摘要:

AbstractIn dual cultures Sitka spruce callus inhibited the growth of several decay and mycorrhizal fungi. This effect was influenced by the quantities of plant growth regulators in the tissue culture medium: higher levels of auxin increased the inhibition, though this effect was partially suppressed by cyto‐kinins.Two compounds with antifungal activity were found in methanol extracts of callus. One of these was soluble in chloroform and present in small quantities in relation to its antifungal activity. The second, present in larger quantities, remained in the aqueous phase on partitioning, but was recovered into ethyl acetate after saturation with NaCl.The structural and histochemical responses of callus to direct application of fungal inoculum were also examined. Reactions were similar with all fungi used; cells adjacent to the inoculum became necrotic and their walls thickened. Groups of cells close to this zone became suberized. Also, an amorphous gel impregnated with phloroglucinol‐HCl reactive material was secreted into intercellular spaces around the necrotic region. Hyphae grew into the gel matrix, but did not penetrate the suberized tiss

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1988.tb00921.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractDescription and distribution of Scleroderris canker on Picea mariana (Mill.) B.S.P.The distribution ofGremmeniella abietinainfecting black spruce in natural regeneration is restricted to an area, 100 km north of Quebec City, Canada. Even with high rates of infection in two studied stands (38 % and 80 %), the disease is not conspicuous; this fact may explain the actual small known distribution of scleroderris canker on natural spruce in North America. The fungus on spruce is morphologically identical to the same species on red pine, but it is different if we compare its sporulation behavior and its reaction to chemical treatments. Its race identification is problematic. A description of symptoms, signs and damages is given.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1988.tb00922.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractEcological studies on Camels Hump mountain in northern Vermont document a decline of many forest tree species since 1965. A forest survey in 1986 shows a continued decline in the density, basal area and biomass of red spruce (Picea rubens) and other dominant tree species. The changes occurring between 1983 and 1986 indicate a rapid and continuing reduction in the productivity of the montane forest ecosystem.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1988.tb00923.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractHigh mortality of dominant tree species, especially red spruce (Picea rubens) in the transition and lower montane coniferous zones on Camels Hump, Vermont, USA, has resulted in changes in the microclimate of the forest floor. Regeneration of tree seedlings (2 em dbh) was measured within one‐meter‐square quadrats and compared with results from the same forest zones in 1965. Yellow birch (Betula allegbaniensis) and heart‐leaved paper birch (B. papyriferavar.cordifolia) show large increases in seedling density, particularly in the zones where canopy decline and light intensity changes have been highest. The effects that increased birch establishment will have on the luture structure and composition of these forests are un

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1988.tb00924.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Book Reviewed in this article:Sinclair, W. A.; Lyan, H. H.; Johnson, W. T.:Diseases of trees and shrubs.Sorauer:Handbuch der Pflanzenkrankheiten. Bd. I: Die nichtparasitären Krankheiten.ScHRODTKR, H.: Wcttcr und Pflanzenkrankheiten.Biometeorologische Grundlagen der Epidcmiologie (Hochschultext).Proceedings: Symposium Klima und Witterung in Zusammenhang mit den neuartigen Waldschäden.hennessey, T. C.; dogherty, P. M.; tauer, C. G. (eds.):Forest Decline; Assessing Impacts of Changing Environment on Forest Productivity.schrödtkr, H.:Wetter und Pflanzenkrankheiten.Barth, W.‐E:Praktischer Umwelt‐ und Naturschutz.Ewers, BrabänderH.D.; Brechtel, H.M.; Both, M. e al.:Zur monetären Bewertung von Umweltschäden.Beckmann, C.H.:The nature of wilt diseases of plants.Waldschäden ‐ Holzwirtschaft.Shigo,A. L.: A New Tree Biology.Deutsche Forschungsgemeinschaft:Anthropogene Einflüsse auf den Bodenwasserhaushalt.The American Phytopathological Society (Ed.):Biological and Cultural Tests for Control of P

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1988.tb00925.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1988.tb00926.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY