Detection of soluble antigens of Erwinia salicis in leaves of Salix alba by Enzyme-linked Immunosorbent Assay

Soluble antigens of Erwinia salicis are transported through the xylem vessels to the leaves of Salix species. These antigens can be detected by the use of the Enzyme-linked Immunosorbent Assay (ELISA) in willow trees in the absence of bacterial cells and are also produced in pure cultures. In this way populations of E. salicis occurring in stem or branches can be traced in the leaves. The possibilities for more general application in the detection of vascular parasites is discussed.     

Untersuchungen zur Wirkung eines Kernpolyeder-Virus ausLeucoma salicis L. (Lep., Lymantriidae) auf einige Lymantriiden-Arten

Zusammenfassung Es wird ein Nuclear-Polyedrose-Virus ausLeucoma salicis-Raupen beschrieben und das Ergebnis von Untersuchungen über seine Wirkung auf 5 Lymantriiden-Arten mitgeteilt. Das Virus zeigte hohe Pathogenität gegenLymantria dispar, Euproctis chrysorrhoea, Leucoma salicis undOrgyia antiqua, dagegen geringe gegenLymantria monacha. Die Lt₅₀- und LD₅₀-Werte für die verschiedenen Wirte werden mitgeteilt.

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On cross infectivity of a nuclear polyhedrosis virus isolated fromLeucoma salicis to some related Lymantriidae

A virus strain isolated from larvae ofLeucoma salicis L. (Lep., Lymantriidae) was tested against 5 species of Lymantriidae. This virus showed a high pathogenicity againstLymantria dispar, Euproctis chrysorrhoea, Leucoma salicis andOrgyia antiqua. The nun moth,Lymantria monocha, was less suspectible to the nuclear polyhedrosis virus; this could be shown by aid of the calculated values of the Lt₅₀ and the LD₅₀.

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Mit 5 Abbildungen und 5 Tabellen     

Studies on Drepanopeziza salicis (Tull.) v. Höhnel,perfect state of Gloeosporium salicis West.

The development of the apothecium of Drepanopeziza salicis– the perfect state of Gloeosporium salicis– following the appearance of the microconidia has been described. The formation of both microconidia, which possibly have a spermatial function of mature ascospores and the incubation period of the ascospore-infection have been related to climatic conditions.     

Geographical distribution of Erwinia salicis strains,the cause of watermark disease of willows

Eighty-six isolates of Erwinia salicis, the causal agent of watermark disease of willow, were obtained from culture collections and collected from various willow plantations in south-east England. These isolates were characterized by their reaction in a competitive enzyme-linked immunosorbent assay, by enzyme electrophoresis, and for lysis by a panel of five bacteriophage. Eighty-one isolates had similar characteristics and clustered at a level of similarity of at least 60%. Five isolates were found to have less than 20% similarity to the other E. salicis. Antiserum raised against E. salicis (NCPPB 2535) was found to be specific to E. salicis and did not cross-react with other bacteria tested. No geographical clustering of electrotypes was found: however, Dutch and English isolates could be distinguished by bacteriophage typing. The local distribution of electrotypes collected from diseased trees suggests that the bacterium is spread via the propagating material and that tree to tree spread is rare.     

The Watermark disease is not transmitted with one-year-old cuttings of Salix alba

Examination of 373 one-year-old Salix alba cuttings collected from both healthy and diseased stools revealed that Erwinia salicis was present in one cutting only, even when the cuttings had been taken from diseased stools. Thus it can be inferred that the transmission of Watermark disease by means of this propagation material is negligible.     

The necessity of using healthy propagation material of Salix alba in connection with the spread of Watermark disease in the Netherlands

Reproduction of White willow (Salix alba) by means of 1- or 2-year old cuttings is recommended, since these cuttings are not yet infected by Erwinia salicis, the cause of the Watermark disease. The use of sets originating from older trees or pollard willows should cease, since there is no guarantee that they are healthy.     

New Chalcidoidea (Hymenoptera) parasitoids of <Emphasis Type="Italic">Dasineura saliciperda</Emphasis> (Dufour) (Diptera,Cecidomyiidae) in Bulgaria

Abstract The parasitoid complex of Dasineura saliciperda (Dufour) (Diptera, Cecidomyiidae) on Salix fragilis L. was studied in 1997 and 2002 in two localities in Bulgaria. As a result, 5 species from 3 families of Chalcidoidea (Hymenoptera) were reared from pest galls: Eurytoma afra Boheman, Eurytoma salicis Walker (Eurytomidae), Torymus microcerus (Walker) (Torymidae), Gastrancistrus sp. and Mesopolobus sp. (Pteromalidae). E. afra and T. microcerus are new species for the fauna of Bulgaria, and E. salicis – a new parasitoid of the host. Total parasitism of D. saliciperda in the studied years ranged between 44.1 and 53.5 %. E. afra was the most important, destroying 21.9-53.5 % of the pest.     

Auffällige Schädlingsvorkommen in Mitteldeutschland (1947)

Zusammenfassung Im Sommer 1947 bot sich Gelegenheit zur Beobachtung st?rkeren Auftretens von u. a.Haplothrips tritici an Weizen,Athalia colibri an Senf,Myzodes latysiphon in Kartoffelkellern, anderen Blattlausarten,Trioza viridula, Hylemyia antiqua, Contarinia nasturtii bei Blumenkohl,Pieris brassicae, Grapholitha nigricana, Stilpnotia salicis an Pyramidenpappeln,Psylliodes affinis an Kartoffeln. Engerlinge,Bruchus rufimanus an Pferdebohnen, undLixus iridis an Liebst?ckel.     

Beobachtungen zur Massenvermehrung des Weiden- oder Pappelspinners,Stilpnotia salicis L. in Windschutzstreifen im Seewinkel des Burgenlandes in den Jahren 1962 und 1963

Summary The present work is dealing with the mass increase ofStilpnotia Salicis L. in the willow windbreaks of northeastern Burgenland in 1962/63. The calamity broke down as soon as the second year because of the spreading of a polyedrosis of the middle intestin which probably was due to a physiological weakening of the small caterpillars during the heavy frosts of the winter of 1962/63. As comparisons of the bioclimatical data of this period of gradation with that of 1926/27 have shown, the hatching of the young caterpillars little after the egg deposit and consequently, the hibernation in the larva stage, is likely to be caused by the very low moisture content of the air in these regions. The evolution ofStilpnotia salicis L. eggs into caterpillars in the year of the egg deposit seems to be a rule in the regions of Pannonian climate and those influenced by it.

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Résumé Le présent travail traite la gradation deStilpnotia salicis L. dans les platations de brise-vent dans le nord-est du Burgenland en 1962/63. Le déclin de la calamité se manifesta dès la deuxième année grâce àu développement d'une polyedrose de l'intestin moyen qui était vraisemblablement due à un affaiblissement physiologique des petites chenilles par suite des fortes gelées de l'hiver 1962/63. Ainsi que l'ont révélé les comparaisons des données bioclimatiques de la période d'évolution en question avec celle des années 1926/27, l'éclosion des jeunes chenilles peu après le dépôt des oeufs et par conséquent, l'hiber, nation au stade larvaire ont leur cause dans la grande sècheresse de l'air de ces régions. L'éclosion des chenilles deStilpnotia salicis L. dans l'année du dépôt des oeufs semble être la règle dans les plantations de brise-vent de la région au climat pannonien et celles influencées par celui-ci.

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Die Erhebungen des Schadauftretens erfolgten in Zusammenarbeit mit der Forstaufsichtsstation Neusiedl am See, wofür an dieser Stelle herzlichst gedankt sei.

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Frau Professor Dr. Francke-Grosmann zum 65. Geburtstag gewidmet.     

Biologische Bekämpfung des Pappelspinners Stilpnotia salicis L. (Lep., Lymantriidae) mit Bacillus thuringiensis Berliner

Larvae of the satin moth,Stilpnotia salicis L., were successfully controlled in May 1978 with aBacillus thuringiensis suspension by means of a helicopter. They occured in an outbreak over an area of 100 ha in western Switzerland. The mortality before the treatment amounted to 9% due to parasitism. It raised to 92% and 94% respectively a week after the treatment. The responsible mortality agent is the endotoxin of the crystalline parasporal inclusion. The inclusion is insensitive to UV radiation. In the laboratory, larvae (L₃) were lethally infected with a dose containing 2×10⁵ of spores and parasporal inclusions. After the field treatment the poplar leaves were coated with a layer of a minimum of 1,4×10⁵ to a maximum of 3,5×10⁶ per cm² of the above mentioned suspension.     

金花茶花朵和叶片UPLC-QTOF-MS分析

[目的]鉴定分析金花茶花朵和叶片中主要化学成分、含量及其变化特征,为金花茶资源的进一步开发利用提供科学依据。[方法]利用超高效液相色谱-飞行时间质谱联用(UPLC-QTOF-MS)技术定性定量分析金花茶花瓣、雄蕊、老叶和新叶中花青苷、类黄酮及儿茶素类成分与含量。[结果]花青苷天竺葵素-3-O-葡萄糖苷和矢车菊素-3-O-葡萄糖苷均为金花茶中首次发现,其中,矢车菊素-3-O-葡萄糖苷仅存在于紫红色新叶中。类黄酮木犀草素-7-O-芸香糖苷和染料木苷为金花茶中首次发现,槲皮素-3-O-葡萄糖苷、槲皮素-7-O-葡萄糖苷、槲皮素-3-O-芸香糖苷和山柰酚-3-O-葡萄糖苷为金花茶叶片中首次发现。金花茶花瓣与雄蕊中花青苷相差不大,但却低于叶片尤其新叶;花朵中儿茶素类远高于叶片尤其新叶。金花茶花瓣和雄蕊中总黄酮及槲皮素-3-O-葡萄糖苷、槲皮素-3-O-芸香糖苷和山柰酚-3-O-葡萄糖苷均相差不大,但却远高于叶片。金花茶新叶中主要类黄酮成分木犀草素-7-O-芸香糖苷及总类黄酮明显高于老叶。[结论]金花茶中共鉴定出2种花青苷、6种类黄酮和2种儿茶素;槲皮素-3-O-葡萄糖苷等类黄酮是金花茶花朵呈现黄色的主要原因,矢车菊素-3-O-葡萄糖苷是金花茶新叶呈现紫红色的主要原因。     

The effects of drying temperature on chemical composition and nutritive value of some tropical fodder shrubs

The effects of drying temperature on chemical composition and nutritive value of leaves of the shrub legumes Acacia angustissima (Miller) Kuntze, Calliandra calothyrsus Meissn and Leucaena leucocephala (Lam.) de Wit were determined in two studies in Zimbabwe. In the first study, the effects of shade-, sun- and oven-drying leaves on chemical composition and protein precipitation capacity of tannin extracts were studied. Drying method affected (P<0.01) chemical composition, with cell wall polysaccharides increasing from shade drying to oven drying. Calliandra calothyrsus leaves had the highest total phenolics, tannin phenolics and the lowest N content. About 40% of phenolics in L. leucocephala were non-tannin compared to less than 15% in A. angustissima and C. calothyrsus. Extractable proanthocyanidins and their capacity to precipitate protein were affected (P<0.01) by drying method; extracts from shade-dried leaves were 10% and 20% more reactive than extracts from sun- and oven-dried leaves, respectively. The relative degree of polymerisation of the proanthocyanidins was higher (P<0.01) for oven-dried (1.44) leaves compared to shade-dried (1.01) and sun-dried (1.00) leaves. Drying temperature influences the nutrient–polyphenolic interactions in A. angustissima, C. calothyrsus and L. leucocephala leaves and these interactions have important implications for feed evaluation protocols and for use of these leaves in ruminant feeding systems. The second study considered the effects of feeding sun-dried or fresh leaves of the three shrub legumes as supplements to native pasture hay on nutrient intake and digestion by goats. Feeding the fresh or dry leaves made no difference in terms of dry matter intake and digestion, and N digestion. This offers farmers flexibility in terms of feeding strategies, as they can feed the browse in any form that suits their farm situation. Increasing the level of C. calothyrsus in the diet increased faecal N. Nitrogen retention was lower for animals fed with C. calothyrsus compared to those fed with the other browses.     

Pre-penetration behaviour of the urediniospores of birch rust,Melampsoridium betulinum,on greenhouse-grown and microcultured leaves of Betula spp.

In two different experiments the urediniospores of Melampsoridium betulinum from Betula pendula and Betula pubescens germinated both on mature leaves of greenhouse-grown plants and on sterile in vitro leaves of micropropagated plantlets, which were cloned from the same B. pendula and B. pubescens genotypes. The urediniospores and germ tubes were more easily detached from the leaf surfaces of in vitro leaves. If germination took place on a leaf vein, the growth continued across the veinal ridges; otherwise, no determined growth towards the stomata could be observed with either of the leaf types studied. In both experiments on the in vitro leaves of B. pubescens clone V5944, the germ tubes of the rust isolate from B. pendula mislocated appressoria significantly more often than the germ tubes of the rust isolate from B. pubescens. On the mature leaves of B. pendula clone E4214 and B. pubescens clone V5940 there were also significant differences in appressorial locations between the two rust isolates but the clonal responses were inconsistent. The results of the inoculations suggest that the incompatibility of the rust isolates from B. pendula on the leaves of B. pubescens is not related to the significantly higher ratio of failures in locating appressoria in this host-rust combination.     

印度黄檀叶多酚提取工艺优化及抗氧化活性研究

目的]印度黄檀叶含有多酚及类黄酮物质,研究印度黄檀叶多酚及其抗氧化活性,可为其利用提供依据。[方法]以印度黄檀叶为原料,乙醇为提取液,经单因素实验与正交试验设计,检测在不同乙醇浓度、提取时间、提取温度及超声功率120 w时3个因素进行响应面优化试验,确定印度黄檀多酚的提取工艺;同时,鉴定印度黄檀叶乙醇-水提取液对DPPH-自由基的清除能力。[结果]低浓度印度黄檀叶多酚能发挥更强的抗氧化能力,其提取液对清除DPPH自由基的半数抑制质量浓度(IC_(50))约为3.2 mg·L~(-1),略大于Vc的2.5 mg·L~(-1);不过,其还原能力略低于Vc。[结论]印度黄檀叶内富含多酚类物质,具有很强的体外抗氧化活性,可作为天然抗氧化植物资源开发利用。     

西南桦与光皮桦幼苗叶片表型特征研究

西南桦和光皮桦幼苗外形特征十分相似,在种源不明确的情况下,苗木调运时很难在现场快速鉴别与区分。由于两个树种各自适宜栽培的海拔和气候条件不尽相同,为避免混淆造成不良影响,对两个树种的幼苗叶片表型特征进行调查对比研究。结果表明,光皮桦与西南桦幼苗的叶柄区别显著,前者明显长于后者;光皮桦与西南桦幼苗叶片长宽比区别显著,前者长宽比小,叶形团圆,后者长宽比大,叶形细长;西南桦与光皮桦幼苗叶片基尖比无明显差别。幼苗叶片表型特征的差异性可作为现场快速鉴别区分西南桦与光皮桦幼苗的依据。     

The emergence of beech leaf disease in Ohio: Probing the plant microbiome in search of the cause

American beech (Fagus grandifolia) is the target of a newly emerging disease in North America called beech leaf disease (BLD) that affects and disfigures leaves and which can lead to tree mortality. Beech leaf disease may be caused by a newly recognized subspecies of the anguinid nematode Litylenchus crenatae subsp. mccannii, but the associations of this nematode with bacterial and fungal taxa are unknown. We examined microbial communities associated with beech leaves affected by BLD in a 16‐year‐old American beech plantation using molecular methods. We detected L. crenatae subsp. mccannii in anywhere from 45% to 90% of leaves depending on the degree of visual BLD symptoms. Approximately 37% of asymptomatic leaves contained L. crenatae subsp. mccannii, whereas 90% of buds associated with symptomatic leaves contained L. crenatae subsp. mccannii. We found that fungal communities on leaves and buds were unaffected by BLD, but bud and leaves had significantly different fungal communities. Bacterial communities on buds also were unaffected by BLD, but bacterial communities were significantly different between symptomatic and asymptomatic leaves suggesting that the nematode could be altering the community of bacteria on the leaves. Clone libraries indicate that Wolbachia, an intracellular endosymbiont of arthropods, was found only on symptomatic leaves and buds associated with either symptomatic or asymptomatic leaves. In addition, only symptomatic leaves contained taxa in the genus Mucilaginibacter, which previous studies suggest could produce exopolysaccharides. These bacterial taxa could represent a marker for the vector of L. crenatae subsp. mccannii that enables spread between trees and a possible endosymbiont that could facilitate nematode feeding and establishment on nematode infested leaves. Our results are the first to examine changes to the leaf microbiome of this newly emerging pest and may aid identification of mechanisms associated with the spread and success of L. crenatae subsp. mccanni.     

Decomposition and nitrogen release patterns of Paraserianthes falcataria tree residues under controlled incubation

Tree legumes can serve as nitrogen (N) source for cereals in resource poor farms where chemical fertilizer is financially unaffordable. Despite the increasing importance of Paraserianthes falcataria in tropical agroforestry systems of Southeast Asia, little information is available on the decomposition and N release patterns of P. falcataria. Quality of P. falcataria roots and leaves, as individual components and as a mixture, was determined before incubating in an ¹⁵N labeled acidic Ultisol under controlled laboratory conditions. Decomposition was monitored as CO₂ evolution and inorganic N released over time. The aim was to determine inorganic soil N and pH dynamics as affected by residue quality. Residue quality assessment based on (Polyphenol + Lignin): N was in the order of P. falcataria leaves > P. falcataria mixture of leaves and roots > P. falcataria roots. The same order was observed for nitrogen and carbon mineralization rate (P <0.05), indicating that mixing of residues of varying quality would provide a means of strategically modifying nutrient release. P. falcataria leaves and the mixture of leaves and roots significantly (P<0.05) mitigated soil acidity while P. falcataria roots alone did not.     

Life History,Host Range and Distribution of Septotinia podophyllina

Viable conidia of Septotinia podophyllina are found on sclerotia on dead last year's leaves of Populus in spring. Prunus serotina is described as a new host. Inoculation experiments on leaves in petri-dishes with Populus- and Prunus isolates demonstrated no host-specificity. A possible introduction of the organism from North-America, its native area, into Europe and Asia is considered.     

Susceptibility of Pedicularis spp. to Cronartium ribicola and C. flaccidum in Finland

Aeciospores of Cronartium ribicola and C. flaccidum were collected from several locations in Finland and used to inoculate Pedicularis spp. and some known and suspected alternate hosts in 2008–2009. In all trials, C. ribicola formed uredinia and telia on leaves of Ribes nigrum. No uredinia or telia of C. ribicola formed on older leaves of Pedicularis spp. but both uredinia and telia were found on young leaves of P. palustris ssp. palustris. Cronartium flaccidum produced uredinia and/or telia on leaves of P. palustris ssp. palustris, P. lapponica, Vincetoxicum hirundinaria and Melampyrum sylvaticum. Neither rust infected P. sceptrum‐carolinum, Vaccinium myrtillus, Calluna vulgaris or Ledum palustre. Similar to rusts in Asia and North America, the results showed that European C. ribicola exhibit more variable host reactions and wider alternate host ranges than earlier described. Pedicularis palustris may play a role in the spread of Cronartium in natural forests.     

Seasonal and genotypic variation of water-soluble polysaccharide content in leaves of Cyclocarya paliurus

Cyclocarya paliurus (Batal) Iljinskaja is an important medicinal woody plant due to numerous bioactive natural products in its leaves. As an important bioactive natural product, water-soluble polysaccharides (WSP) in leaves of C. paliurus possess diverse biological activities, such as hypoglycemic, anticancer and free-radical-scavenging activities. To better understand accumulation patterns of WSP in C. paliurus leaves, seasonal, genotypic and positional variations of WSP content were investigated in this study. The results showed that the mean content of WSP in leaves from three crown positions (upper, middle and lower) within an individual was 38.5?mg g^?1. ANOVA and Duncan's multiple range test indicated that WSP content in leaves of the upper crown was significantly higher than that in the middle and lower crowns, whereas no significant difference was observed between the middle and the lower positions. Seasonal variation of WSP content in the leaves was revealed as a bimodal temporal pattern with the maximum (38.3?mg g^?1) observed in April and the second peak (32.3?mg g^?1) in October, whereas the lowest WSP content was observed in June (20.12?mg g^?1) or in fallen leaves (17.71?mg g^?1). Generally, higher contents of WSP accumulated in the maturity/senescence period (from September to mid-November) than during the rapid growth phase (from May to August). Moreover, WSP content varied significantly among 12 provenances, ranging from 22.09 to 34.56?mg g^?1, in leaves sampled in October. Our results not only provide knowledge of the accumulative dynamics and genotypic variation of WSP, but also establish a basis for determining the optimal time for harvesting and for extensive selection and breeding programs to improve the content of beneficial compounds in the leaves of C. paliurus in the future.