Absorption and translocation of 14C fosamine by three woody plant species

Absorption and translocation of ¹⁴C fosamine (ethyl hydrogen (aminocarbonyl) phosphonate) and/or fosamine metabolites were monitored in intermediately susceptible seedling black cherry (Prunus serotina Ehrh.) and resistant seedling rhododendron (Rhododendron sp.) and magnolia (Magnolia sp.). The mid two-thirds of the third leaf below the apical bud of each plant was treated with 0·5 μCi ¹⁴C fosamine (carbonyl carbon labelled). Plants were harvested 3, 7 and 14 days following treatment. In black cherry the majority of ¹⁴C absorption and translocation occurred during the second week following treatment, while magnolia and rhododendron translocated and absorbed most of the ¹⁴C within 3 days after treatment. Retention of ¹⁴C in the treated portion of the treated leaf did not differ between species. However, total translocated ¹⁴C was greatest in black cherry, less in magnolia, und minimal in rhododendron. Magnolia translocated ¹⁴C basipetally, while black cherry translocated acropetally, as well as basipetally. Absorpiion et migration de la fosamine ¹⁴C chez trois espèces de plantes ligneuses L'absorptlon et la migration de La ¹⁴C fosamine ((amino carbonyl) phosphonate d'éthyle hydrogène) et/ou de ses métabolites, ont étéétudiées chez des plantules moyennement sensibles de Prunus serotina (Ehrh.) et chez des plantules résistantes de rhododendron (Rhododendron sp.) et de magnolia (Magnolia sp). Les deux tiers moyens de la troisième feuille en-dessous du bourgeon apical de chaque plant ont été traités avec 0.5 Ci ¹⁴C de fosamine (marquée sur le carbone du carbonyl). Les plantes ont été récoltées 3, 7 et 14 jours après le traitement. Chez P. serotina, la plus grande partie de l'absorption et de la migration du ¹⁴C a eu lieu durant la deuxième semaine après le traitement, alors que chez le magnolia et le rhododendron, le maximum d'adsorption et de migration s'est situé dans les trois jours qui ont suivi le traitement. La rétention du ¹⁴C dans la partie traitée n'a pas variè d'une espèce à l'autre. Toutefois, la quantité totale de ¹⁴C qui a migré a été plus grande chez P. serotina, moindre chez le magnolia et minimaie chez le rhododendron. Chez le magnolia, la migration du ¹⁴C s'opere dans le sens basipète, alors que chez le P. serotina. elle s'effectue aussi bien dans le sens acropète que dans le sens basipète. Aufnahme- und Trunstokaiion von ¹⁴C-Fosaminc bei drei Gehölzpflanzen Es wurde die Aufnahme und die Translokation von ¹⁴C Fosamine (O-Äthyl-aminocarbonylphosphonsäure) und/oder seiner Abbauprodukte bei drei Gehölzarten beobachtet. Verwendet wurden Sämlinge der Traubenkirsche (Prunus serotina Ehrh.), die eine mittlere Empfindlichkeit zeigt und Sämlinge des resistenten Rhododendron (Rhododendron sp.) und der ebenfalls resistenten Magnolie (Magnolia sp.). Die mittleren zwei Drittel des dritten Blattes unterhalb der Endknospe wurden bei jeder Pflanze mit 0.5 μCi ¹⁴C-Fosamine (markiert am Carbonylkohlenstoff) behandelt. Die Pflanzen wurden nach 3, 7 und 14 Tagen nach der Behandlung geerntet. Bei der Traubenkirsche wurde während der zweiten Woche am meisten ¹⁴C aufgenommen und transloziert, während dies bei der Magnolie und dem Rhododendron bereits innerhalb der ersten drei Tage der Fall war. Bezüglich der Retention von ¹⁴C in der behandelten Blattfläche unterschieden sich die drei Arten nicht. In der Traubenkirsche wurde aber am meisten ¹⁴C transloziert, weniger in der Magnolie und am wenigsten im Rhododendron. Die Magnolie translozierte das ¹⁴C basipetal, während die Traubenkirsche akropetal wie basipetal translozierte.     

Effect of canopy cover,seeding depth,and soil moisture on emergence of Centaurea maculosa and C. diffusa*

The effects of canopy cover, seeding depth, and soil moisture on emergence of Centaurea maculosa Lam. and C. diffusa Lam. were studied. Canopy cover had no effect on ermergence rate (seedlings/day/100 seeds) of either species. Seeds of both species emerged faster when placed on the soil surface. Emergence rate decreased as seeding depth increased. Both species required more than 55% initial soil moisture to initiate emergence, with 65–70% being optimum. Percentage emergence followed exactly the same trend as emergence rate. C. maculosa had better emergence characteristics over a wider range of conditions than C. diffusa, possibly being some of the reasons for the former having a wider geographical distribution in the United States and Canada.     

Precocene II metabolism: Comparative in vivo studies among several species of insects,and structure elucidation of two major metabolites

Several species of insects, exhibiting varying responsiveness to the juvenile hormone antagonist precocene II (6,7-dimethoxy-2,2-dimethylchromene), were challenged topically with a tritiated preparation of the title compound. Metabolism of [³H]precocene II was subsequently examined by withdrawing hemolymph samples from treated animals at appropriate time intervals and characterizing the extractable radiolabel chromatographically. Quantitative (or qualitative) differences observed between the respective metabolic profiles were found not correlative with specimen sensitivity to precocene. Production of two heretofore unreported metabolites, identified by spectral and chemical means as O-β-glucosides of 6- and 7-monodemethylated precocene II, was demonstrated in both sensitive and insensitive species. No evidence for the presence of a hemolymphborne, biologically effective “activated metabolite” produced in vivo by precocene-susceptible insects could be found. The latter finding may well argue for in situ bioactivation of precocene at the target tissue(s) by these sensitive insects.     

Fish oil-induced yellow fat disease in rats. II. Enzyme histochemistry of adipose tissue

Adipose tissue in various stages of fish oil-induced yellow fat disease in the rat had the same acid phosphatase and 5-nucleotidase activity pattern as similar stages of the disorder in mink and pig. A weak acid phosphatase and 5-nucleotidase activity was seen in interstitial lipofuscin-laden macrophages in "stage M" yellow fat disease without fat cell degeneration. Activity of these macrophagic enzymes increased when there was fat cell degeneration ("stage S" and "stage E" yellow fat disease). This different phosphatase activity in the same cell type may result from phagocytosis of substrates with variable digestibility. Macrophages directly surrounding affected fat cells in steatitis areas ("stage S" and "stage E") had strong acid phosphatase and 5-nucleotidase activity. As in the pig, increased 5-nucleotidase activity was found in affected fat cells, which probably indicates plasma membrane damage. Increased nonspecific esterase activity occurred around affected fat cells. Only a small part of this esterase activity originated from inflammatory cells. This indicates that an increase of esterase activity in degenerating adipose tissue may be an endogeneous process in this tissue.     

Differentiation of strains of bean common mosaic virus

Pathogenicity and symptom expression of seventeen described isolates of bean common mosaic virus (BCMV) and five previously unreported isolates were compared on many bean cultivars (Phaseolus vulgaris L.). From these cultivars, a standard set of differentials were assigned to nine groups with different disease reactions. The twenty-two virus isolates comprised seven strain (pathotype) groups, three of which were divided into two subgroups each. To promote international standardization in BCMV research, recommendations are given for test conditions and procedures, criteria for strain differentiation, and maintenance of differential cultivars and virus strains.Samenvatting Zeventien beschreven stammen van het bonerolmozaïekvirus en vijf niet geïdentificeerde isolaten (Tabel 1) werden bestudeerd op een uitgebreide reeks van toetsrassen. De meeste van deze toetsrassen waren in de literatuur als zodanig vermeld, maar door de desbetreffende onderzoekers waren vaak verschillende series toetsrassen gebruikt, hetgeen de onderlinge vergelijking van de stammen bemoeilijkte.De bedoeling van dit onderzoek was: vergelijking en indeling van de virusstammen, samenstelling van een standaard-toetsrassenserie en het ontwerpen en beschrijven van werden zowel in Wageningen als in Prosser, Washington, USA, uitgevoerd met dezelfde virusisolaten en dezelfde zaadmonsters van de toetsrassen.De toetsrassen konden op grond van hun differentiële reacties na inoculatie met de virusstammen worden ingedeeld in negen groepen. De rassen binnen een groep hebben hetzelfde resistentiespectrum t.o.v. een standaardserie virusstammen. Uit elke groep werden op grond van hun geschiktheid (duidelijkheid en reproduceerbaarheid van de symptomen) één of meer vertegenwoordigers gekozen, waaruit een standaardserie van toetsrassen werd samengesteld (Tabel 2).De 22 stammen en isolaten werden op grond van hun pathogeniteitsspectrum t.o.v. de standaardserie van toetsrassen ingedeeld in tien groepen en subgroepen (Tabel 1). De stammen en isolaten binnen een groep of subgroep hebben eenzelfde pathogeniteitsspectrum (Tabellen 4 en 6) en worden op grond daarvan als identiek beschouwd. De differentiële reacties tussen de rassen van de standaardserie en de virusstammen en-isolaten zijn vermeld in de Tabellen 3 en 5. Voorgesteld wordt om de naam van de eerstbeschreven stam van iedere groep te handhaven en de andere stammen in een groep of subgroep op te vatten als isolaten daarvan.De toetsmethodiek wordt uitvoerig beschreven om standaardisatie van de stammenidentificatie te bevorderen. Ter verklaring van de in de literatuur gevonden tegenstrijdigheden in de differentiële reactie van de toetsrassen wordt een negental mogelijke oorzaken genoemd, o.a. het gebruik van planten van toetsrassen die reeds vanuit zaad met een onbekende stam waren besmet en het gebruik van onzuivere virusstammen (mengisolaten).De auteurs stellen zich verantwoordelijk voor het distribueren (op aanvraag) van kleine zaadhoeveelheden van de toetsrassen en, op beperkte schaal, van in zaad aanwezige zuivere virusstammen aan onderzoekers die betrokken zijn bij de identificatie van de stammen van dit virus. Bovendien zal zaad van de standaardserie van toetsrassen worden gedeponeerd in het National Seed Storage Laboratory te Fort Collins, Colorado, USA, terwijl de virusstammen (in zaad) in bewaring worden gegeven bij de American Type Culture Collection te Rockville, Maryland, USA, waar ze beschikbaar zullen blijven voor verder onderzoek.     

Biological Control of Take-all by Phialophora radicicola Cain1

Biological control of take-all by Phialophora radicicola Cain and similar fungi is reviewed, and new evidence is presented on the possible role of hyper-parasites, like Pythium oligandrum Drechsler, to augment this. Phialophora radicicola var. graminicola Deacon is abundant in British grasslands. Its role in biological control of take-all has been demonstrated in the glasshouse with natural soils and natural population levels of this control agent. Also there is much circumstantial evidence for its beneficial role in agriculture, especially in cereal monoculture following grass crops, and in natural and amenity grasslands. Some other similar fungi control take-all in the glasshouse, but their roles in current agricultural practice are not known. The take-all fungus, itself, can reduce infection of roots by P. radicicola, so there is a dynamic interaction between these fungi. This is affected by host type, relative inoculum potentials of the fungi, and possibly by environmental conditions. By careful manipulation, therefore, it might be possible to control take-all under a wide range of field conditions. The chief role of P. radicicola and similar fungi is to delay establishment of severe take-all early in cereal monoculture, rather than to combat an existing high disease level. It may therefore be desirable to combine different biocontrols, and hyperparasites like Pythium oligandrum may be important in this respect. This fungus was tested against varieties of Gaeumannomyces graminis Arx & Olivier and Phialophora radicicola in the laboratory; the host responses differed greatly, from marked susceptibility (P. radicicola var. radicicola) to almost complete resistance (G. graminis var. graminis). Hence, P. oligandrum might be used to alter relative population levels of these fungi in the field, but first its behaviour in natural soils must be studied.     

Biology of the Gaeumannomyces graminis Arx & Olivier/Phialophora radicicola Cain Complex on Roots of the Gramineae

Biological characteristics of the varieties of Gaeumannomyces graminis Arx & Olivier and Phialophora radicicola Cain are reviewed. They include: 1) pathogenicity to roots of cereals; 2) growth on living stem tissues; 3) type of fungal growth-cessation structure formed on or in the host. Together, these provide a simple means of characterizing isolates and standard methods for assessing them are presented.
The role of pigmented cells and tissues (growth-cessation structures) in host penetration is questioned, since they are seldom associated with a progressive infection by G. graminis or P. radicicola . However, they are a taxonomic aid, especially as they are now known to form on cellophane overlying agar.
New evidence is presented on factors affecting conidiation by these fungi. Flooding colonies with distilled water induced formation of conidia by G. graminis var. tritici Walker, P. radicicola var. radicicola (British isolates but not the type) and P. radicicola var. graminicola Deacon, whereas none formed on corresponding unflooded agar plates. Conidia were usually much larger and germinated readily when they formed in response to flooding; many of these fungi therefore have 2 conidial types, distinct in both morphology and behaviour. Preliminary results suggest that biotin and the form of nitrogen also affect the type of conidium formed by P. radicicola var. radicicola .