剂防治效果最佳,平均防效达81 2%。     

Physiological studies on variation in resistance of Pinus sylvestris to Lophodermium pinastri

Buffering capacity and pH values of extracts of pine needles varied with age in the course of the ontogeny of needles. Significant differences between a resistant and a susceptible pine clone group in relation to resistance against Lophodermium pinastri could be shown in autumn and winter. Also the variability of the parasite influences the host-parasite interaction as shown by alteration of pH values by 3 L. pinastri strains in cultural trials on needle extract medium.     

Beobachtungen über Wechselwirkungen dreier Nadelpilze der Kiefer in vitro

Interactions in vitro among three pine needle fungi . Interactions in vitro among Lophodermium pinastri, Naemacyclus niveus and Dothistroma pini, all fungi on conifers, were related to their various host spectra. The results were remarkably conformable, with those species which were mutually tolerant in vitro being joint colonisers of many host species and vice versa.     

冷湿层积法对印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana）种子萌发的影响

研究赤霉素(GA3),冷湿和温度 对五个种源的印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana)种子萌发的影响.种子被浸泡在GA3 (10 mg(L-1)中24小时,然后在3(5(C温度的条件下冷藏15天.设计4个温度(10(C, 15(C, 20(C 和 25(C)条件来促进种子的萌发.结果表明,浸泡和冷湿处理明显增加种子的萌发率.在10 (C时种子的萌发率最高.总体结果表明,种子被浸泡在GA3 (10 mg(L-1)中24小时,冷湿藏15天,可以有效地促进印度冷杉和长叶云杉的种子萌发.统计数据表明,浸泡处理、温度和种源以及与温度的相互作用都对种子的萌发有明显的影响.     

Die Wirkung wäßriger Streuextrakte verschiedener Waldbäume auf Mycelwachstum und Konidiosporenkeimung von Fomes annosus (Fr.) Cke.

The effect of water extracts of leaf and needle litter from different forest trees on the mycelial growth and the germination rate of conidia of Fomes annosus (Fr.) Cke. Litter extracts from various forest trees and stands have distinct effects on mycelial growth and germination rate of conidia of Fomes annosus. The effects depend on concentration of the extract, period of extraction and on date of collecting the litter samples.     

Effect of different pre-sowing seed treatments on the germination of <Emphasis Type="Italic">Leucaena leucocephala</Emphasis> (Lam.) and <Emphasis Type="Italic">Acacia farnesiana</Emphasis> (L.)

Leucaena leucocephala and Acacia farnesiana are tree species used for several agricultural purposes in the Mediterranean region. The seeds of these species exhibit dormancy, causing delayed germination. Two experiments were conducted to investigate the effect of pre-sowing treatments (scarification, hot water, or soaking) on seed germination of L. leucocephala and A. farnesiana. In one experiment, seeds were exposed to three pre-sowing treatments: control, sandpaper scarification, or soaking in 70°C water for 4, 8, 12, 16, 20, or 24 min. In another experiment, seeds were soaked in 70°C water for 20 min, and then soaked in water at room temperature for an additional 24, 48, or 72 h or blade scarified. In general, soaking the seeds of the two species in hot water was more effective in breaking seed dormancy than scarification. Sandpaper scarification was not effective for either species. Blade scarification increased A. farnesiana seed germination to 56%, indicating that seed dormancy was mainly a consequence of hardseededness. L. leucocephala seeds collected from Jordan University of Science and Technology (JUST) site and soaked in 70°C water for 20 min and then soaked for 24, 48, or 72 h had germination rates above 97%. Our results suggest that blade scarification of A. farnesiana seeds and soaking of L. leucocephala seeds in 70°C water for 20 min are effective treatments to break seed dormancy and enhance seed germination of these vital species.     

Endophytische Pilze in Nadeln von gesunden und geschädigten Fichten (Picea abies [L.] Karsten)

Endophytic fungi in needles of healthy-looking and diseased Norway spruce (Picea abies [L.] Karsten). Endophytic fungi were isolated from surface-sterilized, 5 to 6 year old needles of healthy-looking and diseased trees. Two fungal species could be isolated frequently: Lophodermium piceae and Tiarosporella parca. At any site neither L. piceae nor T. parca could be isolated more frequently from needles of diseased trees. The possible types of relationship between these two fungi and Norway spruce are discussed.     

银杉落针病的初步研究

由散斑壳菌Lophoder mium sp.引起的落针病是银杉的一种重要叶部病害,导致针叶大量提早脱落,影响树木生长甚至濒于死亡。百菌清、多菌灵、甲基托布津等杀菌剂对病原菌子囊孢子萌发的抑制作用较强,以营林为主、药剂防治为辅的防治方法能控制该病的发生与流行。     

Effect of electrostatic field on seed germination and seedling growth of <Emphasis Type="Italic">Sorbus pohuashanesis</Emphasis>

A study was conducted to determine the effects of electrostatic field (ESF) treatment on seed germination and seedling growth of Sorbus pohuashanesis. The experiments were arranged by uniform design computed by the Data Processing System (DPS), including three levels of seeds soaking time, four levels of ESF intensity and four levels of ESF treatment time, with 12 treatments. Ten seeds were used in each treatment with three replicates. Seed vigor, seed germinating ability, emergence rate of seedling, survival rate of seedling, and seedling height and diameter, as well as the change in activities of superoxide dismutase (SOD), soluble protein contents, total chlorophyll contents, soluble total sugar contents in leaves of S. pohuashanensis seedlings were measured after ESF treatments. The experiment results show that ESF treatment could improve the water absorption ability of dry seeds of S. pohuashanensis, resulting in fast germination at room temperature under light conditions. Combined treatment of ESF with cold stratification could increase seed germination percentage significantly (to 42.20%), promote seedling height growth, affect leaf SOD activity, and could raise contents of total chlorophyll, soluble protein, and total soluble sugar in leaves. Seed soaking time had a significant effect on seed relative electroconductivity, seed germination under light, SOD activity, soluble protein content and total soluble sugar content of seedling leaves. ESF intensity exerted a moderate effect on these indexes. ESF treatment time only had significant effect on total chlorophyll contents, no evident effect on other indexes.     

高盆樱桃种子萌发特性初探

高盆樱桃 Cerasus cerasoides 原生于西藏和云南地带,为我国唯一冬季开花的樱属树种。其树形优美,花色艳丽,造景效果好,目前多应用于云南地区的绿化及造林。为探索高盆樱桃种子的萌发特性,测定其长、宽、厚、百粒重、吸水特性、发芽特性以及芽苗质量指标,并初步探索种子大小对种子萌发的影响。结果表明：高盆樱桃种子浅褐色,呈卵圆状;平均长 10.56 mm,平均宽 7.89 mm,平均长宽比为 1.34,平均厚 6.06 mm,平均百粒重为 25.48 g;在培养皿铺纱布保湿的环境下种子发芽率为 42.67%;大种子发芽势、发芽率等数值均高于中、小种子,种子大小与发芽率呈正相关。     

不同处理对神黄豆种子发芽的影响

用剪刀剪、锉子锉、与瓜子石混搓等机械处理法以及用5%氢氧化钾、98%浓硫酸等化学处理法对神黄豆种子进行预处理,3倍种子体积沸水浸泡并自然冷却浸种48 h,观察并统计种子吸胀粒数、种皮破裂数后置床进行发芽测定。结果表明,除与瓜子石混搓处理外,其余处理均能促进种子吸水膨胀,显著提高神黄豆种子发芽率。其中以98%浓硫酸浸泡2 h处理效果最好,其吸胀率达98.0%、发芽率最高,达88.3%,吸胀破皮率、不正常发芽率均为0%;其次是锉子锉处理效果好,其吸胀率达99.0%,发芽率可达84.7%,吸胀破皮率、不正常发芽率均为0%;用5%氢氧化钾进行浸泡处理,对种子发芽有一定的促进作用,但发芽不整齐,发芽速度慢,处理14 d吸胀率为59.7%、发芽率最高为48.0%;与瓜子石混搓处理效果相对较差,对神黄豆种子发芽的促进作用不明显,吸胀率为5.0%、发芽率为5.0%。     

Infektionsversuche mit Rhizosphaera kalkhoffii und Lophodermium piceae an unterschiedlich gestreßten Jungfichten (Picea abies [L.] Karst.)

Young spruce trees [Picea abies (L.) Karst.] artificially inoculated with Rhizosphaera kalkhoffii B. and Lophodermium piceae (F.) v. H. were exposed to fumigations with O₃ and SO₂ and drought. These treatments showed no influence on the infection-rates of the fungi. R. kalkhoffii proved to be a saprophyte living for a long period as an epiphyte on the needle surfaces.