Role for ganglionic norepinephrine in sympathetic synaptic transmission

Transmission of nerve impulses in superior cervical sympathetic ganglia of cats and rabbits is markedly enhanced after reserpine-induced depletion of ganglionic norepinephrine. Transmission is also enhanced by administration of adrenergic blocking agents. In contrast, reserpine-induced release of ganglionic norepinephrine in animals pretreated with a monoamine oxidase inhibitor results in a pronounced depression of ganglionic transmission, which lasts until the ganglionic norepinephrine disappears. These results support the concept that norepinephrine in ganglia modulates the action of acetylcholine.     

Gloeosporidina platani sp. nov., the spermatial state of the anthracnose fungus Apiognomonia veneta (Sacc. & Speg.) Höhn.

A new species of the coelomycetous genus Gloeosporidina found on leaves of Platanus × hispanica in Germany is described and illustrated. Culture trials and RAPD patterns demonstrate that the fungus is a part of the developmental cycle of Apiognomonia veneta, the cause of sycamore anthracnose. The relationship between Gloeosporidina moravica and Apiognomonia quercina on oak and between Gloeosporidina sp. and Apiognomonia errabunda on beech is described. The maintenance of the Apiognomonia spp. discussed as separate species is warranted because of differences in spermatial size among the Gloeosporidina states.     

Bile agar migration test: a novel method for testing the viability of Dictyocaulus viviparus larvae in lungworm vaccine

A bile agar migration (BAM) test was used to determine the viability of Dictyocaulus viviparus larvae in lungworm vaccines. Percentage migration values for 10 batches of vaccine varied from 8.8 to 33.2 per cent compared with 99 per cent of unirradiated larvae tested under similar conditions. On the other hand a conventional viability count (CVC), based on subjective assessment of larval shape, gave figures of 95.1 to 98.7 per cent for the 10 vaccine batches. The BAM test may therefore have potential for providing a more discriminatory assessment of vaccine quality than CVC.     

Die Grafrather Anbauversuche

European Journal of Forest Research -     

Diseases of Rubber and their Control

Abstract

Most of the major diseases of Hevea brasiliensis are of worldwide distribution (with the notable exception of South American leaf blight, against which strict quarantine regulations are enforced by rubber-growing countries outside the Americas to prevent the unauthorised import of Hevea) but their local severity and importance vary from one region to another. Root diseases are a serious problem nearly everywhere and regular rounds of inspection and treatment are essential while the trees are still young in order to prevent serious losses. The recently introduced prophylactic collar protectant dressings specific to each of the three main diseases are valuable aids to control.

Diseases of the tapping panel may prevent tapping or hinder bark regeneration; black stripe in particular (Phytophthora palmivora) can be very persistent and is often eradicated only by repeated therapeutic fungicidal treatment of the bark. Stem diseases, chiefly pink disease (Corticium salmonicolor), are important in certain areas in wet weather, and can lead to severe damage and even dieback in the absence of effective treatment.

Four major leaf diseases can have a debilitating effect on the tree. Abnormal leaf fall (Phytophthora spp.) is severe in India, causing the abscission of mature leaves during the monsoon rains; treatment necessitates the application of a pre-monsoon prophylactic copper spray. Secondary leaf fall, caused both by Oidium heveae and Colletotrichum gloeosporioides which infect the flushes of new leaves produced after the annual leaf change (wintering), varies greatly in severity according to local weather and cultivar. It can be controlled by repeated rounds of an appropriate prophylactic fungicide or, under certain conditions, by artificially hastening the onset of wintering (and thus of refoliation) by removing the old leaves with a contact herbicide. By far the most important leaf disease is South American leaf blight (Microcyclus ulei); it is largely responsible for the lack of a vigorous rubber industry in South America, the home of the rubber tree. It can only be effectively countered by the use of resistant cultivars.

The economic importance of the above diseases is discussed and current control measures described.